Chemical Engineers grow nanowires

A team of chemical engineers at the University of Louisville has developed a process for growing nanometer-scale wires that controls the tiny wires size, structure and composition.

The small structures, which are one-thousandth the size of a human hair, are expected to lead to improved design of military, space gear and clothing, fuel cells, sensors and solar devices.

The technique uses pools or thin films of low-melting metals such as gallium to create the nanowires and uses gas-phase chemistry to control its size. Previously, scientists have assumed gold or iron clusters are needed to make a pattern for one-dimensional growth of materials.

The process also allows the scientists to grow nanowires in bulk quantities. The research team grows crops of nanowires by spreading a thin film of molten gallium on a solid suface and exposing it to a gas in an excited state. By controlling the chemistry in a reactor, the group can form multiple nuclei that grow into multiple wires. The process has worked using silicon, carbon, gallium oxide and gallium nitride nanowires.

Chemical engineer Mahendra Sunkara will give a presentation on the process in November at annual meetings of the Materials Research Society and the American Institute of Chemical Engineers.