共价反应型多层有机-无机复合膜组装及其渗透汽化性能
Covalent Crosslinked Assembly of Multilayer Organic-Inorgainc Compesite Membranes for Pervaporation Performance
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摘要: 对共价反应型多层有机-无机复合膜组装及其渗透汽化性能进行了研究.采用经硅烷偶联剂改性后的管式陶瓷膜作为基膜,通过动态层层吸附自组装(layer-by-layer,LbL)技术在管式陶瓷膜内表面分别组装聚丙烯酸(poly acrylic acid,PAA)/聚乙烯醇(poly vinyl alcohol,PVA)/戊二醛(glutaraldehyde,GA),再通过热交联引发层间反应,生成共价键,形成稳定性较强的多层复合分离膜,并将其用于渗透汽化领域.考察了组装层数、复合时间、交联温度和PVA相对分子质量等条件对复合膜性能的影响.结果表明:当组装层数为5层、进料液温度为75℃时,有机-无机复合膜对95%的乙醇/水体系,其透过液水的质量分数为99.5%,渗透通量可达102 g/(m2·h).Abstract: This paper studied covalent crosslinked assembly of multilayer organic-inorganic composite membranes for pervaporation performance. First,tubular ceramic substrates were pre-treated using dynasylan ameo silane coupling agents. Then,poly acrylic acid(PAA)/poly vinyl alcohol(PVA)/glutaraldehyde(GA) was dynamically assembled on to the inner surfaces of tubular ceramic substrates by LbL technique. Subsequently,the composite membranes were thermally cross-linked to form covalent bonds. The covalently crosslinked multilayers were stable,which could be used for pervaporation fields. The effects of layer numbers,filtration time,molecular weight of PVA and crosslinking temperature were investigated.Results show that the organic-inorganic tubular composite membrane shows excellent pervaporation performance for the separation of ethanol/water,and the membrane obtained with five trilayers has a permeate flux of 102 g/(m2·h) while the mass fraction of water in the permeate is 99.5%.