壳聚糖/DNS杂化材料的合成及吸附重金属Cd^(2+)的性能研究

Synthesis of Chitosan/DNS Hybrid Materials and Adsorption Capability on Heavy Metal Cd^(2+)

可分散的纳米SiO2(简称DNS)与丁二酸酐反应,合成的羧基化的DNS与壳聚糖经过脱水生成酰胺,制备了壳聚糖/DNS杂化材料。对杂化材料进行表征,扫描及投射电镜分析结果显示,杂化材料呈现近似球状,形成了一些孔和缝隙分布于微粒的表面及内部,此种结构组成可能有利于对Cd2+的吸附;FT-IR表明壳聚糖与DNS通过丁二酸酐桥连为一个高分子聚合物;热重分析结果可看出杂化材料的热性能有较大提高。研究了壳聚糖和杂化材料微粒吸附Cd2+时pH值、时间、用量对吸附的影响,结果表明其最佳吸附条件为:pH=5,吸附时间为2 h,吸附剂的加入量为0.1g。杂化材料比壳聚糖具有更强的吸附Cd2+的能力,其吸附量可达3.7898 mmol.-g1,吸附率达79.12%。

Carboxyl DNS was prepared by the reaction between carboxylic anhydride and the dispersible nano-SiO2（DNS）.Then chitosan/DNS hybrid materials was synthesized by mixed carboxyl DNS particles and chitosan through dehydration to acyl amine.The hybrid materials were characterized.From SEM and TEM,hybrid material presented globularity and formed some hole and gap,which distributed to surface and interior.The structure might be in favor of absorption on Cd2＋;FI-TR results showed chitosan and DNS was synthesized macromolecule polymer through the bridge of carboxylic anhydride.The data of TG indicated that the thermal properties of the hybrid materials was improved.By using the experiment,three factors such as pH,adsorption time and dosage of composite adsorption on Cd2＋ were investigated.The optimal adsorption conditions were the pH value 5,the adsorption time 2 h,and the dosage of adsorption 0.1 g.Hybrid materials had better adsorption ability on Cd2＋ than chitosan,which adsorption quantity was 3.7898 mmol·g-1,adsorption ratio was 79.12%.