Dispersion of Carbon Nanotubes Using Multiple Rapid Expansion of Supercritical Suspensions

The degree of deagglomeration of carbon nanotubes (CNTs) was correlated with the number of treatments by rapid expansion of supercritical suspensions (RESS) under different conditions. Two RESS treatments make it possible to increase the degree of CNT deagglomeration more efficiently than one treatment. Three treatments in the case of the nitrogen solvent lead to a slight increase in the degree of dispersion compared to two treatments. When the CO₂ solvent is used, three treatments lead to a lower degree of dispersion compared to two treatments. When nitrogen is used as a dispersion medium, changes in the temperature and pressure do not lead to a change in the degree of dispersion of CNTs. In the case of CO₂, a decrease in the fluid density ensures higher efficiency of CNT processing. Thus, for efficient dispersion of CNTs by multiple RESS, it is reasonable to use either two treatments with nitrogen or treatment with low-density CO₂.