CAREER: Confinement and flow effects on synthesis of sol-gel materials

Washington University, Saint Louis MO

Investigators

Abstract

National Science Foundation - Division of Chemical &Transport Systems Particulate & Multiphase Processes Program (1415) ABSTRACT Intellectual Merit The long-term goal of this proposal is to generate fundamental understanding of geometric confinement and flow effects on the synthesis of new materials. Of major interest is the advances that will occur if micron-scale confinement and flow conditions can be harnessed as synthetic tools to make well-controlled nanoporous silica (NPS) materials. NPS materials are made by using self- assembling surfactants or copolymers as templates together with simultaneous sol-gel condensation of inorganic phase (e.g., silica) around the templates. To overcome the long turn-over times and restricted ability to precisely control the orientation of NPS that limiting traditional sol-gel processing, the PI's group recently proposed and validated a technique which exploits flow-induced transitions in surfactant solutions to generate supramolecular structures that act as directing agents for NPS synthesis. This proposal introduces a new approach designed to decouple the micelle formation process from micelle-silica assembly by using microfluidics as a means of confinement, combined with flow-induced self assembly and alignment, to offer break-throughs for the synthesis of tailored NPS materials with continuous manufacturing capacity. This research will combine systematic material synthesis, characterization, and modeling to study NPS synthesis from a mixture of silica-based and surfactant solutions using microfluidics. Broader Impacts A comprehensive educational plan will integrate the proposed research with ongoing educational activities for both students and the general public to foster broad interest in complex fluids and nanotechnology by: (a) Creating undergraduate teaching modules and a graduate course to enhance existing courses and bridge various engineering departments in the college; (b) providing undergraduate and graduate student research opportunities, while continuing our well-established emphasis on recruiting and mentoring members of underrepresented groups; (c) building strong collaborations within academic, industrial, and public educational units. Results from this project will be directly incorporated in undergraduate and graduate courses and disseminated in Missouri Nanoalliance Communities. As part of our outreach effort, we will disseminate results via the St. Louis Science Center (SLSC) annual workshop on emerging technologies, annual workshop at WU, and Public Broadcasting System (PBS) documentary programs.