Streamlining The Hydration of Micron-Sized Aluminum Particle Surface Towards Enhanced Power Generation

Aluminum particles possess a core-shell configuration in which an aluminum core is covered by a passive alumina (Al₂O₃) shell. This Al₂O₃ shell acts as both a heat sink and a barrier for reactions which impedes the process of harnessing the substantial chemical energy potential of Al, which stands at 31MJ/Kg. Hydrating the Al surface has the potential to replace the Al₂O₃ shell with Al(OH)₃, a material with favorable properties for energy extraction. While nano-sized Al particle surfaces can be hydrated by controlling the pH, micron-sized particles require external heating and subsequent aging because of 90% decrease in surface energy. Applying temperature above 35C to Al- water solution can expedite the formation of AlOOH and prolonged aging can lead to excessive consumption of Al core, both of which have adverse effect on the potential energy of the sample. For small amount of Al powder (230mg) controlling the temperature at 35C for a minimum of 18 hrs, Al(OH)₃ shell formation in place of Al₂O₃can be achieved with 96% Al core still unconsumed. To hydrate a larger amount of powder (2gm) in a short period of time, high temperature (100C) is necessary to produce Al(OH)₃. Heating Al powder for 25mins at this temperature can produce 5% Al(OH)₃ with most of the Al cores (95%) unconsumed. Moving up to 30mins the powders have a trace of 3% AlOOH. TEM images of 18hrs at 35C and 25mins at 100C both have similar fuzzy surfaces. Upscaling the hydration process for micron-sized Al powder can lead to a time-saving method for larger quantities of Al and aid in producing modified shell-core properties that can be exploited for enhancing power generation techniques.