Authors: T. Panagiotou, J.M. Bernard, S.V. Mesite
Affilation: Microfluidics, United States
Pages: 39 - 42
Keywords: carbob nanotubes, deagglomeration, dispersions, composites, Microfluidizer
Microfluidizer processors are used for reduction and/or deagglomeration of particles in liquid media. These continuous processors force multiphase fluids through microchannels at velocities of up to 500 m/s, exposing them to high shear and impact stresses. Energy dissipation through turbulence exceeding 107W/kg takes place inside microliter size volumes. Under these conditions the particles deagglomerate and/or break into smaller particles. The energy dissipation level is controlled by the initial pressure of the fluid, which can be as high as 276 MPa (40,000 psi). This technology is scalable to tens of liters per minute. Microfluidizer high shear fluid processors were used successfully to deagglomerate and disperse single- and multi-wall carbon nanotubes in a variety of liquids. Such liquids included polymer resins, mineral oil, organic solvents and water, with CNT concentrations in the range 0.38- 6%. FESEM, optical microscopy, particle size analysis and electrical conductivity were used to determine the effect of processing on these CNT formulations. Single or bundles of nanotubes become apparent in the processed samples using FESEM, while they were absent in the unprocessed samples.Depending on the processing conditions, the length of single nanotubes or bundles either stayed constant or was reduced in a controlled manner.