“…Different loading levels of CB in polymers have been reported to exhibit percolation thresholds from <1 vol.% to tens of vol.% loads [30]. As stated above, PT strongly depends on the nature of the polymer matrix (e.g., the higher the polymer polarity or surface energy, the higher the PT [34]), CB type (particle size, surface area, oxidation state [49,51]), CB structure (the "lower" the structure, the higher the PT [30,45]), the adhesion between CB and polymer [53], the method of the preparation of the composite [48], mixing, and potential addition of salts (which lowers the potential barriers between CB particles) [36,44,47]. Depending on the surface treatment of CB particles, different functional and volatile groups (phenols, carboxylic acids) [49,51,54] can exist on the CB surface.…”