新型掺杂Gemini分子阴离子交换膜的制备与表征

PREPARATION AND CHARACTERACTERIZATION OF A NOVEL ANION EXCHANGE MEMBRANCE BY DOPING THE GEMINI SURFACTANTS

以壳聚糖(CS)和2,3-环氧丙基三甲基氯化铵为原料制备了季铵化壳聚糖(QCS)。将其与Gemini型阳离子表面活性剂(顺丁烯二酸二乙酯撑基双[辛烷基二甲基氯/溴化铵],简写为G8-2-8)共混后,借助戊二醛(GA)的化学交联作用制得一系列不同配比的QCS/G8-2-8阴离子交换膜。利用傅里叶变换红外光谱(FTIR)和热失重分析(TGA)分别对该膜的化学结构和热稳定性进行表征,考察了戊二醛和G8-2-8用量对该阴离子膜含水率、离子交换量、机械强度、电导率等性能的影响。结果表明:戊二醛用量的增加可有效降低含水率,提高机械性能;Gemini阳离子分子用量的增加可以降低含水量,增加离子交换量,提高该膜的断裂伸长率。其中,当G8-2-8和戊二醛质量分数为0.3%和3.5%时,复合膜的含水率、离子交换量、断裂伸长率和80℃的电导率分别为208.3%,3.79mmol/g,18.14%和4.10×10-2 S/cm。

Quaternized-chitosan （QCS） was synthesized by using Chitosan （CS） and 2,3-epoxy propiy trimethyl ammonium chloride as raw materials.The QCS was blended with Gemini cationic surfactant （maleic acid diethyl brace base pairs [essien alkyl dimethyl chloride/ammonium bromide],named as G8-2-8） to make a series of different ratio of QCS/G8-2-8 anion exchange membrane with glutaraldehyde （GA） chemical crosslinking effect.Structure and stability of the membrane were characterized by FTIR and TGA.In addition,the effects of the dosage of glutaraldehyde and G8-2-8 on anion membrane water content,ion exchange capacity,the mechanical strength and electrical conductivity were studied.The results showed that the increase in the amount of glutaraldehyde could effectively reduce the moisture content and improve the mechanical properties.The increase in the amount of Gemini cation molecules could not only reduce the water content,but also increase the ion-exchange capacity and the elongation at break of the membrane.The water content was 208.3％,ion-exchange capacity was 3.79 g,elongation at break was 18.14％ and the electrical conductivity at 80 ℃ was 4.1 × 10-2 S/cm when G8-2-8 and glutaraldehyde mass fraction were 0.3 ％ and 3.5 ％.