摘要
以纺缍形α-Fe2O3超微粉为内核,过硫酸钾为引发剂,聚乙二醇为分散剂和稳定剂,乙醇/水为分散介质,苯乙烯为单体,用改进的分散聚合法合成了核/壳型纺锤形的高分子微球,并用XRD、TEM和IR进行了表征。粒子的分散性较好,粒径分布窄。由于亲水性的α-Fe2O3与亲油性的苯乙烯亲合性较差,在实验中采用了超声分散、预先溶胀和预先吸附引发剂、分散剂的方法,增强了粉末表面的亲油性,合成的高分子微球,其长轴平均为0.26μm,短轴平均为0.09μm,轴比为2.9,同时测定了不同pH值时粒子包膜前后的Zeta电位值,并根据粒子等电点的变化计算出包膜厚度,与电镜照片的结果比较吻合。
The composite polymer microsphere, containing a α-Fe_2O_3 core and a polymer shell, were synthesized by improved dispersion polymerization of styrene in the presence of α-Fe_2O_3 in ethanol/water medium, in which K_2S_2O_8 was used as initiator and poly(ethylene glycol) was stabilizer and disperser. It was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and infrared ray (IR). The products had little size distribution and good dispersion. Because hydrophilic α-Fe_2O_3 and hydrophobicmonomer couldn't combine well, some measures were taken to increase the hydrophobicity of powder surface, such as ultrasonic dispersion, absorbing and swelling in advance and so on. The mean length and mean width of the polymer microsphere were 0.24 μm and 0.09 μm, its axial ratio was 2.9. Zeta-potentials of coated and un-coated particles wre measured respectively at different pH values. The thickness of film calculated by the change of IEP (isoelectric point) is in accordance with that resulted from TEM.
出处
《华东理工大学学报（自然科学版）》
CAS
CSCD
北大核心
2004年第5期592-594,共3页
Journal of East China University of Science and Technology
