The Optimal Design Of Gas-liquid Detonation Tube And Research On The Preparation Of Nanomaterials

The detonation method is a technical method in which the precursors are rearranged to form nanomaterials after cracking under the conditions of high temperature and high pressure caused by detonation.It is a product of the intersection of explosion mechanics,materials science,physics and many other disciplines.It is also one of the popular research directions at home and abroad.The method has a series of characteristics such as simple operation,high efficiency,low pollution and low cost.The gas-liquid detonation method is a new type of technical method,which uses a high-energy igniter to directly detonate a uniformly mixed gas-liquid detonation precursor,which is convenient to operate,and the prepared nanomaterials have high purity and good dispersion However,the nanomaterials prepared by the detonation method are formed in the transient temperature field and pressure field.The prepared nanomaterials are relatively uncertain.It is very important to explore the influence of the initial conditions on the detonation flow field and the preparation of nanomaterials.In this paper,a self-designed gas-liquid detonation device was used to measure the detonation flow field parameters and prepare nano-titania and carbon nanotubes.At the same time,combined with X-ray diffraction(XRD),transmission electron microscope(TEM),and Raman spectroscopy(Raman),X-ray photoelectron spectroscopy(XPS)and other modern analytical methods have investigated the morphology and crystal structure of the synthesized product.The main research contents are as follows:1.Combining the CJ detonation theory,gas-liquid detonation theory and the semi-empirical surface energy model proposed by Canadian scholar Lee and related experimental data and empirical formulas,starting from the critical pipe diameter and the ignition energy of direct detonation,the ignition energy and the pipe body are verified The length and inner diameter are the key factors that can satisfy the stability of explosion propagation;the strength of the tube body is checked according to the pressure,temperature and explosion theory that may be generated in the experiment,which verifies the safety of the gas-liquid detonation equipment.2.The detonation flow field evolution characteristics of a mixture of methane-oxygen,acetylene-oxygen and hydrogen-oxygen were tested using a detonation tube with an inner diameter of 36mm;the pressure data of the detonation process was monitored by a pressure sensor.The size of the detonation cell size of methane-oxygen and hydrogen-oxygen;by changing the initial pressure,the change law of detonation velocity,detonation pressure and detonation cell size was explored,and the feasibility of forming the detonation condition was verified.3.The polycrystalline nano-TiO₂ was synthesized by a gaseous-liquid detonation(GLD)method using H₂,O₂ and Ti Cl₄ as the mixture precursors.The influence of the molar ratio of precursors and initial reaction pressures on the nano-TiO₂ crystalline structures were studied systematically.The product nanocrystal structures,components,particle sizes,and morphology were characterized by the X-ray diffraction(XRD)and transmission electron microscopy(TEM).The experimental results demonstrated that the prepared nano TiO₂ are pure anatase,pure rutile and mixed titanium dioxide,and the basic characteristics are spherical or quasi-spherical.The particle size range is 20-150nm;the relevant detonation parameters are calculated according to the CJ state and related chemical reaction data,and the influence factors of the precursor ratio and initial pressure change on the preparation of polycrystalline nano-TiO₂are explored.4.Using gas-liquid detonation method,using methane,oxygen,ferrocene and naphthalene as precursor to prepare nano-body-centered cubic iron crystals and iron carbide crystals and multi-walled carbon nanotube nanocomposites containing iron-based nanoparticles;The composition and structural properties of the as-obtained composites were investigated by XRD,TEM,XPS and Raman spectroscopy.The obtained composites were also applied to the electric double-layer capacitor.The results showed that the specific capacitance of CNTs@Fe/Fe₃C can reach 125 F·g^-1 at the current density of 100 m A·g^-1 and after 10000 cycles the capacitance retention is 93.1%at a current density of 2 A·g^-1.This paper has 66 figures,15 Tables,and 170 references.