聚乙烯醇/二氧化硅杂化膜的制备及渗透蒸发分离环己醇（酮）/环己烷

以聚乙烯醇（PVA）和正硅酸乙酯（TEOS）为原料，经溶胶-凝胶（sol-gel）法制备了不同二氧化硅（SiO2）含量的 PVA/SiO2杂化膜。傅里叶变换红外光谱（FT-IR）表明，随着SiO2含量增大，1060cm?1和970cm?1处Si—O—Si特征吸收峰的相对强度逐渐加强，说明TEOS与PVA发生了交联反应；同时膜的分解温度从248℃升高到342℃。杂化膜的SiO2含量从10 %增大到40 %，其玻璃态温度从115℃升高到124℃。以水为溶剂，测定了杂化膜的耐溶剂性能，与PVA膜相比，杂化膜的耐溶剂性能显著提高。以质量比为0.950/0.025/0.025的环己烷/环己醇/环己酮为原料，测定杂化膜的分离性能，结果表明SiO2含量从10 %增大到40 %，通量从15.94 g/(m2?h)升高到75.69 g/(m2?h)，环己醇的分离因子从1.8升高到2.65。

Pervaporation separation of cyclohexanol (cyclohexanone)/cyclohexane mixture by polyvinyl alcohol(PVA)/silica(SiO2) hybrid membrane

Polyvinyl alcohol(PVA) / silica(SiO2) hybrid membranes with various silica contents were prepared with the sol-gel method. Fourier transform infrared (FT-IR) spectra showed that the relative intensities of Si—O—Si characteristic absorption peaks at 1060cm-1 and 970cm-1 gradually increased with increasing SiO2 content，indicating crosslinking reaction between tetraethoxysilane（TEOS）and PVA. Thermal gravimetric analysis (TGA) results showed that breakdown temperature increased from 248℃ to 342℃ along with SiO2 content rising from 0 to 40%. Differential scanning calorimetry (DSC) results showed that glass transition temperatures (Tg) rose from 115℃ to 124℃ with increasing SiO2 content from 10% to 40%. Compared with the PVA membrane，solvent resistance of PVA/SiO2 hybrid membranes was significantly improved in water. Using cyclohexane /cyclohexanol/ cyclohexanone mixture with mass fraction of 0.950/0.025/0.025 as feed，separation performance of the hybrid membrane was determined. Total flux increased from 15.94 to 75.69 g/(m2?h) and selectivity of cyclohexanol increased from 1.8 to 2.65 with increasing SiO2 content from 10% to 40%.