聚乙烯吡咯烷酮/黏土纳米复合水凝胶的制备及表征

Preparation and Characterization of PVP/Clay Nanocomposite Hydrogels

通过原位聚合法,以N-乙烯基吡咯烷酮(NVP)和黏土为原料制备了生物相容性有机-无机纳米复合水凝胶,通过黏度、透明度、XRD及力学性能等研究了水凝胶体系的性质和微观结构.结果显示,单体NVP通过氢键作用吸附于黏土粒子周围,从而有效阻止黏土颗粒的凝胶化;通过对聚合过程透明度的变化、凝胶吸水性能以及拉伸力学性能分析发现,其反应机理与丙烯酰胺类体系不同.黏土颗粒间网链较短,导致吸水率和断裂伸长率明显低于聚丙烯酰胺/黏土体系,但模量和拉伸及压缩强度明显增加;XRD结果显示,干凝胶中黏土颗粒呈有序排列,随着黏土含量增加,黏土粒子间距变小,而在含水复合凝胶中,黏土颗粒以剥离态均匀分散;对于凝胶表面的细胞形态观察初步检验了此类纳米复合凝胶的细胞相容性,未观察到显著不良影响.

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.