@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:000309072800094, title = {Photopatternable nano-composite (SU-8/ZnO) thin films for piezo-electric applications}, journal = {Applied Physics Letters}, volume = {101}, number = {10}, year = {2012}, month = {SEP}, pages = {104102}, publisher = {AMER INST PHYSICS}, address = {CIRCULATION \& FULFILLMENT DIV, 2 HUNTINGTON QUADRANGLE, STE 1 N O 1, MELVILLE, NY 11747-4501 USA}, abstract = {

Photo-curable nanocomposite material was formulated by embedding ZnO nanoparticles into a SU-8 matrix and studied for its piezoelectric properties for low cost fabrication of self-powered nanodevices. The piezoelectric coefficient of ZnO nanoparticles was observed to be ranging between 15 and 23 pm/V, which is the highest reported. These experimental studies support the recent theoretical predictions where the piezoelectric coefficients in ZnO nanoparticles were found to be higher compared to the thin films because of the surface relaxation induced volume reductions in the nanometer scale. The photo-curable property of these polymer composite films is exploited to demonstrate fabrication of a micro-cantilever test structure. (C) 2012 American Institute of Physics. [http://dx.doi.org/10.1063/1.4748575]

}, issn = {0003-6951}, doi = {10.1063/1.4748575}, author = {Kandpal, Manoj and Sharan, Chandrashekhar and Poddar, Pankaj and Prashanthi, K. and Apte, Prakash R. and Rao, V. Ramgopal} } @article { ISI:000315751600033, title = {Probing interaction of Gram-positive and Gram-negative bacterial cells with ZnO nanorods}, journal = {Materials Science \& Engineering C-Materials for Biological Applications}, volume = {33}, number = {3}, year = {2013}, month = {APR}, pages = {1247-1253}, publisher = {ELSEVIER SCIENCE BV}, address = {PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS}, abstract = {

In the present work, the physiological effects of the ZnO nanorods on the Gram positive (Staphylococcus aureus and Bacillus subtilis) and Gram-negative (Escherichia coli and Aerobacter aerogenes) bacterial cells have been studied. The analysis of bacterial growth curves for various concentrations of ZnO nanorods indicates that Gram positive and Gram negative bacterial cells show inhibition at concentrations of similar to 64 and similar to 256 mu g/mL respectively. The marked difference in susceptibility towards nanorods was also validated by spread plate and disk diffusion methods. In addition, the scanning electron micrographs show a clear damage to the cells via changed morphology of the cells from rod to coccoid etc. The confocal optical microscopy images of these cells also demonstrate the reduction in live cell count in the presence of ZnO nanorods. These, results clearly indicate that the antibacterial activity of ZnO nanorods is higher towards Gram positive bacterium than Gram negative bacterium which indicates that the structure of the cell wall might play a major role in the interaction with nanostructured materials and shows high sensitivity to the particle concentration. (C) 2012 Elsevier B.V. All rights reserved.

}, keywords = {Confocal, Growth curve, Nanorods, SEM, Zeta potential, ZnO}, issn = {0928-4931}, doi = {10.1016/j.msec.2012.12.019}, author = {Jain, Aanchal and Bhargava, Richa and Poddar, Pankaj} } @article {43529, title = {Physical mechanism behind enhanced photoelectrochemical and photocatalytic properties of superhydrophilic assemblies of 3D-TiO2 microspheres with arrays of oriented, single-crystalline TiO2 nanowires as building blocks deposited on fluorine-doped tin oxid}, journal = {ACS Applied Materials \& Interfaces}, volume = {9}, year = {2017}, month = {MAR}, pages = {11202-11211}, abstract = {In comparison to the one-dimensional (1D) semiconductor nanostructures, the hierarchical, three-dimensional (3D) microstructures, composed of the arrays of 1D nanostructures as building blocks, show quite unique physicochemical properties due to efficient photon capture and enhanced surface to volume ratio, which aid in advancing the performance of various optoelectronic devices. In this contribution, we report the fabrication of surfactant-free, radially assembled, 3D titania (rutile-phase) microsphere arrays (3D-TMSAs) composed of bundles of single-crystalline titania nanowires (NWs) directly on fluorine-doped conducting oxide (FTO) substrates with tunable architecture. The effects of growth parameters on the morphology of the 3D-TMSAs have been studied thoroughly. The 3D-TMSAs grown on the FTO-substrate showed superior photon-harvesting owing to the increase in light-scattering. The photocatalytic and photon to electron conversion efficiency of dye sensitized solar cells (DSSC), where the optimized 3D-TMSAs were used as an anode, showed around 44\% increase in the photoconversion efficiency compared to that of Degussa P-25 as a result of the synergistic effect of higher surface area and enhanced photon scattering probability. The TMSA film showed superhydrophilicity without any prior UV irradiation. In addition, the presence of bundles of almost parallel NWs led to the formation of arrays of microcapacitors, which showed stable dielectric performance. The fabrication of single-crystalline, oriented, self-assembled TMSAs with bundles of titania nanowires as their building blocks deposited on transparent conducting oxide (TCO) substrates has vast potential in the area of photoelectrochemical research.}, doi = {10.1021/acsami.6b15420}, author = {Sadhu, Subha and Gupta, Preeti and Poddar, Pankaj} } @article {44348, title = {Polycrystalline MnGe2 thin films on InAs(001) substrates}, journal = {Thin Solid Films}, volume = {657}, year = {2018}, month = {JUL}, pages = {38-41}, type = {Article}, abstract = {We report on the growth of MnGe2 thin films on InAs(001) substrates using radio frequency-magnetron cosputtering. Polycrystalline thin films were obtained at a substrate temperature of 353 K. X-ray diffractometry was used to identify the tetragonal MnGe2 phase (space group 14/mcm). Measurements of the magnetic field and temperature dependence of the magnetization revealed that the MnGe2 thin films are ferromagnetic with a magnetization of 280 kAm(-1) and a Curie temperature of 62 K. Additionally, an antiferromagnetic component is observed at low temperatures, which may arise atomic disorder at the grain boundaries between MnGe2 crystallites.}, doi = {10.1016/j.tsf.2018.05.007}, author = {Gutierrez-Naranjo, David and Holguin-Momaca, Jose T. and Solis-Canto, Oscar O. and Gupta, Preeti and Poddar, Pankaj and Espinosa Magana, Francisco and Olive-Mendez, Sion F.} } @article {49046, title = {Poly(N-vinylpyrrolidone)-assisted crystal growth of zeolitic imidazolate framework (ZIF-67) and electrochemical properties of its derivatives for flexible supercapacitors}, journal = {Crystal Growth and Design }, volume = {24}, year = {2024}, month = {APR }, pages = {3179-3194}, type = {Article}, abstract = {

A simple and explicit wet chemical method enables the room-temperature crystallization of the zeolitic imidazolate framework (ZIF-67) using cotton-cloth (CC) as a substrate; where time-dependent Avrami{\textquoteright}s kinetic studies demonstrated sluggish nucleation and fast crystal growth resulting in unprecedented morphologies-truncated cubes [synthesized without poly(N-vinylpyrrolidone); PVP], and rhombic dodecahedra (with PVP) with average sizes ranging from 500 nm to 1.41 mu m; wherein amphiphilic PVP plays a crucial function of structure directing agent by modulation of complex formation and deprotonation equilibria. To study the potential of pristine ZIF-67 (ZP0) and PVP-functionalized ZIF-67 (ZP50, ZP100, and ZP200) grown on the CC substrate for application as a flexible electrode in supercapacitors, ZP0, ZP50, ZP100, and ZP200 were annealed to form CZP0, CZP50, and CZP100, respectively. Areal capacitances of 181 and 214 mFcm(-2) were achieved at a current density of 1 mAcm(-2) and a potential window of 1.6 V for CZP0 and CZP100, respectively, and compared to the derivatives without PVP; CZP100 exhibited a superior energy density of 76.3 mu Whcm(-2) and a capacitance retention of 84.3\% after 5000 cycles at a current density of 0.5 mAcm(-2).

}, issn = {1528-7483}, doi = {10.1021/acs.cgd.3c01329}, author = {Jain, Manisha and Joshi, Bhavana and Poddar, Pankaj} }