磁性半纤维素接枝聚丙烯酰胺水凝胶的制备及其性能研究

Preparation and properties of magnetic hemicellulose grafted polyacrylamide hydrogels

以半纤维素和丙烯酰胺为原料,利用自由基聚合法制备了多孔半纤维素接枝聚丙烯酰胺水凝胶,并且通过原位共沉淀法在凝胶上负载Fe3O4粒子,从而得到了磁性水凝胶。分别用FT-IR和SEM对水凝胶的结构和表面形态进行分析;考察了多孔半纤维素接枝聚丙烯酰胺凝胶的溶胀性能并对溶胀动力学进行了数学拟合。研究表明多孔半纤维素接枝聚丙烯酰胺水凝胶的平衡溶胀率随着交联剂量的增大而减小,随着半纤维素/丙烯酰胺比例的增大而增大,随着pH的增大而增大,水凝胶在pH=5.6的溶胀符合Schott溶胀动力学模型。振动样品磁强计(VSM)磁性能测试表明,磁性半纤维素接枝聚丙烯酰胺凝胶具有超顺磁性特征,其饱和磁化强度为10 emu/g。

Porous hemicellulose grafted polyacrylamide hydrogels are synthesized via free radical polymerization.Then,the magnetic hydrogels are obtained by introducing Fe3O4 nanoparticles into the porous hydrogel through in situ chemical co-precipitation method.Fourier transform infrared spectroscopy（FT-IR） and scanning electron microscopy（SEM） are used to study the structure and morphology of the as-prepared hydrogels.The swelling properties of porous hemicellulose grafted polyacrylamide hydrogels are investigated and the swelling kinetics data are fitted.The results show that the swelling ratio of the prepared hydrogels at higher crosslinker amounts has a lower swelling ratio.The swelling ratio increases when hemicellulose/acrylamide rates increase.Moreover,the swelling ratio increases with the increase in pH value.The swelling kinetics can be described by the Schott second-order dynamic equation at pH 5.6.Vibrating Sample Magnetometer（VSM） analysis shows that the magnetic hemicellulose grafted polyacrylamide hydrogels have superparamagnetic characteristics,and its saturation magnetization is 10 emu/g.