Preparation And Catalytic Performance Of Polystyrene Microspheres

The polystyrene microspheres exhibit the advantages of uniform particle size,controllable morphology,large specific surface area and easy surface modification.The surface-modified polystyrene microspheres exist reactive groups such as carboxyl groups,amino groups or hydroxyl groups on the surface,which are easy to be combined with enzymes,proteins,nucleic acids and catalysts.Thus,the polystyrene microspheres were widely used in biology,chemistry,materials and medicine.Nano-silver is a precious metal material with high catalytic performance and surface activity.It play an important role in wastewater treatment,photocatalytic degradation and photocatalytic hydrogen production.The nano-silver is loaded onto the surface of the polystyrene microspheres of the surface work to prepare core/shell polymer microspheres,which can greatly improve the utilization rate of the precious metal materials and cut costs.Polystyrene microspheres with uniform particle size were prepared by dispersion polymerization.The particle size and particle size distribution of polystyrene microspheres were discussed in detail during the polymerization process.The surface of polystyrene microspheres was modified with concentrated sulfuric acid to prepare sulfonated polystyrene microspheres,and the catalytic performance of sulfonated polystyrene microspheres was investigated.Finally,sulfonated polystyrene/nano silver composite microspheres was prepared.And the application of catalytic degradation of methylene blue was also discussed.The main research results are as follows:?1?Polystyrene microspheres were prepared by dispersion polymerization using styrene as a monomer,azobisisobutyronitrile as an initiator,polyvinylpyrrolidone as a dispersant,and anhydrous ethanol and water as a dispersion medium.When the amount of styrene is 15 mL,the amount of azobisisobutyronitrile is 0.3 g,the amount of polyvinylpyrrolidone is 1.5 g,and the ratio of alcohol to water of the dispersion medium is 90:10,the particle size distribution of polystyrene microspheres is ebest.?2?The surface modification of polystyrene microspheres was carried out with concentrated sulfuric acid.Under the reaction conditions of sulfonation time of 5 h and sulfonation temperature of 50°C,the surface acid content of the microspheres was up to 0.750 mmol/g.It exhibits good catalytic performance in catalyzing the esterification of acetic acid with ethanol.When the esterification temperature is 60°C,the esterification time is 5 h,the molar ratio of alkyd is 2:1,and the amount of catalyst is 5%,the esterification rate of acetic acid reaches 69%.?3?Sulfonated polystyrene/nano-silver?SPS/Ag?composite microspheres with good monodispersity and uniform coating of nano-silver particles were prepared by chemical reduction at a reaction temperature of 70°C for 8 h.By changing the amount of reducing agent,it was found that with the increase of the amount of reducing agent,the nano-silver particles deposited on the surface of SPS microspheres gradually increased,and the SPS/Ag composite microspheres prepared t the reducing agent of 3 mL achieveed the best morphology.By catalyzing the reduction of methylene blue?MB?by NaBH₄,the results show that the SPS/Ag composite microspheres produce good catalytic activity and high recyclability,and can catalyze the reduction of MB solution in NaBH₄ in a short time,and the higher the silver content on the surface of the composite microspheres,the faster the catalytic rate.