Department of Chemical Engineering , Hiroshima University , 1-4-1 Kagamiyama , Higashihiroshima 739-8527 , Japan.
National Metrology Institute of Japan , National Institute of Advanced Industrial Science and Technology , 1-1-1 Higashi , Tsukuba 305-8565 , Japan.
ACS Appl Mater Interfaces. 2019 Feb 20;11(7):7164-7173. doi: 10.1021/acsami.9b01462. Epub 2019 Feb 11.
Amine-functionalized organosilica membranes have attracted an increasing amount of attention because of significant potential for the capture of postcombustion CO. The appealing separation performance of these membranes, however, is generally obtained via compromises to gas permeance. In the present study, a novel, ultramicroporosity-tailored composite (organo)silica membrane with high flux was synthesized via sol-gel cocondensation of a pyrimidine-bridged organoalkoxysilane precursor 4,6-bis(3-(triethoxysilyl)-1-propoxy)-1,3-pyrimidine (BTPP) with a second intrinsically rigid network precursor (1,2-bis(triethoxysilyl)ethane or tetraethylorthosilicate). The surface chemistry, ultramicroporosity, and chain-packing state of the initial BTPP-derived membranes can be carefully tuned, which has been verified via Fourier transform infrared spectroscopy, water-contact angle measurement, X-ray diffraction, and positron annihilation lifetime spectroscopy. The composite (organo)silica xerogel specimens presented a slightly improved ultramicroporosity with noticeable increases in gas adsorption (CO and N). However, a surprising increase in CO permeance (>2000 GPU), with moderate CO/N selectivity (∼20), was observed in the resultant composite (organo)silica membranes. Furthermore, gas permeance of the composite membranes far surpassed the values based on Maxwell predictions, indicating a possible molecular-scale dispersion of the composite networks. This novel, porosity-tailored, high-flux membrane holds great potential for use in industrial postcombustion CO capture.
胺功能化有机硅膜因其在捕集燃烧后 CO 方面的巨大潜力而受到越来越多的关注。然而，这些膜吸引人的分离性能通常是通过牺牲气体渗透性来获得的。在本研究中，通过嘧啶桥联的有机烷氧基硅烷前体 4,6-双（3-（三乙氧基硅基）-1-丙氧基）-1,3-嘧啶（BTPP）与第二固有刚性网络前体（1,2-双（三乙氧基硅基）乙烷或正硅酸乙酯）的溶胶-凝胶共缩聚，合成了一种具有高通量的新型超微孔定制复合（有机）硅膜。BTPP 衍生膜的初始表面化学、超微孔和链堆积状态可以通过傅里叶变换红外光谱、水接触角测量、X 射线衍射和正电子湮没寿命光谱进行仔细调整。复合（有机）硅气凝胶标本的超微孔略有改善，气体吸附（CO 和 N）明显增加。然而，在所得复合（有机）硅膜中观察到 CO 渗透率（>2000 GPU）的惊人增加，同时 CO/N 选择性（约 20）适度提高。此外，复合膜的气体渗透率远远超过基于 Maxwell 预测的数值，表明复合网络可能存在分子尺度的分散。这种新型的、具有定制孔隙率的高通量膜在工业燃烧后 CO 捕集中具有很大的应用潜力。
