Title: Ionic strength-driven cavitation nucleation: from energy deposition-based to tension-based cavitation Show Chinese title

Title: 离子强度驱动的空化核化：从基于能量沉积到基于张力的空化

Abstract: In this work, we present a unified experimental and simulation investigation of cavitation in aqueous electrolyte solutions, combining nanosecond laser-induced optical breakdown and all-atom molecular dynamics (MD) simulations under tensile stress. Across both cavitation scenarios, we find that cavitation inception and intensity (bubble nucleation count, cavitation-zone length, vapor-volume fraction) are governed by ionic strength alone, with negligible dependence on the ion species. In laser experiments, increasing ionic strength lowers the breakdown threshold and amplifies bubble generation by supplying extra seed electrons for inverse Bremsstrahlung-driven avalanche ionization. We elucidate the mechanism of action of the ionic strength through the MD simulations, which essentially quantifies the net charge density in the bulk, and thus its combined influence on the generation of seed electrons and the perturbation of the hydration network. These findings identify ionic strength serving as a unifying parameter controlling cavitation in electrolyte solutions: whether driven by rapid energy deposition or by tensile stress imposed. Show Chinese abstract

Abstract: 在这项工作中，我们针对水性电解质溶液中的空化现象进行了统一的实验与模拟研究，结合了纳秒激光诱导光学击穿以及在拉应力下的全原子分子动力学（MD）模拟。在两种空化场景下，我们都发现空化起始和强度（气泡成核计数、空化区域长度、蒸汽体积分数）仅由离子强度决定，且对离子种类的依赖可以忽略不计。在激光实验中，增加离子强度会降低击穿阈值，并通过为逆韧致辐射驱动的雪崩电离提供额外的种子电子来放大气泡生成。我们通过分子动力学模拟阐明了离子强度的作用机制，这些模拟本质上量化了体系内的净电荷密度，从而揭示了其对种子电子生成和水合网络扰动的综合影响。这些发现表明，离子强度是控制电解质溶液中空化的统一参数：无论是由快速能量沉积还是施加的拉应力所驱动。