XU Longfei， ZHANG Zhili， LI Decai， ZHANG Haiming， YANG Yang
（School of Mechanical， Electronic and Control Engineering， Beijing Jiaotong University， Beijing 100044， China）
Abstract：Fe3O4 magnetic particles prepared by chemical coprecipitation and tetraethoxysilane hydrolysis method were coated with SiO2. The prepared particles were characterized by X ray diffractometer, contact angle measuring instrument, vibrating sample magnetometer and transmission electron microscopy and so on. The results show that the surface of the magnetic particles is coated with a layer of SiO2, the size of the coated particles is about 20 nm with superparamagnetic property.The contact angle decreases from 120 to 90°, and the lipophilicity is significantly enhanced. The saturation magnetization of the composite Fe3O4 particles decreases with the increase of the coating amount of SiO2, its value is 84 kA/m, which can meet the application requirements.
Keywords: magnetic particles Fe3O4; morphous SiO2; superparamagnetic; Fe3O4@SiO2 composite particles
文章编号：1008-5548（2017）02-0084-04
DOI：10.13732/j.issn.1008-5548.2017.02.017
收稿日期：2016-05-19，修回日期：2016-09-21，在线出版时间：2017-04-26。
基金项目：国家自然科学基金，编号 ：61271049；教育部创新团队发展计划，编号：IRT13046；北京交通大学人才基金项目，编号：M14RC0040。
第一作者简介：许龙飞（1989—），男，硕士研究生，研究方向为磁性液体理论及应用。E-mail：12121371@bjtu.edu.cn。
通信作者简介：张志力（1966—），女，博士，教授，博士生导师，研究方向为磁性液体理论及应用。E-mail：zlzhang@bjtu.edu.cn。
