SUMMARY

Liquid-swellable polymer networks are natural, synthetic, or hybrid natural-synthetic materials in which constituting polymer chains are all connected to each other either directly or via other connecting chains to form a solid-like structure. These highly permeable, extremely flexible, and yet mechanically sturdy polymeric materials have found an increasingly large number of applications in today’s state-of-the-art technologies.
The objective of this Ph.D. proposal is to develop a coarse-grained computational model for cross-linked polymer networks immersed in Newtonian fluids, and use it to examine the effect of mechanical deformations on transport through random polymer networks, to probe drug release from microgel capsules, and to study friction between gel-coated sliding surfaces.
The results of our studies will reveal important and highly-needed information about the relation between the mechanical deformation of polymer networks and the change in diffusive and convective transport of solutes. This information not only will give us a fundamental insight into the transport processes in anisotropic random networks taking place at the micor/nano scale, but also will yield engineering guidelines for designing a whole host of new systems and devices in which polymer gels are harnessed for solute transport, separation, sensing, and micromechanical actuation. Our calculations of release from responsive microgel capsule will disclose how the gel transport properties change due to network swelling/deswelling and will potentially lead to the discovery of new approaches for regulating the release of drugs from drug delivery micro-carriers by controlling the membrane pore size. Furthermore, our simulations of friction between gel-coated surfaces will unveil how compliance of the surfaces and lubricant composition can be harnessed to alter the friction in a controllable and predictable manner. Finally, our three dimensional fully-coupled model of the cross-linked polymer networks provides a foundation for future studies on a broad range of problems in engineering, medicine, and biology that involve active and responsive polymer gels.