@article { ISI:000233129500063, title = {Cobalt and magnesium ferrite nanoparticles: preparation using liquid foams as templates and their magnetic characteristics}, journal = {Langmuir}, volume = {21}, number = {23}, year = {2005}, month = {NOV}, pages = {10638-10643}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

An easy and convenient method for the synthesis of cobalt and magnesium ferrite nanoparticles is demonstrated using liquid foams as templates. The foam is formed from an aqueous mixture of an anionic surfactant and the desired metal ions, where the metal ions are electrostatically entrapped by the surfactant at the thin borders between the foam bubbles and their junctions. The hydrolysis is carried out using alkali resulting in the formation of desired nanoparticles, with the foam playing the role of a template. However, in the formation of ferrites with the formula MFe2O4, where the metal ion and iron possess oxidation states of +2 and +3, respectively, forming a foam from a 1:2 mixture of the desired ionic solutions would lead to a foam composition at variance with the original solution mixture because of greater electrostatic binding of ions possessing a greater charge with the surfactant. In our procedure, we circumvent this problem by preparing the foam from a 1:2 mixture of M2+ and Fe2+ ions and then utilizing the in situ conversion of Fe2+ to Fe3+ under basic conditions inside the foam matrix to get the desired composition of the metal ions with the required oxidation states. The fact that we could prepare both CoFe2O4 and MgFe2O4 particles shows the vast scope of this method for making even multicomponent oxides. The magnetic nanoparticles thus obtained exhibit a good crystalline nature and are characterized by superparamagnetic properties. The magnetic features observed for CoFe2O4 and MgFe2O4 nanoparticles are well in accordance with the expected behaviors, with CoFe2O4 particles showing higher blocking temperatures and larger coercivities. These features can easily be explained by the contribution of Co2+ sites to the magnetocrystalline anisotropy and the absence of the same from the Mg2+ ions.

}, issn = {0743-7463}, doi = {10.1021/la051595k}, author = {Bala, Tanushree and Sankar, C. R. and Baidakova, Marina and Osipov, V. and Enoki, Toshiaki and Joy, Pattayil Alias and Bhagavatula L. V. Prasad and Sastry, M.} } @article { ISI:000227393300019, title = {Phase transfer of oleic acid capped NicoreAgshell nanoparticles assisted by the flexibility of oleic acid on the surface of silver}, journal = {Journal of Colloid and Interface Science}, volume = {283}, number = {2}, year = {2005}, month = {MAR}, pages = {422-431}, publisher = {ACADEMIC PRESS INC ELSEVIER SCIENCE}, type = {Article}, address = {525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 USA}, abstract = {

The phase transfer protocols in vogue for the oleic acid capped silver nanoparticles, viz., salt-induced precipitation and redispersion or phosphoric acid-induced method, are examined and compared thoroughly. A comprehensive evaluation with respect to the mechanistic aspects involved is made and the merits and demerits of the different procedures are delineated. It is found that the salt-induced precipitation and redispersion is more versatile in that the precipitate can actually be redispersed in both aqueous and organic media. However, in terms of mechanism both the routes seem to be very similar wherein the orientational change of oleic acid on the silver surface in the two different environments-organic and aqueous-plays a crucial role in the adaptability of the system to the different environments. Subsequently, this change of orientation of oleic acid on silver surface in aqueous and organic media has been utilized to phase transfer Ni-based nanoparticulate systems. The nascent oleic acid-capped Ni nanoparticles, which were synthesized by a foam-based protocol, were dispersible in water but not in nonpolar organic media such as cyclohexane or toluene. Then, just by coating a thin shell of silver on them we could achieve complete phase transfer of the NicoreAgshell from aqueous to organic media following similar procedures used for oleic acid-capped silver nanoparticles. Here, the phase transfer seems to be facilitated by the orientational flexibility of oleic acid on the silver surface as opposed to other metal surfaces as evidenced from the infrared and thermogravimetric analyses of oleic acid-capped Ni and NicoreAgshell nanoparticles. This orientation-assisted phase transfer method could be generalized and can be adapted to other systems where, if the nascent nanoparticles cannot be phase transferred as is, they can be coated by a silver shell and oleic acid making them suitable for dispersion in both aqueous and organic media. (C) 2004 Elsevier Inc. All rights reserved.

}, keywords = {(1) HNMR, FTIR, Phase transfer, transmetalation core-shell nanoparticles, UV-Vis}, issn = {0021-9797}, doi = {10.1016/j.jcis.2004.09.018}, author = {Bala, Tanushree and Swami, A. and Bhagavatula L. V. Prasad and Sastry, M.} } @article { ISI:000226614200005, title = {Solvent-adaptable silver nanoparticles}, journal = {Langmuir}, volume = {21}, number = {3}, year = {2005}, month = {FEB}, pages = {822-826}, publisher = {AMER CHEMICAL SOC}, type = {Article}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

A simple and efficient way of obtaining silver nanoparticles that are dispersible both in organic and in aqueous solvents using a single capping agent is described. The silver nanoparticles are initially prepared in water in the presence of aerosol OT [sodium bis(2-ethylhexyl)-sulfosuccinate, AOT]. Thereafter, transfer of the AOT-capped silver nanoparticles to an organic phase is induced by the addition of a small amount of orthophosphoric acid during shaking of the biphasic mixture. The AOT-stabilized silver nanoparticles could be separated out from the organic phase in the form of a powder. The hydrophobic nanoparticles thus prepared are stable and are readily resuspended in a variety of other polar (including water) and nonpolar solvents without further surface treatment. The amphiphatic nature of the silver surface is brought about by a small orientational change in the AOT monolayer on the silver surface in response to the polarity of the solvent.

}, issn = {0743-7463}, doi = {10.1021/la047707+}, author = {Bhagavatula L. V. Prasad and Arumugam, S. K. and Bala, Tanushree and Sastry, M.} } @article { ISI:000242601100010, title = {Assembly of phase transferred nickel nanoparticles at air-water interface using Langmuir-Blodgett technique}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {6}, number = {12}, year = {2006}, month = {DEC}, pages = {3736-3745}, publisher = {AMER SCIENTIFIC PUBLISHERS}, type = {Article}, address = {25650 NORTH LEWIS WAY, STEVENSON RANCH, CA 91381-1439 USA}, abstract = {

Development of simple and efficient protocol for the synthesis of Ni nanoparticles in aqueous media and their subsequent phase transfer to organic media is reported. The synthesis of nickel nanoparticles in aqueous medium is accomplished by reducing the nickel nitrate with sodium borohydricle in presence of oleic acid. It results in the formation of nickel nanoparticles capped with oleic acid. The pristine oleic acid capped nickel nanoparticles were then phase transferred to nonpolar solvents such as toluene using stearic acid. The phase transfer was effective probably due to the space exchange between the oleic acid moiety and stearic acid molecules. The hydrophobized Ni thus obtained was organized at the air-water interface and it was observed that by controlling the pressure and concentration of hydrophobized Ni nanoparticles at air-water interface, linear ribbon like assemblies could be obtained. The organization process was followed by surface pressure-area isotherm measurement and Brewster Angle Microscopy.

}, keywords = {assembly, Langmuir-Blodgett technique, Ni nanoparticles, Phase transfer}, issn = {1533-4880}, doi = {10.1166/jnn.2006.615}, author = {Bala, Tanushree and Joshi, Bhagyashree and Iyer, Neelima and Sastry, Murali and Bhagavatula L. V. Prasad} } @article { ISI:000239793100088, title = {La0.7Sr0.3MnO3 nanoparticles coated with fatty amine}, journal = {Applied Physics Letters}, volume = {89}, number = {2}, year = {2006}, month = {JUL}, pages = {Article No. 023107}, publisher = {AMER INST PHYSICS}, type = {Article}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

We report on the synthesis of La0.7Sr0.3MnO3 (LSMO) nanoparticles having perovskite structure and particle size of the order of 30 rim. The process involves citrate-gel synthesis, size filtering, and; surface coating with a shell of octadecyl amine (ODA) using electrostatic interaction-assisted novel chemical route. Magnetic measurements show the Curie temperature of similar to 360 K establishing the desired stoichiometry and phase. Fourier transform infrared-studies bring out. that the amine group of ODA interacts with the LSMO surface. Refluidization yields uniform redispersion of the coated and dried powder. (c) 2006 American Institute of Physics.

}, issn = {0003-6951}, doi = {10.1063/1.2210080}, author = {Rajagopal, Rajashree and Mona, J. and Kale, Sangeeta N. and Bala, Tanushree and Pasricha, Rem and Poddar, P. and Sastry, M. and Bhagavatula L. V. Prasad and Kundaliya, Darshan C. and Ogale, S. B.} } @article {42684, title = {Ferromagnetic resonance in nanomagnetic metal core and noble metal shell systems}, journal = {Journal of Nanoscience and Nanotechnology}, volume = {9}, year = {2007}, month = {SEP}, pages = {3134-3139}, type = {Article}, abstract = {

The change in the line widths in the ferromagnetic resonance (FMR) spectra of Co and Ni nanoparticles upon shell formation with noble metals like gold or silver are described. The NicoreAgshell, CocoreAgshell, and CocoreAushell nanoparticles were prepared by a simple transmetallation reaction between the Co and Ni nanoparticles and the Ag+ or AuCl-4 ions. It is revealed that the FMR line width decreases upon Ag shell formation whereas it increases upon core{\textendash}shell composite formation with Au. Several probable explanations such as the differences in size distributions before and after the reaction or the changes occurring in shape anisotropy of the particles due to the shell formation or the different extents of electronic interaction between the core and shell materials have been offered for this observation.

}, keywords = {Fmr Study; Line Width Comparison; Magnetic Core-Noble Metal Shell Nanoparticles}, doi = {10.1166/jnn.2007.664}, author = {Bala, Tanushree and Enoki, Toshiaki and Bhagavatula L. V. Prasad} } @article {42685, title = {Interaction of different metal ions with carboxylic acid group: a quantitative study}, journal = {Journal of Physical Chemistry A}, volume = {111}, year = {2007}, month = {JUN}, pages = {6183{\textendash}6190}, type = {Article}, abstract = {

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.

}, doi = {10.1021/jp067906x}, author = {Bala, Tanushree and Bhagavatula L. V. Prasad and Sastry, Murali and Kahaly, Mousumi Upadhyay and Waghmare, Umesh V.} } @article { ISI:000263733200011, title = {Preparation of nearly monodisperse nickel nanoparticles by a facile solution based methodology and their ordered assemblies}, journal = {Journal of Physical Chemistry C}, volume = {113}, number = {9}, year = {2009}, month = {MAR}, pages = {3426-3429}, publisher = {AMER CHEMICAL SOC}, address = {1155 16TH ST, NW, WASHINGTON, DC 20036 USA}, abstract = {

Nickel nanoparticles have been synthesized by a simple wet chemical reduction technique in the presence of a surfactant sodium dodecyl sulfate (SDS) and a capping agent oleic acid. Varying the concentration of the surfactant and the capping agent has been found to critically govern the nature of the nanoparticles prepared. It is observed that at an optimum concentration of SDS and oleic acid, nearly monodisperse Ni nanoparticles are obtained that form highly ordered hexagonally close-packed structures on electron microscopy grids by a simple drop coating procedure. It is also shown that the presence of oleic acid is necessary for the stability of the Ni nanoparticles synthesized. Structural and magnetic characterizations of the nanoparticles are also presented.

}, issn = {1932-7447}, doi = {10.1021/jp807542w}, author = {Sidhaye, Deepti S. and Bala, Tanushree and Srinath, S. and Srikanth, H. and Poddar, Pankaj and Sastry, Murali and Bhagavatula L. V. Prasad} } @article { ISI:000267381100014, title = {Synthesis of catalytically active porous platinum nanoparticles by transmetallation reaction and proposition of the mechanism}, journal = {Small}, volume = {5}, number = {12}, year = {2009}, month = {JUN}, pages = {1467-1473}, publisher = {WILEY-V C H VERLAG GMBH}, address = {PO BOX 10 11 61, D-69451 WEINHEIM, GERMANY}, abstract = {

A facile method for the synthesis of porous platinum nanoparticles by transmetallation reactions between sacrificial nickel nanoparticles and chloroplatinic acid (H(2)PtCl(6)) in solution, as well as at the constrained environment of the air water interface, using a Langmuir-Blodgett instrumental setup is presented. To carry out the transmetallation at the air-water interface hydrophobized nickel nanoparticles are assembled as a monolayer on the sub phase containing platinum ions. The porous Pt nanoparticles obtained as a result of the reaction are found to act as extremely good catalysts for hydrogenation reaction. The products are well characterized by TEM, HRTEM, EDAX, and STEM. Attempts are made to postulate the plausible mechanism of this reaction to generate this kind of nanoparticle with controllable geometric shape and structure. This simple strategy has the potential to synthesize other nanomaterials of interest too.

}, keywords = {Catalysts, Interfaces, Nickel nanoparticles, porous platinum, Transmetallation}, issn = {1613-6810}, doi = {10.1002/smll.200801863}, author = {Pasricha, Renu and Bala, Tanushree and Biradar, Ankush V. and Shubhangi B. Umbarkar and Sastry, Murali} } @article {42679, title = {Foam based synthesis of metal carbonates: establishing the role of spatial confinement for obtaining interesting morphologies}, journal = {Journal of Computational and Theoretical Nanoscience}, volume = {11}, year = {2012}, month = {MAY}, pages = {91-97}, abstract = {

The crystallization of different carbonates namely lead carbonate, cadmium carbonate and strontium carbonate in aqueous foam stabilized by the surfactant sodium dodecyl sulphate (SDS) by a method of cation entrapment is described. Reaction of ammonium carbonate with the respective cations electrostatically entrapped in the foam results in the formation of minerals, possibly in the Plateau border and Plateau junction regions of the foam. The unusual morphology of the crystals obtained from foam based synthetic method as compared to the crystals prepared in aqueous solution shows the utility of the template for the growth of crystals with an unusual morphology due to constrained environment. The materials are well characterized using TEM, SEM, EDAX and FTIR techniques. The large interfacial area of the liquid lamellae in the foam provides a striking possibility for the large-scale synthesis for not only minerals but also other nanoscale materials.

}, doi = {10.1166/asl.2012.2175}, author = {Bala, Tanushree and Sanyal, Ambarish and Pant, Jayashree and Bhagavatula L. V. Prasad} } @article { ISI:000341065800011, title = {Facile method for the synthesis of Co-core Au-shell nanohybrid}, journal = {New Journal Of Chemistry}, volume = {38}, number = {9}, year = {2014}, month = {SEP}, pages = {4107-4114}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Heterostructured Co-Au core-shell nanoparticles have been synthesized by reducing AuCl4- ions on cobalt nanoparticles after a minor but effective modification of cobalt surface by an amine. The core shell morphology is emphatically confirmed by thorough investigation through UV-Vis spectroscopy, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopic analysis (TEM). The chemical composition and topography were determined using STEM-HAADF analysis and EFTEM imaging. Fourier transform infrared (FTIR) spectroscopy confirms the surface modification of Co nanoparticles and the interactions involved between the ligands and the core and shell metals at various steps of the synthetic process. The magnetic properties confirm the material to be superparamagnetic in nature.

}, issn = {1144-0546}, doi = {10.1039/c4nj00733f}, author = {Sardar, Debasmita and Neogi, S. K. and Bandyopadhyay, Sanjoy and Satpati, Biswarup and Jain, Ruchi and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article { ISI:000345826100018, title = {Preferential growth of Au on CdSe quantum dots using langmuir-blodgett technique}, journal = {RSC Advances}, volume = {4}, number = {110}, year = {2014}, month = {NOV}, pages = {64535-64541}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Oleyl amine capped CdSe quantum dots (QD) were synthesised by hot injection technique. These QDs formed a self-assembled monolayer on an aqueous subphase of a Langmuir-Blodgett (LB) trough. Here, in this report we introduced a simple but very efficient route to form a metal (Au)-QD hybrid nanostructure via the LB technique. In this method, the metal counterpart of the hybrid nanostructure could be deposited exclusively on one side of the QDs. The formation of stable monolayer of QDs was evidenced from a surface pressure-area (P-A) isotherm. The development of gold tip was confirmed and monitored by detailed TEM study on the monolayer deposited on TEM grids from the LB trough. Other characterizations like UV-Vis spectroscopy, FTIR, XPS and EDX also suggested the same. Oleyl amine was shown to act both as a reducing agent as well as a capping agent in this strategy.

}, issn = {2046-2069}, doi = {10.1039/c4ra11715h}, author = {Das, Subhasis and Satpati, Biswarup and Chauhan, Himani and Deka, Sasanka and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article { ISI:000363668200036, title = {Multifaceted core-shell nanoparticles: superparamagnetism and biocompatibility}, journal = {New Journal of Chemistry}, volume = {39}, number = {11}, year = {2015}, month = {AUG}, pages = {8513-8521}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

NicoreAgshell nanoparticles were synthesized by redox transmetallation reaction. Reduction potential match was encouraging to attempt the synthesis of the NicoreAushell system too. However, it could be achieved only after an effective surface modification on the Ni-core. Thorough characterization (UV-Vis spectroscopy, fluorescence spectroscopy, XRD, XPS, FTIR, TEM, and EDX) proved the necessity of surface modification and the success of synthesis of both types of core-shell structures. The chemical composition and topography were determined using STEM-HAADF analysis and EFTEM imaging. Fourier transform infrared (FTIR) spectroscopy confirmed the surface modification of Ni nanoparticles and the interactions involved between the ligands and metals (in the core and/or the shell) at various steps of the synthetic process. Even after the formation of the noble metal shell, the magnetic core was found to retain its superparamagnetic nature. In addition, the Au-shell protected the core from aerial oxidation and decreased toxicity as compared to pristine Ni nanoparticles as observed by MTT assay on normal cells (PBMCs).

}, issn = {1144-0546}, doi = {10.1039/c5nj01481f}, author = {Sardar, Debasmita and Neogi, S. K. and Bandyopadhyay, Sanjoy and Satpati, Biswarup and Ahir, Manisha and Adhikary, Arghya and Jain, Ruchi and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article { ISI:000369658100031, title = {Seeding of Au on CdSe/CdS nanoplates using Langmuir-Blodgett technique}, journal = {RSC Advances}, volume = {6}, number = {18}, year = {2016}, month = {JAN}, pages = {14658-14665}, publisher = {ROYAL SOC CHEMISTRY}, address = {THOMAS GRAHAM HOUSE, SCIENCE PARK, MILTON RD, CAMBRIDGE CB4 0WF, CAMBS, ENGLAND}, abstract = {

Oleyl amine capped CdSe/CdS nanoplates were synthesized by hot injection technique which formed a stable monolayer over both a water subphase and an aqueous HAuCl4 subphase using a Langmuir-Blodgett trough. Au islands were generated at the edge as well as on one specific surface of the flat nanoplates by exploiting the reducing capacity of oleyl amine to form Au nanoseeds from AuCl4- ions. The initial Au nanoseeds changed to a shell surrounding these nanoplates on prolonged exposure to the subphase containing the Au precursor. Monolayer of the hybrid structures was deposited onto suitable substrates for characterization by a number of different techniques and to study the photocatalytic activity. The same substrate with the monolayers could be re-used in several cycles of photocatalysis.

}, issn = {2046-2069}, doi = {10.1039/c5ra26018c}, author = {Das, Subhasis and Satpati, Biswarup and Chauhan, Himani and Deka, Sasanka and Ghosalya, Manoj Kumar and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article {44138, title = {Facile synthesis of Al2O3-Pt nanocomposite and its catalytic activity}, journal = {Materials Research Express}, volume = {4}, year = {2017}, month = {NOV}, pages = {Article Number: 115002}, type = {Article}, abstract = {Pt nanoparticles were synthesized on gamma-alumina support in presence of oleic acid which was found to prevent clustering of Pt nanoparticles on the support. Various percentage of Pt loading on the alumina changed the catalytic activity for preferential oxidation of CO at relatively low temperature in H-2 rich stream. Pt nanoparticles when synthesized in absence of oleic acid, were all clustered and did not have any catalytic activity. The presence of oleic acid promoted stability preventing agglomeration of Pt nanoparticles. The catalyst thus prepared was characterized thoroughly and their catalytic activity was studied in details.}, doi = {10.1088/2053-1591/aa9441}, author = {Das, Subhasis and Bordoloi, Ankur and Ghosalya, Manoj Kumar and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article {43705, title = {Facile synthesis of ZnO-Ag nanocomposite and its photocatalytic activity}, journal = {Materials Research Express}, volume = {4}, year = {2017}, month = {MAY}, pages = {Article Number: 055011}, type = {Article}, abstract = {

The evolution of photoactive hybrid materials (e.g. noble metal-semiconductor) has resulted in heterogeneous photocatalysis. We report a facile route for the synthesis of ZnO-Ag nanocomposites with varying percentage of loading of the noble metal, expecting a great boost in the photocatalytic behavior of ZnO. The as prepared material was thoroughly characterized by UV-Vis, FTIR, TEM, FESEM, XRD, XPS analyses. The photocatalytic activities of the nanocomposites have been assessed from the ability to degrade methylene blue dye in aqueous solution. The results suggest that incorporation of Ag nanoparticles on the surface of ZnO particles can enhance catalytic activity in comparison to pure ZnO particles under visible light by minimizing the recombination of photogenerated electron-hole pairs.

}, doi = {10.1088/2053-1591/aa6df1}, author = {Sardar, Debasmita and Maity, Jayeta and Ghosalya, Manoj Kumar and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article {43171, title = {Multiple functionalities of Ni nanoparticles embedded in carboxymethyl guar gum polymer: catalytic activity and superparamagnetism}, journal = {Applied Surface Science}, year = {2017}, month = {JAN}, abstract = {Composites comprising of metallic nanoparticles in polymer matrices have allured significant importance due to multifunctionalities. Here a simple protocol has been described to embed Ni nanoparticles in carboxymethyl guar gum (CMGG) polymer. The composite formation helps in the stabilization of Ni nanoparticles which are otherwise prone towards aerial oxidation. Further the nanoparticles retain their superparamagnetic nature and catalytic capacity. Ni-Polymer composite catalyses the reduction of 4-Nitrophenol to 4-Aminophenol very efficiently in presence of NaBH4, attaining a complete conversion under some experimental conditions. Ni-Polymer composite is well characterized using UV{\textendash}vis spectroscopy, FTIR, XPS, powder XRD, TGA, SEM and TEM. A detailed magnetic measurement using superconducting quantum interference device-vibrating sample magnetometer (SQUID-VSM) reveals superparamagnetic behaviour of the composite.}, author = {Sardar, Debasmita and Sengupta, Manideepa and Bordoloi, Ankur and Ahmed, Md. A. and Neogi, S. K. and Bandyopadhyay, Sanjoy and Jain, Ruchi and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article {44211, title = {Deposition of Au nanoparticles inside porous CeO2 nanocubes using Langmuir-Blodgett technique}, journal = {New Journal of Chemistry}, volume = {42}, year = {2018}, month = {JAN }, pages = {1379-1386}, type = {Article}, abstract = {

Porous 3D CeO2 nanocubes were synthesized using hot injection technique. These nanocubes were able to form a stable monolayer over water and HAuCl4 subphase in Langmuir-Blodgett (LB) trough due to the presence of surface capped oleic acid and oleylamine. CeO2-Au nanocomposites were synthesized exploiting the ability of oleylamine to reduce AuCl4 ions to Au-0, via LB method. CeO2 nanocubes gave rise to excellent long-range assembly at air/water interface and gold nanoparticles were formed inside these porous nanocubes without disturbing this arrangement. The formation of a stable monolayer was evidenced from the surface pressure-area (P-A) isotherm. The development of Au nanoparticles was confirmed with great effort from a comprehensive study using UV-Vis spectroscopy, XRD, XPS, FTIR, TEM, STEM, EDX, tomography and chemical mapping.

}, issn = {1144-0546}, doi = {10.1039/c7nj03948d}, author = {Das, Subhasis and Bhattacharjee, Gourab and Satpati, Biswarup and Kumar, Mukesh and Deka, Sasanka and Ghosalya, Manoj Kumar and Gopinath, Chinnakonda S. and Bala, Tanushree} } @article {45353, title = { Organic phase transmetallation approach for synthesis of hollow Ni-Au nanocomposites with tunable cavity size}, journal = {New Journal Of Chemistry}, volume = {42}, year = {2018}, month = {DEC}, pages = { 19615-19624}, type = {Article }, abstract = {

Ni-Au nanocomposites in the form of hollow spheres with controlled cavity size have been successfully synthesized by the transmetallation reaction between hydrophobized Ni nanoparticles and hydrophobized Au precursors. This can be considered as a fairly unique synthesis strategy that does not require any additional external reductants. The synthesis is carried out in a nonpolar solvent and precise tuning of the cavity size has been achieved only by varying the ratio of the two reacting components. A detailed characterization has been performed via UV-vis spectroscopy, XPS, TEM, EDAX, and SEM. The mechanistic aspect is established from FTIR. SQUID-VSM confirmed the magnificent superparamagnetism of the nanocomposites.

}, issn = {1144-0546}, doi = {10.1039/c8nj03668c}, author = {Sardar, Debasmita and Ahmed, Md Azaharuddin and Bandyopadhyay, Sudipta and Ghosalya, Manoj Kumar and Bala, Tanushree} } @article {46100, title = {Dexterous route for synthesis of hollow spherical ZnO and ZnO-Ag nanocomposite with superior photocatalytic ability}, journal = {ChemistrySelect}, volume = {4}, year = {2019}, month = {MAY }, pages = {5518-5526}, type = {Article}, abstract = {

Hollow spherical ZnO and hollow ZnO-Ag nanocomposites with variable percentage of loading of Ag content were successfully fabricated through a novel, template free and easily reproducible route. Extensive characterizations were carried out using FTIR, XRD, XPS, BET, TEM and SEM. The hollow morphology of the particle and the composite encouraged a detailed photocatalysis study in comparison to solid commercial ZnO and the corresponding ZnO-Ag composite. The photocatalytic activity of the hollow particle and the composite was assessed monitoring the decolouration of methylene blue dye using UV-Vis absorption spectroscopic technique. An increased surface area for hollow morphology as compared to solid particles established a conspicuous boost in photocatalytic activity.

}, keywords = {excellent photocatalysis, synthesis, template free, ZnO hollow nanoparticles, ZnO-Ag nanocomposite}, issn = {2365-6549}, doi = {10.1002/slct.201900760}, author = {Maity, Jayeta and Bhattacharjee, Gourab and Satpati, Biswarup and Sardar, Debasmita and Ghosalya, Manoj Kumar and Bala, Tanushree} }