Study On The Fabrications And Properties Of GO/SWCNT/Polymer Conductive Composite Films

In recent years,nacre has attracted widespread attention due to their unique "brickmortar" structure and excellent mechanical properties.The dissertation selectes twodimensional layered graphene oxide(GO)and polymer which could be “brick” and "mortar" materials respectively to prepare nacre-like structured conductive composites.However,the polymer acts as an interlayer adhesive and hinders the transmission of electrons,which deteriorates the electrical properties of the composites.Therefore,carboxylated single-walled carbon nanotubes(SWCNT)is introduced as the third phase to enhance the electrical properties of the composite films.The main results are as follows:(1)Polylactide(PLLA)is used as a modle polymer to study the preparation of nacrelike GO/polymer composite films.And methods of vacuum filtration with GO solution through PLLA electrospinning membrane,vacuum filtration with GO/PLLA nanofiber mixed solution and preparation of GO/PLLA composite films with evaporation are compared.(2)Different ratios of GO/PVA(SPEEK)and GO/PVA(SPEEK)/SWCNT composite films are prepared by solvent evaporation.Then chemical reduction and double stacking are used to investigate changes in performance of composite films.It is found that the cross-sections of the composite films exhibited regular interlaminar alternating structure;and(r)GO/PVA/SWCNT composite films are superior to(r)GO/PVA composite films in terms of properties.Among them,the conductivity of r GO/PVA/SWCNT composite films is 20-300 times than that of r GO/PVA composite films.Meanwhile,the introduction of SWCNTs results in a slight decrease in the mechanical properties of the composite films,and the electrical properties are greatly improved.The maximum conductivity of the GO/SPEEK/SWCNT composite film is 105-106 times than that of the GO/SPEEK composite films.After reduction,the conductivity is 5-10 times than that of GO/SPEEK/SWCNT composite films.However,due to the weaker interfacial adhesion,the double-stacking composite films have a slight decrease in mechanical and electrical properties.