A method for creating nanoparticles directly from bulk metal by applying ultrasound to the surface in the presence of a two‐part surfactant system is presented. Implosive collapse of cavitation bubbles near the bulk metal surface generates powerful microjets, leading to material ejection. This liberated material is captured and stabilized by a surfactant bilayer in the form of nanoparticles. The method is characterized in detail using gold, but is also demonstrated on other metals and alloys, and is generally applicable. It is shown that nanoparticles can be produced regardless of the bulk metal form factor, and the method is extended to an environmentally important problem, the reclamation of gold from an electronic waste stream.

中文翻译：

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使用超声波直接从大量来源形成金属纳米颗粒，并将其应用于电子废物回收

提出了一种在存在两部分表面活性剂系统的情况下，通过在表面施加超声波直接从块状金属中生成纳米颗粒的方法。大量金属表面附近的气穴气泡爆炸性破裂会产生强大的微射流，从而导致材料弹出。该释放的材料被纳米颗粒形式的表面活性剂双层捕获并稳定。该方法使用金进行了详细表征，但也已在其他金属和合金上得到证明，并且通常适用。结果表明，无论金属块体的形状因素如何，都可以生产纳米颗粒，并且该方法已扩展到对环境重要的问题，即从电子废物流中回收金。