Proposal Number: 0645039 Principal Investigator: Bender, Jonathan Affiliation: University of South Carolina Research Foundation Proposal Title: CAREER: Quantifying the importance of friction in the rheology and structure of dense colloidal dispersions
Intellectual Merit: This cross-disciplinary tribology-rheology proposal will introduce a new, unique research approach to engineering surfaces for tailored mechanical properties. This research will pioneer the use of colloidal force and rheology data, obtained on the same colloidal systems, to link single-particle contact force measurements to bulk rheological measurements in solid-liquid dispersions of hard particles coated with grafted polymers. For surfaces at or near contact, a detailed knowledge of hydrodynamic, frictional, and conformational forces are necessary to integrate nanoscale measurements into predictions of macroscale rheological and tribological behavior. While significant research has focused in separate, distinct arenas on nanotribology, nanorheology, bulk rheology, and macroscale tribology, little work has been done to unify these research areas. Through complementary measurements of interparticle forces obtained using colloidal force microscopy and the rheology of concentrated dispersions, this proposed work will serve as an example of how the field of nanotribology and bulk rheology can be linked.
Broader Impacts: The implications of studying the relationship between nanoscale forces and macroscopic rheology and tribology extend well beyond applications in dispersions. This work forms the foundation for understanding lubrication and biotribology of joints and how cells interact with surfaces both of which are integrated with the Department's and University's efforts to establish more concrete collaborations between Engineering and Medical faculty at USC. These areas have proven ideal for introducing undergraduates to cross-disciplinary research, and this proposal will continue existing efforts. Finally, this proposal will provide a framework for introducing colloid and surface science to middle and secondary school students through collaborations with USC College of Education curriculum developers.
