EDTA改性P（AA-AMPS）/SA耐水解水凝胶的制备及对Cu2 、Cr3 吸附性能测定

Preparation of EDTA modified P (AA-AMPS)/SA hydrolysis-resistant hydrogels and the adsorption properties of Cu2 and Cr3

摘要:

以海藻酸钠（SA）为原料，丙烯酸（AA）、2-丙烯酰胺-2-甲基丙磺酸（AMPS）为单体，四烯丙基溴化铵（TAAB）为交联剂，EDTA二钠为添加剂，制备了一种改性P（AA-AMPS）/SA耐水解多孔水凝胶，对制备的水凝胶吸水性能及对Cu2 、Cr3 吸附性能进行了测定，探究了凝胶吸附等温线及吸附动力学，并利用FTIR、SEM、AFM对凝胶表面形态进行分析。实验结果表明，加入SA可明显提高水凝胶的溶胀速率，制备的改性水凝胶具有优异的耐水解性能，125℃下在蒸馏水中的吸水倍率可达350.4g/g。加入改性剂EDTA二钠，增大溶液pH值均有利于提高水凝胶对Cu2 、Cr3 的吸附性能，最大吸附量分别为539.2、286.7mg/g。水凝胶对Cu2 的吸附机理符合Langmuir吸附等温式，对Cr3 的吸附更符合Freundlich模型。吸附均为自发放热过程，吸附温度升高，达吸附平衡时间缩短，吸附量略有降低。

Abstract:

A kind of hydrolysis resistant porous hydrogel was prepared using sodium alginate (SA) as raw material, acrylic acid (AA)、2-acrylamido-2-methylpropane sulfonic acid (AMPS) as the monomers, tetraallylammonium bromide (TAAB) as crosslinker, EDTA as modifying agent. The water absorbency and adsorption performance of Cu2 、Cr3 were determined and the gel adsorption isotherm and adsorption kinetics were studied. The surface morphology of hydrogels were analyzed by FTIR、SEM、AFM. According to the results, the swelling rate of hydrogel could be significantly improved with the addition of SA, and the modified hydrogel had excellent hydrolysis resistance. The water absorption ratio in distilled water at 125℃ could reach 350.4 g/g.Adding the modifier EDTA disodium and increasing the pH value of the solution were conducive to improving the adsorption performance of the hydrogel on Cu2 and Cr3 , with the maximum adsorption capacity of 539.2 and 286.7 mg/g respectively.The adsorption mechanism of the hydrogel on Cu2 was in line with the Langmuir adsorption isotherm, while the adsorption of Cr3 was in line with the Freundlich model. The adsorption process was spontaneous exothermic. When the adsorption temperature increased, the adsorption equilibrium time decreased, and the adsorption capacity decreased slightly.