Yamaue Tatsuya, Doi Masao
Department of Computational Science and Engineering, Nagoya University, Nagoya 464-8603, Japan.
Phys Rev E Stat Nonlin Soft Matter Phys. 2004 Apr;69(4 Pt 1):041402. doi: 10.1103/PhysRevE.69.041402. Epub 2004 Apr 26.
Recently, the swelling kinetics of thin-plate gels with rectangular surfaces under mechanical constraint was experimentally investigated [J. Chem. Phys. 114, 5012 (2001)]]. In this system, the top and bottom surfaces of gels were chemically clamped on the glass plates, and the gels could swell and shrink only along the thickness direction when the osmotic pressure of the solvent is changed. Here, we analyze this process using the linearized stress-diffusion coupling model of gels based on the two fluids model. The result is somewhat unusual in that the time evolution of the thickness is described by a single exponential even though the swelling is governed by the diffusion of solvent. This result and that the characteristic relaxation time depends on the lengths of the rectangular surfaces and not on the thickness of gels agree well with the experiment.
最近，对机械约束下具有矩形表面的薄板凝胶的溶胀动力学进行了实验研究[《化学物理杂志》114, 5012 (2001)]。在该系统中，凝胶的顶面和底面化学固定在玻璃板上，当溶剂渗透压改变时，凝胶只能沿厚度方向溶胀和收缩。在此，我们基于双流体模型使用凝胶的线性化应力 - 扩散耦合模型来分析此过程。结果有些不同寻常，即尽管溶胀由溶剂扩散控制，但厚度的时间演化由单个指数描述。这一结果以及特征弛豫时间取决于矩形表面的长度而不取决于凝胶的厚度，与实验结果非常吻合。
