NONLINEAR SWELLING OF POLYMER GELS
NONLINEAR SWELLING OF POLYMER GELS
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DOI：
10.1063/1.465034
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发表时间：
1993-03-01
影响因子：
4.4
通讯作者：
MORMAN, KN
中科院分区：
文献类型：
--
作者：
DURNING, CJ;MORMAN, KN
我们提出了一个连续介质理论的非线性溶胀的聚合物凝胶。该方法是在瞬时自由能最小的约束下求解网络和液体的连续性方程。本构关系需要的自由能密度的凝胶，W，和液体扩散电流，J。詹姆斯-古斯幻影网络模型和巴斯蒂德的缩放模型用于W;菲克定律用于J，这相当于忽略凝胶的剪切模量相对于其渗透压缩模量。该理论适用于网络在良好的溶剂中的自由溶胀的半稀凝胶的三种几何形状：球体，长圆柱体，薄板。我们发现一个几何形状依赖性，非局部效应影响的可测量（凝胶形状和液体吸收）。这是由凝胶/液体界面处的网络变形对样品的整个变形场的依赖性引起的。理论给出了合理的协议与实验;差异可能是由于非局部效应J不占菲克定律。
We present a continuum theory for the nonlinear swelling of polymer gels. The approach is to solve the continuity equations for the network and liquid under the constraint that the instantaneous free energy be minimal. Constitutive relations are needed for the free energy density of the gel, W, and for the liquid diffusion current, J. The James-Guth phantom network model and Bastide's scaling model are used for W; Fick's law is used for J which is tantamount to neglecting the gel's shear modulus relative relative to its osmotic compressive modulus. The theory is applied to the free swelling of networks in good solvents to a semidilute gel for three geometries: sphere, long cylinder, and thin slab. We find a geometry-dependent, nonlocal effect influencing the measurables (gel shape and liquid uptake). This arises from the dependence of the network's deformation at the gel/liquid interface on the whole deformation field for the sample. The theory gives reasonable agreement with experiment; discrepancies are likely due to nonlocal effects in J not accounted for by Fick's law.