Abstract:
Amphiphilic block copolymers are promising candidates for the fabrication of ultrafiltration membranes with an isoporous integral asymmetric structure. The membranes are typically fabricated by the combination of block copolymer self-assembly and the non-solvent-induced phase separation (SNIPS) process resulting in isoporous integral asymmetric membranes. Certainly, all these membranes lack thermal and chemical stability limiting the usage of such materials. Within this study, the fabrication of completely cross-linked isoporous integral asymmetric block copolymer membranes is demonstrated by UV cross-linking resulting in chemical and thermal stable ultrafiltration membranes. The UV cross-linking process of PVBCB-b-P4VP (poly(4-vinylbenzocyclobutene)-b-poly(4vinylpyridine)) block copolymer membranes in dependency of irradiation time, intensity, distance between membrane and UV source and the wavelength is investigated. Furthermore, it is shown that the penetration depths can be increased by soaking the membranes in wave-guiding solutions before UV cross-linking is carried out. Moreover, a completely new and easy cross-linking strategy is developed based on isorefractive solvents resulting in thermal and chemically stable membranes that are cross-linked through the whole membrane thickness. Finally, the new cross-linking strategy in isorefractive solutions is transferred to commercial PVDF and PAN-co-PVC polymer membranes paving the way for more stable and sustainable ultrafiltration membranes.
摘要:
两亲性嵌段共聚物是制造具有同孔整体不对称结构的超滤膜的有希望的候选物。膜通常通过嵌段共聚物自组装和非溶剂诱导的相分离(SNIPS)方法的组合来制造,从而产生同孔整体不对称膜。当然,所有这些膜缺乏热和化学稳定性,限制了这些材料的使用。在这项研究中,完全交联的多孔整体不对称嵌段共聚物膜的制造通过UV交联得到化学和热稳定的超滤膜证明。PVBCB-b-P4VP(聚(4-乙烯基苯并环丁烯)-b-聚(4-乙烯基吡啶))嵌段共聚物膜的UV交联过程取决于辐照时间,强度,膜和紫外线源之间的距离和波长进行了研究。此外,表明,在进行紫外线交联之前,可以通过将膜浸入波导溶液中来增加渗透深度。此外,一种全新的和容易的交联策略是基于等折变溶剂开发的热和化学稳定的膜,通过整个膜厚度交联。最后,等折变溶液中的新交联策略被转移到商业PVDF和PAN-co-PVC聚合物膜,为更稳定和可持续的超滤膜铺平了道路。