摘要
首先采用氯甲基化试剂1,4-二氯甲氧基丁烷对水杨羟肟酸(SHA)实施氯甲基化反应,制得氯甲基化水杨羟肟酸(CMSHA);然后以聚甲基丙烯酸羟乙酯(PHEMA)改性的硅胶微粒PHEMA/SiO2为载体,使其表面的醇羟基与CMSHA上的氯甲基基团发生亲核取代反应,制得水杨羟肟酸功能化的复合螯合吸附材料(SHA-PHEMA/SiO2)。考察了取代反应的主要影响因素;并研究了SHA-PHEMA/SiO2对重金属离子的螯合性能。结果表明,CMSHA与PHEMA/SiO2之间的取代反应遵循单分子取代反应(SNl)的机理;较高温度下,强极性溶剂有利于反应的进行。SHA-PHEMA/SiO2对不同重金属离子表现出不同的螯合吸附能力,摩尔吸附容量的顺序为Cu2+>Zn2+>Cd2+>Pb2+;SHA-PHEMA/SiO2对Cu2+离子的吸附动力学符合伪二级速率方程;其吸附行为同时遵循Freundlich和Langmuir模式。
5-Chloromethyl-salicylhydroxamic acid(CMSHA) was first prepared using 1,4-bichloromethoxy-butane(BCMB) as chloromethylation reagent. Using the grafted particles polyhydroethyl methacrylate(PHEMA) /SiO2 as carriers,the nucleophilic substitution reaction between the hydroxyl group of the grafted PHEMA and the chloromethyl group of CMSHA was carried out,resulting in the salicyl-hydroxamic acid(SHA)-functionalized composite particles SHA-PHEMA/SiO2. The effects of main factors on the nucleophilic substitution reaction were investigated. The adsorption properties of SHA-PHEMA/SiO2 for heavy metal ions were researched through batch method. Experimental results show that SHA can be bonded onto the grafted particles PHEMA/SiO2 successfully through the nucleophilic substitution reaction. The reaction has a reaction mechanism of SN1,and the solvent with strong polarity and the higher temperature are helpful to the reaction. The composite chelating particles SHA-PHEMA/SiO2 represent strong chelation adsorption ability towards heavy metal ions. The adsorption of SHA-PHEMA/SiO2 for heavy metal ions is selective,and the mole adsorption capacity is in the order of Cu2 +> Zn2 +> Cd2 +> Pb2 +. Moreover,the adsorption process conforms to the pseudo-second-order model better,and the adsorption isotherm data fits well into the Freundlich and Langmuir model at the same time.
出处
《高分子材料科学与工程》
EI
CAS
CSCD
北大核心
2015年第2期139-144,共6页
Polymer Materials Science & Engineering
基金
国家自然科学基金资助项目(21307116)
山西省自然科学基金资助项目(2014011017-5)
关键词
水杨羟肟酸
聚甲基丙烯酸羟乙酯
硅胶
亲核取代反应
螯合吸附
salicylhydroxamic acid
polyhydroethyl methacrylate
silica gel
nucleophilic substitution reaction
chelation adsorption
