Research Initiation Award: Formation of Porous Polymeric Materials Via Micro-Phase Separation in a Supercritical Solution

本研究将集中在多孔聚合物材料 显示出均匀的亚微米细胞尺寸， 在诸如膜，催化剂载体， 人工皮肤等。目前的液相分离 生产这些材料的技术受到限制， 溶剂去除困难和结构不均匀性 由热梯度引入。 建议生成 均匀的多孔聚合物材料 在由一种或多种聚合物溶胀的聚合物网络中诱导分离 超临界流体 通过利用强者 溶剂力对压力的依赖性，一个独特的 超临界流体的特性，人们可以假设更细 控制多孔材料的微观结构， 目前可使用常规液体溶剂获得。 研究计划将分为两个阶段。 在 首先，平衡溶胀组成和松弛 聚合物网络在超临界CO2中的行为 将使用石英弹簧微量天平测量， 介电谱仪，分别。 这将是 首先在网络/超临界流体上进行这样的测量 系统 在第二阶段，微孔材料将 通过在超临界流体中的相分离而产生， 膨胀的网络 孔隙率将使用常规的 技术和相关的基本热力学 在初始程序阶段编译的信息。

This research will focus upon porous polymeric materials exhibiting a uniform sub-micron cell size which show great promise in applications such as membranes, catalyst supports, artificial skin, etc. Current liquid-based phase separation technologies for producing these materials are limited be difficulties in solvent removal and structural heterogeneity introduced by thermal gradients. It is proposed to generate uniform, cellular polymeric materials via a micro-phase separation induced in a polymer network swollen by a supericrtical fluid. By taking advantage of the strong dependence of solvent power on pressure, a unique characteristic of supercritical fluids, one can assume finer control over the microstructure in porous materials than is presently available using conventional liquid solvents. The research program will be divided into two phases. In the first, the equilibrium swelling composition and the relaxation behavior of a polymer network exposed to supercritical CO2 will be measured using a quartz spring microbalance and dielectric spectrometer, respectively. These will be the first such measurements on a network/supercritical fluid system. In the second phase, microporous materials will be generated via a phase separation in a supercritical fluid- swollen network. Porosity will be measured using conventional techniques and correlated with the fundamental thermodynamic information compiled during the initial program phase.