Abstract: Biocompatible organic-inorganic nanocomposite hydrogels were prepared by in-situ free radical polymerization with N-vinylpyrrolidone(NVP) and clay as monomer and crosslinker. The properties and microstructures of hydrogels were studied through viscosity, transmittance, XRD and mechanical measurement. The viscosity results show that NVP monomer attaches around the clay particles and effectively preventes the solution from gelation. The results of transparency evolvement during the polymerization, swelling properties and tensile mechanical properties of the hydrogels were analyzed. The resuls show that the reactive mechanism of PVP/clay polymerization is different from that of PAM/clay system. The short chains between clay particles result that the swelling ratio and elongation at break significantly lower than that of PAM/clay system, whereas the modulus and mechanical strength increase greatly. XRD results show that clay particles arrange orderly and the spacing between particles decrease with increasing the clay content in xerogels. Clay particles exfoliate and disperse homogenously in hydrogels. Morphology of cartilage cells cultured on the surface of hydrogels shows preliminary that the hydrogel don′t have obvious negative affection on the cell growth.

Key words: Hydrogel, Clay, Polyvinylpyrrolidone, Biocompatibility, Nanocomposite material