Design And Process Application Of Nozzle Device For Melt Electrospinning

Melt electrospinning refers to the process of melt jet cooling and solidifying into fibers under high voltage electric field.It has important applications in the preparation of twodimensional patterns,three-dimensional structures and functional devices.The key to realize melt electrospinning lies in the design of its nozzle device.On the basis of fully investigating the melt electrospinning nozzle devices,a new type of melt electrospinning nozzle device was designed to realize the controllable fabrication of melt electrospinning fibers.On this basis,the complex two-dimensional patterns,three-dimensional structures and organic thin film transistors were fabricated.The main research work of this paper includes:(1)Structural Design and Modeling Optimization of Nozzle Device for Melt Electrospinning.The mechanical structure design and component selection of the melt electrospinning nozzle device were carried out by analyzing the requirements of common polymer melt electrospinning.In order to optimize the design scheme of the device,a threedimensional steady-state heat conduction model of the nozzle was established,and the effects of material parameters and structure dimensions of the nozzle components on the steady-state temperature of the nozzle outlet were studied.The electrostatic field simulation model of the nozzle was established,and the field distribution between the nozzle and the substrate was simulated.The rationality of the designed melt electrospinning nozzle structure was verified by thermal simulation and electrostatic field simulation analysis.(2)Design of temperature control system for the melt electrospinning nozzle device.The test platform of the melt electrospinning nozzle device was built.Using the self-tuning function of temperature control instrument of heating device,the fast selection of temperature PID control parameters was realized.The actual steady-state temperatures of nozzle outlet,inner wall of barrel and side plate outer surface under different heating control temperatures were measured.The simulation results showed that the actual temperature measurement results approached the simulation values,which confirmed the accuracy of steady-state heat conduction simulation analysis of nozzle.(3)Study of the process parameters influence on melt electrospun direct-writing polycaprolactone fibers.On the basis of the existing HEIJ-HII multi-functional current jet printing equipment,a melt electrospinning process experimental platform was built.The effects of voltage,temperature,substrate speed,air pressure and jet height on the morphology and diameter of melt-electrospun direct-writing polycaprolactone fibers were systematically studied,and the controllable melt-electrospun direct-writing process was realized.(4)Fabrication of complex two-dimensional/three-dimensional patterns,structures and organic thin film transistors via melt electrospnning.Based on the technology of melt electrospun direct-writing polycaprolactone fibers,and combined with the secondary development technology of AutoCAD,complex multiple pattern paths were quickly generated.Complex two-dimensional patterns and three-dimensional structures with better positioning were successfully fabricated.Finally,organic thin film transistors were fabricated using melt electrospun fibers as mask.