Functional polyelectrolyte multilayer assemblies for surfaces with controlled wetting behavior

Abstract

Controlled wetting at surfaces and interfaces is an important area of research with numerous potential commercial applications. Both superhydrophobicity and superhydrophilicity can be used to enable applications such as self-cleaning, dropwise condensation, or antifogging. Many strategies for creating such surfaces center around biomimicry, replicating the structure of the lotus leaf, for example. Given the potential impact, creating surfaces with these properties using any number of fabrication is of great interest. One very promising fabrication technique, however, for creating these surfaces is the layer-by-layer (LbL)-directed self-assembly of polyelectrolytes and other charged materials. LbL is a sequential adsorption technique wherein a surface is exposed to first a solution of one charge and then a solution of the opposite charge. LbL has many advantages, including the ability to incorporate many different types of materials and therefore functionality, the ability to conformally coat substrates of complex geometry, and environmentally friendly aqueous processing. This review describes recent progress in using LbL to create surfaces with controlled wetting.