Chemical Separation Through Thermomechanical Nanomolding

We introduce thermomechanical nanomolding (TMNM), a method that can separate an alloy by its constituents’ diffusivities. Filling of the nanocavities which can be extrusion dies of nanoscale dimensions is based on atomic diffusion and the composition of the extruded or nanomolded material is a function of the relative diffusivities of the constituents and their nominal composition. Based on TMNM we developed separation methods for gold from gold containing aluminum alloys, which is challenging to separate with state-of-the-art methods.<br/>We show, particularly through the use of silicon, which is either added to the alloy or used as a mold material, that highly enriched in gold material is separated into the nanocavities. We argue that proposed method is not limited to gold and aluminum separation but can be applied to a wide range of alloys that exhibit alloy constituents with different diffusivities of the constituents.