两性pH敏感凝胶溶胀理论的有限元方法

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

两性pH敏感凝胶同时拥有可电离的酸性基团和碱性基团,与普通凝胶相比,它具有更好的溶胀特性和生物相容性,从而被广泛应用在生物医学、药物输送系统、微流体控制等领域。因其独特的pH敏感特性和非线性溶胀行为,目前还缺乏用于描述两性pH敏感凝胶的有限元方法。据此本文采用修正过的两性pH敏感凝胶平衡溶胀理论,发展了能够描述凝胶溶胀力学行为的有限元计算方法,计算两性pH敏感凝胶在均匀溶胀和非均匀溶胀下的力学行为。结论显示,该有限元方法可以很好地与凝胶溶胀理论的(半)解析解拟合,既可以为生物体中某些关键指标提供重要参数和力学上的理论参考,也可为以聚合物凝胶为材料的微流体控制阀的设计提供重要参考。

The amphotericpH sensitive gel possesses both the ionized acidic group and the basic group. Compared with the conventional gel, it has better swelling properties and biocompatibility. It is widely used in many aspects such as biomedical science, drug delivery systems, micro-fluid control and so forth. However, there is still a lack of the FEM method for the amphoteric pH sensitive gel. Therefore, we use the equilibrium swelling theory of amphoteric pH sensitive gel,andFEM methodwhich is developed to describe the mechanical behavior of gel swelling, to ealeulatemechanical behavior of pH sensitive gel in homogeneous and inhomogeneous swelling. The results shows a very good agreement between results of FEM calculation and the analytical solution of the gel swelling theory. It can provide important parameters and mechanical theoretical guidance for some key indexes in biology,and also provide an important reference for the design of micro fluid control valve.