羟乙基纤维素有机-无机杂化膜用于分离甲醇水溶液

Hydroxyethyl cellulose organic-inorganic hybrid membranes used for pervaporation of methanol/water mixtures

以羟乙基纤维素(HEC)、正硅酸乙酯(TEOS)为原料,通过溶胶-凝胶法制备了不同TEOS含量的新型有机-无机杂化膜。通过红外(FT-IR)、热重(TG)等分析手段对膜进行了表征,并以不同浓度的甲醇水溶液测试了杂化膜的渗透汽化分离性能。结果表明:TEOS的加入有效改善了膜的尺寸稳定性和热力学性能;随着TEOS的加入,膜通量先下降后上升,分离因子则相反。当TEOS添加量为15wt%时,膜的分离因子最高达到819;用阿伦尼乌斯等式分析了温度与渗透汽化性能之间的关系,结果,甲醇与水的活化能分别是68.16kJ/mol、24.76kJ/mol,表明甲醇的温度敏感性高于水,因此分离因子随着温度的升高而降低,通量则增加。

A series of hydroxyethyl cellulose（HEC）/silica（SiO2） hybrid membranes were obtained through the solgel process using different contents of tetraethoxysilane （TEOS）. The resulting membranes were characterized by FT-IR and TGA. And the pervaporation separation property of the hybrid membranes was tested using different concentrations of methanol aqueous solution. The results demonstrated that the dimension stability and thermodynamic performence of the membranes were improved with the addition of TEOS in effect. Meanwhile flux raised first and then declined and separation factor was on the contrary. Maximum separation factor was 819 when the TEOS content was 15%. The relationship between temperature and pervaporation was analyzed by Arrhenius equation. The activation energies of methanol and water were 68.16kJ/mol and 24.76kJ/mol,respectively. This suggested the temperature sensitivity of methanol was higher than water,thus separation factor decreased and flux increased with temperature increasing.