Study On Poly（ether Imide）/amino-modified SiO₂ Hybrid Membranes

Poly(ether imide)(PEI)membrane with many good properties,such as good thermal,good corrosion resistance,toughness,chemical inertness,and biocompatibility,has been widely used in filtration and biomedical applications.Nano-silicon is a kind of inorganic nanoparticles and can increase the water flux of membrane.The hydroxyl groups of nano-silicon particles surface can easily react with silane coupling agent.The dispersion of the inorganic and organic phase was possible in the nanoscale with addition of(3-aminopropyl)triethoxysilane(APTES).With addition of APTES,amine groups form on the SiO2 particles,which are a good enzyme immobilization carrier.Moreover SiO2 particles containing amine groups have higher activity and recyclability.In this paper,organic-inorganic hybrids of poly(ether imide)and amino-modified SiO2 were in situ prepared via sol-gel process in the presence of tetraethylortho silicate(TEOS)and APTES)in a mixed solvent of N,N-Dimethylacetamide and 1-Methyl-2-pyrrolidone(DMAc/NMP).The hybrid membrane was crosslinked with ethylene diamine to improve resistances to solvent corrosion of membranes.The hybrid membrane properties were investigated by scanning electron microscope(SEM)observations,pure water flux,and lysozyme(Lys)adsorption.The article contents are as follows:1.PEI/SiO2 hybrid membranes were prepared by using DMAc and NMP as solvent.The structure and properties of hybrid membranes were studied.Equilibrium data coincide with the langmuir model by nonlinear least-squares regression analysis.The solid line in the figure is the langmuir isotherm that best fit the data.With the increase of the PEI concentration,water flux decreased,and tensile strength and breaking elongation ratio were improved.But the hydrophilicity of hybrid membrane reduces.PEI/SiO2 hybrid membranes were prepared by using water as coagulation bath and 18%PEI content in the next step.2.PEI/SiO2 hybrid membranes with 18%PEI content were prepared by changing NMP/DMAc ratio.The pure water flux of the hybrid membranes decrease gradually and then increase with NMP concentration increasing.When NMP/DMAc ratio is 5:5,water flux reaches the minimum value.With the increase of APTES,the pure water flux decreases and tensile strength,breaking elongation ratio,Lys adsorption capacity of hybrid membranes constantly increases respectively.Lys adsorption capacity of hybrid membrane reaches maximum at pH 8.With the increase of TEOS content,the tensile strength of hybrid membrane,hydrophilicity was improved.4%of TEOS content,9:1 of NMP/DMAc ratio,13:1 of APTES/TEOS ratio were used for the next step of the experiment.3.The hybrid membrane was crosslinked with ethylene diamine based on the above selected condition.With the increase of the concentration of crosslinking agent,the tensile strength of hybrid membrane and solvent resistance were improved.breaking elongation ratio,lysozyme adsorption,hydrophilicity decreased respectively.With the extension of crosslinking time,pure water flux and solvent resistance were also improved,and the tensile strength increases first,then decreases.The breaking elongation ratio,lysozyme adsorption and hydrophilicity decreased respectively.In conclusion,the hybrid membrane was crosslinked for 12 hours with concentration of ethylenediamine at 8%.The research results provide evidence on the optimal parameters of preparation for PEI/SiO2 hybrid membranes.It also provides a potential application for the hybrid membrane on protein adsorption.