硅胶表面上聚酰胺-胺的合成及其对Fe(Ⅲ)的吸附

Synthesis of Dendrimer-like Polyamidoamine on Surface of Silica Gel and Its Adsorption for Fe(Ⅲ) from Aqueous Solution

用硅烷偶联剂对硅胶表面进行氨基功能化,利用氨基与丙烯酸甲酯发生的Michael加成反应和乙二胺与酯进行的交换反应在硅胶表面合成了聚酰胺-胺树状大分子(PAMAM-SG)。利用红外光谱对PAMAM-SG的结构进行了表征。研究了溶液pH值、浓度和温度对PAMAM-SG吸附Fe(Ⅲ)的影响。结果表明,溶液的最佳pH值为3.0～6.0;吸附速率随时间的增加而逐渐降低,随温度的升高显著升高;在40℃时具有较好的吸附性能,吸附3h后均达到了完全吸附,吸附量达55.85mg/g。吸附容量随浓度的增大而增加直至平衡。各代PAMAM-SG的吸附量依次为2.0G>1.0G>1.5G>0.5G>0G。

Amino functional silica gel was synthesized by reacting silane coupling agent with silica gel. Then dendrimer-like polyamidoamine on the silica gel surface（PAMAM-SG） was prepared using Micheal addition of the amino and methyl acrylate, and ester-exchange of ethylene diamine and the ester group. FTIR was used to characterize the structure of PAMAM-SG. The effects of solution pH, concentration and temperature on the adsorption capacity of PAMAM-SG for Fe （ Ⅲ ） were studied. It was found that the optimum pH range for the adsorption was 3.0 - 6. 0. The adsorption rate decreased with the increase of time, but increased remarkably with temperature. The adsorption was saturated in 3 h at 40℃, and the adsorption capacity reached 55.85 mg/g. The adsorption capacity increased with the increase of concentration until it reached balance. The adsorption capacities for each generation of PAMAM-SG were in the order of 2.0 G 〉 1.0 G 〉 1.5 G 〉 0.5 G〉0 G.