Gary-Bobo C M, Solomon A K
J Gen Physiol. 1971 May;57(5):610-22. doi: 10.1085/jgp.57.5.610.
Studies have been made on the temperature dependence of both the hydraulic conductivity, L(p), and the THO diffusion coefficient, omega, for a series of cellulose acetate membranes (CA) of varying porosity. A similar study was also made of a much less polar cellulose triacetate membrane (CTA). The apparent activation energies, E(a), for diffusion across CA membranes vary with porosity, being 7.8 kcal/mole for the nonporous membrane and 5.5 kcal/mole for the most porous one. E(a) for diffusion across the less polar CTA membrane is smaller than E(a) for the CA membrane of equivalent porosity. Classical viscous flow, in which the hydraulic conductivity is inversely related to bulk water viscosity, has been demonstrated across membranes with very small equivalent pores. Water-membrane interactions, which depend upon both chemical and geometrical factors are of particular importance in diffusion. The implication of these findings for the interpretation of water permeability experiments across biological membranes is discussed.
针对一系列孔隙率不同的醋酸纤维素膜（CA），研究了其水力传导率L(p)和THO扩散系数ω与温度的相关性。对极性小得多的三醋酸纤维素膜（CTA）也进行了类似研究。跨CA膜扩散的表观活化能E(a)随孔隙率而变化，无孔膜的E(a)为7.8千卡/摩尔，孔隙率最大的膜的E(a)为5.5千卡/摩尔。跨极性较小的CTA膜扩散的E(a)小于孔隙率相当的CA膜的E(a)。在具有非常小的等效孔隙的膜中，已证明存在经典粘性流动，其中水力传导率与本体水粘度成反比。取决于化学和几何因素的水-膜相互作用在扩散中尤为重要。讨论了这些发现对解释跨生物膜的水渗透性实验的意义。
