Nanoparticles are used as additives to make composite materials with specific mechanical, thermal, and optical properties. Controlling the transport and distribution of the nanoparticles during processing is critical to obtaining desired properties. This award will support research into the transport and distribution of nanoparticles in polymeric fluids. The project will focus on the diffusion and flow-driven transport of nanoparticles in the case where the nanoparticles are comparable in size to the size of the polymer molecules in the fluid. The research will combine experiments that image particle motions in polymeric fluids with computer simulations that reveal various mechanisms of nanoparticle dynamics and interactions between nanoparticles and polymers. Results of the research will lead to improved predictions of nanoparticle transport, which will enhance a variety of important technological applications, including wastewater reuse, drug delivery, and advanced materials processing for energy storage and generation. The research team will participate in several activities that engage K-12 students and the general public in science and engineering, including a hands-on team-based design program for students in grades 7-10, the GRADE summer camp for women and students from underrepresented groups, and Energy Day and Earth Day festivals for the general public in Houston. In addition, the researchers will disseminate results of the project to local industrial scientists and engineers at the Texas Soft Matter Meeting.
This project will deploy particle-imaging experiments and computational models to understand coupling between particle-polymer dynamics in solution. To achieve this objective, advanced simulation techniques will be integrated with imaging and particle synthesis to identify physical mechanisms dictating coupling between particles and similarly-sized polymers in solution, and to determine effects of particle anisotropy on particle-polymer dynamics. Stochastic rotational dynamics simulations will be used to measure the structure and dynamics of particles and polymers on experimentally relevant time scales. Simulation predictions for dynamics will be tested against experimental measurements in carefully chosen nanoparticle-polymer mixtures. This combination of simulation and experiment will elucidate the effects of particle shape, size, and anisotropy on the dynamics of these mixtures and thereby transform understanding of the physical processes controlling coupled transport in multicomponent complex fluids. Results will lead to modifications of existing theories to account for changes in dynamical coupling on these scales and provides the necessary strong foundation for future studies of flow-driven nanoparticle transport
