Research On The Spatial Motion Model Of Fiber Jet And Experiment In High-speed Centrifugal Spinning

High speed centrifugal is a neoteric method for nanofibers fabrication whose jets are driven by centrifugal force.It has received extensive attention and research,because of its simple spinning principle,abundant spinning materials,high-production efficiency,scalable production and excellent fiber quality.The jet is the main stage of nanofibers fabrication in the high-speed centrifugal spinning.Therefore,the jet motion of the spinning solution will directly affect the morphological of nanofibers.This article aims to study the jet movement of the fibers.The jet motion stage and influencing factors of the spinning solution are analyzed by the principle of high-speed centrifugal spinning.The jet motion of the spinning solution is analyzed by the fluid dynamics of the non-Newtonian viscous fluid.Then,high-speed centrifugal spinning experiments are carried out by using polyethylene oxide(PEO)spinning solution.First,this article introduces the principle,research status and progress of high-speed centrifugal spinning.The jet motion stage of the spinning solution,the principle and law of jet motion are analyzed.Secondly,the force and motion rules of the solution are analyzed in the jet process by establishing the theoretical model of the solution jet in the dynamic coordinate system.The theoretical model of jet motion under the micro-element curve coordinate system is established.Then this paper simulates the jet motion state of the spinning solution and analyzes influence of process parameters on the jet motion of the spinning solution.Finally,the high-speed centrifugal spinning experiment is performed to analyze the factors that caused changes in the diameter and morphological of the nanofibers.The main research contents of this paper are as follows:1.The principle of the high-speed centrifugal spinning mechanism is studied.The main process of fabricating nanofibers is explored by high-speed centrifugal spinning.The research status of centrifugal spinning jet is introduced.The factors that affect the jet movement in the high-speed centrifugal spinning process are summarized,such as the concentration of the spinning solution and the spinning speed.The main process of the fiber jet motion is analyzed.2.The jet principle and mechanism of centrifugal spinning have been studied.The effects of velocity distribution,surface tension,centrifugal force and Coriolis force are analyzed on jet motion of viscous fluid.The influence of different forces is analyzed in each stage of jet movement.The principle of spinning solution jet formation is studied.3.The force and motion law of the spinning solution jet is analyzed.Then,the theoretical model of fiber jet motion is established by the theory of high-speed centrifugal spinning and the knowledge of fluid mechanics.The force of the jet fiber is analyzed comprehensively in the curvilinear coordinate system.And the jet motion equation of high-speed centrifugal spinning is established.4.The jet movement is simulated.The parameters of the polyethylene oxide spinning solution are measured by rheological experiments,which are imported into simulation software.Discrete phase model analysis is performed on the spinning solution jet motion of high-speed centrifugal.The jet trajectory and velocity are simulated under different spinning speeds and solution concentrations.Not only does the paper state the relationship between motor speed,jet trajectory and jet velocity,but also it analyzed the influence of solution concentration on jet trajectory and velocity.5.The high-speed centrifugal nanofiber preparation experiment is carried out by changing the jet parameters individually,such as motor speed,solution concentration,and collection distance.The relationship between the morphology,diameter distribution and experimental parameters of the polyethylene oxide nanofibers is analyzed.The universal law which is about the effect of experiment parameters on fiber morphology is studied in centrifugal spinning.The experimental results show that the quality of PEO nanofibers fabricated by 6wt.% PEO spinning solution can be better when the motor speed is 5500 rpm and the collection distance is 40 cm.Finally,the research on the jet space motion of high-speed centrifugal spinning is summarized.The shortcomings and deficiencies in existing research work are pointed out.The further research directions and prospects of polymer solution jet are discussed in high-speed centrifugal spinning.