Construction of highly stretchable silica/polyacrylamide nanocomposite hydrogels through hydrogen bond strategy

Abstract

Highly stretchable silica/polyacrylamide (PAM) nanocomposite hydrogels were synthesized via in situ free radical polymerization in the presence of silica nanoparticles. The effect of particle size and content of silica nanoparticles on tensile properties and swelling behavior were investigated. The hydrogen bond between PAM molecule and silica nanoparticles was evidenced by Fourier transform infrared spectroscopy and the swelling behavior of hydrogels. The tensile strength of silica/PAM hydrogels is 2 times that of PAM gels, and the elongation at break is nearly 2800% when the silica particle size is 15 nm and the content is 10 wt%. This excellent stretching property of hydrogels was ascribed to the presence of hydrogen bond between PAM molecule and silica nanoparticles.