PVA/PEG/TEOS杂化膜制备及性能研究

以聚乙烯醇(PVA)与聚乙二醇(PEG)共混,并与正硅酸乙酯(TEOS)进行交联反应制备杂化膜。FTIR证实杂化溶胶液发生交联反应形成共价键Si—O—C,WXRD观察表明加入TEOS改变了膜结晶度,加入PEG提高了PVA膜对乙醇/水溶液的渗透通量,但分离因子下降,随着TEOS的加入,膜的分离因子提高。在TEOS质量分数为10%时,杂化膜的分离因子达到最大。提高退火温度可以提高膜的分离因子,但通量下降。在100℃下退火12 h的杂化膜对乙醇质量分数为85%的乙醇/水溶液的分离性能最佳。

Preparation and permeation characteristics of PVA/PEG/TEOS hybrid membranes

Poly(vinyl alcohol)(PVA) was mixed with poly(ethylene glycol)(PEG) and then cross-linked by tetraethoxysilane (TEOS) to prepare organic-inorganic hybrid membranes.Fourier transform infrared spectroscopy(FTIR) proved that covalent bond Si—O—C was formed in the hybrid membranes.Wide-angle X-ray diffraction(WAXD) was used to observe the effect of TEOS and annealing on crystallinity.The hybrid membranes were tested in separation ethanol/water mixture by pervaporation.The effect of PEG,TEOS content and annealing temperature on the PVA hybrid membrane performance was discussed.The addition of PEG increased the PVA membrane flux,but its selectivity decreased.Water permselectivity increased with the addition of TEOS into the PVA/PEG membrane.The hybrid membrane exhibited the highest water permselectivity when TEOS mass fraction was 10%.Water permselectivity increased by increasing the annealing temperature,but permeation flux decreased at the same time.The hybrid membrane separation performance was best for pervaporation of water/ethanol(85%mass fraction of ethanol) mixture when annealing at 100 ℃ for 12 h.