GOALI: The Dynamics of Phase Inversion

安东尼·麦克休伊利诺伊 研究提出了相转化，该过程中，一个铸聚合物溶液转化为多孔，聚合物凝胶通过热或非溶剂淬火。 固化的聚合物中的孔径和孔径分布使得性质有利于膜应用。 这种膜在分离和生物医学工业中无处不在，每年的商业基础超过16亿美元。 因此，了解和控制它们的最佳制造条件具有技术和科学重要性。 实验和建模分析将直接对膜结构形成和锁定在淬火过程中的动态的基本理解。 实验将利用基于暗场显微镜和小角度光散射的原位测量技术，再加上视频成像。 这些提供了独特的定量数据的扩散和液-液相分离动力学与相转化，以及冻结在凝胶结构的玻璃化转变或结晶。 将使用电子显微镜对形成的形态进行微观结构分析。 淬灭实验将涉及许多聚合物/溶剂/非溶剂系统，包括可结晶和无定形聚合物。 数据将被分析的基础上的旋节分解与外部传质的数学模型。 建模的目标是量化指状或海绵状多孔结构在液-液相分离过程中形成并随后被冻结的机制。 原位技术也将被应用于研究相转化现象有关的控制释放药物输送膜，在生物医学和制药行业的日益重要的领域在体内形成。 膜形成动力学将在可生物降解的共聚物，聚（乳酸-共-乙二醇酸）PLGA中监测，溶解在各种无毒溶剂中，并在水中淬灭。 还将测定模型蛋白质溶菌酶从所形成的膜的溶出特性。 我们的目标将是量化溶剂的水溶解度，系统的玻璃形成特性，并有利于同时，原位封装和控制释放的蛋白质的膜结构的形成之间的关系。 这些研究结果将直接应用于药物控制释放领域。 ***

CTS-9731509 Anthony McHugh U. of Illinois Studies are proposed of phase inversion, the process by which a cast polymer solution is converted into a porous, polymer gel by either thermal or nonsolvent quenching. Pore size and pore size distribution in the solidified polymer render properties favorable for membrane applications. Such membranes are ubiquitous in the separations and biomedical industries, having an annual commercial basis in excess of $1.6 billion. Hence understanding and controlling the conditions for their optimal fabrication has technological and scientific importance. Experimental and modeling analyses will be directed towards fundamental understanding of the dynamics by which membrane structures are formed and locked-in during quenching. Experiments will utilize a combination of in-situ measurements techniques based on dark-ground microscopy and small angle light scattering, coupled with video imaging. These provide unique quantitative data on the diffusion and liquid-liquid phase separation kinetics associated with phase inversion, as well as the freezing in of gel structure by glass transition or crystallization. Microstructural analysis of the formed morphologies will be carried out using electron microscopy. Quenching experiments will involve a number of polymer/solvent/nonsolvent systems, including crystallizable and amorphous polymers. Data will be analyzed in terms of mathematical models based o spinodal decomposition coupled with external mass transfer. The goal of modeling will be to quantify the mechanisms by which finger-like or spongy porous structures form during liquid-liquid phase separation and are then frozen in. In-situ techniques will also be applied to study phase inversion phenomena related to the in-vivo formation of controlled release drug delivery membranes, an area of growing importance in the biomedical and pharmaceutical industries. Membrane formation dynamics will be monitored in the biodegradable copolymer, poly (lactic-co-glycol ic acid) PLGA, dissolved in various nontoxic solvents, and quenched in water. The simultanoeus release characteristics of a model protein, lysozyme, from the as-formed membranes will also be determined. The objective will be to quantify relations among solvent water solubility, system glass-forming characteristics, and the formation of membrane structure favorable for simultaneous, in-situ encapsulation and controlled release of protein. Results of these studies will have direct application in the field of controlled drug delivery. ***