Selective wetting of carbon nanotubes in rubber compounds – Effect of the ionic liquid as dispersing and coupling agent

Abstract The role of the room temperature ionic liquid, 1-decyl 3-methyl imidazolium chloride (DMIC) as dispersing and coupling agent in multi-walled carbon nanotubes (CNTs)/styrene butadiene rubber (SBR) compounds was investigated. The kinetics of the selective wetting and dispersion of CNTs, which were pre-treated by DMIC, in SBR compounds was studied by means of two methods: (i) the online measured electrical conductance and, (ii) the modified wetting concept . It was found that DMIC shows a good compatibility to SBR and improves the CNT dispersion significantly. A DMIC layer, which is physically pre-bound to the CNT surface, is partly or completely replaced by the SBR molecules during mixing as a result of thermodynamic driving forces. The filler network formation of CNTs in SBR and its effect on the electrical and mechanical properties of the compounds were characterized and discussed by taking into consideration the selective wetting of CNT surface.