摘要
为解决磁性纳米Fe_(3)O_(4)颗粒易腐蚀、团聚等问题,对其进行功能化修饰改进。在超声波辐照下以FeCl_(3)和FeSO_(4)为原料,氨水为沉淀剂,然后加入正硅酸乙酯(TEOS)和3-氨丙基三甲氧基硅烷(APTMS)进行功能化修饰,制备得到SiO_(2)包覆的氨基功能化纳米复合材料Fe_(3)O_(4)@SiO_(2)-APTMS,并采用TEM、FTIR、VSM、TGA、低温氮吸附、XRD等对其进行表征测试,证实了超声波辐照下制备的复合材料具有磁响应强度强、耐酸碱性强、分散性高、比表面积大、粒径小等特点,同时探究了纳米复合材料对Pb(Ⅱ)的吸附性能。结果表明:溶液初始pH值为5.86,吸附剂投加量为1.0~1.5 g·L^(−1)时Pb(Ⅱ)吸附效果较好;Langmuir模型适合模拟该等温吸附过程,吉布斯自由能变ΔG^(0)<0,吸附过程是一个自发过程;准二级动力学可以较好地描述Pb(Ⅱ)在复合材料上的吸附行为,准二级动力学常数k2=0.0401 g·mg^(−1)·min^(−1),达到吸附平衡时的吸附量qe=80.041 mg·g^(−1);推测得到吸附机制主要为离子交换和络合吸附。
In order to solve the indefects that magnetic nano-Fe_(3)O_(4)particles were corroded and agglomerated easily,functional modification was carried out.FeCl_(3)and FeSO_(4)were used as raw materials and ammonia as precipitant in the presence of ultrasonic irradiation,then functionalized by ethyl orthosilicate(TEOS)and 3-aminopropyltrimethoxysilane(APTMS)to prepare SiO_(2)-coated amino-functional nanocomposites Fe_(3)O_(4)@SiO_(2)-APTMS.The magnetic nanocomposites were characterized by TEM,FTIR,VSM,TGA,low temperature nitrogen adsorption and XRD,etc.The characterized results show that the magnetic nanocomposites prepared by ultrasonic strengthening method have the characteristics of strong magnetic response,strong acid and alkali resistance,high dispersion,large specific surface area and small particle size.Meanwhile,the adsorption effects of magnetic nanocomposites for Pb(Ⅱ)were investigated.The results show that the initial pH value of the solution and the dosage of adsorbent have greatest effects on the adsorption effect of Pb(Ⅱ)with the initial pH value of the solution 5.86 and the dosage of adsorbent 1.0-1.5 g·L^(−1).The Langmuir model is suitable for simulating the isothermal adsorption process,and the adsorption process is a spontaneous process when Gibbs free energy changeΔG^(0)<0.The adsorption behavior of Pb(Ⅱ)can be well described by quasi-second-order kinetics on the composites,Quasi-second-order kinetic constant k2=0.0401 g·mg^(−1)·min^(−1),equilibrium adsorption capacity qe=80.041 mg·g^(−1);it is speculated that the adsorption mechanism is mainly complex adsorption and ion exchange.
作者
牛乙涛
包国庆
吴纯鑫
赵德明
NIU Yitao;BAO Guoqing;WU Chunxin;ZHAO Deming(School of Chemical Engineering,Zhejiang University of Technology,Hangzhou 310014,China)
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2023年第6期3350-3365,共16页
Acta Materiae Compositae Sinica
基金
浙江省自然科学基金(LY19B070006)
浙江省基础公益研究计划项目(LGF20B070003)。
关键词
超声波
磁性纳米复合材料
络合吸附
吸附动力学
铅离子
ultrasonic
magnetic nanocomposites
complex adsorption
adsorption kinetics
lead ions
