高表面电荷密度单分散苯乙烯磺酸钠纳米微球的制备

Preparation of Highly-charged and Monodisperse Poly(styrene/sodium styrene sulfonate) Nano-spheres

利用无皂乳液聚合 ,在苯乙烯 (St)的反应体系中引入适量的苯乙烯磺酸钠 (NaSS)参加共聚合 ,在聚合过程中分两阶段加料 ,第一阶段中NaSS浓度是决定乳胶粒粒径及单分散性的关键因素。当反应达到较高转化率 ( >90 % )时加入第二阶段单体混合物 ,此阶段中NaSS与St的比例决定了最终胶粒的表面电荷密度。利用上述两阶段无皂乳液聚合法成功地制备了粒径小于 10 0nm、单分散性指数小于 1.0 5以及表面电荷密度大于 3 0 μC·cm-2

A two stage emulsifier free emulsion copolymerization of styrene/sodium styrene sulfonate (NaSS) was conducted to prepare monodisperse nano spheres. In the first stage, the amount of NaSS was a determining factor for controlling the dispersity and size for the colloidal particles. At the second stage the monomers was added into the reacting system as the conversion of first stage exceeded 90%. The ratio of St to NaSS of the second stage monomer mixture determined the surface charge density of the ultimately prepared spheres. The nano spheres with monodisperse (U<1.05), high surface charge density(>30 ?μC·cm -2 ) and small particle diameter(<100?nm) were successfully obtained with this method.