Seamless control of the electrical property of carbon nanotube buckypapers by a simple mixing approach

•Properties of buckypapers can be seamlessly controlled by mixing.•Electrical conductivities and thermal diffusivities are correlated.•Crystallinity affects above properties only in higher ranges. Controlling the properties of materials such as electrical conductivities has become more important to satisfy the requirement for objective applications. Carbon nanotubes (CNTs) exhibit high electrical conductivities thus are potential to fabricate high performance electrically conductive materials. However, controlling these electrical conductivities into a desired range is still challenging due to the difficulty of adjusting their dispersion state. In this study, we aimed to achieve the control on electrical conductivities of CNT buckypapers, by utilizing mixed dispersions of several kinds of CNTs. This simple mixing approach realized seamless transitions of electrical conductivity between those of two sole counterparts. Moreover, we have also investigated the thermal diffusivities of obtained buckypapers, revealing an intriguing correlation between electrical conductivities and thermal diffusivities. This finding would provide profound suggestions to the applications which both electrical and thermal conductions by CNTs are employed.