多步种子溶胀法制备微米级大粒径单分散胶体微球

Preparation of micron-large-sized monodisperse colloidal microspheres by multistep seed swelling method

为制备大粒径(接近20μm)、单分散聚苯乙烯(PS)微球,首先采用分散聚合法制备PS种子微球,再经过多步种子溶胀策略实现制备目标。讨论了多步溶胀过程中稳定剂聚乙烯醇(PVA)浓度对PS微球的粒径和单分散性Cv的影响,以及阻聚剂NaNO_2对聚合过程中二次核心的影响。结果表明:种子PS微球粒径为(3. 15±0. 13)μm,在种子溶胀过程中,随着变异系数先减小后增大;加入NaNO_2可有效抑制二次核心生成;经三步种子溶胀最终制得平均粒径为18. 76μm、变异系数为0. 209的PS微球。

In order to prepare large size (nearly 20 μm),monodisperse polystyrene (PS) micro-spheres,PS seed microspheres were prepared by dispersion polymerization method,and then PS microspheres was prepared by multistep seed swelling method.The effect of PVA concentration on the particle size and monodispersity of PS microspheres were discussed,and the effect of the inhibitor NaNO 2 on the secondary particles was discussed.The results showed that the diameter of seed PS microshperes was 3.15(±0.13)μm.In each step of the seed swelling process,the particle size of PS microspheres decreased gradually,and the variation coefficient ( C v) decreased first and then increased with the increase of PVA concentration.The addition of NaNO 2 could effectively inhibit the generation of secondary particles.The average particle diameter and C v of PS microspheres prepared by the three-step seed swelling was 18.76 μm and 0.209,respectively.