具有半互穿网络结构的电场响应性水凝胶正渗透脱盐性能

Synthesis of Electric-Responsive Hydrogel with Semi-Interpenetrating Network and Its Performance in Forward Osmosis Desalination

为了提高凝胶驱动正渗透(FO)脱盐过程的性能,利用互穿聚合物网络技术制备一种具有半互穿网络的电场响应性水凝胶聚(2-丙烯酰胺基-2-甲基丙磺酸-co-丙烯酰胺)/羧甲基纤维素钠(P(AMPS-AM)/CMC)用作新型汲取剂。使用红外光谱和扫描电镜表征其化学结构和形貌,考察其在水中的溶胀性及在电场刺激下的响应性,并探究其在FO脱盐过程中的性能。结果表明,P(AMPS-AM)/CMC呈现孔洞结构;溶胀过程符合二级溶胀动力学模型且理论平衡溶胀度为181.5 g/g;在15 V电压刺激下具有明显的消溶胀性。在FO试验中,与未经CMC改性的P(AMPS-AM)相比,P(AMPS-AM)/CMC产生类似的初始水通量但其在15 V电压刺激下的水回收率是前者的1.9倍,且连续3次再生后水回收率仅下降7.97%。此外,与已报道的水凝胶汲取剂相比,P(AMPS-AM)/CMC不仅可获得较高的水通量而且在水回收率上具有一定的优势。

In order to improve the performance of hydrogel-driven forward osmosis(FO) desalination,electricresponsive hydrogel poly(2-acrylamido-2-methyl-1-propanesulfonic acid-co-acrylamide)/sodium carboxymethyl cellulose(P(AMPS-AM)/CMC) with semi-interpenetrating network was prepared by the interpenetrating polymer network(IPN) technology and used as novel draw agent.The chemical structure and morphology of the hydrogel were investigated by Fourier transform infrared spectroscopy(FT-IR) and scanning electron microscope(SEM).The swelling behavior and electro-responsive nature of the hydrogel were investigated.The performance of the hydrogel in the FO desalination process was also explored.Results show that the hydrogel exhibits a porous structure,and the swelling behavior follows the second-order swelling kinetic model with a theoretical equilibrium swelling capacity of 181.5 g/g.The hydrogel shows a significant deswelling behavior under the electric stimuli of 15 V.In FO test,in comparison with P(AMPS-AM) without CMC modification,the P(AMPS-AM)/CMC achieves a similar initial water flux but its water recovery rate under the electric stimuli of 15 V is 1.9 times higher than that of the former,and the water recovery rate is only reduced by 7.97% after three cycles of continuous regeneration.Besides,the P(AMPS-AM)/CMC can not only obtain a higher water flux but also have a certain advantage in water recovery compared with the reported hydrogel draw agents.