Preparation And Application Of Porous Modified Polystyrene Magnetic Microspheres

In this paper,a new method for preparing porous modified polystyrene magnetic microspheres is developed.The phase inversion emulsification technique is used to prepare porous PS magnetic microspheres,porous P(St-EVA)composite magnetic microspheres,P(St-HEA)composite magnetic microspheres and porous P(St-ES403)composite magnetic microspheres.The formulation of preparing these kinds of microspheres are studied.The microstructure and properties of porous modified polystyrene magnetic microspheres are characterized by infrared spectroscopy(FTIR),scanning electron microscopy(SEM),transmission electron microscopy(TEM),laser particle size distribution analyzer,thermogravimetric analyzer(TGA),specific surface area analyzer(BET),Fourier transform.Porous PS magnetic microspheres are prepared by using styrene(St)as monomer,azobisisobutyronitrile(AIBN)as initiator,divinylbenzene(DVB)as crosslinker and cyclohexane as porogen.The HLB value,phase transition temperature(PIT)and cloud point of the system are discussed.The phase inversion process is tracked by recording conductivity.The test data shows that the optimal HLB value is 14,the cloud point is 80°C,the phase transition temperature is 86°C.Porous PS magnetic microspheres,porous P(St-EVA)composite magnetic microspheres,porous P(St-HEA)composite magnetic microspheres and porous P(St-ES403)composite magnetic microspheres are prepared and their micromorphology,particle size distribution,magnetic content and specific surface area are characterized.The particle size results shows that the particle size of these porous magnetic microspheres is all in the range of 1 and 170?m.SEM and TEM indicate the Fe₃O₄ particles are both existed in the inner and the surface of the microspheres.The magnetic content of porous PS magnetic microspheres and porous P(St-EVA)composite magnetic microspheres are34.23 wt%and 28.81 wt%respectively according to TGA.The BET data indicates the specific surface area of the porous PS magnetic microspheres,porous P(St-EVA)composite magnetic microspheres,porous P(St-HEA)composite magnetic microspheres are 274.32 m²g^-1,336.04 m²g^-1and 312.69 m²g^-1 respectively.The pore size distribution(PSD)profile of porous PS/Fe₃O₄ demonstrates both microporous and mesopores existing in the particles.The porosity of porous PS/EVA/Fe₃O₄ and porous PS/HEA/Fe₃O₄ are mainly between 2-50nm(mesopores)and few macropores presented.The treatment effects of porous PS magnetic microspheres,porous P(St-EVA)composite magnetic microspheres,porous P(St-HEA)composite magnetic microspheres and porous P(St-ES403)composite magnetic microspheres on the sewages contaminating with dyes,such as methylene blue,acid magenta,methyl orange,and contaminating with organic solvents,such as toluene,xylene,petroleum ether,cyclohexane and n-octane,and contaminating with oils,such as lubricating oil,engine oil,kerosene,silicone oil and soybean oil,are investigated in this paper.The effects of p H and adsoption time in the sewages containminating with analyzing and the results indicates that the prepared microspheres have best adsorption effects to methylene blue under in alkaline conditions.The effects of adsoption time are analyzed in the sewages containminating with organic solvents and oils,the test data shows that the the prepared microspheres have best adsorption effects to xylene among organic solvents and to lubricating oil among oils.