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将聚胺大分子聚乙烯亚胺(PEI)接枝于微米级硅胶微粒表面,制得接枝微粒PEI/SiO2,然后使氯乙酸与PEI大分子中的伯、仲胺基发生亲核取代反应,形成亚氨乙酸(IAA)型螯合吸附材料IAA-PEI/SiO2.研究了IAA-PEI/SiO2对重金属离子的螯合吸附行为和吸附机理.结果表明,由于亚氨乙酸基团与重金属离子之间的静电作用与配位螯合作用,IAA-PEI/SiO2对重金属离子可产生强的螯合吸附作用,对Ni2+的吸附容量可达1.4mmol/g;吸附过程为放热过程;在可抑制重金属离子水解的pH范围内,pH值越高,吸附能力越强;IAA-PEI/SiO2对重金属离子的吸附容量顺序为Ni2+>Pb2+>Cu2+>Cd2+.
Polyethyleneimine polyethyleneimine (PEI) was grafted onto the surface of micron-sized silica particles to prepare PEI / SiO2 grafted microparticles, and then nucleophilic substitution of chloroacetic acid with primary and secondary amine groups in PEI macromolecules (IAA) -type chelating sorbent material IAA-PEI / SiO2 was synthesized.The chelating adsorption behavior and adsorption mechanism of IAA-PEI / SiO2 on heavy metal ions were studied.The results showed that due to the interaction between the imine group and heavy metal ions The electrostatic interaction and coordination chelation between IAA-PEI / SiO2 and heavy metal ions can produce strong chelating adsorption, the adsorption capacity of Ni2 + can reach 1.4mmol / g; the adsorption process is exothermic; In the pH range of inhibiting the hydrolysis of heavy metal ions, the higher the pH value, the stronger the adsorption capacity; the order of adsorption capacity of heavy metal ions for IAA-PEI / SiO2 is Ni2 +> Pb2 +> Cu2 +> Cd2 +.