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

美国国家科学基金会-化学与输运系统部粒子与多相过程计划（1415）摘要智力成就本提案的长期目标是对新材料合成中的几何约束和流动效应产生基本的理解。如果可以利用微米尺度的限制和流动条件作为合成工具来制造控制良好的纳米多孔二氧化硅（NPS）材料，将会取得重大进展。NPS材料是通过使用自组装表面活性剂或共聚物作为模板，并在模板周围同时发生无机相（例如二氧化硅）的溶胶-凝胶缩聚而制成的。为了克服长时间的周转时间和精确控制NPS方向的能力限制，限制了传统的溶胶-凝胶工艺，PI的团队最近提出并验证了一种技术，利用表面活性剂溶液中的流动诱导转变来产生超分子结构，作为NPS合成的指导剂。该提案引入了一种新的方法，旨在通过使用微流体作为约束手段，结合流动诱导的自组装和对准，将胶束形成过程与胶束-二氧化硅组装分离，从而为具有连续制造能力的定制NPS材料的合成提供突破。本研究将结合系统的材料合成、表征和建模，利用微流体技术研究由硅基和表面活性剂溶液的混合物合成NPS。更广泛的影响一项全面的教育计划将把拟议的研究与正在进行的教育活动结合起来，为学生和公众培养对复杂流体和纳米技术的广泛兴趣：(a)创建本科教学单元和研究生课程，以加强现有课程，并连接学院的各个工程学系；(b)为本科生和研究生提供研究机会，同时继续强调招募和指导代表性不足群体的成员；(c)在学术、工业和公共教育单位之间建立强有力的合作。这个项目的结果将直接纳入本科和研究生课程，并在密苏里纳米联盟社区传播。作为我们外联工作的一部分，我们将通过圣路易斯科学中心（SLSC）新兴技术年度研讨会，WU年度研讨会和公共广播系统（PBS）纪录片节目传播结果。

National Science Foundation - Division of Chemical &Transport Systems Particulate & Multiphase Processes Program (1415)ABSTRACTIntellectual MeritThe 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 ImpactsA 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.