Photoacoustically Measured Speeds of Sound of Liquid HBO₂: Semi-Empirical Modeling of Boron-Containing Explosives

Elucidation of geodynamic, geochemical, and shock-induced processes is often limited by challenges to determine accurately molecular fluid equations of state (EOS). High-pressure liquid-state reactions of carbon species underlie physicochemical mechanisms such as differentiation of planetary interiors, deep carbon sequestration, propellant deflagration, and shock chemistry. Here we introduce a versatile photoacoustic technique developed to measure precise adiabatic speeds of sound of high-pressure molecular fluids and fluid mixtures. Metaboric acid, HBO2 speeds of sound are measured up to 0.5 GPa along the 277 °C isotherm. A polarized Exponential-6 interatomic potential form, parametrized using our data, enables EOS determinations and corresponding semiempirical evaluations of >2000 °C thermodynamic states including energy release from bororganic formulations. Our thermochemical model predictions of boronated hydrocarbon shock Hugoniot states differ from experiment by <3%.准确测定分子流体状态方程（Equation of State，EOS）所面临的诸多挑战，往往制约了人们对地球动力学、地球化学以及冲击诱导过程的阐明。碳物种的高压液态反应是诸多物理化学机制的核心基础，包括行星内部分异、深部碳封存、推进剂爆燃以及冲击化学过程。本文介绍了一种通用光声技术，该技术可精准测定高压分子流体及其混合体系的绝热声速。本研究沿277℃等温线，在最高0.5吉帕斯卡（GPa）的压力条件下，测定了偏硼酸（HBO₂）的声速。基于本研究数据参数化得到的极化型指数-6（Exponential-6）原子间势模型，可用于状态方程（EOS）的计算，并能对超过2000℃的热力学状态开展半经验评估，涵盖含硼有机配方的能量释放过程。本研究构建的热化学模型对含硼烃类冲击雨贡纽（Hugoniot）状态的预测结果与实验值的偏差小于3%。