Air-assisted Preparation Of Ultra-fine Nanofibers And Research On Large-scale Preparation Of Nanofibers

In the era of rapid development of nanotechnology,nanomaterials have become the hottest research topic for researchers at home and abroad because of their superior performance with other materials.It can be said that nanomaterials are now the key technology to promote social science progress.Among them,the electrospinning nanofiber technology is widely used due to its advantages of rapid and continuous preparation of polymer nanofibers,and can be applied to energy,biomedicine,and sensors according to the type and nature of electrospun materials.In the third chapter,the spinning equipment is further modified on the basis of the preparation of nanofibers in the traditional electrospinning device.The highpressure airflow-assisted electrospinning has successfully prepared polyvinyl alcohol/poly(3,4-ethylenedioxy).Thiophene): Poly(styrene sulfonate)(PVA / PEDOT: PSS)composite microfiber.The ultra-fine nanofibers with a true diameter of 100 nm or less were prepared and applied to gas sensors in comparison with the performance of conventional electrospun fiber sensors.The electrical properties of PVA / PEDOT:PSS nanofibers of different diameters were characterized.The average diameter of the nanofibers can be as low as 100 nm or less.Due to its large specific surface area,the ammonia sensitivity of ultrafine nanofibers is more sensitive than conventional electrospun fibers.The ammonia sensing properties of the samples were tested by impedance analysis.The results show that the ultra-fine PVA / PEDOT: PSS nanofibers are more suitable for detecting low concentration ammonia,and the sensitivity is higher.Although the nanofibers prepared by electrostatic spinning are simpler,faster and smaller in diameter than other fibers,they are greatly hindered in the large-scale industrial production process due to the difficulty in mass preparation.In view of this problem,this paper studies the solution jet spinning technology that can realize largescale production and rapid preparation of nanofibers in the second chapter,and summarizes the mechanism,device,influencing parameters,application in various fields and the shortcomings of solution jet spinning.In addition,in chapter 4,we independently developed and designed a new device,multi-needle external fluid device,for large-scale preparation of nanofibers,which can realize industrial scale production,so as to improve the production efficiency of nanofibers.We successfully prepared TPU nanofibers with a multi-needle external fluid device,and the feasibility of the device was confirmed.At the same time for the preparation of nanometer fiber have been characterized and hydrophobic test,pervious to light,breathable and haze circulation test and so on a series of tests,to prove our preparation of TPU nanometer fiber yarn net with good usability,significant PM2.5 removal efficiency,drafty and good optical transparency,can be used in commercial scale production of anti fog screen window.