Physics
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Rajendra Kumar Singh

Professor
Atomic & Molecular Physics
Banaras Hindu University
Bahamas

Biography

Academic Qualifications: S. No. Degree University Year 1. M.Sc. Gorakhpur University 1988 2. D.Phil. University of Allahabad 1993 Brief writeup on area of specialization Ionic liquids,materials science,solid state ionics and ultrasonics Ionic liquids,Ionic liquids in confined geometry,Micro and mesoporous materials,Ion conducting polymers/gels,Solid state ionics,PDLCs,Ultrasonics etc Ionic Liquids: We are studying various physico-chemical properties of ionic liquids such as surface tension,viscosity,ultrasonic velocity,adiabatic compressibility,density,thermal expansion etc. at different temperatures. We have fabricated resonator technique,modified pulse echo technique for acoustic loss and velocity measurement of small sample volume at different temperatures and frequencies. A novel technique for interfacial measurement of ionic liquids has also been developed by us. Studying these properties for a number of ionic liquids will be helpful for structure-property correlation. We are also using ionic liquids for the synthesis of nanoparticles. Ionic Liquids in Confined Geometry: An understanding of materials in confined geometry is of fundamental and practical interest. Confined geometry term implies confining molecular system in pores of dimension (at least one dimension) comparable to the size of the molecules being confined. Surface interaction due to spatial restriction and low dimensionality of the confining matrix have been found to result in physical and chemical behavior of confined systems much different from the bulk viz. new/different phase transitions,wetting,layering near surface walls as well as shift in glass transition,melting and freezing point. The questions of interest are concerned with how the length scale,dimensionality and surface properties of walls of confining matrix modify the dynamics and thermodynamics and structure of the molecules compared with its bulk counterparts. Expanding upon the ideas of confinement of water and other fluids,some attempts have been made to confine ionic liquids (ILs) in microemulsions,micelles,controlled pore glasses,kaolinites,silica-gels etc. Studies on these neoteric solvents (ionic liquids) in confinement is still in its infancy and poses many intriguing questions; answers to which could pave the way to enhance their potential applications. We are confining ionic liquids in different matrices (SiO2,TiO2 etc) and studying changes in various properties compared to their bulk counterparts. Experimental techniques being used for characterization are: BET characterization,DSC,TGA,XRD,TEM,FTIR,Impedance spectroscopy etc. Ion Conducting Polymers/gels: ILs are thermally stable,non-vaporizable,possess wide electrochemical window,consist of dissociated/poorly coordinated ionic species. ILs are widely used for obtaining thermally and mechanically stable and safe electrolytes for electrochemical applications. We are studying IL based polymer electrolytes. We are investigating the effect of IL on ionic conductivity,phase transition temperature (Tm and Tg),crystallinity,crystallization behavior,thermal stability,complexing behavior etc of polymeric membranes/polymeric electrolytes. Ongoing/completed projects : (2 projects already completed) Title of the project Funding Agency/Major/Minor /Role Date of implementation Amount Sanctioned (Rs.) Ongoing/completed Synthesis and characterization of ionic liquid gel polymer electrolyte (ionogel) and gel nanocomposite for application in devices" UGC,Major/PI Feb. 01,2011 11.30 lacs Ongoing Electrical and Viscoelstic studies on some recently discovered materials viz organic ionic liquids and their composites DST,Major,PI 1 Aug. 2008- 35.86 lacs Completed Development of ionic liquid based porous gel composites for application in electrochemical devices. DAE-BRNS,Major,P.I. 2009 ~35.00 lacs Ongoing Relaxational Processes and chemical kinetic studies in Ionic Liquids by ultrasonic measurements UGC,Major,P.I. 1-4-2007-31-03-2010 11 lacs Completed A study on nano granular magnetic phase embedded in semiconductor for spintronics DST,Major,Co-PI 2007-2010 Rs 34.20 lacs Completed Studies on structure property relation in Liquid crystals DST,Major,Co-PI 2012-2015 Rs. 17.65 lacs Ongoing National Merit Scholarship,Qualified Joint UGC/CSIR exam for award of JRF Treasurer and life member, Solid State Ionics Society of India Life member,Ultrasonic Society of India Member,American Nano-Society

Research Interest

Ionic liquids,materials science,solid state ionics and ultrasonics

Publications

  • Phase digram and morphology of polymer dispersed liquid crystals: an analysis,Srivastava Jagdeesh Kumar; Singh Rajendra Kumar Singh; Dhar Ravindra,Singh Shri Liquid Crystals 39 (11) 1402-1413 (2012).

  • Low density ionogels obtained by rapid gellification of tetraethyl orthosilane assisted by ionic liquids,Abhishek Kumar Gupta,Manish Pratap Singh, Rajendra Kumar Singh and S Chandra, Dalton Transactions 41 (6263-6271 (2012) (IF=3.837)

  • Thermal Stability,Complexing Behaviour and Ionic Transport of Polymeric Gel Membranes Based on Polymer PVdF-HFP and Ionic Liquid,[BMIM][BF4], Kataria, Shalu; Chaurasia,Sujeet; Singh,Rajendra; Chandra,Suresh,J Phys. Chem. B. ,117 (3) (897-906) 2013 (IF 3.63)

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