Electrokinetic transport near soft surfaces, or surfaces penetrable by fluid flow, is the foundation of engineering techniques such as electroosmotic flow control by polymer coating and electrokinetic characterization of polymer?]coated particles. While many experimental observations of this transport have been rationalized by semi?]phenomenological macroscopic models, understanding of this transport at the atomistic and mesoscopic scales is still limited. Hence, the validity of key assumptions in the current macroscopic models is not firmly established and the physical origins of fitting parameters in the models remain elusive. Thus it is imperative to improve our understanding of such transport at the atomistic and mesoscopic scale. The objective of this research is to investigate the electrokinetic transport near surfaces grafted with neutral polymers. Specifically, the PIs will study the effects of polymer coating on the structure and dynamics of the electrical double layer and the atomistic mechanisms of electroosmotic flow screening by end?]grafted polymers, and the two?]way coupling between the mesoscopic structure of end?]grafted polymers and electroosmotic. Both topics will be performed by using atomistic (molecular dynamics) and mesoscopic (dissipative particle dynamics) simulations, respectively. The planned simulation studies will be complemented with experimental studies by collaborators. The PI?fs research will provide vital details of the transport that current modeling and experiments are unable to elucidate. Such atomistic and mesoscopic details will provide firm theoretical underpinning for the macroscopic models of this transport and also lay foundation for developing new models when the current models are proven inadequate. The planned research is built upon the PI?fs expertise in atomistic and mesoscopic modeling of electrokinetic transport and is supported by state?]of?]art computing facilities. The project will be tied intimately with the undergraduate and graduate education at Clemson University. Students participating in this project will be exposed to diverse fields such as hydrodynamics, polymer physics and physical chemistry. Undergraduate students will be involved in the research through the Creative Inquiry program (the flagship undergraduate research program at Clemson) and the Honors Research Program in the PI?fs home department. Various resources, e.g., the minority recruitment programs at Clemson University, will be utilized to recruit students from underrepresented groups to participate in this project. Research results will be developed into modules for graduate and undergraduate courses. A website centering on the electrokinetic transport near soft surfaces will be designed and maintained. In addition to providing access to all the research and education materials developed in this project, the website will feature reviews of electrokinetic transport near soft surfaces and links to active researchers in this important field.
