03077nas a2200181 4500008004100000245008900041210006900130260000800199300001600207490000800223520242800231100002002659700003002679700001902709700003002728700002402758856011302782 2007 eng d00aInteraction of different metal ions with carboxylic acid group: a quantitative study0 aInteraction of different metal ions with carboxylic acid group a cJUN a6183–61900 v1113 a

The binding strength of the carboxylic acid group (-COOH) with different divalent metal ions displays considerable variation in arachidic acid (AA) thin films. It is considered that in AA thin films the metal ions straddle the hydrophilic regions of the stacked bilayers of AA molecules via formation of carboxylates. In this study first the uptake of different divalent cations in films of AA is estimated by atomic absorption spectroscopy (AAS). Through the amount of cation uptake, it is found that the strength of binding of different cations varies as Ca2+ > Co2+ > Pb2+ > Cd2+. Variation in the binding strength of different ions is also manifested in experiments where AA thin films are exposed to metal ion mixtures. The higher binding strength of AA with certain metal ions when exposed individually, as well as the preference over the other metal ions when exposed to mixtures, reveal some interesting deviation from the expected behavior based on considerations of ionic radii. For example, Pb2+ is always found to bind to AA much more strongly than Cd2+ even though the latter has smaller ionic radius, indicating that other factors also play an important role in governing the binding strength trends apart from the effects of ionic radii. Then, to get a more meaningful knowledge regarding the binding capability, first-principles calculations based on density functional theory have been applied to study the interaction of different cations with the simplest carboxylic acid, acetic acid, that can result in formation of metal diacetates. Their electronic and molecular structures, cohesive energies, and stiffness of the local potential energy well at the cation (M) site are determined and attempts are made to understand the diversity in geometry and the properties of binding of different metal ions with -COOH group. We find that the calculated M−O bond energies depend sensitively on the chemistry of M atom and follow the experimentally observed trends quite accurately. The trends in M−O bond energies and hence the total M−acetate binding energy trends can actually be related to their molecular structures that fall into different categories:  Ca and Cd have tetrahedral coordination; Fe, Ni, and Co exhibit planar 4-fold coordination; and Pb is off-centered from the planar structure (forming pyramidal structure) due to its stereochemically active lone pair of electrons.

1 aBala, Tanushree1 aPrasad, Bhagavatula L. V.1 aSastry, Murali1 aKahaly, Mousumi, Upadhyay1 aWaghmare, Umesh, V. uhttps://library.ncl.res.in/content/interaction-different-metal-ions-carboxylic-acid-group-quantitative-study01413nas a2200253 4500008004100000022001400041245015500055210006900210260010200279300001200381490000800393520040600401653002900807653002600836653002500862653001700887100002000904700001400924700002100938700001900959700002100978700003000999856013001029 2008 eng d a0974-362600aIn situ synthesis of ligand reduced/capped silver nanoparticles and the effect of temperature and ligand structure on the size of silver nanoparticles0 aIn situ synthesis of ligand reducedcapped silver nanoparticles a aC V RAMAN AVENUE, SADASHIVANAGAR, P B \#8005, BANGALORE 560 080, INDIAbINDIAN ACAD SCIENCEScJAN a515-5200 v1203 a

We report in situ synthesis of silver nanoparticles using biosurfactants called sophorolipids as reducing and capping agents. We further study the effect of temperature and the structure of sophorolipid on the size of silver nanoparticles obtained. The silver nanoparticles were characterized by UV-visible, transmission electron microscope (TEM) and light scattering (DLS) analysis techniques.

10adynamic light scattering10aNucleation and growth10asilver nanoparticles10aSophorolipid1 aKasture, M., B.1 aPatel, P.1 aPrabhune, Asmita1 aRamana, C., V.1 aKulkarni, A., A.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/situ-synthesis-ligand-reducedcapped-silver-nanoparticles-and-effect-temperature-and-ligand01875nas a2200241 4500008004100000022001400041245013700055210006900192260007300261300001200334490000700346520092200353653002801275653002501303653002201328653003101350653002401381100002301405700002001428700002301448700003001471856013201501 2009 eng d a0927-776500aIn situ synthesis of water dispersible bovine serum albumin capped gold and silver nanoparticles and their cytocompatibility studies0 aIn situ synthesis of water dispersible bovine serum albumin capp aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcOCT a224-2280 v733 a

A simple and convenient one step room temperature method is described for the synthesis of bovine serum albumin (BSA) capped gold and silver nanoparticles. BSA reduces silver ions to silver nanoparticles but does not directly reduce gold ions to gold nanoparticles at room temperature and varying pH conditions. However, when silver and gold ions are simultaneously added to BSA, silver ions get reduced to metallic silver first and these in turn reduce gold ions to gold nanoparticles through a galvanic exchange reaction. The so synthesized silver and gold nanoparticles are easily water dispersible and can withstand addition of salt even at high concentrations. It is shown that the capped protein retains its secondary structure and the helicity to a large extent on the nanoparticles surface and that the protein capping makes the nanoparticles cytocompatible. (C) 2009 Elsevier B.V. All rights reserved.

10aAg and Au nanoparticles10aBovine serum albumin10aCytocompatibility10aGalvanic exchange reaction10aReductive synthesis1 aMurawala, Priyanka1 aPhadnis, S., M.1 aBhonde, Ramesh, R.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/situ-synthesis-water-dispersible-bovine-serum-albumin-capped-gold-and-silver-nanoparticles-001274nas a2200157 4500008004100000022001400041245013100055210006900186260007100255300001600326490000700342520058600349100002400935700003000959856012700989 2009 eng d a0743-746300aIntracellular biogenic silver nanoparticles for the generation of carbon supported antiviral and sustained bactericidal agents0 aIntracellular biogenic silver nanoparticles for the generation o a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcOCT a11741-117470 v253 a

Intracellular silver nanoparticles produced by exposing silver ions to the fungus Aspergillus ochraceus were heat-treated in nitrogen environment to yield silver nanoparticles embedded in carbonaceous supports. This carbonaceous matrix embedded silver nanoparticles showed antimicrobial properties against both bacteria (Gram-positive and Gram-negative) and virus (M 13 phage virus). The bactericidal effects were noticed even after washing and repealed exposure of these carbon supported silver nanoparticles to fresh bacterial Cultures, revealing their sustained activity.

1 aVijayakumar, P., S.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/intracellular-biogenic-silver-nanoparticles-generation-carbon-supported-antiviral-and-001629nas a2200181 4500008004100000245010100041210006900142260000800211490000800219520096000227100002001187700002001207700002001227700002401247700003001271700001601301856013001317 2010 eng d00aInvestigation of magnetic anisotropy in Co nanoparticles using ferromagnetic resonance technique0 aInvestigation of magnetic anisotropy in Co nanoparticles using f cJAN0 v2003 a

Using ferromagnetic resonance (FMR) technique, we have investigated the temperature dependence and angular dependence of line width and resonance magnetic field of Co nanoparticles capped with novel alkane carboxylic acids of varying chain lengths. The magnetic properties such as blocking temperature and anisotropy sensitively depend on the chain length as evidenced by the temperature dependence of line width. These results indicate that the magnetic properties of these samples are critically governed by the interparticle interactions which are decided by the chain length. The presence of anisotropy even up to very high temperature above the blocking temperature observed in these studies confirms the presence of inter-particle magnetic interactions as well as intra-particle exchange interaction between the core and shell regions as evidenced by our earlier ac susceptibility and transverse susceptibility measurements on similar system.

1 aSendilkumar, A.1 aKasture, Manasi1 aPatel, Pitamber1 aRamana, Chepuri, V.1 aPrasad, Bhagavatula L. V.1 aSrinath, S. uhttps://library.ncl.res.in/content/investigation-magnetic-anisotropy-co-nanoparticles-using-ferromagnetic-resonance-technique01697nas a2200169 4500008004100000022001400041245010400055210006900159260007100228300001600299490000700315520100200322100002301324700003001347700002101377856012901398 2013 eng d a0888-588500aImpinging jet micromixer for flow synthesis of nanocrystalline MgO: role of mixing/impingement zone0 aImpinging jet micromixer for flow synthesis of nanocrystalline M a1155 16TH ST, NW, WASHINGTON, DC 20036 USAbAMER CHEMICAL SOCcDEC a17376-173820 v523 a

Continuous flow synthesis of nanomaterials via sol-gel process using microreactors has not received much attention. For the synthesis of gels where the reaction time is of the order of few seconds to few tens of seconds, microchannel reactors are an excellent processing option. However since a `gel' does not `flow' easily, making it in a microchannel usually clogs the microchannel. We envisaged that by using an impinging jet micromixer, where the two reactants impinge and collide to form a mixing zone outside the micromixer, this problem could be circumvented. Here we report a successful implementation of continuous flow synthesis of metal oxides formed by the rapid sol-gel process taking the nanocrystalline MgO (NC-MgO) as a specific example. Furthermore, we clearly demonstrate that the nature of the mixing zone formed by the impinging jets governs the surface area of the product. Specific flow rate and impingement angle are identified that yield high surface area materials.

1 aKumar, D., V. Ravi1 aPrasad, Bhagavatula L. V.1 aKulkarni, A., A. uhttps://library.ncl.res.in/content/impinging-jet-micromixer-flow-synthesis-nanocrystalline-mgo-role-mixingimpingement-zone-000852nas a2200229 4500008004100000022001400041245008800055210006900143260007700212300001200289490000600301653002000307653002300327653001700350653001800367653001800385100002200403700002400425700002800449700003000477856011500507 2013 eng d a1861-472800aInfluence of the sophorolipid molecular geometry on their self-assembled structures0 aInfluence of the sophorolipid molecular geometry on their selfas aBOSCHSTRASSE 12, D-69469 WEINHEIM, GERMANYbWILEY-V C H VERLAG GMBHcFEB a369-3720 v810abolaamphiphiles10ahelical structures10ap-p stacking10aSelf-assembly10asophorolipids1 aDhasaiyan, Prabhu1 aBanerjee, Agnimitra1 aVisaveliya, Nikunjkumar1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/influence-sophorolipid-molecular-geometry-their-self-assembled-structures-002002nas a2200253 4500008004100000022001400041245013400055210006900189260007300258300001200331490000700343520106300350653001401413653002501427653001901452653001701471653002301488653002301511100002301534700002001557700001901577700003001596856012201626 2014 eng d a0928-493100aIn situ synthesized BSA capped gold nanoparticles: effective carrier of anticancer drug methotrexate to MCF-7 breast cancer cells0 aIn situ synthesized BSA capped gold nanoparticles effective carr aPO BOX 211, 1000 AE AMSTERDAM, NETHERLANDSbELSEVIER SCIENCE BVcJAN a158-1670 v343 a

The proficiency of MTX loaded BSA capped gold nanoparticles (Au-BSA-MTX) in inhibiting the proliferation of breast cancer cells MCF-7 as compared to the free drug Methotrexate (MTX) is demonstrated based on MTT and Ki-67 proliferation assays. In addition, DNA ladder gel electrophoresis studies, flow cytometry and TUNEL assay confirmed the induction of apoptosis by MTX and Au-BSA-MTX in MCF-7 cells. Notably, Au-BSA-MTX: was found to have higher cytotoxicity on MCF-7 cells compared with an equivalent dose of free MTX. The enhanced activity is attributed to the preferential uptake of Au-BSA-MTX particles by MCF-7 cells due to the presence of BSA that acts as a source of nutrient and energy to the rapidly proliferating MCF-7 cells. Moreover, the targeting ability of the drug MTX to the over expressed folate receptors on MCF-7 cells also contributes to the enhanced uptake and activity. Taken together, these results unveil that Au-BSA-MTX could be more effective than free drug for cancer treatment. (C) 2013 Elsevier B.V. All rights reserved.

10aApoptosis10aBovine serum albumin10aCancer therapy10aCytotoxicity10aDual active agents10agold nanoparticles1 aMurawala, Priyanka1 aTirmale, Amruta1 aShiras, Anjali1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/situ-synthesized-bsa-capped-gold-nanoparticles-effective-carrier-anticancer-drug-001570nas a2200169 4500008004100000245016400041210006900205260000800274300001400282490000600296520087000302100002601172700002001198700002301218700003001241856012901271 2016 eng d00aIn situ electrochemical transformation of Ni3S2 and Ni3S2-Ni from sheets to nanodisks: towards efficient electrocatalysis for hydrogen evolution reaction (HER)0 aIn situ electrochemical transformation of Ni3S2 and Ni3S2Ni from cDEC a6708-67120 v13 aTransition metal sulphides have been viewed as alternatives to platinum based electrocatalysts for HER. Herein, we report the preparation of Ni3S2 in conjunction with Ni in a novel nanosheet morphology and verified its performance for HER. During cyclic polarization, exotic morphological transformation of Ni-3 S-2-Ni from nanosheets to nanodisks has been noted. This change is accompanied with initial increase in over-potential that passed through maxima (similar to 100mV above the starting potential) and decreased to similar to 50mV below the starting value. Enhanced electrocatalytic activity due to the morphological changes from sheets to nanodisks has been attributed to the formation of more number of exposed edge-planes known to promote HER. Kinetic analysis based on Tafel slope displayed by this composite is comparable to that of Pt based catalysts.1 aBusupalli, Balanagulu1 aBattu, Shateesh1 aHaram, Santosh, K.1 aPrasad, Bhagavatula L. V. uhttps://library.ncl.res.in/content/situ-electrochemical-transformation-ni3s2-and-ni3s2-ni-sheets-nanodisks-towards-efficient02808nas a2200277 4500008004100000022001400041245012400055210006900179260000900248300001100257490000800268520186200276653002402138653001802162653001802180653001602198653002602214100002102240700002402261700002202285700002302307700001902330700003002349700002002379856013102399 2020 eng d a0167-732200aInfluence of gold nanorods on the structure and photonic bandgap in a twist grain boundary phase with smectic C* blocks0 aInfluence of gold nanorods on the structure and photonic bandgap cFEB  a1121170 v2993 a

We describe the first report of the influence of gold nanorods (GNR) on the induced twist grain boundary smectic C* (TGBC*) phase in a binary mixture of achiral bent-core and chiral linear liquid crystals. The GNR concentration-dependent phase diagram of these nanocomposites shows that the thermal range of this twist grain boundary phase having smectic C* blocks phase increases by 50% for an intermediate composition compared to that for the host binary mixture without nanorods. The inclusion of the nanorods is seen to have substantial effect on the structural and photonic bandgap features of the TGBC* phase. For example, the helical periodidty gets altered in all the three dimensions: while those within the block undergo a huge increase, the one which is orthogonal to the blocks, shrinks. The spacing of the square grid pattern arising normal to the TGB helix direction increases for the nanocomposites getting even doubled for a certain composition, a feature evidenced by optical microscopy as well as optical diffraction. Xray diffraction clearly brings out the feature that the presence of GNR alters the thermal character of the transition between the TGBC* and the cholesteric phase. Quantitative analysis of the data indicates that the system would remain in the vicinity of a possible tricritical point, a behavior having wider ramifications to understand the underlying critical phenomenon. Based on the experimental observations, and capturing the essence of the reported adaptive defect core targeting mechanism we propose a model wherein GNRs get confined in the grain boundary region. This feature offers a potential to have periodic and anisotropic plasmonic structure arising out of the synergetic interactions between the metal nanorod and the twisted grain boundary structure. (C) 2019 Elsevier B.V. All rights reserved.

10a3D photonic bandgap10aGold nanorods10aInduced phase10aTGBC* phase10aTricritical phenomena1 aSahoo, Rajalaxmi1 aRao, D., S. Shankar1 aHiremath, Uma, S.1 aYelamaggad, V., C.1 aShinde, Pravin1 aPrasad, Bhagavatula L. V.1 aPrasad, Krishna uhttps://library.ncl.res.in/content/influence-gold-nanorods-structure-and-photonic-bandgap-twist-grain-boundary-phase-smectic-c