Preparation of Monodispersed Polystyrene Microspheres As Standard Particles in a Flow Microreactor System

Anionic copolymerization of prepolymerized styrene with divinylbenzene using AIBN as an initiator to prepare standard particles was conducted in a microfludic system. Monodispersed polystyrene microspheres (20-150 μm, Cv<4%) as standard particles were achieved under easily controlled conditions. The system including a set of quartz glass coil and a coagulation bath for continuously preparing particles was set up. We studied the effects of the solution composition, the extent of prepolymerization and other reaction variables on particle size, size distribution and stability. The ability to use different channel sizes and flow patterns to control the particle size was evaluated. The experimental results showed the increase of divinylbenzene concentration and prepolymerization time contributed to prepare monodispersed and stable particles. The process has been proved to be an easy high-throughput method to prepare standard particles, which are needed for many biochemical applications and standard measurement.