The present invention attaches a molecule that contains a hydroxyl group (OH) attached to a carbon chain which is attached to a coordinating atom or atoms, the acidity of which is greater than that of silica (i.e., pKA <10). The condensation is achieved by mixing silica gel, appropriate amount of ligand, and a drop of conc. sulfuric acid in toluene in a flask attached to a Dean-Stark tube. Heating of the mixture is continued until the amount of water, obtained by azeotropic distillation and condensation, reaches a constant value. Toluene is filtered off, and recycled. The supported ligand is dried under reduced pressure to remove residual toluene. The composite (ligand attached to silica) can then be used by batch or column method to remove heavy metal ions from aqueous solution.
该发明涉及将一个含有羟基(OH)连接到碳链上的分子附着到一个酸度大于
硅的协同原子或原子上(即pKA <10)。通过在连接到Dean-Stark管的烧瓶中混合硅胶、适量的配体和一滴浓硫酸的甲苯缩合实现。继续加热混合物,直到通过共沸蒸馏和冷凝得到的水量达到恒定值。甲苯被过滤掉并回收利用。支持的配体在减压下干燥,以去除残留的甲苯。然后可以通过批处理或柱法使用复合物(配体附着在硅上)从水溶液中去除重
金属离子。