A novel surface modification method upon halloysite nanotubes: A desirable cross-linking agent to construct hydrogels

Abstract Halloysite nanotubes (Hal), a kind of attractive natural one-dimensional nanomaterials, possess hollow tubular nanostructures, high aspect ratio and difference structures between external and internal surfaces. Hal show promising applications in various fields. A novel modification method was facilely achieved in this study via the click reaction between -CNO and –OH groups to functionalize vinyl groups onto the nanotubes, in which the product was carefully characterized by solid-state nuclear magnetic resonance (SSNMR), fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Then the modified Hal were used as cross-linking agent in the free radical copolymerization together with acrylamide (AM) to afford a uniform chemical hydrogel. The obtained hydrogel Hal-IM-AM showed good rheological property, low cytotoxicity and a much better absorption ability upon phosphorus than original Hal.