pH敏感凝胶平衡溶胀的有限元研究

A Finite Element Method for Equilibrium Swelling Analysis of pH-Sensitive Hydrogel

1943年Flory提出第一个凝胶溶胀理论以来,凝胶溶胀理论的发展极大地促进了凝胶科学的发展.在诸多凝胶溶胀理论中,Flory-Rehner凝胶溶胀理论是最为经典的理论之一,成功地预测了聚合物胶体的诸多溶胀变形特性.但该模型是基于一种最为简单的自由连接链模型,存在精度较差的局限.因此,本文采用能够表征网络缠结拓扑等微观结构影响的弹性自由能模型,即由Edwards-Vilgis提出的Slip-Link模型,构造自由能模型并形成pH敏感凝胶的平衡溶胀理论,并基于Abaqus有限元分析了微观结构及几何限制作用对pH敏感凝胶力学行为的影响.分析结果可为微流体控制阀的设计提供参考.

Since the first gel swelling theory was put forward by Flory in 1943, the development of the gel swelling theories has tremendously improved the science and technology of the Sol-Gel. Among these gel swelling theories, Flory-Rehner gel swelling theory is one of the most classic theories. The characteristics of get swelling deformation are well predicted from the gel swelling theory. However, the model is based on the simple assumption of free link chain and has the limitation of low computational accuracy. Therefore, the elastic free energy model, namely Slip-Link model developed by Edwards-Vilgis, was introduced in the paper. And this model is able to reflect the network topological microstructure such as entanglement. The equilibrium swelling theory of pH-sensitive hydrogel was developed, and a finite element method in the commercial software Abaqus was implemented, to analyze effects of microstructure and geometrical constraints on the mechanical behaviors of pH sensitive gel. The results can provide reference for the design of the micro-fluid control valve.