Reinforcement Effects of Inorganic Nanoparticles for PAM‐ g ‐carboxymethyl Xylan Nanocomposite Hydrogels

A variety of 0D nanoparticles (MgO, ZnO, Al2O3, Fe2O3, SiO2, and TiO2) as nanofiller materials are introduced into polyacrylamide-g-carboxymethyl xylan (PAM-g-CMX) composite hydrogel. The effects of different shapes and different sizes of nanoparticles on the properties of hydrogels are investigated. The properties of nanocomposite hydrogels are analyzed by Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy (SEM), rheological analysis, swelling analysis, and mechanical test. Composite hydrogels with nanoparticles exhibit uniform pore structure and smaller pore size in SEM images, resulting in a reduced equilibrium swelling ratio. In addition, the results show that the hydroxyl groups on the surface of the nanoparticles forms hydrogen bonds with the amino groups and carboxyl groups in the PAM-g-CMX cross-linked network which improve the mechanical strength of nanocomposite hydrogels. The hydrogel with 20 nm MgO has the maximum compressive strength (550.9 kPa), tensile strength (28.6 kPa), and the longest elongation (813%) owing to the spherical shape and small size of MnO (20 nm). The hydrogels with nanoparticles maintain the originated 90% strength after 30 cycles of compressive test. The hydrogels with nanoparticles will offer new insights for xylan application.