以偶氮二异丁腈（AIBN）为光引发剂，甲醇为溶剂，聚乙烯吡咯烷酮 (PVP)为稳定剂，通过抽真空取代氮气保护，利用8 W 365nm波长的紫外灯光照，环境温度下引发分散聚合制备聚苯乙烯微球。这种真空状态下的聚合只适合于光聚合，当紫外光照射反应体系时，AIBN将吸收光子使C-N键断裂而形成自由基，进一步引发苯乙烯单体聚合。研究表明引发剂、稳定剂和单体用量以及光强度和反应时间对微球尺寸和单分散性有规律性影响，适当调节这些参数可获得一定尺寸和单分散度的微球，例如溶剂与单体的比值3:1，引发剂与稳定剂的比为3:1,光照时间为24 h，光照强度为（0.71 mW/cm2）时可获得一定尺寸的单分散性较好的微球。这种方法成本低廉、操作简便、具有一定的普适性，可适用于其它聚合物微球和功能化有机-无机复合微球的制备，例如PMMA、PMAA微球及P(MMA-co-MAA)共聚微球等。
This paper reports on the dispersion photopolymerization of polystyrene microspheres by low-power ultraviolet light in vacuum with styrene as initial monomer, 2,2'-Azobisisobutyronitrile (AIBN) as photo-initiator, methanol as solvent, and polyvinylpyrrolidone(PVP) as dispersant. The microspheres were obtained at room temperature by the irradiation of 8 W 365nm ultraviolet light. Instead of N2 protection, the vacuum was first introduced to help the polymerization and it had been proved that only the photopolymerization could be used in vacuum. When UV light irradiated the reaction system, the C-N bond of AIBN could be broken for the absorption of photons and free radicals would form, and then these radicals would induce the polymerization of styrene. The experiments showed that quantity of initiators, quantity of dispersants, quantity of monomers, power of light and reaction time could regularly affect the size and size distributions of the finally obtained microspheres. Tuning these factors properly, for example, keeping the volume ratio between solvent and monomer as 3:1, the weight ratio between initiator and dispersant as 3:1 , after irradiated 24 hrs with 0.71 mW/cm2 UV light, monodispersed microspheres with certain size could be easily prepared. This method is low-cost, simple, safe and universal for the preparation of microspheres. It could be also used to fabricate other polymer microspheres, such as PMMA, PMAA, P(MMA-co-MAA) copolymer microspheres and even the functional organic-inorganic composite microspheres.