表面接枝聚乙烯亚胺硅胶微粒对铬酸根的吸附特性  

ADSORPTION CHARACTER OF POLYETHYLENEIMINE-GRAFTED SILICA GEL PARTICLES FOR CHROMATE

作　　者：李延斌[1] 高保娇[1] 安富强[1] 

机构地区：[1]中北大学化学工程系,太原030051

出　　处：《环境化学》2008年第4期463-467,共5页Environmental Chemistry

摘　　要：通过γ-氯丙基三甲氧基硅烷的偶联,将聚乙烯亚胺(PEI)偶合接枝在硅胶微粒表面,制得对铬酸根有强吸附作用的复合型吸附材料PEI/SiO2,并对其化学结构进行了表征;采用静态法研究了PEI/SiO2对铬酸根的吸附性能及脱附性能.结果表明,凭借强烈的静电相互作用,硅胶表面的聚胺大分子PEI对铬酸根阴离子可产生很强的吸附作用,饱和吸附量可达0.07g·g-1(pH=6);等温吸附满足Langmuir吸附等温方程;介质的pH值对吸附作用有很大的影响,pH值愈小,吸附容量愈大;升高温度吸附量减小,表明静电相互作用导致的吸附作用为一放热过程.以NaOH水溶液为洗脱液,吸附在PEI/SiO2表面的铬酸根阴离子很容易被解吸脱附,便于PEI/SiO2的重复使用.Polyethyleneimine was grafted onto the surfaces of silica gel particles via the coupling action of γ-chloropropyl trimethoxy silane, and the composite material PEI/SiO2 with strong adsorption ability for chromate was prepared. The infrared spectrum of PEI/SiO2 was determined and its chemical structure was characterized. The adsorption property of PEI/SiO2 for chromate was studied with static method, and the effects of various factors on the adsorption property were examined. The elution behaviour of chromate from PEI/SiO2 also was tested. The experimental results show that the macromolecular chains of PEI on the surface of PEI/SiO2 have very strong adsorption ability for chromate by right of intense electrostatic interaction. As pH 6, the saturated adsorption amount can reach 0. 07 g ·g^-1. The isothermal adsorption is suited to Langmuir equation. The pH value of the medium has a great effect on the adsorption capacity. The lower the pH value, the greater adsorption capacity is. The temperature also has effect on the adsorption property of PEI/SiO2. The adsorption capacity is decreased with the increase of the temperature. This fact implies that the adsorption leaded to by electrostatic interaction is an exothermic process. The chromate adsorbed on the particles PEI/SiO2 is easy to be desorbed by the aqueous solution of NaOH as eluent, and it is convenient for the reuse of PEI/SiO2.

关 键 词：铬酸根 聚乙烯亚胺 硅胶 偶合接枝 静电相互作用 

分 类 号：X132[环境科学与工程—环境科学]