Swelling-controlled solute diffusion in glassy polymers

玻璃聚合物中的渗透传输在传统的工程应用中发挥了重要作用，如膜、包装和屏障材料。最近，这种现象在从微纳米制造到设计用于药物输送的肿胀控制水凝胶的应用中变得越来越重要。在后一种情况下，大量体积膨胀的存在和被困溶质的扩散可能会使整个速率过程进一步复杂化。这种膨胀和扩散通常不遵循菲克扩散机制。虽然玻璃聚合物中单一渗透传输的情况已经得到了广泛的研究，但聚合物中初始溶质浓度水平对溶剂渗透特性的影响尚未得到适当的研究，并且与观察到的溶质从玻璃聚合物（特别是水凝胶）中释放行为相关的溶质膨胀过程的作用尚未得到最终解决。

Penetrant transport in glassy polymers has played a major role in traditional engineering applications such as membranes, packaging and barrier materials. More recently, this phenomenon has become increasingly important in applications ranging from micro and nanofabrication to the design of swelling-controlled hydrogels for drug delivery. In the latter case, the presence of a substantial volume swelling and the diffusion of entrapped solute may further complicate the overall rate process. Such swelling and diffusion generally do not follow a Fickian diffusion mechanism. Although the case of a single penetrant transport in glassy polymers has been studied extensively, the effect of initial solute concentration level in the polymer on the solvent penetration characteristics has not been properly studied, and the role of the swelling process in relation to the observed solute release behaviour from glassy polymers, in particular hydrogels, has not been conclusively resolved.