Insights into Stimuli-Responsive Polymers: Theoretical and Simulation Study

The phase behavior of temperature-responsive polymers with tunable lower critical solution temperatures (LCST) and light-responsive polymers was explored using statistical mechanics and molecular dynamics simulations. The LCST in water of (ethylene oxide)/ethylene copolymers is tailored by their chemical composition. For the first time, the general formalism of the lattice-fluid with hydrogen-bonding (LFHB) theory has been successfully applied to a water-polymer system. This theory, modified here to account for multiple types of hydrogen bonds, has been shown to be effective when making theoretical predictions as justified by comparison with experimental results. The series of (ethylene oxide)/ethylene copolymers were studied further with the modified Flory-Huggins with hydrogen bonding (FHHB) approach. Expanding beyond temperature-responsive polymer solutions, systems that can potentially find applications in antifouling, drug delivery, and surfaces with switchable tackiness, the work subsequently focused on a light-responsive polymer film systems that have applications in photolithography.