Vapor Deposition Polymerization of Porous Polymers

多孔聚合物的气相沉积聚合

• 批准号: 0828437
• 负责人: Mitchell Anthamatten
• 金额: $ 25.82万
• 依托单位: University of Rochester
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0828437&HistoricalAwards=false
• 关键词: Vapor; Deposition; Polymerization; Porous; Polymers

CBET-0828437Anthamatten Intellectual Merit. Micro-, meso-, and macroporous polymers greatly benefit the fields of tissue engineering, photovoltaics, microelectronics, hydrogen storage, and gas separations. Porous polymers are often produced through polymerization-induced phase separation (PIPS), thermal-induced phase separation (TIPS), or other phase-inversion techniques. This study represents a departure from traditional solution- or melt-phase methods. The goal is to develop vapor deposition polymerization (VDP) as a controllable, environmentally sound technique to producing porous and micro-structured polymers. Reactive monomers and non-reactive species (porogens) will be co-deposited onto a cooled substrate to force phase separation and arrest kinetically trapped micro- and nano-scale microstructures. The concept will be studied via two avenues: i) radical chain-growth polymerization of amorphous polymers and ii) condensation polymerization of rigid-rod, high performance polymers. For both cases, reactant and porogen concentrations will be systematically varied with time to create depth-dependent morphologies and densities. This will enable new routes to custom-designing asymmetric membranes. A second goal is to mechanistically relate observed morphologies to process conditions and to models of phase behavior. To achieve this, cross-sectional analysis of as-deposited films will be studied using optical and electron microscopy techniques. Initial experiments have focused on poly(methyl methacrylate) as a system to study free-radical growth of polymers in the presence of a porogen. Results indicate that films can be grown from the vapor phase in a controlled and repeatable manner. When a low-molar mass porogen is introduced, phase separatio occurs. To study condensation polymerization, a second low pressure (~10-6 Torr) VDP reactor has been reconfigured for co-deposition of polyimide precursors with thermally-degradable porogens. Similar experiments will be conducted using p-type phthalocyanine dyes (instead of a porogen) to fabricate and test polymer-stabilized photovoltaics. Broader Impacts. The research has strong connections to potential applications. Specifically, VDP of microporous rigid-rod polymers will provide new routes to 1) all-organic gas separation membranes and hydrogen storage materials, 2) low-K dielectric materials that are compatible with current trends in microelectronics processing, and 3) to polymer-stabilized organic photovoltaics. It is expected that future research programs in at least one of these directions will spawn from this study. Research will also lead to an improved understanding of bulk polymerization, phase separation, and vitrification occurring in micron-thick polymer films. The study will ultimately improve the ability to control micron-scale membrane features and their one dimensional spatial distribution. The integration of research and education will be through curriculum development of hands-on application projects and special topics in undergraduate and graduate-level courses. Community outreach activities include organizing professional development, Green Engineering, lectures for local high school teachers. These lectures will highlight environmental issues and solutions, and provide new teaching tools to bridge the gap between real-life problems and traditional textbook learning.

anthamatten Intellectual Merit。微孔、中孔和大孔聚合物极大地促进了组织工程、光伏、微电子、储氢和气体分离等领域的发展。多孔聚合物通常是通过聚合诱导相分离（PIPS）、热诱导相分离（TIPS）或其他相转化技术生产的。这项研究代表了对传统溶液或熔融相方法的背离。目标是发展气相沉积聚合（VDP）作为一种可控的、环保的技术来生产多孔和微结构聚合物。反应性单体和非反应性物质（孔隙原）将共同沉积在冷却的衬底上，以强制相分离并阻止动力学捕获的微和纳米级微观结构。该概念将通过两种途径进行研究：i)非晶聚合物的自由基链生长聚合和ii)刚性棒、高性能聚合物的缩聚。在这两种情况下，反应物和孔隙浓度将随时间系统地变化，以产生与深度相关的形态和密度。这将为定制设计不对称膜提供新的途径。第二个目标是将观察到的形态与工艺条件和相行为模型机械地联系起来。为了实现这一点，将使用光学和电子显微镜技术研究沉积薄膜的横截面分析。最初的实验集中在聚（甲基丙烯酸甲酯）作为一个系统，以研究自由基生长的聚合物在一个存在的孔隙。结果表明，薄膜可以在可控和可重复的条件下从气相生长。当引入低摩尔质量的孔隙时，就会发生相分离。为了研究缩聚反应，重新配置了第二个低压（~10-6 Torr） VDP反应器，用于聚酰亚胺前驱体与热降解多孔原的共沉积。类似的实验将使用p型酞菁染料（而不是多孔素）来制造和测试聚合物稳定的光伏电池。更广泛的影响。这项研究与潜在的应用有着密切的联系。具体来说，微孔刚性棒聚合物的VDP将为1)全有机气体分离膜和储氢材料，2)与当前微电子加工趋势兼容的低k介电材料以及3)聚合物稳定有机光伏提供新的途径。预计未来在这些方向中至少有一个方向的研究项目将从这项研究中产生。研究还将导致对体聚合，相分离和玻璃化发生在微米厚聚合物薄膜的理解的提高。该研究将最终提高对微米尺度膜特征及其一维空间分布的控制能力。研究和教育的整合将通过在本科和研究生水平的课程中开发实践应用项目和专题来实现。社区外展活动包括组织专业发展、绿色工程、为当地高中教师举办讲座。这些讲座将突出环境问题及其解决方案，并提供新的教学工具，以弥合现实问题与传统教科书学习之间的差距。