基于壳聚糖的磁性吸附水凝胶微球的制备与表征

Preparation and Characterization of Magnetic Adsorption Hydrogel Based on Chitosan

通过原位共沉淀法制备了含有Fe_(3)O_(4)纳米粒子的埃洛石纳米管(HNTs)/壳聚糖(CS)磁性复合水凝胶微球,并对产物的形貌和结构进行了表征。引入纳米Fe_(3)O_(4)后,Fe_(3)O_(4)@HNTs/CS微球成型快且球形度好,在溶液中可通过磁场快速分离。扫描电子显微镜表明Fe_(3)O_(4)@HNTs/CS微球具有三维多孔结构。以亚甲基蓝(MB)、刚果红(CR)为模型染料,研究了Fe_(3)O_(4)@HNTs/CS对带有不同电荷的离子型染料的吸附性能。结果表明Fe_(3)O_(4)@HNTs/CS可吸附MB、CR染料分子。Fe_(3)O_(4)@HNTs/CS对CR染料的脱色率可达98%;当HNTs含量为CS质量的40%时,MB脱色率是不含HNTs微球的12倍。研究结果表明:吸附机理主要基于微球和染料分子的静电相互作用;Fe_(3)O_(4)@HNTs/CS内部电荷分布独特,能吸附阴离子染料和阳离子染料,磁性则使其更易分离回收。

Halloysite nanotubes(HNTs)/chitosan(CS)magnetic composite hydrogel microspheres containing Fe_(3)O_(4) nanopaticles were prepared by co-precipitation method and the morphology and structure of the products were characterized.The Fe_(3)O_(4)@HNTs/CS microspheres were formed quickly and had good sphericity when Fe_(3)O_(4) nanopaticles were introduced in this system by co-precipitation method,and could be separated quickly from solution by magnetic field.The scanning electron microscope images show that Fe_(3)O_(4)@HNTs/CS microspheres have three-dimensional porous structures.The adsorption performance of Fe_(3)O_(4)@HNTs/CS on ionic dyes with different charges was investigated by using methylene blue(MB)and Congo red(CR)as model dyes.The results show that Fe_(3)O_(4)@HNTs/CS can adsorb MB and CR molecules through electrostatic interaction.Its decolorization rate of CR dye can reach 98%.When the mass of HNTs is 40%of CS,its decolorization rate of MB is 12 times that of the microspheres without HNTs.The results show that the adsorption mechanism is mainly based on the electrostatic interaction between microspheres and dye molecules.With unique charge distribution,the Fe_(3)O_(4)@HNTs/CS can adsorb both anionic and cationic dyes.The magnetism makes it be seperated and recovered easily.