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%.

地球动力学、地球化学以及冲击诱发过程的阐明，常受限于分子流体状态方程（EOS, Equation of State）精准测定的技术难题。碳组分的高压液相反应，是行星内部分异、深部碳封存、推进剂爆燃以及冲击化学等物理化学机制的核心基础。本研究引入一种通用型光声技术，用于精准测定高压分子流体及其混合物的绝热声速。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Exponential-6原子间势模型，可用于状态方程的求解，以及对2000℃以上热力学状态（包括硼有机配方的能量释放过程）开展对应的半经验评估。本研究的热化学模型对含硼烃类冲击雨贡纽状态的预测结果，与实验值的偏差小于3%。