Preparation And Spectral Study Of Fluorescent Polystyrene Microspheres

Monodisperse polystyrene microspheres play an important role in many fields; they can be used as instrument calibration particles in standard measurement and as signal carriers in high-throughput drug screening, they are also indispensible in liquid chip testing technology. Unfortunately, preparation technology for monodisperse microspheres is not yet mature in our country and we still need to import expensive foreign products, which limits the relevant application technology seriously. In this thesis we synthesize PS microspheres by dispersion polymerization and two-step swelling technology, and then we get fluorescent microspheres loaded BODIPIY fluorophore, the fluorescence emission spectra are also studied.1. Monodisperse PS microspheres of2.4μm are prepared using dispersion polymerization, by compared experiments the reaction conditions are optimized. The seed particles are swelled to5.5μm through two-step swelling method, and we get high swelling efficiency when swelling at40℃, PVP K30and DBP used as stabilizer and swelling agent respectively. It turns out that intensive pores appear when crosslinking agent exceeds25wt%of the whole monomers.2. Carboxyl functional monomers have an effect on the morphology of polystyrene microspheres, which is indicated from the different morphology of carboxyl microspheres prepared with ita conic acid and MA A. The surface carboxyl group is charactered by FT-IR and conductometric titration.3. Phenyl-BODIPY is loaded into microspheres through swelling-adsorption procedure, and H2O-THF is proved to be a better swelling system. Both the dye content and fluorescent emission spectra of fluorescent microspheres are investigated and we conclude that the emission spectrum will not be influenced by the dispersion medium.