Nanostructured thin films made by dewetting method of layer-by-layer assembly.

Abstract

Layer-by-layer (LBL) assembly is one of the most ubiquitous coating techniques today. It also offers a pathway for multifunctional/multicomponent materials with molecular-scale control of stratified structures. However, technological applications of LBL are impeded by laborious and fluid-demanding nature of the process. While vertical organization of LBL films is natural for this technique, the control of lateral organization of the films is fairly difficult. Using the deposition of carbon nanotubes (SWNTs) and other nanoscale colloids, we introduce here a new approach to LBL based on dewetting phenomena, d-LBL. Its strengths include: (1) elimination of rinsing steps, (2) significant acceleration of the process, (3) improvement of lateral organization of LBL films, and (4) ability to produce nanostructured coatings from colloids when classical LBL fails. The generality of d-LBL can compete with traditional LBL and is demonstrated for cellulose nanowires, polyelectrolyte pairs, and semiconductor nanoparticles, metal oxides, and Au nanorods.