Preparation And Study Of Modified Silica And Polystyrene Microspheres

Multifunctional microspheres play a significant role in biomedicine,food,petrochemical and other fields.With the economic development,water pollution has become more and more serious.Adsorption is a very suitable technique for water treatment due to its simplicity,low cost,easy to operate and other advantages.The key of adsorption is the choice of adsorbent.Silica and polystyrene microspheres are widely studied and utilized,owing to monodisperse,shape control,stable chemical properties and mechanical stability and other advantages.However,Silica and polystyrene microspheres are subject to various limitations in practical applications prior to be modified due to lack of adsorption sites.By introducing functional groups,adsorption properties of these microspheres can be effectively enhanced.Specific adsorption,absorption to a variety of adsorbate,etc.can be achieved.Based on the analysis above we developed a new method for modification of silica and comprehensively investigated preparation and surface modification of porous polystyrene microspheres.These methods maintain the advantages of silica and polystyrene.The modified Silica and polystyrene microspheres were then utilized as adsorbents for water treatment.The main aspects of our work are listed as follows:1.Using the modified method?St?ber method?,the silica microspheres with an average particle size of about 2 ?m were synthesized,by adjusting the concentration of silicon,the ammonia content and the dropping speed of the raw materials and other conditions.The SiO₂/DR/EDTA microspheres were prepared by introducing the metal ion chelator,ethanediamine tetraacetic acid disodium salt?EDTA?,on the silica surface.And then,this material was applied as adsorbent for effectively adsorbing the heavy metal ion?Cu2+?.2.Magnetic porous polystyrene microspheres?SPS/Fe₃O₄/DR?were synthesized by two-step seed swelling polymerization,followed by surface modification and self-assembly method.Then this material,which possesses rich acid and basic groups,was applied as the adsorbent.The adsorbent had high adsorption performance to the dyes with acidic or basic groups in the aqueous solution,and had excellent selective adsorption capacity to the cationic dye?methylene blue?,saturated adsorption of dyes can be realized within 20 min,and adsorption operation can be carried out in the whole pH range.3.Sulfonated porous polystyrene-polymethylmethacrylate S?PS-PMMA?microspheres were synthesized by two-step seed swelling polymerization and surfacemodification.Then this material was used as packing materials for high performance liquid chromatography?HPLC?.The results demonstrated that the material can be used for organic acid separation.