【作者】 王世珍；

【导师】 彭红；

【作者基本信息】 华中科技大学 ， 有机化学， 2009， 硕士

【摘要】 重金属对人体的危害十分明显,当人体内重金属累积到一定程度将会产生各种病变。高效去除环境中的重金属的新材料一直是国内外研究的热点。磁性纳米Fe₃O₄比表面积大、磁感应强、表面易引入多种螯合重金属离子的化学官能团,因此可以改性成为一种理想的吸附材料,使其具有高的吸附重金属离子特性的同时,还便于在外界磁场中进行固液分离,并重复使用。本文研究了强磁性Fe₃O₄微球（MNP）以及核壳式磁性二氧化硅微球（MS）的合成,并采用溶液聚合法将含有螯合官能基IDA的乙烯基单体（GMA-IDA）接枝聚合在MS表面,得到新型磁性硅球吸附剂PMS,同时对PMS和MS吸附重金属离子的特性进行了比较,主要结果如下:1.采用溶剂热还原法制备了高磁性Fe₃O₄微球,并以其为内核,TEOS为硅源,采用溶胶-凝胶法合成了磁性硅球（MS）。在此基础上将GMA-IDA单体接枝聚合至MS表面得到PMS,并用IR, SEM, VSM及TG等对MS及PMS进行了表征。结果显示MS为单分散球形,饱和磁化率为63.5 emu/g,PMS的聚合物接枝率为46.5%,饱和磁化率为28.4 emu/g ,具有超顺磁性。2.研究了MS和PMS对重金属铅离子的吸附作用,结果表明:PMS及MS对重金属的吸附去除效率随pH值的增大而增大,PMS在酸性介质中对Pb²⁺的吸附去除性能大大优于MS,在pH =3或小于3时MS对Pb²⁺基本没有吸附,而PMS在pH=3时对Pb²⁺吸附去除率达到80%以上。MS和PMS对铅离子的吸附均符合Langmuir等温吸附,MS和PMS的最大吸附量q*分别为8.94 mg/g与54.35 mg/g。PMS对Pb²⁺的吸附平衡在5 min内达到,而MS则需要5 h以上。在同样条件下,PMS的重复使用性能也优于MS。更多还原

【Abstract】 Lots of research have focused on development of new magnetic absorbents for removal of heavy metals from enviroment due to its fast and easy separation from solution using an external magnetic field in recent years In this paper, mono-dispersed magnetic core-shell silic microsphere （MS） was prepared, and then abundant chelator groups （IDA） were grafted on MS by a modified solvent polymerization of GMA-IDA monomer. A novel magnetic absorbent named PMS full of chelators was prepared and characterized, and its application in removal of heavy metal ions was further investigated:1. MS was prepared in sol-gel method using high magnetic Fe₃O₄ microsphere synthesized by solvent reduction method as core and SiO₂ as shell .and then PMS was prepared in graft polymerization of GMA-IDA monomer with MS. The structures and properties of MS and PMS were characterized by IR,SEM,VSM and TG.. The results showed that MS was mono-dispersed microsphere, and the polymer-grafted ratio of PMS was 46.5%. Both MS and PMS were super-paramagnetism with saturation magnetization of 63.5 and 28.4 emu/g respectively at room temperature.2. The adsorption properties of PMS and MS to heavy metals especially for Pb²⁺ were investigated. The results indicated that PMS was much better than MS in absorption of Pb²⁺. MS had nearly no adsorption ability when the pH values of the solutions were less than 3, however the removal ratio of PMS was above 80%. The absorption equilibrium for PMS absorption of Pb²⁺achieved was within 5 min, while for MS was more than 5h. Both absorption pattern of Pb²⁺onto MS and PMS highly fitted Langmuir adsorption isotherm equation. The maxium adsorption capacity of MS and PMS for Pb²⁺ was 8.94 and 54.35 mg/g, respectively.更多还原