Transcript – Generating Nanoparticles Using Supercritical Fluids

My name is Dorrin Jarrahbashi, assistant professor at the Mechanical Engineering Department. The topic of this research is generating nanoparticles using supercritical fluids. At the objective of this research is to introduce a novel process for bottom up fabrication of engineered nanostructures using self-assembly of nanoparticles through evaporation or particle laden droplets. This process includes the dispersion and stabilization of nanoparticles in a solvent to make particle suspension that contains a single type or hybrid system of nanoparticles because it is different types of nanoparticles, including carbon nanotube, graphene, nitride and cellulose nanocrystals. The second step includes this framing of this colloidal suspension to form a control size droplet distribution that carries these nano particles and delivers them on a substrate we use of critical CO2 to enhance atomization because supercritical CO2 reduces the interfacial tension of the liquid solvent and also it enables these all gas atomization.

Both of these effects helps to reduce the size of the droplets and create a very uniform distribution of droplets. This is critical for coating purposes, especially when you would like to control the uniformity of the flow of the field that is formed on a substrate. Our results showed that regardless of the shape and size of these nanoparticles, we were able to control the patterns and we were able to resolve very interesting and different patterns forming with these hybrid nanoparticles. And the patterns are varied from a shape to uniform distribution of nanoparticles to a ring with a wireline structures of nanoparticles. And this is very important in applications such as pharmaceutical and electronics or manufacturing composites. That is really critical to control the patterns of these nanoparticles on a substrate.