Okor R S
J Pharm Pharmacol. 1982 Feb;34(2):83-6. doi: 10.1111/j.2042-7158.1982.tb04190.x.
Mixing of two acrylate-methacrylate copolymers designated A and B and differing only in cation (quaternary ammonium) content in the ratio 2:1 (A:B) provided a means of varying polymer cation content in resulting films. Film permeability to the permeant urea, increased with increase in cation content; a two phase change characterized by a slow increase at a low cation content level followed by about 13 times more rapid increase at high cation content level. The point of transition from the slow to the rapid phase was 53 moles cation per mole polymer chain. On average a fold increase in cation content resulted in a 500 fold increase in permeation rate. Increases in film swelling and pore size also accompanied the increase in cation content, but the change in permeability was more positively correlated with the corresponding change in film pore size. Mutual repulsion by charged groups during film formation is suggested as a factor promoting the formation of large pores in the film at high cation content.
将两种仅在阳离子（季铵）含量上有所不同的丙烯酸酯 - 甲基丙烯酸酯共聚物A和B按2:1（A:B）的比例混合，为改变所得薄膜中的聚合物阳离子含量提供了一种方法。薄膜对渗透剂尿素的渗透性随阳离子含量的增加而增加；呈现出两相变化，其特征是在低阳离子含量水平下缓慢增加，随后在高阳离子含量水平下增加速度快约13倍。从缓慢相转变为快速相的转折点是每摩尔聚合物链含53摩尔阳离子。平均而言，阳离子含量增加一倍会导致渗透速率增加500倍。薄膜溶胀和孔径的增加也伴随着阳离子含量的增加，但渗透性的变化与薄膜孔径的相应变化更呈正相关。在薄膜形成过程中，带电基团的相互排斥被认为是在高阳离子含量下促进薄膜中形成大孔的一个因素。
