01240nas a2200169   4500008004100000022001400041245013800055210006900193260007400262300001200336490000800348520050800356100002100864700003200885700002300917856013000940       2006                        eng d  a0009-261400aEnhancing cross-peak intensity in 2D-SLF spectroscopy - the role of equilibrium carbon magnetization in cross-polarization experiment0 aEnhancing crosspeak intensity in 2DSLF spectroscopy the role of   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAUG   a422-4250 v4263 a<p>A modification to the standard Hartmann-Hahn cross-polarization experiment has been proposed in which the initial 90 degrees pulses are applied both on the I and S spins. The inclusion of the available equilibrium polarization in the static magnetic field for the S spins is shown to have a beneficial effect for the 2D-SLF experiment, contributing to an increase in the cross-peak intensity and hence to a better resolution of the dipolar cross-peaks. (c) 2006 Elsevier B.V. All rights reserved.</p>1 aDas, Bibhuti, B.1 aAjithkumar, Thalasseril, G.1 aRamanathan, K., V.  uhttps://library.ncl.res.in/content/enhancing-cross-peak-intensity-2d-slf-spectroscopy-role-equilibrium-carbon-magnetization-002131nas a2200241   4500008004100000022001400041245012900055210006900184260009500253300001200348490000800360520120900368653002301577653002301600653001101623653000801634100002101642700003201663700001801695700002401713700002301737856012901760       2007                        eng d  a1090-780700aCross- and axial-peak intensities in 2D-SLF experiments based on cross-polarization - the role of the initial density matrix0 aCross and axialpeak intensities in 2DSLF experiments based on cr  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcAPR  a308-3170 v1853 a<p>Simulations and experiments on simple oriented systems have been used to estimate the relative ratio of cross-peak to axial-peak intensities in 2D-SLF experiments based on dipolar oscillations during cross-polarization (CP). The density matrix prior to dipolar evolution is considered and for an isolated spin pair, it is shown that direct calculations of the ratios match well with simulations and experimental results. Along with the standard CP pulse sequence, two other pulse sequences namely CP with polarization inversion (PI-CP) and another novel variation of the standard CP experiment (EXE-CP) reported recently have been considered. Inclusion of homonuclear dipolar coupling has been observed to increase the axial-peak intensities. In combination with Lee-Goldburg (LG) decoupling, experiments on an oriented liquid crystalline sample have been carried out and the performance of the pulse schemes have been compared. The applicability of the new pulse sequence for different samples and different nuclei is discussed. Such studies are expected to lead to a better understanding of the experiments and to the design of useful pulse sequences. (C) 2007 Elsevier Inc. All rights reserved.</p>10across polarization10aoriented molecules10aPISEMA10aSLF1 aDas, Bibhuti, B.1 aAjithkumar, Thalasseril, G.1 aSinha, Neeraj1 aOpella, Stanley, J.1 aRamanathan, K., V.  uhttps://library.ncl.res.in/content/cross-and-axial-peak-intensities-2d-slf-experiments-based-cross-polarization-role-initial02386nas a2200205   4500008004100000022001400041245011200055210006900167260007100236300001400307490000800321520157900329100002101908700001801929700003201947700002401979700001902003700002702022856013102049       2008                        eng d  a1520-610600aGelation of covalently edge-modified laponites in aqueous media. 1. rheology and nuclear magnetic resonance0 aGelation of covalently edgemodified laponites in aqueous media 1  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAPR  a4536-45440 v1123 a<p>We describe the covalent modification of the edges of laponite with organic groups and the influence of this modification on gelation behavior. We compare three materials: an unmodified laponite, a laponite edge modified with a trimethyl moiety (MLap), and an octyldimethyl moiety (OLap). Gelation is investigated using rheology and NMR T-1 relaxation measurements and nuclear Overhauser enhancement spectroscopy (NOESY). MLap and OLap show qualitatively different gelation. Gelation of MLap is very similar to laponite: MLap gels over the same time scale as laponite and has about the same solid modulus, and the MLap gel is almost as transparent as laponite. In contrast, OLap gels rapidly relative to laponite and forms a weak, turbid gel. We believe that gelation in laponite and MLap results from the formation of a network of well-dispersed platelets (or a few platelets), while in OLap, gelation results from a network of stacks of several platelets. NMR relaxation measurements indicate that gelation does not affect the average relaxation of water protons. However, T, increases marginally for the protons in the organic moieties in MLap and decreases for protons in the organic moieties in OLap. Relaxation measurements, analyses of line width, and NOESY taken together suggest that, in OLap, gelation is a consequence of association of the organic moieties on the laponite edges, and that this association strengthens with time. Thus, the time-dependent changes in NMR suggest a structural origin for the time-dependent changes in the rheological behavior.</p>1 aPatil, Suhas, P.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aMahesh, T., S.1 aKumaraswamy, Guruswamy  uhttps://library.ncl.res.in/content/gelation-covalently-edge-modified-laponites-aqueous-media-1-rheology-and-nuclear-magnetic-001665nas a2200205   4500008004100000022001400041245009800055210006900153260009500222300001000317490000700327520087700334653002601211653001101237653000801248100002101256700003201277700002301309856012701332       2008                        eng d  a0926-204000aImproved pulse schemes for separated local field spectroscopy for static and spinning samples0 aImproved pulse schemes for separated local field spectroscopy fo  a525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USAbACADEMIC PRESS INC ELSEVIER SCIENCEcMAR  a57-630 v333 a<p>An improved pulse sequence for SLF experiments based on the magic sandwich (MS) scheme for homonuclear dipolar decoupling is proposed. The sequence incorporates a double MS, both on I and S spins and has been named as EXE-MS2. The proposed scheme which has a scaling factor of 1 is observed to be free from low intensity artifacts and provides better line-widths particularly for S spins labeled at multiple sites. The pulse sequence which has been applied on static oriented samples incorporates the EXE scheme where direct polarization of the S spin in the B-0 field is utilized in the place of polarization inversion and is observed to perform well without any loss of sensitivity while ensuring considerable reduction in rf power input into the sample. The EXE scheme has also been tested for solid samples under MAS. (C) 2008 Elsevier Inc. All rights reserved.</p>10amagic sandwich pulses10aPISEMA10aSLF1 aDas, Bibhuti, B.1 aAjithkumar, Thalasseril, G.1 aRamanathan, K., V.  uhttps://library.ncl.res.in/content/improved-pulse-schemes-separated-local-field-spectroscopy-static-and-spinning-samples-002173nas a2200193   4500008004100000022001400041245012500055210006900180260007100249300001600320490000800336520139700344100001501741700001901756700001701775700003201792700002501824856013001849       2008                        eng d  a1932-744700aSize dependent coordination behavior and cation distribution in MgAl2O4 nanoparticles from Al-27 solid state NMR studies0 aSize dependent coordination behavior and cation distribution in   a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcSEP  a14737-147440 v1123 a<p>Nanoparticles of spinel-type oxides such as ferrites offer great advantages and applications in many important areas. Decreasing the size of the particles to nanometer size will increase the surface-to-volume ratio and this will strongly influence the physical and chemical properties of these materials. For magnetic nanoparticles, the exchange interactions at the surface of a particle will be different from those inside due to changes in the coordination behavior at the surface. Therefore, studying and understanding the coordination and distribution behavior of the different metal ions in the nanoparticles of spinel-type oxides is very important. Solid state NMR is a useful and important technique to obtain information on local structural variations. The degree of the distribution of the Al3+ ions in the tetrahedral and octahedral sites in the nanoparticles of the nonmagnetic spinet MgAl2O4 having different particle sizes has been determined by Al-27 magic-angle spinning (MAS) NMR spectroscopy. It has been observed that the inversion parameter decreases with increasing particle size. Apart from the usual tetrahedral and octahedral coordinations present in the bulk material, the presence of five- and three-coordinated At has been observed in nanoparticles with sizes less than 18 nm and a second octahedral coordination is observed for nanoparticles of larger sizes.</p>1 aSreeja, V.1 aSmitha, T., S.1 aNand, Deepak1 aAjithkumar, Thalasseril, G.1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/size-dependent-coordination-behavior-and-cation-distribution-mgal2o4-nanoparticles-al-27-002173nas a2200205   4500008004100000022001400041245010300055210006900158260011000227300001400337490000700351520135100358100002001709700002301729700001801752700001801770700003201788700002201820856012501842       2009                        eng d  a0959-942800aClickable SBA-15 mesoporous materials: synthesis, characterization and their reaction with alkynes0 aClickable SBA15 mesoporous materials synthesis characterization   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJAN  a1409-14160 v193 a<p>SBA-15 mesoporous silica has been functionalized with azidopropyl groups through both one-pot co-condensation and post-synthetic grafting. For both these methodologies, azidopropyltriethoxysilane was used to introduce the azidopropyl groups. The azidopropyl modified SBA-15 material synthesized by one-pot co-condensation had hexagonal crystallographic order, pore diameters up of 50 angstrom, and the content of azidopropyl groups was found to be 1.3 mmol g(-1). The presence of the azidopropyl group was confirmed by multinuclear ((13)C, (29)Si) solid state NMR and IR spectroscopy. Both these materials underwent very efficient Cu(I)-catalyzed azide alkyne ``click'' reaction (CuAAC) with a variety of alkynes. Nearly 85% of the azide present in the SBA-15 material was converted to the corresponding triazole when propargyl alcohol was used as the substrate. This methodology was also used to incorporate mannose into SBA-15. Incubation of this mannose labeled SBA-15 with fluorescein labeled Concanavalin-A led to the formation of a fluorescent silica-protein hybrid material. The ease of synthesis for the azide labeled SBA-15 material together with its ability to undergo very efficient chemoselective CuAAC in water would make it a very attractive platform for the development of covalently anchored catalysts, enzymes and sensors.</p>1 aMalvi, Bharmana1 aSarkar, Bibhas, R.1 aPati, Debasis1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aGupta, Sayam, Sen  uhttps://library.ncl.res.in/content/clickable-sba-15-mesoporous-materials-synthesis-characterization-and-their-reaction-001826nas a2200217   4500008004100000022001400041245016400055210006900219260007100288300001600359490000800375520093400383100002301317700001901340700001501359700002101374700002801395700002401423700003201447856012901479       2009                        eng d  a1932-744700aImmobilization of phosphotungstic acid (PTA) on imidazole functionalized silica: evidence for the nature of PTA binding by solid state NMR and reaction studies0 aImmobilization of phosphotungstic acid PTA on imidazole function  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC  a21114-211220 v1133 a<p>Phosphotungstic acid (PTA) immobilized onto imidazole functionalized fumed silica and was used its an efficient catalyst for epoxidation of a variety of olefins using aqueous H(2)O(2) as all oxidant. Negligible leaching of PTA under the reaction conditions employed indicates a strong interaction between PTA and imidazole The immobilized catalysts Could be separated and reused after the catalytic cycle Evidence for the heterogenization of PTA oil the imidazole functionalized fumed silica has been inferred from different spectroscopic techniques like IR, UV-vis, and NMR. Importantly, the nature of binding of PTA oil the support has been studied in detail by solid state NMR spectroscopy using (15)N labeled imidazole Support. It is clear from the NMR Studies that the effective heterogenization of PTA is mainly due to imidazolium ion Formation oil the support by the acidic protons of PTA and the resultant ion pair</p>1 aSofia, L., T. Aany1 aKrishnan, Asha1 aSankar, M.1 aRaj, N., K. Kala1 aManikandan, Palanichamy1 aRajamohanan, P., R.1 aAjithkumar, Thalasseril, G.  uhttps://library.ncl.res.in/content/immobilization-phosphotungstic-acid-pta-imidazole-functionalized-silica-evidence-nature-001071nas a2200205   4500008004100000022001400041245010800055210006900163260007100232300001400303490000800317520026600325100002100591700001800612700003200630700002400662700001900686700003000705856013000735       2009                        eng d  a1932-744700aMgCl2 center dot 4(CH3)(2)CHOH: a new molecular adduct and super active polymerization catalyst support0 aMgCl2 center dot 4CH32CHOH a new molecular adduct and super acti  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a8556-85590 v1133 a<p>A new molecular adduct, MgCl(2 center dot)4(CH3)(2)CHOH, has been synthesized and characterized for structural aspects and demonstrated for super active ethylene polymerization activity with TiCl4 to ultrahigh molecular weight polyethylene in high yield.</p>1 aThushara, K., S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/mgcl2-center-dot-4ch32choh-new-molecular-adduct-and-super-active-polymerization-catalyst-001993nas a2200265   4500008004100000022001400041245013600055210006900191260010600260300001200366490000800378520095700386653002001343653001001363653003101373653002401404100002101428700002301449700002001472700002301492700002901515700003201544700002501576856012601601       2010                        eng d  a0038-109800aEvidence for the co-existence of distorted tetrahedral and trigonal bipyramidal aluminium sites in SrAl12O19 from Al-27 NMR studies0 aEvidence for the coexistence of distorted tetrahedral and trigon  aTHE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLANDbPERGAMON-ELSEVIER SCIENCE LTDcJAN  a262-2660 v1503 a<p>Strontium aluminate, SrAl12O19, is a ceramic material having the hexagonal magnetoplumbite-type structure, with multiple Al coordination environments. An earlier low-field Al-27 solid-state NMR study reported five different Al sites in this system: one AlO4, one AlO5, and three AlO6 sites; whereas a later high-field study showed that the AlO5 site is a distorted AlO4 site with a very large quadrupolar coupling constant (similar to 20 MHz). Our magic angle spinning (MAS) and 3-quantum magic angle spinning (3QMAS) NMR studies at 7.05 T unambiguously show evidence for an AlO5 site. However, evidence for the presence of a distorted AlO4 site is obtained from studies at high fields (16.4 and 17.6 T), in addition to the AlO5 site. Thus the present solid-state NMR studies give evidence for the simultaneous presence of both the five-coordinated and distorted four-coordinated sites in this system. (C) 2009 Elsevier Ltd. All rights reserved.</p>10aLocal structure10aMQMAS10aNuclear magnetic resonance10aStrontium aluminate1 aHarindranath, K.1 aViswanath, Anusree1 aChandran, Vinod1 aBraeuniger, Thomas1 aMadhu, Perunthiruthy, K.1 aAjithkumar, Thalasseril, G.1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/evidence-co-existence-distorted-tetrahedral-and-trigonal-bipyramidal-aluminium-sites-002591nas a2200229   4500008004100000022001400041245007700055210006900132260007100201300001400272490000700286520177200293100001702065700002502082700001802107700002202125700002402147700003202171700002502203700002702228856010602255       2010                        eng d  a0024-929700aVolume transition of PNIPAM in a nonionic surfactant hexagonal mesophase0 aVolume transition of PNIPAM in a nonionic surfactant hexagonal m  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAY  a4782-47900 v433 a<p>We investigate the volume transition of a thermoresponsive polymer, poly(N-isopropylacrylamide), PNIPAM, in the presence of an aqueous solution of nonionic surfactant, C(12)E(9). We combine turbidimetry with optical microscopy, NMR, and SAXS to follow the volume transition of the PNIPAM and the H(1)-isotropic transition of the surfactant/water system. Nonionic surfactants such as C(12)E(9) are known to interact weakly with PNIPAM. Accordingly, we show that there is only a small change in the volume transition temperature for the PNIPAM in isotropic micellar solutions of C(12)E(9), even for relatively high concentrations of C(12)E(9). Interestingly, once the surfactant forms an H(1) phase, there is a dramatic decrease in the coil globule transition onset temperature. We believe that this behavior results from a competition between C(12)E(9) in the H(1) phase, and PNIPAM to associate with water. When PNIPAM in the H(1) phase is cooled to low enough temperatures so as to be in the coil state, it locally disturbs the hexagonal phase ordering. Thus, we show that for PNIPAM in a weakly interacting surfactant matrix, it is the phase behavior of the matrix rather than the matrix chemistry that governs the coil globule transition. Finally, we show that in a PNIPAM copolymer with a higher LCST we observe an interesting sequence of transitions in the surfactant phase: on cooling from a high temperature free-blowing turbid globular state (similar to 75 degrees C), we enter a free-flowing translucent coil phase (similar to 47 degrees C), then a turbid gel (similar to 25 degrees C) where the copolymer is collapsed in the HI phase, and finally a low-temperature clear gel (similar to 5 degrees C) where the copolymer is in the expanded coil state.</p>1 aJijo, V., J.1 aSharma, Kamendra, P.1 aMathew, Renny1 aKamble, Samruddhi1 aRajamohanan, P., R.1 aAjithkumar, Thalasseril, G.1 aBadiger, Manohar, V.1 aKumaraswamy, Guruswamy  uhttps://library.ncl.res.in/content/volume-transition-pnipam-nonionic-surfactant-hexagonal-mesophase-002746nas a2200253   4500008004100000022001400041245015000055210006900205260007300274300001200347490000700359520183000366653001302196653001602209653001402225100001802239700001402257700001702271700003202288700001402320700001502334700001302349856013002362       2011                        eng d  a0928-493100aComposition-structure-property (Zn2+ and Ca2+ ion release) evaluation of Si-Na-Ca-Zn-Ce glasses: potential components for nerve guidance conduits0 aCompositionstructureproperty Zn2 and Ca2 ion release evaluation   aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcAPR  a669-6760 v313 a<p>Bioactive glasses have demonstrated tailored therapeutic ion release, primarily with respect to the augmentation of hard tissues. However, controlled degradation and release of therapeutic ions from biomaterials may also play an important role in soft tissue regeneration such as repair of peripheral nerve discontinuities. In this study, three silica based glasses (0.5SiO(2)-0.2CaO-0.13ZnO-XNa2O-(0.17-X) CeO2) where, (0.04 &lt; X &lt; 0.14) were synthesised and characterised. The local environment of the Si-29 isotope was probed for each glass using Si-29 MAS-NMR, whilst the thermal characteristics of each glass were examined using DTA. Following these analyses, ion release profiles for Ca2+ and Zn2+ were evaluated; an equivalent specific surface area of 1 m(2) of each glass powder was incubated (37 degrees C) in 10 ml of citric acid buffer and TRIS-HCl buffer solution (pH 3.0 and pH 7.4 respectively) for incubation periods of up to 30 days. The Zn2+ concentration of each filtrate was analysed using flame Atomic Absorption Spectroscopy (Varian AA240FS Fast Sequential AAS) and the Ca2+ concentration of each filtrate was determined using Inductively Coupled Plasma-Mass Spectrometer (Varian 820 ICP-MS). Results obtained from the Si-29 MAS-NMR spectra indicated Q(2) structures pervading the network. An analytical model was proposed to analyse the ion release profiles for each glass, and indicated heterogeneous dissolution of glass networks. The ion release data demonstrates that ion release in the range (19.26-3130 ppm) for Ca2+ and in the range (5.97-4904 ppm) for Zn2+ occurred. Release of such elements, at appropriate levels, from peripheral nerve guidance conduits may be advantageous with respect to the repair of peripheral nerve discontinuities. (C) 2011 Elsevier B.V. All rights reserved.</p>10aBioglass10aDissolution10aModelling1 aZhang, X., F.1 aKehoe, S.1 aAdhi, S., K.1 aAjithkumar, Thalasseril, G.1 aMoane, S.1 aO'Shea, H.1 aBoyd, D.  uhttps://library.ncl.res.in/content/composition-structure-property-zn2-and-ca2-ion-release-evaluation-si-na-ca-zn-ce-glasses-001846nas a2200229   4500008004100000022001400041245015600055210006900211260011000280300001600390490000700406520088500413100002601298700002101324700002001345700001801365700003201383700002401415700001901439700003001458856012801488       2011                        eng d  a1477-922600aMgCl2 center dot 6PhCH(2)OH - a new molecular adduct as support material for ziegler-natta catalyst: synthesis, characterization and catalytic activity0 aMgCl2 center dot 6PhCH2OH a new molecular adduct as support mate  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcSEP  a10936-109440 v403 a<p>Benzyl alcohol has been used to prepare a single phase MgCl2 center dot 6BzOH molecular adduct as a support for an ethylene polymerization catalyst (Ziegler catalyst). The structural, spectroscopic and morphological aspects of the MgCl2 center dot 6BzOH molecular adduct and the Ziegler catalyst have been thoroughly studied by various physicochemical characterization techniques. The presence of MgO6 octahedrons due to the interaction of Mg2+ with six -OH groups of the benzyl alcohol is confirmed from a Raman feature at 703 cm(-1), and structural studies. The supported catalyst activity has been evaluated for the ethylene polymerization reaction. The lower polymerization activity of the titanated Ziegler-Natta catalyst compared with a standard catalyst is attributed to the strong interaction of titanium chloride with the support and associated electronic factors.</p>1 aGnanakumar, Edwin, S.1 aThushara, K., S.1 aBhange, Deu, S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/mgcl2-center-dot-6phch2oh-new-molecular-adduct-support-material-ziegler-natta-catalyst-002024nas a2200253   4500008004100000022001400041245014100055210006900196260007100265300001400336490000800350520104100358100002101399700002601420700001801446700002401464700003201488700002401520700001901544700002601563700001901589700003001608856013201638       2011                        eng d  a1932-744700aToward an understanding of the molecular level properties of ziegler-natta catalyst support with and without the internal electron donor0 aToward an understanding of the molecular level properties of zie  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a1952-19600 v1153 a<p>Two Ziegler-Natta catalysts supported on molecular adducts, namely, MgCl2 center dot 6EtOH (ME) and MgCl2 center dot 5EtOH center dot EtOOCPh (Est-ME), have been prepared. A systematic effort has been made to unravel the molecular level structure property relationships of the catalysts and adducts. Ethylbenzoate is an internal electron donor, and its in situ formation through EtOH+PhCOCl coupling is successfully achieved. The above adduct has been treated with TiCl4, and the resultant catalyst (Ti/Est-ME) is evaluated for ethylene polymerization activity. Rand C-13 CP/MAS NMR of Est-ME (Ti/Est-ME) show carbonyl features at 1730 (1680) cm(-1) and 169 (170) delta, respectively, providing direct support for the presence of ester as an integral part. In spite of low surface area, Ti/Est-ME gives higher yield for ethylene polymerization than the one derived from ME. The results indicate that electronic environment is more important than surface area or any other single factor in determining the polymerization activity.</p>1 aThushara, K., S.1 aGnanakumar, Edwin, S.1 aMathew, Renny1 aJha, Ratnesh, Kumar1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aSarma, Krishna1 aPadmanabhan, Sudhakar1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/toward-understanding-molecular-level-properties-ziegler-natta-catalyst-support-and-without-002834nas a2200253   4500008004100000022001400041245009400055210006900149260007100218300001400289490000700303520192800310100002702238700002202265700001802287700002002305700001902325700002402344700001702368700003202385700002402417700001902441856012002460       2012                        eng d  a0024-929700aLamellar melting, not crystal motion, results in softening of polyoxymethylene on heating0 aLamellar melting not crystal motion results in softening of poly  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a5967-59780 v453 a<p>We probe temperature-dependent changes in the semicrystalline microstructure of polyoxymethylene using a combination of modulated DSC, SAXS, and solid-state NMR to characterize macroscopic behavior, lamellar-level structure, and molecular environments, respectively, and correlate these with the change in mechanical properties probed using DMA and AFM. Two model samples are investigated: a melt crystallized sample prepared by injection molding and a sample obtained by crystallization from dilute solution. Our investigations reveal that, for both samples, there is an increase in crystalline motions and in the amorphous content on heating. DMA and AFM measurements reveal that the modulus of the molded sample decreases on heating to about 100 degrees C; however, there is a significant difference in behavior of the solution crystals, where we observe no significant decrease in stiffness (from AFM measurements). Thus, in contrast to previous reports, we demonstrate that the decrease in modulus on heating polyoxymethylene does not correlate with chain motions in the crystalline regions. We use SAXS to probe the semicrystalline morphology for the samples on heating and show that, for the molded sample, there is a distribution of lamellar thickness at room temperature and that the thin lamellae in this distribution melt on heating. In contrast to the behavior of the melt crystallized samples, the solution crystals exhibit no change in the lamellar stacking on heating to 150 degrees C. We also demonstrate that, on heating, the amorphous regions in the solution crystals always appear to have restricted mobility while there are mobile and low mobility amorphous regions in the molded samples. Our results suggest that, contrary to conventional belief, the decrease in modulus on heating polyoxymethylene arises not from motions in the crystalline lamellae but primarily from melting of thin lamellae.</p>1 aKumaraswamy, Guruswamy1 aSurve, Nikita, S.1 aMathew, Renny1 aRana, Abhimanyu1 aJha, Saroj, K.1 aBulakh, Neelima, N.1 aNisal, Anuya1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aRatnagiri, Ram  uhttps://library.ncl.res.in/content/lamellar-melting-not-crystal-motion-results-softening-polyoxymethylene-heating-001978nas a2200217   4500008004100000022001400041245013400055210006900189260011000258300001600368490000700384520106800391100002101459700002601480700001801506700003201524700002401556700001901580700003001599856013101629       2012                        eng d  a1477-922600aMgCl2 center dot 4((CH3)(2)CHCH2OH): a new molecular adduct for the preparation of TiClx/MgCl2 catalyst for olefin polymerization0 aMgCl2 center dot 4CH32CHCH2OH a new molecular adduct for the pre  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcJUL  a11311-113180 v413 a<p>A new molecular adduct of MgCl2 with isobutanol, namely MgCl2 center dot 4((CH3)(2)CHCH2OH) (MgiBOH), has been prepared as a precursor to the supporting material for an olefin polymerization catalyst. The MgiBOH adduct and final titanated Ziegler-Natta catalysts have been thoroughly characterized by powder XRD, thermal analysis, Raman spectroscopy and solid-state NMR for structural and spectroscopy aspects. A peak observed at 712 cm(-1) in the Raman spectra of MgiBOH indicates the characteristic Mg-O-6 breathing mode and the formation of the adduct. The diffraction feature at 2 theta = 7.8 degrees (d = 11.223 angstrom) in the XRD confirms the adduct formation and the layered structure. The aim of the present article is to study how the insertion of a bulky isobutanol moiety affects the structural and electronic properties of the MgCl2 isobutanol molecular adduct. Indeed, the focus of the present study is to explore how the presence of isobutanol, in the initial molecular adduct, influences the final Z-N catalyst properties and its activity.</p>1 aThushara, K., S.1 aGnanakumar, Edwin, S.1 aMathew, Renny1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aBhaduri, Sumit1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/mgcl2-center-dot-4ch32chch2oh-new-molecular-adduct-preparation-ticlxmgcl2-catalyst-olefin-002012nas a2200229   4500008004100000022001400041245009200055210006900147260007100216300001600287490000800303520114700311100002601458700002101484700002501505700002201530700003201552700002401584700002601608700003001634856011801664       2012                        eng d  a1932-744700aMgCl2 center dot 6C(6)H(11)OH: a high mileage porous support for ziegler-natta catalyst0 aMgCl2 center dot 6C6H11OH a high mileage porous support for zieg  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcNOV  a24115-241220 v1163 a<p>A new and single phase molecular adduct of MgCl2 with six cyclohexanol molecules MgCl2 center dot 6C(6)H(11)OH (MgCyOH) has been synthesized. Structural insight to this adduct was obtained by a variety of physicochemical methods. C-13 CPMAS spectrum and single pulse MAS spectra with high power proton decoupling recorded at different relaxation time showed the presence of two different sets of magnetically unequal cylcohexanol molecules present around Mg2+. A Raman feature of MgCyOH at 712 cm(-1) confirms that cylcohexanol molecules are present around Mg2+ in an octahedral environment. MgCyOH has been used as support material to prepare Ziegler-Natta (Z-N) active catalyst. Textural property of above Z-N catalyst exhibits high surface area (236 m(2)/g) with high porosity. Above active catalyst has been screened for ethylene polymerization. Depending on the cocatalyst employed (Me3Al, Et3Al, and iso-Bu3Al) and ethylene pressure, polyethylene yield varies an order of magnitude, from 378 to 3570 g/g catalyst, indicating a possible creation of different active sites and different interaction between cocatalyst and catalyst.</p>1 aGnanakumar, Edwin, S.1 aThushara, K., S.1 aGowda, Ravikumar, R.1 aRaman, Sumesh, K.1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/mgcl2-center-dot-6c6h11oh-high-mileage-porous-support-ziegler-natta-catalyst-002539nas a2200277   4500008004100000022001400041245012100055210006900176260007100245300001200316490000600328520150200334653002801836653001001864653002101874653002601895653002701921100002601948700002501974700002101999700003202020700002402052700002602076700003002102856012902132       2013                        eng d  a2155-543500aMgCl2 center dot 6CH(3)OH: a simple molecular adduct and its influence as a porous support for olefin polymerization0 aMgCl2 center dot 6CH3OH a simple molecular adduct and its influe  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcMAR  a303-3110 v33 a<p>A single phase molecular adduct, MgCl2 center dot 6CH(3)OH has been synthesized using MgCl2 and the simplest alcohol, methanol. Structural, spectroscopic, and morphological studies have been carried out for a better understanding of the single phase MgCl2 center dot 6CH(3)OH adduct. C-13 CPMAS solid state NMR studies show all six methanol molecules are magnetically equivalent and present in a single environment around the Mg2+ center. Raman spectral analysis of the characteristic peak at 708 cm(-1) substantiates octahedral coordination of six CH3OH molecules around Mg2+. Solid state C-13 NMR measurements, made after heat treatment at different temperatures, have been utilized to understand the variations in CH3OH stoichiometry and coordination around Mg2+ with temperature. A titanated active catalyst, TiCl4 on MgCl2 center dot 6CH(3)OH, has also been synthesized and subjected to detailed characterizations. The active catalyst shows high surface area (102 m(2)/g) and mesoporosity. The titanated catalyst has been screened for ethylene polymerization reactions using different cocatalysts (R3Al; R= -CH3, -CH2CH3, and -CH2CH(CH3)(2)). A total of 7.25 kg of polyethylene per gram of catalyst has been obtained with Me3Al cocatalyst, which is six times higher in activity compared with commercial Me3Al/TiCl4/MgCl2 center dot 6EtOH-supported orted catalystAlthough porosity influences the catalytic activity, other factors also seem to contribute to the total catalytic activity.</p>10aheterogeneous catalysis10aMgCl210aMolecular adduct10aolefin polymerization10aZiegler-Natta catalyst1 aGnanakumar, Edwin, S.1 aGowda, Ravikumar, R.1 aKunjir, Shrikant1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/mgcl2-center-dot-6ch3oh-simple-molecular-adduct-and-its-influence-porous-support-olefin-002320nas a2200217   4500008004100000022001400041245009500055210006900150260011000219300001400329490000700343520144200350100002601792700002601818700002101844700003201865700002401897700002601921700003001947856012501977       2014                        eng d  a1477-922600a9-Fluorenemethanol: an internal electron donor to fine tune olefin polymerization activity0 a9Fluorenemethanol an internal electron donor to fine tune olefin  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcMAR  a9143-91510 v433 a<p>A new MgCl2 based molecular adduct has been synthesized with 9-fluorenemethanol (9FM) as a novel internal electron donor (IED), along with ethanol (EtOH) (MgCl2 center dot n9FM center dot xEtOH). The above molecular adduct has been subjected to a variety of structural, spectroscopic and morphological characterization techniques. The results of the solid state C-13 CPMAS NMR technique suggests the coordination of 9FM to MgCl2. Observation of a low angle diffraction peak at 2 theta = 5.7 degrees (d = 15.5 angstrom) underscores the coordination of 9FM along the z-axis, and ethanol in the molecular adduct. Active Ziegler-Natta catalysts were prepared by two different synthesis methods; the conventional method to obtain a high surface area active catalyst, and other one with 9FM as an integral part of the active catalyst in order to study the influence of 9FM as an IED over the active sites. The active catalysts were also characterized thoroughly with different analytical tools. The XRD results show (003) facets of delta-MgCl2 (alpha-MgCl2) for the conventional (non-conventional) titanated catalyst. Results of the ethylene polymerization activity study reveals that the conventionally prepared highly porous active catalyst shows 1.7-2.5 times higher activity than the non-conventional prepared catalyst; however, the latter shows a low molecular weight distribution and confirms the role of the Lewis base as an IED.</p>1 aGnanakumar, Edwin, S.1 aChokkapu, Eswara, Rao1 aKunjir, Shrikant1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aChakraborty, Debashis1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/9-fluorenemethanol-internal-electron-donor-fine-tune-olefin-polymerization-activity-002064nas a2200181   4500008004100000022001400041245011400055210006900169260000800238300001400246490000700260520139700267100001701664700002101681700003201702700002201734856012601756       2014                        eng d  a0002-782000aIdentification of the Zn substitution sites in La-Zn substituted SrAl12O19 from Al-27 solid-state NMR studies0 aIdentification of the Zn substitution sites in LaZn substituted   cSEP  a2990-29950 v973 a<p>The La-Zn substituted hexagonal strontium aluminate, Sr1-xLaxAl12-xZnxO19, with the magnetoplumbite structure and having five different coordination environments for Al with different symmetries, is investigated using Al-27 solid-state NMR to get detailed information on the sites of substitution of Zn and the associated changes in the local coordination environments of Al. The objective of the study was to get information on the local structural variations in the isostructural La-Co substituted strontium ferrite, Sr1-xLaxFe12-xCoxO19, showing enhanced magnetic performance on substitution. The NMR studies on the aluminate give direct evidence for the sites of substitution and the changes in the local coordination environments. It is found that Zn is substituted at the 2a and 4f(2) AlO6 octahedral sites. However, an interesting observation from the NMR studies is the stabilization of the Al site occupancy at the penta-coordinated 2b site over the distorted tetrahedral 4eAl site, without any substitution at these sites. Large changes in the quadrupolar coupling constant of the 2a and 4e sites are observed between x=0.2 and 0.3, corresponding to the compositional region showing higher performance in the case of Sr1-xLaxFe12-xCoxO19, indicating the role of distortion of local coordination environments on suitable substitution in controlling the performance parameters.</p>1 aBaby, Bindhu1 aDey, Krishna, K.1 aAjithkumar, Thalasseril, G.1 aJoy, Pattayil, A.  uhttps://library.ncl.res.in/content/identification-zn-substitution-sites-la-zn-substituted-sral12o19-al-27-solid-state-nmr01758nas a2200229   4500008004100000022001400041245011200055210006900167260011000236300001400346490000700360520082900367100002901196700002401225700003201249700002801281700002301309700002101332700002601353700001801379856013101397       2014                        eng d  a1477-922600aInvestigations into variations in local cationic environment in layered oxide series InGaO3(ZnO)(m) (m=1-4)0 aInvestigations into variations in local cationic environment in   aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcNOV  a2120-21260 v433 a<p>Layered oxides of the series InGaO3(ZnO)(m) (m = 1-4) are interesting due to their structural anisotropy. Here, we report a comprehensive study of their structural details, focusing on the local cationic environment in bulk powder samples by MASNMR and EXAFS, which is hitherto not attempted. It is found that the Ga geometry varies gradually from pure pentacoordinated to a mixture of penta and tetracoordinated with increasing amounts of tetracoordination as we move across the series, contrary to previous reports suggesting exclusively trigonal bipyramidal coordination in all the compounds. A similar observation is also made in the case of Zn and structural evolution involving the dissolution of Ga in a ZnO4 tetrahedral network in a sandwich layer can be discerned, as the insulating ZnO layer size increases.</p>1 aNarendranath, Soumya, B.1 aYadav, Ashok, Kumar1 aAjithkumar, Thalasseril, G.1 aBhattacharyya, Dibyendu1 aJha, Shambhu, Nath1 aDey, Krishna, K.1 aRaja, Thirumalaiswamy1 aDevi, Nandini  uhttps://library.ncl.res.in/content/investigations-variations-local-cationic-environment-layered-oxide-series-ingao3znom-m1-4-001814nas a2200241   4500008004100000022001400041245011200055210006900167260007300236300001200309490000800321520088500329653002101214653002301235653003001258653002201288653002201310100002401332700002501356700003201381700002801413856013101441       2014                        eng d  a0926-860X00aSBA-15 intercalated Mg-Al hydrotalcite: an environmental friendly catalyst for hydroisomerization of olefin0 aSBA15 intercalated MgAl hydrotalcite an environmental friendly c  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcNOV  a119-1270 v4883 a<p>SBA-15 Molecular sieve-intercalated Mg-Al hydrotalcite (MASBA-HT) was synthesized for the first time by a simple straightforward method. The intercalation of SBA-15 molecular sieve between the interlayer of HT was evident from powder XRD, TEM and FT-IR studies. The presence of SBA-15 facilitates retention of the layered structure for first time, even after calcination at high temperature of 550 degrees C. The resultant material possesses moderate acidity which comes from incorporation of aluminum into the framework of SBA-15 and also contained soluble basicity similar to HT materials. The material shows promising activity for hydroisomerization of 1-octene resulting in good substrate conversion (80%) and branched isomers selectivity (45%). The catalytic activity remains constant over longer duration and repeated runs. (C) 2014 Elsevier B.V. All rights reserved.</p>10aBranched alkenes10aHydroisomerization10aIntercalated-hydrotalcite10alayered materials10aMesoporous SBA-151 aBaskaran, Thangaraj1 aChristopher, Jayaraj1 aAjithkumar, Thalasseril, G.1 aSakthivel, Ayyamperumal  uhttps://library.ncl.res.in/content/sba-15-intercalated-mg-al-hydrotalcite-environmental-friendly-catalyst-hydroisomerization-001926nas a2200181   4500008004100000022001400041245015300055210006900208260007100277300001400348490000800362520113900370100002101509700003201530700002401562700003001586856012801616       2014                        eng d  a1089-563900aSolid-state NMR investigations of a MgCl2 center dot 4(CH3)(2)CHCH2OH molecular adduct: a peculiar case of reversible equilibrium between two phases0 aSolidstate NMR investigations of a MgCl2 center dot 4CH32CHCH2OH  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcFEB  a1213-12190 v1183 a<p>MgCl2 center dot xROH molecular adducts are extensively employed as a support material for Ziegler-Natta polyolefin catalysis. However, their structural properties are not well understood. Recently, we reported on the preparation of an isobutanol adduct, MgCl2 center dot 4(CH3)(2)CHCH2OH (MgiBuOH) (Dalton Trans. 2012, 41, 11311), which is very sensitive to the preparation conditions, such as the temperature and refluxing time. For the present study, the structural properties of MgiBuOH adducts prepared under different conditions have been investigated thoroughly by solid-state NMR and nonambient XRD. Formation of two phases has been confirmed, and in situ variable temperature solid-state NMR measurements confirm the coexistence of two phases as well as the oscillation from one to another phase. It is expected that such molecular adducts could have a significant role in organic transformation reactions due to an oscillating structural component. An understanding of phase oscillation with the Mg2+ ion as the central metal ion might shed some light toward understanding various biological and structural functions.</p>1 aThushara, K., S.1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/solid-state-nmr-investigations-mgcl2-center-dot-4ch32chch2oh-molecular-adduct-peculiar-001693nas a2200253   4500008004100000022001400041245011000055210006900165260007300234300001200307490000800319520077400327653002801101653001001129653002101139653000801160653001501168653002701183100002101210700003201231700002401263700003001287856012201317       2014                        eng d  a0926-860X00aStructural investigations of porous MgCl2-2-butanol molecular adduct as support for olefin polymerization0 aStructural investigations of porous MgCl22butanol molecular addu  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN  a267-2740 v4693 a<p>A new heterogeneous Ziegler-Natta (Z-N) catalyst support material, MgCl2 center dot 4(CH3CH(OH)CH2CH3) (Mg2BuOH) has been synthesized. 2-Butanol, a linear, secondary alcohol was chosen for the generation of an active MgCl2 support which results in a Z-N catalyst with TiCl4. Significant feature of this work is the formation of rod shaped molecular adduct with highly porous character. Adduct material is characterized by XRD, TG-DTA, Raman spectroscopy, solid-state NMR and SEM. Activity of the Z-N catalyst supported on Mg2BuOH for ethylene polymerization is comparable with that of commercially available heterogeneous Z-N catalyst. However, there is scope to improve the activity by optimizing textural properties. (C) 2013 Elsevier B.V. All rights reserved.</p>10aheterogeneous catalysis10aMgCl210aMolecular adduct10aNMR10aPolyolefin10aZiegler-Natta catalyst1 aThushara, K., S.1 aAjithkumar, Thalasseril, G.1 aRajamohanan, P., R.1 aGopinath, Chinnakonda, S.  uhttps://library.ncl.res.in/content/structural-investigations-porous-mgcl2-2-butanol-molecular-adduct-support-olefin-000629nas a2200145   4500008004100000245013700041210006900178260000800247300002100255490000600276100001500282700003200297700002500329856012900354       2015                        eng d00aCorrelations between structure, microstructure, density and dielectric properties of the lead-free ferroelectrics Bi0.5(Na,K)0.5TiO30 aCorrelations between structure microstructure density and dielec  cNOV  a1550028 Page 1-60 v51 aAnjali, K.1 aAjithkumar, Thalasseril, G.1 aJoy, Pattayil, Alias  uhttps://library.ncl.res.in/content/correlations-between-structure-microstructure-density-and-dielectric-properties-lead-free01440nas a2200193   4500008004100000022001400041245017400055210006900229260011000298300001400408490000700422520055700429100002400986700002001010700002501030700003201055700002801087856013101115       2015                        eng d  a1144-054600aEnvironmentally friendly route for grafting of molybdenum carbonyl onto a diaminosilane-modified SBA-15 molecular sieve and its catalytic behaviour in olefin epoxidation0 aEnvironmentally friendly route for grafting of molybdenum carbon  aTHOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLANDbROYAL SOC CHEMISTRYcFEB  a3758-37640 v393 a<p>A simple route has been established for grafting molybdenum carbonyl onto the surface of a diaminosilane-modified SBA-15 molecular sieve. The successful grafting of the molybdenum carbonyl species onto diamine-functionalized SBA-15 was evident from FT-IR studies. The resultant molybdenum-carbonyl-complex-grafted SBA-15 (SBA-DA-Mo) materials show promising activity for the epoxidation of various olefins with good conversion (90-95%) and the formation of epoxide as the major product. The catalytic activity remains constant over several runs.</p>1 aBaskaran, Thangaraj1 aKumaravel, Raju1 aChristopher, Jayaraj1 aAjithkumar, Thalasseril, G.1 aSakthivel, Ayyamperumal  uhttps://library.ncl.res.in/content/environmentally-friendly-route-grafting-molybdenum-carbonyl-diaminosilane-modified-sba-15-001697nas a2200205   4500008004100000022001400041245010300055210006900158260007100227300001600298490000800314520090100322100002901223700002401252700001501276700002401291700002101315700003201336856012301368       2015                        eng d  a1520-610600aInsights into the molecular dynamics in polysulfone polymers from C-13 solid-state NMR experiments0 aInsights into the molecular dynamics in polysulfone polymers fro  a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcAUG  a11287-112940 v1193 a<p>The molecular and segmental motions in three different grades of ductile polysulfone polymers; poly(ether sulfone) (PESU), polysulfone (PSU), and poly(phenyl sulfone) (PPSU) are probed using C-13 solid-state NMR experiments. Polarization inversion spin exchange at magic angle (PISEMA) experiments indicates that the phenyl rings in the polymers are undergoing pi-flip motions on the order of 100 kHz. The temperature dependent PISEMA experiments show that the fraction of mobile regions that undergoes aromatic pi-flips is higher in PPSU than in the other two polymers. The center band only detection of exchange (CODEX) experiments was carried out and was unable to detect any slow segmental motions in the chains. A combination of C-13 spin-lattice relaxation time (T-1) and T-1-filtered PISEMA experiments show that the mobile regions in all the polymers are dynamically heterogeneous.</p>1 aEldho, Kavalakal, Mathai1 aRajamohanan, P., R.1 aAnto, Ralf1 aBulakh, Neelima, N.1 aLele, Ashish, K.1 aAjithkumar, Thalasseril, G.  uhttps://library.ncl.res.in/content/insights-molecular-dynamics-polysulfone-polymers-c-13-solid-state-nmr-experiments-002134nas a2200265   4500008004100000022001400041245010400055210006900159260007300228300001200301490000800313520113300321653006501454653003301519653002501552100002201577700002201599700001801621700001201639700001701651700002401668700003201692700001701724856012701741       2015                        eng d  a0022-311500aStudy on fused/cast AZS refractories for deployment in vitrification of radioactive waste effluents0 aStudy on fusedcast AZS refractories for deployment in vitrificat  aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcDEC  a144-1540 v4673 a<p>Fused/cast Al2O3-ZrO2-SiO2 (FC-AZS)' is being considered as `glass contact refractory' within ceramic melters, to be used for nuclear waste immobilization. Microstructural analyses reveal random distributions of baddeleyite (ZrO2) within aluminosilicate (Al2SiO5) matrix. Al-27 and Si-29 NMR data suggest that within aluminosilicate matrix Al occurs in both 4- and 6-fold co-ordinations whereas Si prefers a 4-fold environment. Polydispersity of pores has been studied with small-angle neutron scattering (SANS) technique. Corrosion rates of FC-AZS within 6 M HNO3, simulated wastes (500 h exposure), and borosilicate melt (975 degrees C, 800 h exposure) are found to be 0.38 x 10(3) mu my(-1), 0.13 x 10(3) mu my(-1) and 4.75 x 10(3) mu my(-1) respectively. A comparison of chemical interaction data clearly suggests that FC-AZS exhibits better chemical durability than AZC refractory (Al2O3-ZrO2-Cr2O3, also used for similar purpose). Thermal cycling studies indicate that FC-AZS retains structural integrity (including compressive strength and density) even up to 20 cycles. (C) 2015 Elsevier B.V. All rights reserved.</p>10aInteraction between refractory material and hazardous liquid10aNuclear waste immobilization10aVitrification melter1 aSengupta, Pranesh1 aMishra, Raman, K.1 aSoudamini, N.1 aSen, D.1 aMazumder, S.1 aKaushik, Chetan, P.1 aAjithkumar, Thalasseril, G.1 aBanerjee, K.  uhttps://library.ncl.res.in/content/study-fusedcast-azs-refractories-deployment-vitrification-radioactive-waste-effluents-001538nas a2200229   4500008004100000022001400041245011100055210006900166260000900235300001200244490000700256520072700263653002300990653002001013653002201033653001301055100003001068700003201098700002301130700002801153856012701181       2015                        eng d  a1566-736700aSupported imidazole as heterogeneous catalyst for the synthesis of cyclic carbonates from epoxides and CO20 aSupported imidazole as heterogeneous catalyst for the synthesis   cJAN   a201-2050 v593 a<p>Imidazole anchored onto a silica matrix, by means of a propyl linkage, is found to be an effective heterogeneous catalyst for the synthesis of cyclic carbonates from epoxides and CO2 in near quantitative yield. The versatility of this catalyst is demonstrated by using different substrates (epichlorohydrin, propylene oxide, butylene oxide and styrene oxide) for this cycloaddition reaction. These CO2 insertion reactions were typically carried out in the temperature range of 343 to 403 K at 0.6 MPa CO2 pressure under solvent-free conditions. Several spectroscopic methods were used to characterize the catalyst and study the integrity of the fresh and spent catalysts. (C) 2014 Elsevier B.V. All rights reserved.</p>10aAnchored imidazole10aCO2 utilization10acyclic carbonates10aepoxides1 aSankar, Meenakshisundaram1 aAjithkumar, Thalasseril, G.1 aSankar, Gopinathan1 aManikandan, Palanichamy  uhttps://library.ncl.res.in/content/supported-imidazole-heterogeneous-catalyst-synthesis-cyclic-carbonates-epoxides-and-co202137nas a2200229   4500008004100000022001400041245003500055210003500090260006700125300001000192490000700202520145200209100002201661700002101683700001701704700003201721700001901753700002201772700002401794700002001818856006901838       2015                        eng d  a0002-782000aVanadium in borosilicate glass0 aVanadium in borosilicate glass  a111 RIVER ST, HOBOKEN 07030-5774, NJ USAbWILEY-BLACKWELLcJAN  a88-960 v983 a<p>Understanding the role of V2O5 within borosilicate glass matrices is important for the development of novel matrices toward immobilization of sulfate containing high-level nuclear wastes. Present investigation shows, within sodium barium borosilicate glass matrix V2O5 can be homogeneously added up to 5mol% and beyond which it separates out into three phases, for example, (i) silica (ii) Barium (Ba) - Vanadium (V) oxide, and (iii) glass matrix. Si-29 MAS NMR (Nuclear Magnetic Resonance) studies of the samples show that below 5mol% V2O5 addition, silicate network is dominantly constituted of Q(2) and Q(3) structural units, whereas above this, the network gets more polymerized through formation of Q(3) and Q(4) units. In case of borate network, B-11 MAS NMR investigations revealed that the concentration of BO4 [(0B, 4Si)] unit increases gradually up to 5mol% and then it decreases at the cost of BO4 [(1B, 3Si)], BO3 (symmetric) and BO3 (asymmetric) units. Micro-Raman analyses of the samples showed that with additions of V2O5 in diluted concentrations, amorphous silicate network remained unaltered, whereas some amplification in signals corresponding to ring-type metaborate and VO5 units exists. It is therefore apparent from both MAS-NMR and micro-Raman studies that with V2O5 additions within the solubility limit (5mol%), borate network gets depolymerized leading to decrease in hardness from an average value of 5.0-4.2GPa.</p>1 aSengupta, Pranesh1 aDey, Krishna, K.1 aHalder, Rumu1 aAjithkumar, Thalasseril, G.1 aAbraham, Geogy1 aMishra, Raman, K.1 aKaushik, Chetan, P.1 aDey, Goutam, K.  uhttps://library.ncl.res.in/content/vanadium-borosilicate-glass-001386nas a2200205   4500008004100000022001400041245011200055210006900167260009000236300001000326490000600336520055300342100002000895700002400915700002900939700002400968700003200992700003001024856012601054       2016                        eng d  a2045-232200a1000-fold enhancement in proton conductivity of a MOF using post-synthetically anchored proton transporters0 a1000fold enhancement in proton conductivity of a MOF using posts  aMACMILLAN BUILDING, 4 CRINAN ST, LONDON N1 9XW, ENGLANDbNATURE PUBLISHING GROUPcAUG  a324890 v63 a<p>Pyridinol, a coordinating zwitter-ionic species serves as stoichiometrically loadable and non-leachable proton carrier. The partial replacement of the pyridinol by stronger hydrogen bonding, coordinating guest, ethylene glycol (EG), offers 1000-fold enhancement in conductivity (10(-6) to 10(-3) Scm(-1)) with record low activation energy (0.11 eV). Atomic modeling coupled with C-13-SSNMR provides insights into the potential proton conduction pathway functionalized with post-synthetically anchored dynamic proton transporting EG moieties.</p>1 aShalini, Sorout1 aDhavale, Vishal, M.1 aEldho, Kavalakal, Mathai1 aKurungot, Sreekumar1 aAjithkumar, Thalasseril, G.1 aVaidhyanathan, Ramanathan  uhttps://library.ncl.res.in/content/1000-fold-enhancement-proton-conductivity-mof-using-post-synthetically-anchored-proton02670nas a2200157   4500008004100000245014400041210006900185260000800254300001400262490000600276520202600282100002302308700003202331700002702363856012202390       2017                        eng d00aL-Proline functionalized dicationic framework of bifunctional mesoporous organosilica for the simultaneous removal of lead and nitrate ions0 aLProline functionalized dicationic framework of bifunctional mes  cMAY  a4188-41960 v53 aA novel bifunctional mesoporous organosilica, PEG-functionalized bis-prolinium chloride bridged mesoporous organosilica (BPBMO) was synthesized by reacting the precursor, PEG-functionalized bis-prolinium chloride bridged organosilane (BPRIL) with tetraethyl orthosilicate (TEOS) in the presence of surfactant. The chemical conformation of BPBMO was investigated by using Fourier transform infrared (FTIR), thermogravimentric analysis (TGA), C-13, and Si-29 cross-polarization/magic angle spinning (CP/MAS) NMR techniques. The characterization represents PEG-linked-prolinium (-N+Cl-) and carboxyl (-COOH) entities, constructing the dicationic framework through siloxane (Si-O-Si) linkages. The pore-wall distribution and the periodicity of BPBMO retained during the synthesis were examined by small-angle X-ray scattering (SAXS), Brunauer-Emmett-TellerBarrett-Joyner-Halenda (BET-BJH), and transmission electron microscopy (TEM) techniques. The results revealed BPBMO as a spherical shaped solid (50-100 nm) having mesopore channels hexagonally arranged with interparticle porosity (S-BET = 487 m(2)/g and D-BJH = 5.1 nm). The material has provided active binding sites for the simultaneous removal of NO3- and Pb2+ ions when introduced in the aqueous solutions of Pb(NO3)(2) (50 mg/L, pH 6). The removal of NO3- by ion-exchange with prolinium (-N+Cl-) entities and the electrostatic interaction of Pb2+ with carboxylate (-COO-) group were characterized by using Raman spectroscopy, ion chromatography, and X-ray photoelectron spectroscopy (XPS) technique. The maximum removal of NO3- and Pia' ions were achieved within 1 h of the adsorption reaction. The adsorption has followed the Langmuir isotherm model with the adsorption capacities (q(m)) of 23.04 and 21.92 mg/g for NO3- and Pb2+ ions, respectively. The efficiency of the adsorbent was also compared with other adsorbents. Further, the BPBMO material has depicted three consecutive adsorption/desorption cycles with negligible loss in the structural conformation.1 aDinker, Manish, K.1 aAjithkumar, Thalasseril, G.1 aKulkarni, Prashant, S.  uhttps://library.ncl.res.in/content/l-proline-functionalized-dicationic-framework-bifunctional-mesoporous-organosilica01893nas a2200193   4500008004100000245006700041210006700108260000800175300001200183490000700195520124100202100003401443700002901477700002401506700003201530700001701562700002701579856009301606       2017                        eng d00aMolecular motifs for additives that retard PEO crystallization0 aMolecular motifs for additives that retard PEO crystallization  cAUG  a857-8640 v573 a<p>We investigate the influence of several bifunctional phenol additives (resorcinol: RES, hydroquinone: HYD, p-hydroxybenzoic acid: PHBA, and p-nitrophenol: PNP) on the crystallization of matrix polymer, polyethyleneoxide. We employ solid state Nuclear Magnetic Resonance spectroscopy (NMR), Differential Scanning Calorimetry (DSC), optical microscopy, and Small Angle X-ray Scattering (SAXS) to investigate crystallization of the additivated PEO and compare with Density Functional Theory (DFT) calculations of additive-PEO interactions. Additive-polymer interactions are a function of the functional groups on the additive. Temperature-dependent spherulitic growth rate measurements from optical microscopy and SAXS lamellar long spacings indicate a distinct trend in the effect of additives on PEO crystallization. Change in PEO crystallization is most pronounced with PNP, followed by PHBA and finally RES and HYD. This trend correlates qualitatively with the binding energies of additive-PEO interactions from DFT studies. Our results suggest that DFT calculations might be a useful screening tool to evaluate the influence of additives on polymer crystallization. POLYM. ENG. SCI., 2016. © 2016 Society of Plastics Engineers</p>1 aShrivastava, Sudhakar, Dinesh1 aEldho, Kavalakal, Mathai1 aRajamohanan, P., R.1 aAjithkumar, Thalasseril, G.1 aVanka, Kumar1 aKumaraswamy, Guruswamy  uhttps://library.ncl.res.in/content/molecular-motifs-additives-retard-peo-crystallization02545nas a2200229   4500008004100000022001400041245013500055210006900190260000900259300001000268490000800278520171400286100002802000700001802028700002202046700001702068700001902085700003202104700003202136700002002168856012702188       2019                        eng d  a0002-786300aCovalent self-assembly in two dimensions: connecting covalent organic framework nanospheres into crystalline and porous thin films0 aCovalent selfassembly in two dimensions connecting covalent orga  cDEC   a203790 v1413 a<p>Insolubility of covalent organic frameworks (COFs) in organic solvents is one of the major obstacles for the potential application of these extended networks such as drug delivery, sensing, optoelectronics, and semiconductor device fabrication. The present work proposes a unique way to make uniform, solution-processable, crystalline, and porous COF nanospheres directly from the homogeneous solution of amine and aldehyde via spatial and temporal control of the nucleation and growth. This strategy of direct nucleation simultaneously showcases the caliber to tune the size of the COF nanospheres from 25 to 570 nm. We have also demonstrated the concept of mesoscale covalent self-assembly of those solution-processable COF nanospheres in the liquid-liquid interface (DCM-water bilayer) for the very first time, transmuting them into self-standing COF thin films with long-range ordered arrangements in two dimensions. The crystalline and porous (with TpAzo showing highest S-BET of 1932 m(2) g(-1)) free-standing COF thin films could be fabricated in a wide range of thicknesses from as low as 21 nm to as high as 630 nm. Both beta-ketoenamine (TpAzo, TpDPP) and imine (TpOMeAzo, TpOMeDPP) linked COF thin films have been synthesized via mesoscale covalent self-assembly of the solution-processable COF nanospheres illustrating the generality of this eloquent methodology. Further, the solution processability has been tested and utilized to cast COF thin films uniformly in the inner and outer surface of an alumina hollow fiber membrane. The COF thin film-alumina hollow fiber membrane composites have showcased promising selective molecular separation of He and O-2, He and CO2, and He and N-2.</p>
1 aSasmal, Himadri, Sekhar1 aHalder, Arjun1 aKunjattu, Shebeeb1 aDey, Kaushik1 aNadol, Athulya1 aAjithkumar, Thalasseril, G.1 aBedadur, Prachiti, Ravindra1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/covalent-self-assembly-two-dimensions-connecting-covalent-organic-framework-nanospheres02436nas a2200241   4500008004100000022001400041245015800055210006900213260000900282300001400291490000800305520154300313100002801856700002301884700002701907700001901934700001801953700002201971700002201993700003202015700002002047856012702067       2020                        eng d  a0002-786300aConnecting microscopic structures, mesoscale assemblies, and macroscopic architectures in 3D-printed hierarchical porous covalent organic framework foams0 aConnecting microscopic structures mesoscale assemblies and macro  cMAY   a8252-82610 v1423 a<p>The induction of macro and mesopores into two-dimensional porous covalent organic frameworks (COFs) could enhance the exposure of the intrinsic micropores toward the pollutant environment, thereby, improving the performance. However, the challenge is to build a continuous hierarchically porous macro-architecture of crystalline organic materials in the bulk scale. In this regard, we have strategized a novel synthetic method to create hierarchically porous COF foams consisting of ordered micropores (2-2.2 nm) and disordered meso and macropores (50 nm to 200 mu m) as well as ordered macropores (1.5 mm to 2 cm). Herein, graphene oxide was used for creating disordered macro and mesopores in COF-GO foams. Considering the rheological features of the precursor hydrogel, we could integrate crystalline and porous COF-GO foams into self-supported three-dimensional (3D)-printed objects with the desired shapes and sizes. Therefore, we have engineered the 3D macro-architecture of COF-GO foams into complex geometries keeping their structural order and continuous porosity intact over a range of more than a million (10(-9) m to 10(-3) m). The interconnected 3D openings in these COF-GO foams further enhance the rapid and efficient uptake of organic and inorganic pollutants from water (&gt;95% removal within 30 s). The abundant distribution of interconnected macroporous volume (55%) throughout the COF-GO foam matrix enhances the flow of water (1.13 x 10(-3) m.s(-1)) which results in efficient mass transport and adsorption.</p>
1 aMohammed, Abdul, Khayum1 aUsgaonkar, Saurabh1 aKanheerampockil, Fayis1 aKarak, Suvendu1 aHalder, Arjun1 aTharkar, Minakshi1 aAddicoat, Matthew1 aAjithkumar, Thalasseril, G.1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/connecting-microscopic-structures-mesoscale-assemblies-and-macroscopic-architectures-3d02882nas a2200265   4500008004100000022001400041245008500055210006900140260000900209300001600218490000700234520201500241100002302256700002302279700001802302700002002320700001802340700003202358700002302390700001802413700002102431700002702452700002302479856011402502       2021                        eng d  a0020-166900aIonic conductivity of Na3Al2P3O12 glass electrolytes role of charge compensators0 aIonic conductivity of Na3Al2P3O12 glass electrolytes role of cha  cSEP   a12893-129050 v603 aIn glasses, a sodium ion (Na+) is a significant mobile cation that takes up a dual role, that is, as a charge compensator and also as a network modifier. As a network modifier, Na+ cations modify the structural distributions and create nonbridging oxygens. As a charge compensator, Na+ cations provide imbalanced charge for oxygen that is linked between two network-forming tetrahedra. However, the factors controlling the mobility of Na+ ions in glasses, which in turn affects the ionic conductivity, remain unclear. In the current work, using high-fidelity experiments and atomistic simulations, we demonstrate that the ionic conductivity of the Na3Al2P3O12 (Si0) glass material is dependent not only on the concentration of Na+ charge carriers but also on the number of charge-compensated oxygens within its first coordination sphere. To investigate, we chose a series of glasses formulated by the substitution of Si for P in Si0 glass based on the hypothesis that Si substitution in the presence of Na+ cations increases the number of SiOAl bonds, which enhances the role of Na as a charge compensator. The structural and conductivity properties of bulk glass materials are evaluated by molecular dynamics (MD) simulations, magic angle spinning-nuclear magnetic resonance, Raman spectroscopy, and impedance spectroscopy. We observe that the increasing number of charge-imbalanced bridging oxygens (BOs) with the substitution of Si for P in Si0 glass enhances the ionic conductivity by an order of magnitudefrom 3.7 x 10(-8) S.cm(-1) to 3.3 x 10(7) S.cm(-1) at 100 degrees C. By rigorously quantifying the channel regions in the glass structure, using MD simulations, we demonstrate that the enhanced ionic conductivity can be attributed to the increased connectivity of Na-rich channels because of the increased charge-compensated BOs around the Na atoms. Overall, this study provides new insights for designing next-generation glass-based electrolytes with superior ionic conductivity for Na-ion batteries1 aKeshri, Shweta, R.1 aGanisetti, Sudheer1 aKumar, Rajesh1 aGaddam, Anuraag1 aIllath, Kavya1 aAjithkumar, Thalasseril, G.1 aBalaji, Sathravada1 aAnnapurna, K.1 aNasani, Narendar1 aKrishnan, N., M. Anoop1 aAllu, Amarnath, R.  uhttps://library.ncl.res.in/content/ionic-conductivity-na3al2p3o12-glass-electrolytes-role-charge-compensators02471nas a2200229   4500008004100000022001400041245009400055210006900149260000800218300001200226490000800238520170800246100002001954700001701974700002001991700001902011700001602030700003202046700001702078700002002095856012602115       2022                        eng d  a0002-786300aDual nanomechanics in anisotropic porous covalent organic framework janus-type thin films0 aDual nanomechanics in anisotropic porous covalent organic framew  cJAN  a400-4090 v1443 a<p>
	Empowered by crystalline ordered structures and homogeneous fabrication techniques, covalent organic frameworks (COFs) have been realized with uniform morphologies and isotropic properties. However, such homogeneity often hinders various surface-dependent properties observed in asymmetric nanostructures. The challenge remains to induce heterogeneity in COFs by creating an asymmetric superstructure such as a Janus thin film. In this regard, we propose a versatile yet straightforward interfacial layer-grafting strategy to fabricate free-standing Janus-type COF-graphene thin films. Herein, two-dimensional graphene sheets were utilized as the suitable grafter due to the possibility of noncovalent interactions between the layers. The versatility of the approach was demonstrated by fabricating two distinct Janus-type films, with the COF surface interwoven with nanofibers and nanospheres. The Janus-type films showcase opposing surface morphologies originating from graphene sheets and COF nanofibers or nanospheres, preserving the porosity (552-600 m(2) g(-1)). The unique surface chemistries of the constituent layers further endow the films with orthogonal mechanical properties, as confirmed by the nanoindentation technique. Interestingly, the graphene sheets favor the Janus-type assembly of COF nanofibers over the nanospheres. This is reflected in the better nanomechanical properties of COFfiber-graphene films (E-gra(phene) = 300-1200 MPa; E-COF( )= 15-60 MPa) compared to the COFsphere-graphene films (E-gra(phe)ne = 11-14 MPa; E-CO(F )= 2-5 MPa). These results indicate a direct relationship between the mechanical properties and homo/heterogeneity of Janus-type COF films.</p>
1 aMohata, Shibani1 aDey, Kaushik1 aBhunia, Surojit1 aThomas, Neethu1 aGowd, Bhoje1 aAjithkumar, Thalasseril, G.1 aReddy, Malla1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/dual-nanomechanics-anisotropic-porous-covalent-organic-framework-janus-type-thin-films03045nas a2200325   4500008004100000022001400041245015900055210006900214260000900283300001100292490000800303520193300311653001402244653001702258653002302275653001902298653002402317100002302341700002202364700002302386700002502409700001802434700002002452700001902472700003202491700002502523700002702548700002302575856012102598       2022                        eng d  a1359-645400aElucidating the influence of structure and Ag+ -Na+ ion-exchange on crack-resistance and ionic conductivity of Na3Al1.8Si1.65 P-1.8 O-12 glass electrolyte0 aElucidating the influence of structure and Ag Na ionexchange on   cAPR   a1177450 v2273 a<p>
	Glasses are emerging as promising and efficient solid electrolytes for all-solid-state sodium-ion batteries. However, they still suffer from poor ionic conductivity and crack-resistance, which need to be improved for better battery performance, reliability, and service life. The current study shows a significant enhancement in crack resistance (from 11.3 N to 32.9 N) for Na3Al (1.8) Si-1.65 P1.8O12 glass (Ag-0 glass) upon Na+ -Ag+ ion-exchange (IE) due to compressive stresses generated in the glass surface while the ionic conductivity values (similar to 10(-5) S/cm at 473 K) were retained. In this study, magic angle spinning-nuclear magnetic resonance (MAS-NMR), molecular dynamics (MD) simulations, Vickers micro hardness, and impedance spectroscopic techniques were used to evaluate the intermediate-range structure, atomic structure, crack resistance and conductivity of the glass. MAS-NMR and MD simulations confirm the presence of Si-OAl-O-P groups in the glass, thus enabling formation of Na percolated channel regions. AC-conductivity analysis for Ag-0 and ion-exchanged Ag-0 glass suggests that the mobility of Na+ ion increases with increasing temperature. It is observed that the measured mean square displacement (root &lt; R-2(t(p))&gt;) for sodium cations using AC-conductivity isotherms is nearly constant up to 448 K and then increases with increasing temperature up to 523 K. From the impedance spectra for ion-exchanged Ag-0 glass, it is identified that the increase in root &lt; R-2 (t(nu))&gt; and thereby, the mobility of sodium-ions for Ag-0 glass is due to the structural variations in the Ag-0 glass with increasing the temperature. Overall, the mechanisms presented in this article helps in formulating better glass based electrolyte materials for room temperature or high temperature sodium-ion batteries. (C) 2022 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.</p>
10aamorphous10aIon-exchange10aIonic-conductivity10aMD simulations10aMechanical property1 aKeshri, Shweta, R.1 aMandal, Indrajeet1 aGanisetti, Sudheer1 aKasimuthumaniyan, S.1 aKumar, Rajesh1 aGaddam, Anuraag1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aGosvami, Nitya, Nand1 aKrishnan, N., M. Anoop1 aAllu, Amarnath, R.  uhttps://library.ncl.res.in/content/elucidating-influence-structure-and-ag-na-ion-exchange-crack-resistance-and-ionic01978nas a2200301   4500008004100000022001400041245007800055210006900133260000800202300000900210490000700219520105200226100002001278700001801298700002401316700001901340700001901359700001801378700002001396700001601416700002201432700001701454700001901471700003201490700002401522700002001546856011001566       2022                        eng d  a1755-433000aPorous covalent organic nanotubes and their assembly in loops and toroids0 aPorous covalent organic nanotubes and their assembly in loops an  cMAY  a507+0 v143 a<p>
	Carbon nanotubes, and synthetic organic nanotubes more generally, have in recent decades been widely explored for application in electronic devices, energy storage, catalysis and biosensors. Despite noteworthy progress made in the synthesis of nanotubular architectures with well-defined lengths and diameters, purely covalently bonded organic nanotubes have remained somewhat challenging to prepare. Here we report the synthesis of covalently bonded porous organic nanotubes (CONTs) by Schiff base reaction between a tetratopic amine-functionalized triptycene and a linear dialdehyde. The spatial orientation of the functional groups promotes the growth of the framework in one dimension, and the strong covalent bonds between carbon, nitrogen and oxygen impart the resulting CONTs with high thermal and chemical stability. Upon ultrasonication, the CONTs form intertwined structures that go on to coil and form toroidal superstructures. Computational studies give some insight into the effect of the solvent in this assembly process.</p>
1 aKoner, Kalipada1 aKarak, Shayan1 aKandambeth, Sharath1 aKarak, Suvendu1 aThomas, Neethu1 aLeanza, Luigi1 aPerego, Claudio1 aPesce, Luca1 aCapelli, Riccardo1 aMoun, Monika1 aBhakar, Monika1 aAjithkumar, Thalasseril, G.1 aPavan, Giovanni, M.1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/porous-covalent-organic-nanotubes-and-their-assembly-loops-and-toroids02542nas a2200241   4500008004100000022001400041245008900055210006900144260000900213300001600222490000800238520175100246100002501997700001502022700001702037700001702054700001902071700001902090700003202109700001802141700002002159856012102179       2023                        eng d  a0002-786300aCovalent organic framework cladding on peptide-amphiphile-based biomimetic catalysts0 aCovalent organic framework cladding on peptideamphiphilebased bi  cJUN   a12793-128010 v1453 a<p>
	Peptide-based biomimetic catalysts are promising materialsforefficient catalytic activity in various biochemical transformations.However, their lack of operational stability and fragile nature innon-aqueous media limit their practical applications. In this study,we have developed a cladding technique to stabilize biomimetic catalystswithin porous covalent organic framework (COF) scaffolds. This methodologyallows for the homogeneous distribution of peptide nanotubes insidethe COF (TpAzo and TpDPP) backbone, creating strong noncovalent interactionsthat prevent leaching. We synthesized two different peptide-amphiphiles,C10FFVK and C10FFVR, with lysine (K) and arginine(R) at the C-termini, respectively, which formed nanotubular morphologies.The C10FFVK peptide-amphiphile nanotubes exhibit enzyme-likebehavior and efficiently catalyze C-C bond cleavage in a buffermedium (pH 7.5). We produced nanotubular structures of TpAzo-C10FFVK and TpDPP-C10FFVK through COF claddingby using interfacial crystallization (IC). The peptide nanotubes encasedin the COF catalyze C-C bond cleavage in a buffer medium aswell as in different organic solvents (such as acetonitrile, acetone,and dichloromethane). The TpAzo-C10FFVK catalyst,being heterogeneous, is easily recoverable, enabling the reactionto be performed for multiple cycles. Additionally, the synthesis ofTpAzo-C10FFVK thin films facilitates catalysis inflow. As control, we synthesized another peptide-amphiphile, C10FFVR, which also forms tubular assemblies. By depositingTpAzo COF crystallites on C10FFVR nanotubes through IC,we produced TpAzo-C10FFVR nanotubular structuresthat expectedly did not show catalysis, suggesting the critical roleof the lysines in the TpAzo-C10FFVK.</p>
1 aMahato, Ashok, Kumar1 aPal, Sumit1 aDey, Kaushik1 aReja, Antara1 aPaul, Satyadip1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aDas, Dibyendu1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/covalent-organic-framework-cladding-peptide-amphiphile-based-biomimetic-catalysts02903nas a2200325   4500008004100000022001400041245010100055210006900156260000800225300001400233490000800247520183600255100001602091700002802107700002802135700001702163700002102180700002202201700002002223700002002243700001902263700001902282700003302301700003202334700002502366700001802391700001702409700002002426856013102446       2023                        eng d  a0002-786300aCovalent organic framework thin-film photodetectors from solution-processable porous nanospheres0 aCovalent organic framework thinfilm photodetectors from solution  cJAN  a1649-16590 v1453 a<p>
	The synthesis of homogeneous covalent organic framework (COF) thin films on a desired substrate with decent crystallinity, porosity, and uniform thickness has great potential for optoelectronic applications. We have used a solution-processable sphere transmutation process to synthesize 300 +/- 20 nm uniform COF thin films on a 2 x 2 cm2 TiO2-coated fluorine-doped tin oxide (FTO) surface. This process controls the nucleation of COF crystallites and molecular morphology that helps the nanospheres to arrange periodically to form homogeneous COF thin films. We have synthesized four COF thin films (TpDPP, TpEtBt, TpTab, and TpTta) with different functional backbones. In a close agreement between the experiment and density functional theory, the TpEtBr COF film showed the lowest optical band gap (2.26 eV) and highest excited-state lifetime (8.52 ns) among all four COF films. Hence, the TpEtBr COF film can participate in efficient charge generation and separation. We constructed optoelectronic devices having a glass/FTO/TiO2/COF-film/Au architecture, which serves as a model system to study the optoelectronic charge transport properties of COF thin films under dark and illuminated conditions. Visible light with a calibrated intensity of 100 mW cm-2 was used for the excitation of COF thin films. All of the COF thin films exhibit significant photocurrent after illumination with visible light in comparison to the dark. Hence, all of the COF films behave as good photoactive substrates with minimal pinhole defects. The fabricated out-of-plane photodetector device based on the TpEtBr COF thin film exhibits high photocurrent density (2.65 +/- 0.24 mA cm-2 at 0.5 V) and hole mobility (8.15 +/- 0.64 x10-3 cm2 V-1 S-1) compared to other as synthesized films, indicating the best photoactive characteristics.</p>
1 aBag, Saikat1 aSasmal, Himadri, Sekhar1 aChaudhary, Sonu, Pratap1 aDey, Kaushik1 aBlaette, Dominic1 aGuntermann, Roman1 aZhang, Yingying1 aPoloz, Miroslav1 aKuc, Agnieszka1 aShelke, Ankita1 aVijayaraghavan, Ratheesh, K.1 aAjithkumar, Thalasseril, G.1 aBhattacharyya, Sayan1 aHeine, Thomas1 aBein, Thomas1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/covalent-organic-framework-thin-film-photodetectors-solution-processable-porous-nanospheres03138nas a2200253   4500008004100000022001400041245012100055210006900176260000900245300001200254490000600266520224700272100001702519700002702536700002202563700002202585700001802607700002602625700002102651700001902672700003202691700003002723856013102753       2023                        eng d  a2055-675600aHydroxide ion-conducting viologen-bakelite organic frameworks for flexible solid-state zinc-air battery applications0 aHydroxide ionconducting viologenbakelite organic frameworks for   cJAN   a224-2340 v83 a<p>
	Adaptable polymer-based solid-state electrolytes can be a game-changer toward safe, lightweight flexible batteries. We present a robust Bakelite-type organic polymer covalently decked with viologen, triazine, and phenolic moieties. Its flexible structure with cationic viologen centers incorporates counter-balancing free hydroxide ions into the polymeric framework. By design, the aromatic groups and heteroatoms in the framework can be activated under an applied potential to prompt a push-pull drive, setting off the towing of hydroxide ions via weak electrostatic, van der Waals, and hydrogen-bond interactions. The frontier orbitals from a DFT-modeled structure certify this. The hydroxyl-polymer requires minimal KOH wetting to maintain a humid environment for Grotthuss-type transport. The hydroxide ion conductivity reaches a value of 1.4 x 10(-2) S cm(-1) at 80 degrees C and 95% RH, which is retained for over 15 h. We enhanced its practical utility by coating it as a thin solid-state separator-cum-electrolyte on readily available filter paper. The composite exhibits a conductivity of 4.5 x 10(-3) S cm(-1) at 80 degrees C and 95% RH. A zinc-air battery (ZAB) constructed using this polymer-coated paper as electrolyte yields a maximum power density of 115 mW cm(-2) and high specific capacitance of 435 mA h g(-1). The power density recorded for our ZAB is among the best reported for polymer electrolyte-based batteries. Subsequently, the flexible battery fabricated with IISERP-POF11_OH@FilterPaper exhibits an OCV of 1.44 V, and three batteries in series power a demo traffic signal. To underscore the efficiency of hydroxide ion transport through the complex multifunctional backbone of the polymer, we calculated the diffusion coefficient for OH- (Exp: 2.9 x 10(-5) cm(2) s(-1); Comp. 5.2 x 10(-6) cm(2) s(-1)) using electrochemical methods and MD simulations. Climbing-edge NEB calculations reveal a large energy barrier of 2.11 eV for Zn2+ to penetrate the polymer and identify hydroxide ions within the polymer, suggesting no undesirable Zn2+ crossover. Our findings assert the readily accessible C-C-linked cationic polymer's capacity as a solid-state electrolyte for ZABs and any anion-conducting membrane.</p>
1 aRase, Deepak1 aIllathvalappil, Rajith1 aSingh, Himan, Dev1 aShekhar, Pragalbh1 aLeo, Liya, S.1 aChakraborty, Debanjan1 aHaldar, Sattwick1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aVaidhyanathan, Ramanathan  uhttps://library.ncl.res.in/content/hydroxide-ion-conducting-viologen-bakelite-organic-frameworks-flexible-solid-state-zinc-air02758nas a2200241   4500008004100000022001400041245014000055210006900195260000800264300001400272490000700286520189900293100002002192700002202212700002002234700001902254700001602273700003202289700002302321700002202344700002002366856013002386       2023                        eng d  a0020-166900aLead-free solid state mechanochemical synthesis of Cs2NaBi1-XFeXCl6 double perovskite: reduces band gap and enhances optical properties0 aLeadfree solid state mechanochemical synthesis of Cs2NaBi1XFeXCl  cMAR  a4861-48710 v623 a<p>
	Efficient and stable lead-free halide double perovskites (DPs) have attracted great attention for the future generation of electronic devices. Herein, we have developed a doping approach to incorporate Fe3+ ions into the Cs2NaBiCl6 crystal unit and reveal a crystallographic and optoelectronic study of the Cs2NaBi1-xFexCl6 double perovskite. We report a simple solid-state mechanochemical method that has a solvent-free, one-step, green chemistry approach for the synthesis of Cs2NaBi1-xFexCl6 phosphor. The analysis of powder X-ray diffraction (XRD) data determines the contraction of the lattice due to the incorporation of Fe3+ cations, and this effect is well supported by X-ray photoelectron spectroscopy (XPS), field emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and solid-state nuclear magnetic resonance spectroscopy (ss-NMR). The band gap is reduced with increasing Fe content owing to the strong overlap of the Fe-3d orbitals with Cl-3p orbitals and shift of the valence band maxima (VBM) toward higher energies, as confirmed by ultraviolet photoelectron spectroscopy (UPS) and density functional theory (DFT) analyses. Photoluminescence (PL) studies of Cs2NaBi1-xFexCl6 phosphors exhibit a large Stokes shift, broadband emission, and increased PL intensity more than ten times for 15% of Fe content phosphor with enhancement in the average decay lifetimes (up to 38 ns) compared to pristine Cs2NaBiCl6 DP. These results indicate that the transition of dark self-trapping of excitons (STEs) into bright STEs enhances yellow emission. XRD, UV, and thermo-gravimetric analysis (TGA) confirmed that the Cs2NaB1-xFexCl6 DPs have good structural and thermal stabilities. Our findings indicate that the doping of Fe3+ cations into the Cs2NaBiCl6 lattice is a constructive strategy to enhance significantly the optoelectronic properties of these phosphors.</p>
1 aUdavant, Rohini1 aThawarkar, Sachin1 aRondiya, Sachin1 aShelke, Ankita1 aAher, Rahul1 aAjithkumar, Thalasseril, G.1 aCross, Russell, W.1 aDzade, Nelson, Y.1 aJadkar, Sandesh  uhttps://library.ncl.res.in/content/lead-free-solid-state-mechanochemical-synthesis-cs2nabi1-xfexcl6-double-perovskite-reduces02348nas a2200265   4500008004100000022001400041245014300055210006900198260000800267300001200275490000800287520138500295653003201680653002801712100001801740700002001758700001701778700002201795700001901817700001901836700003201855700003601887700003001923856012901953       2023                        eng d  a0002-786300aTailoring COFs: transforming nonconducting 2D layered COF into a conducting quasi-3D architecture via interlayer knitting with polypyrrole0 aTailoring COFs transforming nonconducting 2D layered COF into a   cDEC  a487-4990 v1463 a<p>Improving the electronic conductivity and the structural robustness of covalent organic frameworks (COFs) is paramount. Here, we covalently cross-link a 2D COF with polypyrrole (Ppy) chains to form a quasi-3D COF. The 3D COF shows well-defined reflections in the SAED patterns distinctly indexed to its modeled crystal structure. This knitting of 2D COF layers with conjugated polypyrrole units improves electronic conductivity from 10(-9) to 10(-2 )S m(-1). This conductivity boost is affirmed by the presence of density of states near the Fermi level in the 3D COF, and this elevates the COF's valence band maximum by 0.52 eV with respect to the parent 2D pyrrole-functionalized COF, which agrees well with the opto-electro band gaps. The extent of HOMO elevation suggests the predominant existence of a polaron state (radical cation), giving rise to a strong EPR signal, most likely sourced from the cross-linking polypyrrole chains. A supercapacitor devised with COF20-Ppy records a high areal capacitance of 377.6 mF cm(-2), higher than that of the COF loaded with noncovalently linked polypyrrole chains. Thus, the polypyrrole acts as a ``conjugation bridge'' across the layers, lowering the band gap and providing polarons and additional conduction pathways. This marks a far-reaching approach to converting many 2D COFs into highly ordered and conducting 3D ones.</p>
10acovalent organic frameworks10aElectrical conductivity1 aJain, Chitvan1 aKushwaha, Rinku1 aRase, Deepak1 aShekhar, Pragalbh1 aShelke, Ankita1 aSonwani, Disha1 aAjithkumar, Thalasseril, G.1 aVinod, Chathakudath, Prabhakara1 aVaidhyanathan, Ramanathan  uhttps://library.ncl.res.in/content/tailoring-cofs-transforming-nonconducting-2d-layered-cof-conducting-quasi-3d-architecture00915nas a2200253   4500008004100000022001400041245012200055210006900177260000900246300001400255490000700269653001700276653003100293653002900324100002500353700001700378700001800395700002300413700002300436700002200459700003200481700001800513856013000531       2024                        eng d  a2168-048500aAtmospheric-pressure continuous-flow methane oxidation to methanol and acetic acid using H2O2 over the Au-Fe catalyst0 aAtmosphericpressure continuousflow methane oxidation to methanol  cMAY   a8958-89670 v1210aCO oxidation10aHIGHLY SELECTIVE OXIDATION10ametal-organic frameworks1 aJagtap, Anuradha, V.1 aKumar, Pawan1 aGupta, Sharad1 aNagendra, Abharana1 aJha, Shambhu, Nath1 aBhattacharyya, D.1 aAjithkumar, Thalasseril, G.1 aVinod, C., P.  uhttps://library.ncl.res.in/content/atmospheric-pressure-continuous-flow-methane-oxidation-methanol-and-acetic-acid-using-h2o202162nas a2200313   4500008004100000022001400041245006800055210006700123260000900190300001600199490000700215520118200222653002401404653002301428653003201451653001601483653003301499100001601532700002101548700002201569700002401591700002701615700001901642700003201661700001601693700002101709700001901730856009901749       2024                        eng d  a1530-698400aBiexciton emission in CsPbBr3 nanocrystals: polar facet matters0 aBiexciton emission in CsPbBr3 nanocrystals polar facet matters  cAUG   a10434-104420 v243 a<p>
	The metal halide perovskite nanocrystals exhibit a remarkable tolerance to midgap defect states, resulting in high photoluminescence quantum yields. However, the potential of these nanocrystals for applications in display devices is hindered by the suppression of biexcitonic emission due to various Auger recombination processes. By adopting single-particle photoluminescence spectroscopy, herein, we establish that the biexcitonic quantum efficiency increases with the increase in the number of facets on cesium lead bromide perovskite nanocrystals, progressing from cube to rhombic dodecahedron to rhombicuboctahedron nanostructures. The observed enhancement is attributed mainly to an increase in their surface polarity as the number of facets increases, which reduces the Coulomb interaction of charge carriers, thereby suppressing Auger recombination. Moreover, Auger recombination rate constants obtained from the time-gated photon correlation studies exhibited a discernible decrease as the number of facets increased. These findings underscore the significance of facet engineering in fine-tuning biexciton emission in metal halide perovskite nanocrystals.</p>
10aAuger recombination10abiexciton emission10aCs-133 MAS NMR spectroscopy10aPerovskites10atime-gatedphoton correlation1 aTitus, Timi1 aVishnu, Krishnan1 aGarai, Arghyadeep1 aDutta, Sumit, Kumar1 aSandeep, Kuttysankaran1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aShaji, Anil1 aPradhan, Narayan1 aThomas, George  uhttps://library.ncl.res.in/content/biexciton-emission-cspbbr3-nanocrystals-polar-facet-matters02469nas a2200241   4500008004100000022001400041245013900055210006900194260000900263300001600272490000700288520157200295100002101867700002001888700003701908700002601945700002501971700001901996700003202015700001902047700002602066856013502092       2024                        eng d  a1144-054600aNew insights into the composition and catalytic performance of VOx-Ga/γ-Al2O3 for the oxidative dehydrogenation of propane to propene0 aNew insights into the composition and catalytic performance of V  cAUG   a15077-150870 v483 a<p>
	Oxidative dehydrogenation (ODH) of propane is a promising alternative route for propene production. In this work, we developed a series of vanadium and gallium oxides supported on gamma-Al2O3 catalysts by an incipient wetness impregnation method. Among the employed catalysts, the VGA-2 showed superior catalytic activity, and the catalyst was demonstrated for longevity in ODH of propane with a stable activity using a continuous flow fixed bed reactor at 400 degrees C. H-2-TPR and UV-visible spectra showed the presence of highly dispersed monomeric VOx species with tetrahedral coordination geometry, which influences product selectivity. The characterization results also conferred that the redox nature of vanadium (V5+ and V4+) oxide and higher V5+ content on the surface of the VGA-2 catalysts are more favourable for C-H activation. In addition, the pyridine-FTIR and Ga-71 solid-state NMR studies further substantiated the presence of Lewis acid sites and tetrahedrally coordinated Ga3+Ox species that are highly responsible for the ODHP activity, respectively. Furthermore, in situ-DRIFTS studies conferred that the propane adsorption at ambient temperature showed the formation of intermediate propoxide species with the evolution of sigma-bonds and with further increase in the temperature to 325 degrees C; the stretching vibrations of the =C-H and -C-H bonds in the propylene molecule were observed. The spent catalysts were also analyzed by thermogravimetric analysis, where the optimized catalyst (VGA-2) showed the least coke deposition.</p>
1 aKandasamy, Prabu1 aGawali, Sheetal1 aVenugopalan, Aswathy, Thareparam1 aManikandan, Marimuthu1 aMekala, Siva, Prasad1 aShelke, Ankita1 aAjithkumar, Thalasseril, G.1 aBhatte, Kushal1 aRaja, Thirumalaiswamy  uhttps://library.ncl.res.in/content/new-insights-composition-and-catalytic-performance-vox-ga%CE%B3-al2o3-oxidative-dehydrogenation02285nas a2200265   4500008004100000022001400041245008800055210006900143260000800212490000700220520133500227653003301562653001401595653001501609653003101624653003001655100003001685700003401715700002901749700003301778700003201811700002601843700003001869856012001899       2025                        eng d  a2192-650600aMechanochemical large-scale rapid synthesis of ultrapure sodium hexafluorophosphate0 aMechanochemical largescale rapid synthesis of ultrapure sodium h  cJUL0 v903 a<p>
	Among the sodium battery electrolytes, sodium hexafluorophosphate (NaPF6) exhibits superior conductivity, anodic stability, and stable cathode electrolyte interface compared to other electrolytes. Therefore, the synthesis of pure NaPF6 through a simple process is very important. Usually, NaPF6 is synthesized using HF. In our approach, NaPF6 is synthesized by grinding dry ammonium hexafluorophosphate (NH4PF6) and sodium metal. Sodium injects an electron into the ammonium ion, which results in the formation of ammonia and hydrogen. The gram scale synthesis is completed in about 30 min. Purification of the product is not needed. The product purity is confirmed by various spectroscopic and electrochemical techniques. Usually, NaPF6 comprises NaF, HF, and solvents as impurities that affect the performance of SIBs. It has been confirmed that the NaPF6 synthesized by our mechanochemical approach in the absence of solvent is devoid of impurities despite the absence of product purification step. Furthermore, the synthesis of pure NaPF6 (250 g) is demonstrated using a grinder used as household item in cooking Indian pancakes, which costs about 300 USD. The duration of the synthesis of 250 g pure NaPF6 is 1 h. The purity of this sample is comparable to that of NaPF6 (5 g) synthesized using mortar and pestle.</p>
10aammonium hexafluorophosphate10aBatteries10acarbonates10asodium hexafluorophosphate10asodium vanadium phosphate1 aSenthilkumaran, Marimuthu1 aJavaregowda, Bharathkumar, H.1 aRajendran, Prakash, Babu1 aBalasubramanian, Rajalakshmi1 aAjithkumar, Thalasseril, G.1 aRavindranathan, Sapna1 aKrishnamoorthy, Kothandam  uhttps://library.ncl.res.in/content/mechanochemical-large-scale-rapid-synthesis-ultrapure-sodium-hexafluorophosphate02724nas a2200325   4500008004100000022001400041245014100055210006900196260000800265490000700273520157300280653002101853653004001874653004101914653002801955100001601983700002601999700002102025700002802046700002002074700002002094700001902114700001902133700002002152700002402172700003202196700002202228700002002250856012802270       2026                        eng d  a0935-964800aChirality transfer from covalent organic framework nanotubes to covalent organic framework films via chirality induction crystallization0 aChirality transfer from covalent organic framework nanotubes to   cAPR0 v383 a<p>
	We report the synthesis of homochiral crystalline covalent organic framework (COF) films that combine rigidity and porosity, offering significant promise for heterogeneous asymmetric catalysis. We prepared enantiopure COF films from achiral diamine and trialdehyde precursors using a chiral induction crystallization strategy. A Schiff-base reaction, catalyzed by a chiral acid, namely (R)- and (S)-camphorsulfonic acids (CSA) generated a beta-ketoenamine backbone with induced chirality. (R)- and (S)-camphorsulfonic acids direct the diamine-trialdehyde condensation and induce chirality during the nucleation of COF nanotubes, enabling their periodic arrangement and the formation of homochiral thin films. We successfully synthesized six distinct COF films with three different backbone functionalities: R-, S-TpAzo; R-, S-TpDPP; and R-, S-TpBDMe2, using the two enantiomers of the chiral camphorsulfonic acids. All films displayed strong circular dichroism signals and pronounced Cotton effects, confirming their enhanced enantiopurity. Both R- and S-TpAzo films exhibited the highest crystallinity, long-range order, and permanent porosity, making them particularly well-suited for catalytic applications. To demonstrate their utility, we encapsulated a bioinspired catalyst, (Et4N)2[FeIII(Cl)bTAML], within the chiral channels of the R- and S-TpAzo films. The resulting composite created a robust heterogeneous catalytic platform for the asymmetric epoxidation of alkenes, achieving excellent activity and enantioselectivity under ambient conditions.</p>
10achiral induction10acovalent organic framework nanotube10acovalent organic framework thin film10aheterogeneous catalysis1 aBag, Saikat1 aChatterjee, Debasmita1 aMahapatra, Rohan1 aSasmal, Himadri, Sekhar1 aKhatua, Arindam1 aGiri, Madhurima1 aPaul, Satyadip1 aShelke, Ankita1 aAlmasoud, Najla1 aAlomar, Taghrid, S.1 aAjithkumar, Thalasseril, G.1 aGupta, Sayam, Sen1 aBanerjee, Rahul  uhttps://library.ncl.res.in/content/chirality-transfer-covalent-organic-framework-nanotubes-covalent-organic-framework-films02583nas a2200253   4500008004100000022001400041245011100055210006900166260000800235300001600243490000700259520168600266100002001952700001701972700001801989700002202007700002402029700003202053700003202085700002702117700003202144700002302176856013002199       2026                        eng d  a2470-134300aSustainable nanocellulose extraction from salacca zalacca peel using chlorine-free and low-acid treatments0 aSustainable nanocellulose extraction from salacca zalacca peel u  cMAR  a13253-132670 v113 a<p>
	Conversion of agro-waste to value-added products is one of the important principles of a green circular economy. A novel sustainable technique has been reported by using chlorine-free extraction of cellulose nanofibers (CNFs) from the peels of Salacca zalacca, a common fruit found in Asia. The fruit peels were exposed to alkali treatment using 2% NaOH (60 degrees C, 2 h), chlorine-free bleaching using 15% hydrogen peroxide (60 degrees C, 2 h), and sulfuric acid hydrolysis (15% v/v) for the extraction of CNFs. Various analytical methods were employed to characterize the prepared CNFs. The Fourier transform infrared spectroscopy (FTIR) and 13C solid state nuclear magnetic resonance (NMR) spectra showed the complete elimination of lignin and hemicellulose in the prepared CNFs. The elemental composition and high purity of CNFs were further verified by energy-dispersive X-ray analysis (EDX). The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images proved the fibrous morphology of the prepared CNFs, and the diameters of the cellulose nanofibers were found to be 15-30 nm. The X-ray diffraction (XRD) studies disclosed the type-I cellulosic structure in the prepared CNFs with a high crystallinity index (73%). The thermogravimetric analysis (TGA) demonstrated the superior thermal stability of the prepared CNFs (T max is 350 degrees C) compared to the raw fiber (T max is 320 degrees C). Based on the obtained results, it has been explored that the extracted highly pure CNFs can be used for fabricating bionanocomposites for high performance applications, including food packaging, sensors, water treatment, green tires, etc.</p>
1 aKrishnan, Akhil1 aPaul, Sharon1 aPhiri, Resego1 aSrisuk, Rapeeporn1 aSingh, Manoj, Kumar1 aPalaniappan, Sathish, Kumar1 aRangappa, Sanjay, Mavinkere1 aDominic, C., D. Midhun1 aAjithkumar, Thalasseril, G.1 aSiengchin, Suchart  uhttps://library.ncl.res.in/content/sustainable-nanocellulose-extraction-salacca-zalacca-peel-using-chlorine-free-and-low-acid