Polymers that respond to external stimuli including temperature, pH, and solvent changes show great promise as novel materials for a variety of applications, including drug delivery and sensors. Recent work in our lab has studied two types of stimuli-responsive polymers. The first are amphiphilic polymers comprised of long hydrophilic and hydrophobic chains linked to a backbone. Our molecular dynamics simulations of a variety of polymers based on this motif using a combination of advanced sampling methods and GPU-enabled simulations reveal both the structural changes induced by solvent and the time scales for this response. Constant pH simulations are used to examine the pH responsive polymer, polymethacrylic acid (PMAA). This polymer undergoes significant structural changes as the pH is changed. The constant pH simulations reveal the details of the structural changes including how the pKa depends on structure, the position along the polymer chain, and the chirality of the monomer. The cooperativity of deprotonization is also analyzed.

Solvent and pH responsive polymers

251st National Meeting (2016)

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