Preparation And Properties Of Functional Polyacrylonitrile-based Electrospun Fibers

The separation of oil-water/oil-oil and treatment of dyestuff in wastewater are important subjects in industrial production at present.Among them,the preparation and utilization of functional nanofiber materials for the separation of oil-water/oil-oil and the degradation of dyes in wastewater is an important research direction.In view of the excellent chemical stability,large specific surface area,high temperature resistance,chemical resistance,good spinnability and easy preparation of polyacrylonitrile（PAN）electrospun fibers,the functional PAN-based electrospun fibers were prepared by surface graft modification and metal ion loadings method using PAN electrospun fibers as matrix materials in this work,and the corresponding properties were studied and discussed,and the achieved conclusions were as follows:（1）Preparation and properties of amphiphobic polyacrylonitrile electrospun fibrous membranes.The amphiphobic PAN electrospun fibrous membranes were prepared by modifying with dopamine（DA）and tridecafluorooctyltriethoxysilane（G617）.At the same time,the wear resistance,oil-water and oil-oil separation performance of the amphiphobic PAN membranes were investigated.The experimental results show that when the mass concentration of PAN was13.8%and the applied voltage was 18 kV,the morphology of the fibers was better.The amphiphobic PAN membranes were successfully prepared by surface modification by DA and G617.The contact angles of water and salad oil were141.9°and 131.2°,respectively.The wear resistance of the amphiphobic PAN membranes was better.The oil-water,oil-oil and oil-water emulsion separation ability of the amphiphobic PAN membranes were better.（2）Preparation and properties of PAN-based carbon fibers supported platinum catalysts.In this work,the supported platinum（Pt）catalysts were prepared by two schemes.The first scheme was prepared by carbonization of PAN/H₂PtCl₆ electrospun fibrous membranes after reduction;and the second scheme was prepared by carbonization of PAN electrospun fibrous membranes and then impregnation.The surface properties of the two catalysts were compared,and the adsorption and catalytic degradation of the catalyst were studied.It can be concluded that when the mass ratio of PAN in spinning solution was13.8%,the spinning voltage was 18 kV and the spray speed was 0.7 mL/h,the morphology of fibers was better.For the catalyst of the first scheme,when the amount of H₂PtCl₆ was 0.3g,the surface morphology was better and the supported Pt particles were more.When the amount of H₂PtCl₆ was 0.3g,the surface properties of catalyst in the second scheme were better than the catalyst in the first scheme.Compared with PAN-based carbon fibers,the specific surface area of the two catalyst was slightly decreased,but it was still larger.The two catalyst can realize simple recycling of dye degradation on a self-made fixed-bed catalytic reactor,but scheme 1 had more cycles and scneme 2 had higher degradation efficiency.