Preparation of polymer-carbon nanotubes composite hydrogel and its application as forward osmosis draw agent

In this study, we functionalized multiwall carbon nanotube with polar groups including -COOH and -OH groups (F.MWCNT) and synthesized composite polymer hydrogel via dispersion in monomer solution and by using a simple poly (acrylic acid-co-maleic anhydride) (PAA-co-PMA) crosslinking reaction. Incorporation of the F.MWCNT phase into the PAA-co-PMA hydrogel network was verified using Fourier transformation infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) analysis. The physico-chemical properties of the composite polymer hydrogels were investigated and compered to pure hydrogel. In addition, the effect of F.MWCNT incorporation on polymer hydrogels performance as forward osmosis draw agent was studied. The results indicated that the addition of F.MWCNT (1.2 wt%) within the polymer hydrogel enhanced the water adsorbing capacity of the composite hydrogel as expected. Furthermore, the composite hydrogel (1.2 wt% of incorporated F.MWCNT) displayed a much higher water flux compared with the pure PAA-co-PMA polymer hydrogel during the FO test. The facile and efficient preparation of the F.MWCNT incorporated PAA-co-PMA composite hydrogel means it will have potential applications as a novel draw agent.