Colloidal Films: Local Nanoparticle Self-Structuring and Novel Type of Detergency

美国国家科学基金会-化学运输系统分部颗粒多相过程计划（1415）摘要提案编号：CTS-0553738主要研究者：Wasan，Darsh隶属机构： 伊利诺伊理工学院提案题目：胶体膜：局部纳米颗粒自结构化和新型去污剂该提案是对包含球形纳米颗粒或表面活性剂胶束和溶剂的胶体流体的润湿和铺展现象的研究。 胶体流体被限制在固体表面上的液膜的三相接触区域中。基础研究已经揭示了楔膜的受限几何形状内的颗粒和/或胶束有序和有序-无序结构转变的现象。智力MeritThe拟议的研究的目标是阐明，实验和理论上，结构分离压力梯度（即膜张力梯度）的润湿，扩散和粘附的纳米流体在固体表面上的作用，并开发一种新型的使用纳米颗粒的去污力。具体工作包括：1）利用微分显微干涉技术监测纳米流体在固体表面的铺展; 2）利用激光扫描共聚焦显微镜和Kossel衍射技术直接观察纳米流体在楔形膜中的自结构; 3）开发一种新型的纳米流体去污剂;以及4）使用统计力学的积分方程方法和蒙特卡罗模拟来模拟纳米流体结构和扩散动力学。将研究极大地影响纳米颗粒结构形成的技术因素，从而在膜弯月面区域中的结构分离压力，例如颗粒浓度、颗粒电荷、颗粒尺寸和多分散性。待研究的系统包括带电和空间稳定的胶体颗粒，如二氧化硅和乳胶。扩散动力学将在各种表面上进行，包括玻璃、云母、硅片和塑料。更广泛的冲击润湿含有自组织结构的胶体膜，如纳米颗粒悬浮液、聚合物胶乳、球状蛋白质、表面活性剂胶束等，在纳米技术和生物系统中具有重要的技术应用。例如，它们在固体表面上的铺展和粘附行为可以产生具有期望的结构和光学性质的材料。研究人员还寻求通过开发演示，研讨会和关于胶体现象和去污力的课程来有效地整合研究和教育，这些课程由IIT的数学和科学教育部以及IIT的科学和数学学习和提高倡议（SMILE）提供，强调实践现象学方法。 这些演示和课程也将纳入IIT针对高中生的外展计划，包括女性科学与工程计划（WISE）。研究生和本科生将参与研究，短期国际实习将加强他们的跨文化培训。

National Science Foundation - Division of Chemical &Transport Systems Particulate & Multiphase Processes Program (1415)ABSTRACTProposal Number: CTS-0553738Principal Investigator: Wasan, DarshAffiliation: Illinois Institute of TechnologyProposal Title: Colloidal Films: Local Nanoparticle Self-Structuring and Novel Type of DetergencyThis proposal is a study of the wetting and spreading phenomenon of a colloidal fluid comprising spherical nanosized particles or surfactant micelles and a solvent. The colloidal fluid is confined in a three-phase contact region of a liquid film on a solid surface. Fundamental research has revealed the phenomenon of particle and/or micelle ordering and order-disorder structural transitions inside the confined geometry of the wedge film. Intellectual MeritThe objectives of the proposed research are to elucidate, both experimentally and theoretically, the role of structural disjoining pressure gradient (that is, film tension gradient) in the wetting, spreading and adhesion of nanofluids on solid surfaces, and to develop a novel type of detergency using nanoparticles. The specific tasks to be undertaken are: 1) monitor spreading of nanofluids on solid surfaces using differential microinterferometry; 2) directly observe nanofluid self-structuring within wedge films using laser scanning confocal microscopy and Kossel diffraction; 3) develop a novel type of detergency using nanoparticles; and 4)model nanofluid structuring and spreading dynamics using the integral equation method of statistical mechanics and Monte Carlo simulations. Technological factors which greatly influence nanoparticle structure formation and thereby structural disjoining pressure in the film-meniscus region, such as particle concentration, particle charge, particle size, and polydispersity will be investigated. Systems to be investigated include charged and sterically stabilized colloidal particles, such as silica and latexes. The spreading dynamics will be carried out on various surfaces including glass, mica, silicon wafer and plastic.Broader ImpactWetting of colloidal films that contain self-organized structures, such as suspensions of nanoparticles, polymer latexes, globular proteins, surfactant micelles, etc. have significant technological applications in both nanotechnology and biological systems. For example, their spreading and adhesion behavior on solid surfaces can yield materials with desirable structural and optical properties. The researchers also seek to effectively integrate research and education by developing demonstrations, workshops, and lessons on colloidal phenomena and detergency for grades K-12 science teachers training and continuing education programs offered by IITs Department of Mathematics and Science Education, and IITs Science and Mathematics Initiative for Learningand Enhancement (SMILE) which emphasizes a hands-on phenomenological approach. These demonstrations and lessons will also be incorporated into IITs outreach programs for high school students including the Women in Science and Engineering Program (WISE). Graduate and undergraduate students will be involved in the research and short-term international placement will enhance their intercultural training.