Hydrogel composite based on thermal modified carboxymethyl cellulose and nanozeolite

The present study aimed at producing bio-based superabsorbents with minimum use of polymeric materials and crosslinkers. Thus, nano-zeolites were used as high potential minerals for development of an environmentally friendly, durable, accessible, absorbent and cost-effective organic nano-hybrid composite in low amounts of crosslinkers and polymeric materials as an alternative for synthetic hydrogels. In the experimental stages, the modified heat-treated carboxymethyl cellulose (CMC) powder developed in the previous research as well as the unmodified powder (control sample) were individually dispersed in distilled water and then a 3:1 ratio of nano-zeolite and hydroxyethyl cellulose together with citric acid as a crosslinker were added. The solution was then cast in a petri dish. The prepared samples were then measured and evaluated using centrifuge, absorption under load, deformation and swelling time tests. The results showed that the combination of nano-zeolite with heat-treated CMC increased absorption capacity both free and under load, fine toughness and higher absorption rate of hydrogel. In addition, thermal modification successfully decreased the need for crosslinking so that nanocomposite hydrogels had considerable mechanical hardness. Besides, this combination of hydrogels demonstrated the highest amount of absorption in centrifuge and AUL tests with the most desirable results in the swelling time. Also, the addition of nano-zeolite increased the water absorption in samples in the absence of hydroxyethyl cellulose, however, in presence of hydroxyethyl cellulose, two properties of absorption rate and toughness showed higher values.