Preparation And Properties Of Aligned Conductive Composite Nanofibers By Electrospinning

Due to their high length-diameter ratio,specific surface area and good conductive electricity,conductive nanofibers are potentially of great interest for the application of electrochemistry,textile,aerospace,electron and constructional engineering,and others.Electrospinning is a simple and efficient technique for the preparation of conductive micro/nanofibers.However,these randomly oriented electrospun nanofibers usually have relatively low mechanical and conductive electricity properties,which limit their application in electron device,tissue engineering etc.Therefore,it is a hot subject to generate highly aligned conductive nanofibers to broaden the application areas.Based on the previous studies,a modified parallel electrode method?MPEM?by placing a positively charged ring between the needle and the parallel electrode collectors was developed to fabricate highly aligned conductive composite nanofibers?ACCNFs?,such as single wall nanotubes/polyacrylonitrile?SWNTs/PAN?,graphene/PAN?Gr/PAN?and Fe₃O₄/Gr/PAN ACCNFs.These ACCNFs were characterized and carbonized.And the conductive properties of the carbonized composite nanofibers were analyzed.The specific work was as follows:?1?The preparation,characterization and properties of SWNTs/PAN ACCNFs were studied.The effects of different SWNTs concentrations on morphology,alignment,conductive and other properties of ACCNFs were investigated.The results showed the properties of PAN nanofibers were improved by adding SWNTs.When the spinning voltage was 15 k V,spinning distance was 18 cm and SWNTs concentration was 0.5 wt%,the ACCNFs with the best comprehensive properties could be obtained.And the alignment of nanofibers could make hydrophobic materials more hydrophobic and make hydrophilic materials more hydrophilic.?2?The preparation,characterization and properties of Gr/PAN ACCNFs were studied.The influences of different concentrations of Gr and water on the morphology,porosity,alignment,conductivity and other properties of the ACCNFs were explored.Theresults showed that when the spinning voltage was 18 k V,ring voltage was 5 k V,spinning distance was 18 cm,the distance of electrodes was 4 cm,Gr concentration was 0.5 wt%and the concentration of water was 2 wt%,the porous ACCNFs with optimum overall performance were generated.However,the porous ACCNFs have relatively lower electrical conductivity than nonporous ACCNFs.?3?The preparation,characterization and properties of magnetic Fe₃O₄/Gr/PAN ACCNFs were studied.The influences of different Fe₃O₄ concentrations on the morphology,alignment,conductivity and other properties of the ACCNFs were illustrated.The results showed that when Fe₃O₄ concentration was 0.5 wt% the ACCNFs with the best comprehensive properties could be obtained.And the addition of Fe₃O₄ made the thermal stability and electrical conductivity of the composite nanofiber membranes increase.?4?The carbonization,characterization and properties of SWNTs/PAN,porous Gr/PAN and magnetic Fe₃O₄/Gr/PAN ACCNFs were studied.And the electrical properties of the three kind of nanofiber membranes were compared.The results showed these carbonized ACCNFs could be used as electrode or supercapacitor materials in future.