Microstructure and Swelling Behaviour of Poly (Acrylamide-co-Acrylic Acid) based Nanocomposite Superabsorbent Hydrogels

In this paper, microstructure and swelling behavior of five superabsorbent hydrogels have been investigated. These samples were prepared by dispersing watermelon shell powder (WSP) and cucumber shell powder (CSP), mixture bentonite and WSP, mixture bentonite and CSP, zeolite (Z) bentonite (B), into poly(acrylamide-co-acrylic acid) (P) backbone in an aqueous medium. The nanocomposites have been synthesized through chemical cross-linking by polymerization technique using N,N-methylenebis acrylamide as a cross-linker and potassium persulfate as an initiator in simple aqueous environmental conditions. The nanocomposite hydrogels named as P-WSP-CSP، P-WSP-B، P-CSP-B, P-Z, P-B, respectively. These superabsorbent nanocomposites were characterized by X-ray diffraction, Fourier transforms infrared and field emission-scanning electron microscope measurements. The water absorption and desorption of the superabsorbent nanocomposites have also been studied. Our findings show that very high water absorption and lower drying rate of P-CSP-B are attributed to higher porous surfaces observed in FE-SEM images. The results show the superabsorbent hydrogels based on CSP represent very high water absorbency capacity and water retention ability that make them suitable for technology applications.