Preparation And Experimental Study Of Nanofiber Twist Based On Melt Differentiation

With the advancement of science and technology,nanotechnology has developed rapidly,and many derivative products have been produced Nanofiber is one of them.Nanofiber refers to a linear material with a nanometer diameter and a certain aspect ratio.Nanofibers are widely used in the fields of high-efficiency filtration,microsensors,biomedicine,etc.Due to their high specific surface area,high porosity,and excellent physical and chemical properties,Nanofibers have become an important material for strategic development and have broad market prospects.Electrospinning is a widely used technique for preparing nanofibers.The electrostatic spinning method uses electrostatic force as the driving force for fiber formation and refinement,and can prepare high-performance nanofibers with special structures.However,the electrospinning method is difficult to break through the bottleneck of low output,and there is still a certain distance from the industrial application.In addition,most of the fibers prepared by the electrospinning method are collected in the form of non-woven fabrics.This collection method limits the application of nanofibers in the fields of tissue scaffolds,flexible sensors,and wearable fabrics.In order to solve the above problems,this paper firstly carried out an experimental investigation on centrifugal electrospun polypropylene(PP)nanofiber twisting.The average diameter of the fiber prepared by centrifugal electrospinning under the optimal process parameters is 790 nm.The mechanical properties of PP nanofibers were studied.The results show that the PP fibers prepared at a spinning voltage of 45 kV have relatively good mechanical properties performance.Combining the twisted fibers with cyclonic airflow,a fiber twist with a diameter of 61 ?m and a twist angle of 30.4°was obtained,which verified the feasibility of centrifugal spinning nanofiber twist.In order to further obtain high-performance fiber twisting,polyphenylene sulfide(PPS)was used as the spinning raw material to conduct melt differential multi-jet electrospinning experiment.The average diameter of the fiber prepared under the optimal process parameters was 1.28 ?m.The crystallinity,thermal stability and filtration performance of the prepared PPS fiber were studied.The research results show that within a certain range,with the increase of the spinning voltage,the fiber crystalline peak height increases and the mechanical properties improve;the best process conditions The PPS fiber prepared below has a mass retention rate of 98.53%at 460?,which has certain advantages compared with commercial filter bags;the PPS fiber membrane with a grammage of 186 g/m2 has a filtration efficiency of 0.3-10?m flue gas of 99.96%.Designed and developed a melt centrifugal fiber twisting device,and successfully prepared PPS fiber twisting through the device,and realized high-efficiency fiber twisting preparation.The effect of centrifugal disk speed on the twist shape of PPS fiber was studied.The results show that the spinning temperature of 310? and the spin speed of 3000 rpm are the best process conditions for preparing PPS fiber twist.A single fiber has a diameter of about 4 ?m,a twisted wire diameter of about 60?m,and a twisted PPS fiber with a twist angle of 26.6°.And the surface of the twisted wire is smooth,without polymer droplets,and the degree of twisting is high.In summary,a two-step method for twisting nanofibers prepared by melt differential centrifugal electrospinning is proposed to achieve efficient preparation of PP nanofiber twisted yarns;further experimental research on PPS melt differential multi-jet electrospinning is carried out.Successfully prepared PPS nanofibers with excellent properties;on the basis of melt differential centrifugal electrospinning and PPS melt differential multi-jet electrospinning,a melt centrifugal twisting device was further developed and PPS nanofiber twisting was carried out Preparation research,successfully prepared high-performance PPS nanofiber twisted wire.In this paper,the preparation process of nanofiber twisted wire is explored.This research result is of great significance for expanding the application field of nanofibers.