DiPolo R, Sha'afi R I, Solomon A K
J Gen Physiol. 1970 Jan;55(1):63-76. doi: 10.1085/jgp.55.1.63.
The transport parameters of a cellulose acetate membrane prepared from a mixture of cellulose acetate, formamide, and acetone, 25:25:50 by weight, were studied. The membrane consists of a thin, porous layer, the skin, in series with a thick, highly porous layer, the coarse support. In the skin the diffusional permeability coefficient, omega, of a number of small amides and alcohols depends critically upon the partition coefficient, K(s), the size of the molecule, and the apparent hydrogen-bonding ability, N(s), of the solute. These observations are in general agreement with our earlier conclusions on the properties of nonporous membranes. On the other hand, the corrected reflection coefficient, sigma', is not a very sensitive function of either N(s) or K(s) taken separately. The correlation between sigma' and molecular diameter is reasonably good; however, it is much improved when both N(s) and K(s) are taken into consideration. Isotope interaction was also studied in the present preparation and was found to provide only a small (5-8%) contribution to the diffusional permeability coefficient of ethylene glycol. The contribution of solute-water friction was found to be less than 24% of the total solute friction.
对由重量比为25:25:50的醋酸纤维素、甲酰胺和丙酮混合物制备的醋酸纤维素膜的传输参数进行了研究。该膜由一层薄的多孔层（皮层）和一层厚的高度多孔层（粗支撑层）串联组成。在皮层中，多种小酰胺和醇的扩散渗透系数ω关键取决于分配系数K(s)、分子大小以及溶质的表观氢键结合能力N(s)。这些观察结果与我们早期关于无孔膜性质的结论总体一致。另一方面，校正反射系数σ′单独来看对N(s)或K(s)都不是非常敏感的函数。σ′与分子直径之间的相关性相当好；然而，当同时考虑N(s)和K(s)时，相关性有很大改善。在本制备过程中还研究了同位素相互作用，发现其对乙二醇扩散渗透系数的贡献仅为很小一部分（5 - 8%）。发现溶质 - 水摩擦的贡献不到总溶质摩擦的24%。
