Study On Nano-electrospinning Technique Based On Inducted-electrode Method

Because of producing nanofibers with high specific area conveniently,electrospinning technology has been widely concerned and applied.With more than ten years of rapid development,electrospinning technology has become increasingly mature and perfect.However,using current electrospinning thecnology,it is still difficult to produce three-dimensional,large area,oriented nanofibers and it is hard to precisely control the distribution of diameter of the as-spun nanofibers.In this paper,a new kind of electrospinning method named inducted-electrode method,which can solve these above problems by adding a parallel introuction electrode in the traditional electrospinning device,will be introduced.Firstly,the electric field distribution of the induced-electrode device and the influence mechanism of nanofibers' movement mode are studied in this paper.The analytic results of electric field which based on COMSOL software show that the electric field of electrospinning is divided into two parts.One part starts from the tip of needle to the inducted plate and the other points to the fixed receiving plate from the needle.There are three kinds of nanofibers' movement during electrospinning,including moving toward the surface of inducted plate,moving toward the fixed receiving plate,and moving toward the space between the both plates.The experimental results show that there are three kinds of fibers between the both receiving plates,such as the random fibers attach to the surface of the inducted plate,the fibers randomly distribute on the surface of the fixed receiving plate,and the orientated fibers suspend between the two plates.The preparation technology of the suspensed orientation PVA nanofibers is explored.The result shows that these suspended fibers arrange in a large area,three-dimensional,symmetrical,and multi-layer oriented nanofiber array centered on the spinneret needle between the both plates.After statisticing these collected aligned fibers,it finds that the tilt angle of eighty-one percent of the nanofiber is less than or equal to 5°,showing these fibers have good orientation.Through adjusted the electrospinning parameters,the fibers with the length ranging from 60 mm to 140 mm can be produced.Meanwhile,these oriented fibers can be prepared to make the fiber array with different angles.The relationship between electrospinning parameters and the diameter distribution of randomly distributed PVA nanofibers is studied.The experimental results show that when spinning PVA nanofibers,the electric field strength of inducted-electrode Method is 0.164KV/cm,which is only one tenth of that of traditional electrospinning method.At the same time,the inducted plate increases the swing angle of the E-jet effectively,so that it can obtain PVA nanofibers which are smaller and more uniform than that making by the traditional electrospinning.When the electrospinning distance is 8cm,the diameter and variance of the as-spun fiber obtained by the inducted-electrode Method are only 37.2% and 6.3% of the traditional electrospun fibers respectively.In addition,through adjusting the receiving distance,loading voltage,solution concentration,spinning needle diameter,solution conductivity and other parameters,it can easily control the diameter and morphology of the randomly distributed PVA fibers.