The Thermodynamics of Gas Sorption in Glassy Polymers

混合气体的分离是一个具有重大工业意义的问题。聚合物技术的最新进展导致越来越多地使用膜进行这些分离。对于给定的分离，通常通过测量气体吸附等温线和扩散系数来评估不同的聚合物材料。通常，所获得的吸附数据使用双模式模型来解释。虽然这个模型在实践中被证明是有用的，但它在本质上主要是经验的，并不直接将吸附性质与其他材料性质联系起来。本项目是从热力学的角度研究气体在玻璃态聚合物中的吸附。将建立玻璃聚合物中气体吸附热力学的理论框架。吸附热将通过实验测量，并用于验证理论结果。初步结果表明，吸附、机械性能、以及混合热，这可能有助于气体分离材料的筛选。将结果与双模模型进行比较，可以从力学和热力学性质的角度解释某些双模参数。

The separation of gas mixtures is a problem of great industrial significance. Recent advances in polymeric technology have led to an increasingly greater use of membranes for these separations. Different polymeric materials are commonly evaluated for a given separation by measuring gas sorption isotherms and diffusion coefficients. Frequently, the sorption data obtained is interpreted using the dual mode model. While this model has proved useful in practice, it is largely empirical in nature and does not directly relate sorption properties to other material properties. This project is an investigation of the sorption of gases in glassy polymers from a thermodynamic point of view. A theoretical framework for the thermodynamics of gas sorption in glassy polymers will be established. Heats of sorption will be measured experimentally and used to validate the theoretical results. Preliminary results suggest a relationship between sorption, mechanical properties, and the heat of mixing which might aid in the screening of materials for gas separation. A comparison of the results to the dual mode model allows an interpretation of certain dual mode parameters in terms of mechanical and thermodynamic properties.