Dry coating polymer powder particles with deagglomerated carbon nanotubes to improve their dispersion in nanocomposites

Deagglomerated multi-walled carbon nanotubes (MWCNTs) were dry coated onto the surfaces of polyethylene oxide powder particles by magnetic assisted impact coater (MAIC). The deagglomeration of the tightly agglomerated MWCNTs was carried out using two procedures: rapid expansion of supercritical suspension (RESS) of MWCNTs and CO2, and high-intensity ultrasonic agitation of a suspension of MWCNTs in acetone, using an ultrasonic probe. FESEM images show that the high-intensity ultrasonic probe was more effective in deagglomerating the agglomerated MWCNTs than the RESS method. Furthermore, it was found that the extent of PEO particle surface coverage by MWCNTs greatly depends on the extent of deagglomeration.

The SEM image shows multi-walled carbon nanotubes which have aggregated into a massive agglomerate, due to their small size and high inter-particle Van der Waals forces. In order to enhance their dispersion during melt processing, polyethylene oxide particles were initially dry coated with the deagglomerated carbon nanotubes.Figure optionsDownload as PowerPoint slide