Preparation Of Inorganic Nano-micron Fibers By Electrostatic Solution Blowing Technology And Its Properties

The inorganic nano-micro fibers have excellent optical,electrical,magnetic and thermal properties because of their large specific surface area,high surface energy and strong surface activity.These make them have potential applications in the fields of environment,biomedicine,optoelectronics,etc..Among numerous inorganic materials,metal nitrides and metal oxide have attracted people's attention because of high temperature resistance,outstanding corrosion resistance and excellent functional magnetism.And these one dimension micro/nano fibers using these materials have been prepared successfully.However,the traditional electrospinning technique for the preparation of inorganic nano-micro fibers remains some problems such as high spinning voltage and low production efficiency.In order to solve these problems,in this paper,magnetic Fe/FeNx and porous Al₂O₃ nano-micro fibers were selected as the research object.Meanwhile,a kind of technology based on the dual function of electrostatic and airflow?electro-blowing spinning method?was proposed and applied in the preparation inorganic nanofibers.Firstly,the Fe/FeNx nano-micro fibers were prepared through the electro-blowing spinning method coupled with high temperature calcination techniques by using FeCl₃ as iron salt,PVP as fiber-forming polymer and H2O as solvent.And the influence of spinning solution concentration,air pressure,spinning voltage and the calcination temperature on the morphology of as-spun fibers and Fe/FeNx nano-micro fibers were investigated.The specific surface area,crystallization properties and hysteresis loops of Fe/FeNx nano-micro fibers at different calcination temperatures were analyzed.The adsorption properties of nano-micro fibers at different carbonized temperatures to Pb?II?ions and Cr?VI?ions were tested.The results showed that the obtained nano-micro fibers possessed a relatively better morphology when the spinning conditions meet the following demands:38%spinning solution concentration?FeCl₃:PVP=5:2 corresponding to the viscosity of it was 1.81 Pa·s?;spinning voltage of 40 kV and air pressure of 0.1 Mpa.The super paramagnetic Fe/FeNx nano-micro fibers were prepared successfully after the process of carbonized temperature at 800?.The specific surface area of the resultant fibers can reach to 155.866 m2/g which was approximately 50 times higher than that of the corresponding as-spun fibers.Meanwhile the magnetizations of these fibers reach up to 47.3emu/g and have excellent adsorption ability to Pb?II?ions,Cr?VI?ions.The saturated adsorption amounts of two ions reach 79.21mg/g and 64.13mg/g,and the adsorption rates were 78.2%,83.7%,respectively.Secondly,the porous Al₂O₃ nano-micro fibers were prepared by electro-blowing spinning method using alumina sol as the spinning solution and PTFE nanoparticles as the pore-forming agent.The effects of different spinning voltage,spinning pressure and extrusion rate on the morphology of the porous Al₂O₃ nanofibers were explored.Furthermore,the influence of the addition amount of PTFE to the size of pores and porosity in the fibers was also discussed.The chemical components and crystalline structure of the fibers were characterized through the EDS,XPS and XRD technologies.The experimental results showed that the morphology of the as-spun fibers and the calcined fibers was the optimal when the spinning voltage was 30 kV,the spinning pressure was 0.10 MPa and the extrusion rate was 30 mL/h.And the addition amount of PTFE had no significant effect on the pore size of the fiber,but changed the porosity of the fibers.Furthermore,when the amount of PTFE was larger,the pores of the obtained fibers were more.