Development Of Intelligent Rotating Micro-bomb Calorimeter

In the field of combustion calorimetry,bomb calorimeter is a most direct and effective instrument for determining the thermal values of substance.The oxygen bomb calorimeter has a wide application to determine the combustion heat of pure substance in basic and applied research.The standard combustion enthalpy and standard enthalpy of formation are calculated on the basis of the combustion heat of pure substance,which is a quite significant issue.Rotating bomb calorimetry attaracted serious concern,because chemical reaction is easy to reach thermodynamic and chemical equilibrium,and the obtained data is more accurate and reliable.The massive literature shows that the use of small sample and accuracy is the prominent contradiction.Based on the thermochemical principle,a rotating micro-bomb calorimeter is established to resolve the contradiction between sample quantity and accurate measurement.The research will promote the development of microcalorimetry.This thesis is supported by National Natural Science Foundation of China,NO.21127004,namely "the development of intelligent rotating micro-bomb calorimeter".The main research work includes the following four parts:1.Overview of the development of bomb calorimeter at home and abroad.Based on the calorimetric principle of the oxygen bomb calorimeter,a new design ideology is established about the bomb calorimeter,which breaked through the design idea of reducing the heat leakage for traditional bomb calorimeter,redefined the testing system and environment of oxygen bomb calorimeter,and harmonized the conflict between a small quantity of sample and measured accuracy.2.Development of intelligent rotating micro-bomb calorimeter.Based on the target of reducing the amount of samples,improving the precision and accuracy of measuring result,this thesis successfully designed and developed an intelligent controlled rotating micro-bomb calorimeter with samples of mass about 10?30 mg.The instrument consists of a burning system,adiabatic system,measurement and control system and software system.The combustion system is designed to ensure complete combustion of sample in excess oxygen.The adiabatic system by air adiabatic mode controlls the can temperature to(25±0.001)?.The measurement and control system realizes the real-time monitoring,temperature signal acquisition and processing,signal output and amplification for temperature change of bomb and can of calorimeter.The developed software system can automatically analysis and process the collected data,and realize the function of curve correction,calculation,storage,printing,and so on.3.Evaluating the accuracy and precision of established rotating micro-bomb calorimeter through the calibration experiment.The energy equivalent of the instrument was determined by the calibration of electrical energy and standard benzoic acid.The experimental results show that the instrument has a good reproducibility,its run is stable and reliable,and each part can work in coordination,which basically meets the design requirement.The test experiment results of salicylic acid,urea,1,2,4-triazole,thianthrene and 4-chlorobenzoic acid demonstrate that the calorimeter is completely suitable for the determination of compound containing the element of C,H,O,N,S and Cl.Its measurement accuracy and precision can reach 0.6%and 0.09%,respectively.4.An energetic compound was synthesized with ligands containing high nitrogen and Zn ion,and its structure was characterized by single crystal X-ray diffraction.Its thermal stability,impact and friction sensitivity were also determined.The heat of explosion,explosion pressure and explosion rate is calculated by using the density functional theory.The results demonstrate that the synthesized compound is a high-energy-density material with good thermal stability,low sensitivity and high heat of explosion.Moreover,the combustion heat of energetic compound was firstly determined using the developed calorimeter,and the standard molar enthalpy of combustion and standard molar enthalpy of formation of the compound were calculated.These results laid a foundation for the instrument applying to the determination of energetic materials in the future.