Water-Assisted Transformation of Aluminum Alloys to Ceramic Nanowires and Aerogels

Ceramic nanowires (NWs) and their-based aerogels hold great promise for manufacturing and applications of polymer nanocomposites with otherwise unattainable mechanical and thermal properties. Unfortunately, conventional routes for the synthesis of ceramic NWs commonly suffer from the use of costly or toxic chemicals, low production rate, and complex and expensive procedures. Here, we report on a water-assisted route for the cost-effective, scalable transformation of bulk aluminum-lithium alloys into ceramic alumina NWs and aerogels. In this study, we employ water as the intermediary solvent for dealloying to form monolithic porous Li-doped aluminum metal, which can then be converted to ultralong metal-organic NWs, then to hydroxide NWs after hydrolysis and finally to NW aerogels after freeze-drying. As a high-performance thermal interface material for electronic devices, the oxidized alumina NW aerogels infiltrated with epoxy show significantly improved thermal properties. Our study shows great potential for the scalable production of ceramic NWs using a low-cost and environmental-friendly route for various applications.