Fabrication of directionally aligned carbon nanotube thin films on solid surfaces using chemical patterns

Abstract

We propose a simple fabrication process of directionally aligned single-walled carbon nanotube (SWCNT) thin films. This process consists of dropping of a highly dispersed SWCNT suspension followed by its drying. We used a substrate surface on which hydrophilic and hydrophobic patterns are formed by chemical processes. A SWCNT suspension dropped on the hydrophobic areas is transferred to the hydrophilic areas in the early stage of the drying. During the drying, the SWCNTs in the suspension are self-aligned by the surface tension. When the degree of hydrophilicity on the hydrophilic areas is too large, deposition of the SWCNTs on small hydrophilic areas is blocked by the repulsive force owing to hydration between the hydrophilic substrate and the SWCNT surfaces. We demonstrated that narrow line patterns of the SWCNT thin films can be fabricated by controlling the hydrophilicity on the hydrophilic areas on the substrate. © 2010 The Surface Science Society of Japan.