紫外辐照法制备金属钴包覆苯乙烯-甲基丙烯酸共聚物复合粒子

Preparation of Cobalt Coated PS-MAA Composite Particles by Ultraviolet Irradiation

采用悬浮聚合法制备苯乙烯-甲基丙烯酸共聚(PS-MAA)小球,通过紫外辐照法,制备了金属钴包覆PS-MAA复合粒子,复合粒子表面金属粒子的形状因表面活性剂用量的不同,可以是片状、棒状或球状的。研究了表面活性剂、Co2+浓度、搅拌等工艺因素对反应速率及包覆效果的影响。研究表明,使用复合表面活性剂,Co2+浓度由0.01 mol/L降为0.005 mol/L,搅拌次数1次/d增加到3次/d,均可以提高包覆效果。阴离子型表面活性剂体系较非离子型表面活性剂体系反应速率高;体系中表面活性剂浓度过高,胶束缔合成层状液晶,复合粒子表面生成的金属钴是非晶态的;降低表面活性剂的浓度,可以制得晶态钴包覆的复合粒子。

PS-MAA copolymer particles were prepared by suspension polymerization, which was used to prepare metal cobalt coated PS-MAA composite particles by ultraviolet irradiation. The shapes of metal cobalt on the surface of composite particles could be changed from flaky, rod to Spherical with the amount of surfactant used. The influencing factors on coating formation and composite reaction rate such as surfactant,concentration of Co^2＋, stirring, etc. were also studied. The study shows that the coating formation can be increased by using composite surfactant, decreasing the concentration of Co^2＋ from 0.01 mol/L to 0. 005 mol/L, or increasing the number of stirring from once to 3 times a day. The composite reaction rate of the anion surfactant system is higher than that of the nonionic surfactant system. When the surfactant concentration in the system is too high, the micelle will be associated with liquid crystal layer, resulting in amorphous metal cobalt coated on the surface of composite particles, while crystal cobalt coated composite particles can be prepared on decreasing the surfactant concentration.