A Study On Preparation And Properties Of Silver Based Conductive Nanofibers By Electrospinning

Recently,conductive nanofibers have received extensive attentions because of their excellent conductivity,flexibility,and large aspect ratio between length and diameter.Among the fabrication methods of conductive nanofibers,electrospinning is considered as the most simple,common and versatile one.However,the conductive nanofibers derived from this method are always exist several drawbacks,such as the poor conductivity and stability of polymer conductive nanofibers,the bad atomosphere resistance and complex preparation of copper conductive nanofibers,which would severely limits the nanofibers applications in manyfields.In this work,silver based conductive nanofibers were successfully fabricated through electrospin non-particulate organic silver conductive inks.During this process,the effects of the sorts and amounts of silver salts,amine compexing agents and reducing agents on the conductivity and stability of organic silver conductive inks were investigated.The results show that the conductivity and stability of the conductive ink are the best when silver nitrate,isopropylamine and ethylene glycol are used to prepare organic silver conductive ink.The conductive ink can form a silver film with sheet resistance of 0.8 ?/sq after treatment at 150? for 60 min.The conductive ink has good stability for long-term storage.Then this organic silver conductive ink was used to fabricate conductive nanofibers subsequently.During this process,the effects of the ratio between PVP and PEO,the amount of organic silver conductive ink,the humidity of environment,and the temperature of calcination on the morphology and conductivity of conductive nanofbiers were studied.It was found that the precurse solution composed of 8 wt% PVP,4 wt% PEO and organic silver conductive ink containing 0.5 g silver nitrate can ensure the nanofiber with good morphology and conductivity.While the higher silver content always leads to bead morphology of nanofibers.Besides,the humidity also affects the fiber morphology greatly.And it was found that the humidity lower than 65% can provide the nanofiber with smooth surface.Two type of conductive films were prepared by attaching the silver based conductive nanofibers on PI and PET substrates,respectively.The properties of the conductive films were studied,such as the temperature resistance,bending property and adhesion property.The conductive film prepared by directly depositing nanofibers on PI substrate have the sheet resistance of 70 ?/sq after calcinated at 270? for 60 min.Applausively,the conductive nanofibers would partially embedded into the PI substrate,which would provide the film with good thermal and mechanical resistance.Moreover,the silver nanoparticles are closely packed into thick nanofibers which can ensure the film good conductivity.On the other hand,free standing silver based conductive nanofibers were prepared by accepting the nanofibers with a metal frame and calcinating at 300? for 60 min.Then these conductive nanofibers were transfered onto a PET substrate to form conductive film.It was found that the silver nanoparticles were compactly sintered on the conductive nanofibers,which provide the conductive film with sheet resistance of 36 ?/sq.And this conductive film had excellent bending and adhesion property.