CAREER: Vapor-Phase Deposition onto Ordered Liquid Surfaces to Create Oriented and Hierarchical Materials

科学家模拟生物组装机制，形成具有独特和技术上有用的结构-功能关系的合成材料。生物系统经常在液体表面或液体溶液中形成结构。这项教师早期职业发展（Career）计划将研究液晶表面上聚合物薄膜的组装，并支持基于液体表面组装的基础研究，以生产有序和定向的材料。液晶具有长程有序，可用于指导沉积在其表面上的有序或结构化聚合物薄膜的形成。这些自然结构的聚合物薄膜可以影响许多技术领域，为促进国家繁荣提供帮助，例如生产具有定向孔的水过滤膜，在不牺牲选择性的情况下增加渗透性。目前，没有一种可扩展的方法可以制造出具有高孔隙密度的定向膜。这项工作的广泛影响将通过结合材料工程、物理和聚合物科学领域来促进跨学科创新。该赠款旨在通过与女性工程师协会和全国黑人工程师协会的同伴指导计划，扩大女性和代表性不足群体在STEM活动中的参与。利用流体界面上的连续二维组装为自下而上制造分层和各向异性聚合物材料开辟了新的途径。气相沉积方法为控制聚合物形成的沉积和化学反应提供了独特的能力。当聚合物沉积在液体衬底上时，聚合物-液体界面的表面扩散和聚集机制将在受控聚合物组装的基础上进行。气相沉积到液体上提供了一种通用的方法来控制材料连续输送到液体表面，而不依赖于界面组装机制。为了解决生产均匀有序形态的挑战，有序的液体衬底，特别是液晶，将被用作模板来指导聚合物表面的成核和生长。CAREER资助的核心目标是阐明气相输运和液晶介导组装协同耦合的潜在机制，以在流体界面上进行自下而上的材料加工。这一过程可能为胶体基薄膜的发展开辟新的途径。这些薄膜可以在广泛的技术应用中产生影响，例如膜形成，柔性电子和传感应用类型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Scientists emulate biological assembly mechanisms to form synthetic materials with unique and technologically useful structure-function relationships. Biological systems often form structures at liquid surfaces or within liquid solutions. This Faculty Early Career Development (CAREER) Program grant will investigate the assembly of polymer films on liquid crystal surfaces and support fundamental research into harnessing liquid-surface-based assembly for producing materials with ordered and oriented. The liquid crystals possess a long-range order which can serve to direct the formation of an ordered or structured polymer film deposited on its surface. These naturally-structured polymer films could impact many areas of technology providing to increase national prosperity such as in the production of water filtration membranes with oriented pores that increase permeability without sacrificing selectivity. Currently, no scalable method makes oriented membranes with high pore densities. Broader impacts of this work will promote interdisciplinary innovation by combining the fields of materials engineering, physics, and polymer science. The grant provides for the broadening participation of women and underrepresented groups in STEM activities through peer mentoring programs with the Society of Women Engineers and the National Society of Black Engineers. Harnessing continuous two-dimensional assembly at fluid interfaces opens new routes for bottom-up fabrication of hierarchical and anisotropic polymeric materials. Vapor-phase deposition methods offer unique capabilities for controlling the deposition and chemistry of polymer formation. When polymer deposition occurs on liquid substrates, surface diffusion and aggregation mechanisms at the polymer-liquid interface will processes underlying the controlled polymer assembly. Vapor-phase deposition onto liquids provides a versatile approach to control continuous materials transport to the liquid surface independently of interfacial assembly mechanisms. To address challenges in producing uniform and ordered morphologies, ordered liquid substrates, specifically liquid crystals, will be used as a template to direct nucleation and growth of polymers at the surfaces. The central goal of this CAREER grant is to elucidate underlying mechanisms in which vapor-phase transport and liquid crystal-mediated assembly are cooperatively coupled for bottom-up materials processing at fluid interfaces. The process could open up new regimes for the development of colloidal-based thin films. These films could have impact in a wide cross-section of technological applications such as membrane formation, flexible electronics, and types of sensing applications.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.