Study On Preparation And Performance Of HPAN Ultrafiltration Membrane

In order to improve the hydrophilicity and anti-pollution ability of polyacrylonitrile?PAN?ultrafiltration membranes,a series of HPAN with different degrees of hydrolysis were prepared by alkaline hydrolysis of PAN by controlling the hydrolysis time,and HPAN was used as the membrane material L-S phase inversion method successfully prepared HPAN ultrafiltration membrane,through ultrafiltration test,hydrophilicity test,SEM,FTIR,XPS and other means to investigate the effect of PAN hydrolysis time on ultrafiltration membrane performance and structure.The results show that with the gradual increase of PAN hydrolysis time,the hydrophilicity and ultrafiltration performance of HPAN ultrafiltration membranes are improved,but when the hydrolysis time is too long,the rejection rate and mechanical properties will be reduced to some extent.Comprehensive consideration,when the hydrolysis time of PAN is 2h,the ultrafiltration membrane has excellent ultrafiltration performance,the water flux can reach 580L/?h?m²?,the rejection rate is 93%,the porosity?80%?and good resistance Pollution capacity.In order to improve the mechanical strength of the HPAN UF membrane,we consider using the interaction between nanoparticles and HPAN membrane to improve the mechanical strength of HPAN membrane.In this study,a series of HPAN/TiO₂ composite membranes were prepared by changing the content of nano-TiO₂.Infrared characterization proves that there is indeed an interaction between HPAN and titanium dioxide.The effects of TiO₂concentration on the performance of the composite membranes were investigated by means of ultrafiltration test,hydrophilicity test and mechanical strength test.Comprehensive research results show that when the concentration of nano-TiO₂ is 2%,the water flux can reach 545L/?h?m²?,the rejection rate is 92.2%,and the tensile strength is increased from1.1Mpa to 1.7Mpa.Therefore,the introduction of nano-titanium dioxide can effectively improve the mechanical properties while ensuring the ultrafiltration performance.In addition,HPAN/TiO₂ ultrafiltration membranes,because of their high activity of carboxyl groups,can provide unlimited possibilities for further functional modification of HPAN membranes,which will have great research value for broadening the application range of PAN ultrafiltration membranes.