The manner in which nanoparticles travel and diffuse in a fluid or on a surface under extreme to non-ideal conditions is the basis of some of the latest nanotechnology advancements.
Rigoberto Hernandez
A research team of Rigoberto Hernandez from Georgia Tech probes these relationships by investigating simulations of three-dimensional particle dynamics on high-performance computers. During the simulation study, the research team aligned the nanorod scatterers either in ordered (nematic) state or in disordered (isotropic) state.
When the nanorods were misaligned and made to point in different directions, the team discovered that there was a uniform diffusion of a particle in all directions. In the nematic state wherein the rods are pointing in one direction, the diffusion of the particle, on an average, occurred more in the direction of the rods than in the direction of the grain of the rods. In this ordered state, the movement of the probe imitated the scatterers’ elongated shape.
The research team also discovered that sometimes the particles diffused quicker in the ordered state than in the isotropic state. This means that by keeping the channels open between the nanorods in the nematic state not only direct the nanoparticles but also accelerate them to move along a direction. The channels get crowded due to the rise in the density of the scatterers, thus significantly slowing down the particle diffusion in the simulation. However, even at this state, the nematic scatterers allow faster diffusion when compared to disordered scatterers.
According to Hernandez, these findings are helpful in designing a nanorod device capable of controlling the flow of nanoparticles. These devices pave the way to develop novel information flow, light patterns and other microscopic triggers, Hernandez added.