Effect of Conditions on Formation of String-like Structures in CNT Dispersions under Alternating Simple Shear Flows

Abstract

In this study, we have investigated formation processes of string-like structures (Helical Band; HB) in carbon nanotube (CNT) dispersions under alternating simple shear flows applied. Two types of UV curable insulating resins having different viscosities were utilized as carrier liquid and CNT suspensions were cured with a UV light after the HB formation processes. The conductivities in parallel and cross directions to the HB structures in composites were measured and influence of the viscosities was examined with the two types of composites. In the suspension with the low-viscosity carrier liquid, HB were formed with smaller strain applied, but the resistivity of the parallel direction became larger and then insulated as the strain was increased. In contrast, larger amount of strain was necessary to form HB structures with high-viscosity resin and an almost constant conductivity of the parallel direction was kept regardless of the strain applied.