Prof. Upendra's Talk

Sep 23, 2010 - 16:00

Sep 23, 2010 - 17:30

Creativity Hall (Room No. 118)

Seminars

Prof. Upendra Natarajan

Abstract: We have theoretically investigated the effect of the chemical bonding structure on mean-squared optical anisotropy of chains by statistical mechanics for a certain class of macromolecules by introducing different molecular groups and atomic species at various positions on the backbone with a motivation to reduce the birefringence. We present results of recent calculations on some real systems as well as some preliminary studies on model bead-spring chains (homopolymers). The principal components of the optical polarizability tensor the number and dihedral angle values of the conformational states at single bond and at two successive bonds have been varied in order to mimic a wider range of conditions as compared to our earlier studies. The longer term plan via generalized simulations using is to map homopolymers copolymers (via Monte Carlo) such as alternating and statistically random graft copolymers including side-chains (groups). We present our recent work in looking at aggregation and adsorption of polymers and surfactants in solution containing solid surfaces using Lattice Monte Carlo simulations in the canonical ensemble. The effect of intermolecular energies for surfactant head-group tails and polymer chain have been studied at different levels of overall solutionconcentration in this investigation using a model system. We present our recent work in which we have devised a simple new method to predict the optical birefringence on polymer surfaces via molecular simulations. The approach was implemented for first to amorphous polyethylene and polyethylene oxide melts as classical examples using united-atom and atomistic model descriptions via Configurational-Bias Monte Carlo (CBMC) simulations. Structure surface energy and optical birefringence and the variation of optical anisotropy across the surface layers were estimated using a classical approach containing bond and group polarizability tensors.About the speaker Dr. Upendra Natarajan received his B.Tech. degree in chemical engineering from Indian Institute of Technology Bombay in 1990 followed by M.S. and Ph.D. degrees from the University of Kansas and University of Akron (in polymer science). Following post-doctoral stint at Cornell University and research experience in industry he served as Scientist at the National Chemical Laboratory Pune from 2000 to 2006. He has been Associate Professor at the department of chemical engineering at IIT Madras since 2007. His areas of interest are broadly statistical thermodynamics molecular simulation polymer science and engineering colloidal fluids interfacial science and engineering.