Process And Parameter Analysis Of Carbon Nano Materials Prepared By Electric Explosion Graphite

Carbon nanomaterials have a wide range of applications in sensors,solar cells,biomedicine and other fields due to their excellent properties.With the in-depth research on the application of carbon nanomaterials in various fields by researchers,how to prepare carbon nanomaterials efficiently,at low cost,and on a large scale has become a new research hotspot.At present,the preparation of carbon nanomaterials has problems such as high cost,complex process flow,and damaged product structure.The preparation of carbon nanomaterials by electric explosion method has the characteristics of high efficiency,low cost,high product purity,easy adjustment of parameters,and environmental protection.Therefore,the preparation of carbon nanomaterials by electric explosion method has important research significance.In this thesis,based on the characteristics of pulsed power technology,an electric explosion experiment platform for the preparation of carbon nanomaterials was constructed by using the electric explosion method of gas discharge to introduce pulsed high current.The experimental platform uses the electric explosion control system to control the electric explosion process to realize the functions of continuous electric explosion and automatic powder feeding.According to the working principle of the electric explosive device,the control target is determined,and the control system based on the programmable logic controller is designed.The control system is divided into a high-voltage charging part and a low-voltage control part.After completing the wiring of related components and debugging of the electric explosion device,the electric explosion experimental platform can run stably and continuously.Based on the analysis of electric explosion mechanism and experimental data,the equivalent circuit model and specific action model of electric explosion discharge circuit are established.On this basis,PSpice software is used to simulate the process of graphite powder electric explosion.The simulation results show that the current peak value can be increased by increasing the charging voltage or reducing the resistance and inductance in the electric explosion discharge circuit,thereby increasing the deposition energy on the graphite powder and reducing the size of the electric explosion product.Using the self-developed electro-explosive graphite preparation experimental platform for carbon nanomaterials,the graphite powder electro-explosion experiments were carried out under different charging voltages,graphite powder particle sizes,and confinement tube diameters.Electron microscope of the product was used to analyze the influence of different parameters on the deposition energy and the microscopic morphology of the electro-explosive products.The results show that under the condition of the same confinement tube diameter and graphite powder particle size,with the gradual increase of the charging voltage,the graphite powder is heated evenly,the current rising rate decreases,and the current peak value and the deposition energy of the graphite powder increase.Under the condition of tube diameter,the resistance of graphite powder with larger particle size is relatively large,the temperature rises rapidly,the gas on the surface of graphite particles is ionized earlier,the bypass discharge circuit is turned on in advance,and the gas temperature in the restricted tube increases rapidly and the gas volume expands rapidly.,the electric explosion occurred in advance to prevent the further deposition of energy on the graphite powder;under the conditions of the same charging voltage and graphite powder particle size,the smaller confinement tube has better high temperature regulation and restraint,the pressure in the confinement tube is larger,and the electric When the explosion occurs,the initial velocity of the graphite particles is higher,and the fragmentation and peeling effect of the graphite particles is good.Under this experimental platform,the electroexplosive products prepared under the experimental conditions of 600 mesh graphite powder,14 k V charging voltage,and 4mm confinement tube diameter are mainly nanoscale products.