Formation Mechanism Of Taylor Cone And Coaxial Electrospinning Experimental Research

With the rapid development of Nanotechnology, Nano material have shown exhibit unique properties in the field of filtration, biomedicine, sensor and nano electronic devices. Due to its advantages of small diameter, large specific surface to area, simple preparation, low cost, controllable process etc, nanofibers obtained by electrospinning have become focus of research. At present, it is the key to research that how to prepare high performance and multifunctional composite nanofibers. Coaxial electrospinning is developed on the basis of electrospinning apparatus, it appears to make up defects that the preparation of certain non-electrospun fiber material or abnormal structural by electrospinning, which has the advantage of one-step shaping.In this paper, the composite Taylor cone appearance as the main line elaborated mainly from the following parts:Firstly, coaxial electrospinning is the common role of inner and outer layers of the two kinds of solution under the action of electric field, so coaxial electrospinning are more sensitive to the variation of parameters. Then this paper analyzes the mechanism that electro spun into filaments, which effected by solution parameters such as injection fluid viscosity, miscible, interfacial tension, volatile solvent etc, and the process parameters such as flow rate, concentration etc.Secondly, based on momentum, mass and charge conservation mechanism of steady jet on electrospinning process, the relationship is obtained between axial dimensions and cone radius, as follows:1/ 2r(bz1)-= × +, which is based on compound Taylor cone morphology and stable spinning process. At the same time, the experiment with inner using 3wt% chitosan solution and outer 8wt% PEO solution is built to analyze Taylor cone of the action of the tension changes in subcritical, critical and supercritical voltage.Then, in order to research the change of compound Taylor cone morphology on spinning nozzle, a visual electrospinning platform based CCD is built, which includes high voltage DC power supply, syringe pump, spinneret, CCD and control devices. Conventional electrospinning platform could only use roller or flat receiver to obtain nanofibrous membranes, while, in this paper cone locking swivel clip holding mechanism was presented, which made the flexible medical balloon surface direct spinning realisable. Using the platform, it is convenient to observe real-time changes of the composite Taylor cone and jet.Finally, a series of experiment by this platform was carried out in order to getting the change regular of compound Taylor cone formation process. Through observating the formation process of compound Taylor cone, we can obtain that PAN/PLGA solution and chitosan/PEO solution could be more suitable for electrospinning; CCD was used to get Taylor cone morphology, and Markman software was used to get the Taylor cone pixels and the change curve of compound Taylor cone. By analysis the effect of experimental conditions of voltage, concentration, flow rate etc, we include the solution is easy to stretch into cone with the numerical concentration, flow rate and voltage increasing. By electrospinning experiments with PLGA/PAN solution and chitosan/PEO solution, comparing Taylor cone morphology curves with theoretical models, the results can be draw that the experimental results agree well with the theoretical model, when the axial dimension is greater than the initial radius of the stage.