Mass production of nanowires and nanorods using ball milling and annealing processes
The fundamental problem of commercialising emerging technologies related to nanomaterials is in the scaling-up of materials successfully grown in the laboratory so that they can be produced in bulk and also tested at that level. Only when this is achieved can the hope of efficient commercialisation be realised. This research direction is related to the development of a new synthesis route for nanowires and nanorods based on ball milling and annealing.
Major achievements
A solid-state, mass-quantity transformation from V2O5 powders to nanorods has been realised by ball milling with the subsequent annealing in a fluidised bed. The nanorods were formed through controlled nanoscale growth from the nanocrystalline V2O5 phase created by a ball milling treatment. The nanorods grow along the [010] direction and are dominated by {001} surfaces. Surface energy minimisation and surface diffusion play important roles in their growth mechanism. Large quantity production can be achieved when the annealing process is conducted in a fluidised bed which can treat large quantities of the milled materials at once.
We have also demonstrated a new method for mass production of TiO2 nanorods from mineral ilmenite sands (FeTiO3). In this process, powder mixtures of ilmenite and activated carbon were first ball milled; the milled samples were then heated twice at two different temperatures. First high-temperature annealing produced metastable titanium oxide phases, and subsequent second low-temperature annealing in N2-5%H2 activates the growth of rutile nanorods. This solid-state growth process allows large-quantity production of rutile nanorods.
Future plans and directions
Mass production of Nanowires and nanorods using ball milling and annealing process.
