Investigation into the Liquid Absorption Performance of MSNs@CTS-g-P(AA-co-AM) Absorbent Resin

Mesoporous silica nanoparticles (MSNs) were synthesized by alkaline catalysis, hydrolysis condensation reactions, and template removal of tetraethoxysilane (TEOS). MSNs were used as fillers and carriers to immobilize polymer components and form three-dimensional grids within the material, thus imparting the absorbent resin with the required mechanical strength. Carboxymethyl chitosan (CTS) was used as the substrate for synthesizing composite water absorbent resin. A composite superabsorbent resin was prepared by grafting copolymerization with acrylamide (AM) and acrylic acid (AA) and it was referred to as MSNs@CTS-g-P(AA-co-AM). The liquid absorption and adsorption performances of heavy metal ions were examined in different environments. The results showed that the water absorption rate of MSNs@CTS-g-P(AA-co-AM) reached 740 g/g at water absorption equilibrium. Compared with known organic/inorganic composite water absorbing resins, the composite resin involving MSNs had good water retention performance, which was evident from the water retention rate reaching a maximum of 91.8% when the resin was dried at 80°C for 6 h. This was attributed to the composite resin forming a stable three-dimensional network structure due to the MSNs, strong salt resistance, and better adsorption performance.