Perforated monolayers : fabrication of calix[6]arene-based composite membranes that function as molecular sieves
Perforated monolayers : fabrication of calix[6]arene-based composite membranes that function as molecular sieves
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穿孔单层膜：制备具有分子筛功能的杯[6]芳烃基复合膜
作者：
M. Conner;V. Janout;I. Kudelka;P. Dědek;Jiayi Zhu;S. Regen
本文报道了三种新型杯[6]芳烃的合成、单分子膜行为、聚合特性以及由其衍生的一系列复合膜的制备和渗透选择性。5，11，17，23，29，35-六烷基的单层（N-（2-（甲基二硫代）-乙基）氨基甲酰基）-37，38，39，40，41，42-六烷基（辛氧基）杯[6]芳烃（I）表现出53达因/厘米的塌陷压力;由5，11，17，23，29，35-六烷基（巯基甲基）-37，38，39，40，41，42-六烷基（正丁氧基）杯[6]芳烃（II）和5，11，17，23，29，35-六乙烯基-37，38，39，40，41，42-六（3，6-二氧杂-1-庚氧基）-杯[6]芳烃（III）分别在16和26 dyn/cm下塌陷。在塌缩点，I-III占据的面积分别为165、150和155 A2 34/分子。通过紫外线诱导的二硫键缩合和通过空气氧化的II的聚合导致表面压力的适度降低。相比之下，紫外线照射III的结果在表面压力的完全损失和一个明显的“萌芽”的电影。复合膜已制成的Langmuir-Blodgett多层膜的I，加上具有大的永久性孔（即，Celgard和Nuclepore膜）的聚合物支持，显示出显着降低对他的渗透性，和SFg，但没有增强渗透选择性（permselectivity）。与此形成鲜明对比的是，使用聚[1-（三甲基甲硅烷基）-1-丙炔]作为载体材料构建的类似复合材料起到分子筛的作用;即，He和N2容易渗透复合材料，但SF6不能。根据计算的He和N_2的本征磁导率系数与LB膜厚度的函数关系，得出这种选择性渗透是由于I.
This paper reports the synthesis, monolayer behavior, and polymerization characteristics of three new calix [6] arenes, and the fabrication and permeation selectivity (permselectivity) of a series of composite membranes derived from one such amphiphile. Monolayers of5, ll, 17, 23, 29, 35-hexakis (/V-(2-(methyldithio)-ethyl) carbamoyl)-37, 38, 39, 40, 41, 42-hexakis (octyloxy) calix [6] arene (I) exhibit a collapse pressure of 53 dyn/cm; those prepared from 5, ll, 17, 23, 29, 35-hexakis (mercaptomethyl)-37, 38, 39, 40, 41, 42-hexakis (nbutyloxy) calix [6] arene (II), and 5, ll, 17, 23, 29, 35-hexavinyl-37, 38, 39, 40, 41, 42-hexaki8 (3, 6-dioxa-l-heptyloxy)-calix [6] arene (III) collapse at 16 and 26 dyn/cm, respectively. At the collapse point, the areas that are occupied by I-III are 165,150, and 155 A2 34/molecule, respectively. Polymerization ofI via UV-induced disulfide disproportionation and II by air oxidation result in a modest reductionin surface pressure. In contrast, UV irradiation of III results in the complete loss of surface pressure and an apparent “budding” of the film. Composite membranes that have been fabricated from Langmuir-Blodgett multilayers of I, plus polymeric supports having large permanent pores (ie, Celgard and Nuclepore membranes), show a significant reduction in permeability toward He, and SFg but no enhancement in permeation selectivity (permselectivity). In striking contrast, analogous composites that have been constructed using poly [l-(trimethylsilyl)-l-propyne] as support material, function as molecular sieves; ie, He andN2 readily permeate the composites, but SF6 does not. On the basis of intrinsic permeability coefficients that have been calculated for He and N2 as a function of LB film thickness, it is concluded that this permselectivity is due tothe selective transport across homogeneous multilayers of I.