2.1.1. Carbon Nanotubes

The SWCNTs and MWCNTs used in experiments were acquired from RheinChemie-Lanxess, Germany. They are water-based suspensions and can be directly used for production of formulations; their labels are Rhenofit® CNT-3 and Rhenofit® CNT-2, respectively. Table 2 shows the technical data of Rhenofit® CNT-3 and Rhenofit® CNT-2. Figure 1 shows their transmission electron microscope (TEM) images [60]. Agglomerates of CNTs can be observed in the pictures.


**Figure 1.** Transmission electron microscope images of: Rhenofit® CNT-3 (**a**); and Rhenofit® CNT-2 (**b**) from [60].
