(13h) Meso-Scale Modeling of PNIPAM Brushes

Authors: 
Deshmukh, S. A. - Presenter, Virginia Polytechnic Institute and State University
Bejagam, K. K., Virginia Polytechnic Institute and State University
An, Y., Virginia Polytechnic Institute and State University
Singh, S., Virginia Polytechnic Institute and State University
Poly(N-isopropylacrylamide) (PNIPAM) is a temperature sensitive polymer with a lower critical solution temperature (LCST) of ~305 K. Below its LCST, PNIPAM is in a coil-state and above the LCST it is in a globule-state. Recently, we have developed a new coarse-grained (CG) model of PNIPAM, which can predict its LCST with a reasonable accuracy. Here, we have utilized this new CG model to perform molecular dynamics (MD) simulations of PNIPAM grafted planar brush structures. Our study is focused on the effect of temperature and grafting density on the coil-to-globule transition in PNIPAM. The CG MD simulations were carried out for ~1 µs at 295 K and 315 K, which is below and above the LCST of PNIPAM, respectively. Simulation trajectories were analyzed for structural and dynamical properties of polymer chains and water.