Selective Recovery of Metal Ion by Using Hydrogel With Different Inner pH
Selective Recovery of Metal Ion by Using Hydrogel With Different Inner pH
复制标题
不同内pH水凝胶选择性回收金属离子
DOI：
10.1002/masy.201800163
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发表时间：
2019
影响因子：
--
通讯作者：
Nakai Satoshi
中科院分区：
文献类型：
--
作者：
Gotoh Takehiko;Sano Masahide;Nakai Satoshi
研究了以水凝胶为反应分离介质的金属离子回收新方法。制备了基于甲基丙烯酸2-（二甲氨基）乙酯、N-3-（二甲氨基）丙基丙烯酰胺和N，N-二甲基丙烯酰胺共聚物的水凝胶。二甘醇二甲基丙烯酸酯用作交联剂。由于叔氨基被水质子化，产生的氢氧离子保留在水凝胶中，因此含有叔氨基的水凝胶在水中膨胀时，其内部呈现高pH值。当将水凝胶浸入金属离子水溶液中时，金属离子扩散到水凝胶中以在水凝胶中产生金属氢氧化物。水凝胶中的金属氢氧化物容易从溶液中分离。水凝胶中金属的回收量随着溶液中金属离子的浓度而增加。水凝胶的pH值可以通过制备时单体的浓度来控制。通过控制水凝胶的pH值实现从混合金属离子溶液中选择性地回收某种金属离子。这里得到的结果表明，新的金属离子回收方法取代凝聚和/或吸附方法的可能性。
New metal ion recovery method with hydrogels as a reaction and separation media has been investigated. Hydrogels based on copolymers of 2‐(Dimethylamino)ethyl methacrylate,N‐3‐(Dimethylamino)propyl acrylamide, andN,N‐dimethylacrylamide are prepared. Diethyleneglycol dimethacrylate is used as a crosslinker. The hydrogel with tertiary amino group exhibited high pH value inside of them when they swelled in water because the tertiary amino group was protonated by water and produced hydroxide ion was retained in the hydrogel. When the hydrogel is immersed in the metal ion aqueous solution, the metal ion diffused into the hydrogels to produce metal hydroxide in the hydrogel. The metal hydroxide within hydrogel is easily separated from the solution. The recovery amount of the metal in the hydrogel is increased with the concentration of the metal ions in the solution. The pH value of the hydrogel could be controlled by the concentration monomers at the preparation. The selective recovery of a certain metal ion from the mixed metal ion solution is attained by controlling the pH value of the hydrogel. The results obtained here suggest the possibilities of the novel metal ion recovery method replacing the coagulation and/or adsorption methods.