温度响应型PNIPAM/γ-PGA水凝胶正渗透汲取剂的制备及其性能评价

摘要

Thermo-responsive semi-interpenetrating polymer network hydrogels were prepared using Nisopropylacrylamide (NIPAM) and γ-polyglutamic acid (γ-PGA) as monomers.The structure and morphology of the hydrogels were characterized by Fourier transform infrared spectroscope and scanning electron microscope.The effects of NIPAM and γ-PGA weight ratio on the hydrogel swelling and deswelling properties were investigated.And the effectiveness of the hydrogels as forward osmosis draw agents was also evaluated.The results showed that the hydrogels possess porous structure and the equilibrium swelling ratio of hydrogels improved with increasing γ-PGA mass ratio.When the mass ratio of NIPAM to γ-PGA was 5:1,the hydrogel equilibrium swelling ratio was 40.3 g/g,and the deswelling ratio reached over 80％ after a continuous dehydration for 6 h at 40℃.When applied as forward osmosis draw agents,the binary hydrogels showed water flux ranging from 1.1 to 1.4 L/(m2 · h) and good regeneration efficiency.The water flux was gradually decreased with the increasing of the feed solution concentration.When the feed solution concentration was 2 g/L,the water flux within 0.5 h was about 1.0 L/(m2 · h).%采用N-异丙基丙烯酰胺(NIPAM)和γ-聚谷氨酸(γ-PGA)为合成单体,制备温度响应型半互穿网络聚合二元水凝胶,利用红外光谱和扫描电镜对其结构和形态进行表征,研究不同单体配比条件下水凝胶的溶胀和退溶胀性能,并考察二元水凝胶作为正渗透汲取荆的应用效能.结果表明,二元水凝胶具有明显的孔状结构,其平衡溶胀率随γ-PGA单体比例的增加而升高,在NIPAM∶γ-PGA(质量比)=5∶1时,平衡溶胀率为40.3 g/g;在40℃下持续脱水6h,脱水率可达80％以上.将所制备的二元水凝胶作为正渗透汲取剂时,0.5h内的水通量为1.1～1.4 L/(m2·h),且重复利用效果较好.随着原料液NaCl浓度不断升高,水通量逐渐降低,当原料液NaC1浓度为2 g/L时,0.5h内水通量约为1.0 L/(m2·h).