摘要
以聚丙烯腈(PAN)中空纤维超滤膜为底膜,以聚乙烯醇(PVA)和正硅酸乙酯(TEOS)的混合液为涂膜液,采用溶胶-凝胶法制备了PVA-TEOS/PAN渗透汽化复合膜,并用于乙酸乙酯脱水.FT-IR和XRD谱图证实复合膜表层中由于PVA与TEOS的交联反应而形成了Si-O-C共价键,且PVA的结晶度下降.另外,利用静态接触角测量对复合膜表层的亲水性进行了表征.考察了复合膜在乙酸乙酯水溶液中的溶胀性能及涂膜液中TEOS含量和料液温度与浓度对PVA-TEOS/PAN复合膜分离性能的影响.结果表明,TEOS的加入有效降低了复合膜在乙酸乙酯水溶液中的溶胀度,使其对水具有较好的分离选择性.40℃下,涂膜液中TEOS质量含量分别为5%和30%的PVA-TEOS/PAN复合膜分离98%的乙酸乙酯水溶液时,其分离因子分别为2830和4448,渗透通量分别为49.4和41.4g/(m2·h).
The composite membrane of polyvinyl alcohol （PVA）-tetraethoxysilane （TEOS）/polyacrylonitrile （PAN） （PVA-TEOS/PAN） was prepared by sol-gel reaction of mixtures of PVA and TEOS for pervaporation separation of ethyl acetate-water solution, where the support layer was PAN hollow fiber ultrafiltration membrane. FT-IR spectra and XRD patterns proved that the covalent bond Si-O-C formed and the crystallinity of PVA descended in the top layer of PVA-TEOS/PAN composite membrane of the cross-linking reaction between PVA and TEOS, respectively. In addition, the hydrophilicity of composite membrane was characterized by static contact angle for methylene iodide. The swelling degree of composite membrane in ethyl acetate aqueous solution, and the effects of TEOS concentration in coating solution, feed temperature and concentration on pervaporation performance of PVA-TEOS/PAN composite membrane for ethyl acetate-water solution were investigated. The results showed that the swelling of PVA in the solution was inhibited with addition of TEOS, leading to PVA-TEOS/PAN composite membrane with good dehydration performance. For PVA-TEOS/PAN composite membranes with 5% and 30% TEOS, their pervaporation performance of 98% ethyl acetate aqueous solution were evaluated as follows： the separation factors were 2830 and 4448, and their permeation fluxes 49.4 and 41.4 g/（m^2·h） at 40℃, respectively.
出处
《过程工程学报》
EI
CAS
CSCD
北大核心
2008年第5期872-876,共5页
The Chinese Journal of Process Engineering
基金
国家“十一五”科技支撑计划重大基金资助项目(编号:2006BAE02A01)
上海华谊(集团)公司-华东理工大学先进化学与化工技术研究中心基金资助项目(编号:A200-8608)
