聚(N-异丙基丙烯酰胺)/黏土纳米复合水凝胶的制备及结构性能表征

Preparation and Characterization of Poly (N-isopropylacrylamide)/Clay Nanocomposite Hydrogel

以无机黏土作为交联剂制备了新型聚(N-异丙基丙烯酰胺)/黏土(PNIPA/Clay)纳米复合水凝胶,对其结构、形态、溶胀行为和力学性能等进行了研究.实验表明,无机黏土被剥离成纳米尺寸的片层,均匀分散在凝胶网络中,起交联剂的作用.PNIPA/Clay水凝胶的体积相转变温度(VPTT)在35℃左右,与交联方式和交联剂的用量无关.随着黏土含量的增加,水凝胶的溶胀速率和溶胀度降低.PNIPA/Clay水凝胶具有较高强度和良好的韧性,断裂伸长率可达1000%以上,且卸去载荷后其伸长几乎可以瞬时完全回复.

A new kind of poly （N- isopropylacrylamide）/ Clay （PNIPA/Clay） nanocomposite hydrogel was prepared using inorganic clay as a crosslinker. The structure and morphology, swelling behaviors and mechanical properties of these hydrogels were investigated. The results show that the inorganic clay was substantially exfoliated to the nano-dimension platelets which dispersed homogeneously in the hydrogel and acted as a multifunctional crosslinker. The PNIPA/Clay hydrogel exhibited a volume phase transition temperature around 35 ℃, independent of the type and content of the crosslinker. The swelling ratios and swelling rates of the PNIPA/Clay hydrogels decreased with increasing the clay content. Moreover, this novel nanocomposite hydrogel exhibited extraordinary mechanical toughness and tensile strengths. It could be elongated to more than 1000% and the long elongation could be recovered almost completely and instantaneously when the stress was released.