Nanomaterials must have consistent and predictable shapes and surfaces as well as scalable production techniques to provide reliable mechanical and electrical properties. Engineers solve this problem by evaporating metals in a magnetic field to direct the rearrangement of metal atoms into predictable shapes. A research related to the field has been published in the Journal of Physical Chemistry Letters. Nanomaterials are made up of particles between 1 and 100 nanometers in size which are usually created in a liquid matrix that is expensive for mass production applications and, in many cases, unmade from pure metals like aluminum or magnesium. The most economical production techniques typically involve vapor phase approaches to create a cloud of particles that condense from the vapor.
Reza Abbaschian, distinguished professor of Mechanical Engineering; and Michael Zachariah, distinguished professor of Chemical and Environmental Engineering at UC Riverside Marlan and Rosemary Bourns College of Engineering; have teamed up to produce nanomaterials from iron, copper and nickel in the gas phase. They put solid metal in a powerful electromagnetic levitation coil to heat the metal above its melting point and vaporize it. The metal droplets are then floated in the gas within the coil and their directions are determined by their inherent reactions to magnetic forces and where they applied magnetic fields. The nanoparticles formed filamentary aggregates while the copper nanoparticles formed spherical clusters. When deposited on a carbon film, the iron and nickel aggregates gave the film a porous surface, while the carbon aggregates gave the film a porous solid surface. Properties of every type of nanoparticle were reflected at a larger scale on the carbon film.
Since the field can be thought of as a 'complement', this approach could be applied to any source of vapor phase generation of nanoparticles where structure is important. This field-directed approach allows you to manipulate the assembly process and change the architecture of the resulting particles from high-dimensional fractal objects to lower-dimensional chain-like structures.
