(660h) Micro/Nano Topographical Multilayer Thin Films By Tuning Dipping Time and Molecular Weight of Polyelectrolytes

Surface topography of materials plays an essential role in surface wettability and cell adhesion, which facilitates many applications, such as anti-fouling coatings, self-cleaning surfaces, microfluidic devices and medical implants. For different circumstances, controlled surface topography within different length scales is required. Layer-by-layer (LbL) assembly is considered as a highly versatile deposition technique for fabricating functional thin films. In this work, poly(allylamine hydrochloride) (PAH)/ poly(acrylic acid) (PAA) multilayers were fabricated. In order to study the molecular weight effect on the surface topography thoroughly, we fabricated the multilayer thin films using polyelectrolytes with widely different molecular weights for both PAA and PAH. The effect of dipping time on the surface topography was also studied in details. The dipping time was applied ranging from 10 s to conventional 15 min. It was found that both dipping time and molecular weight of polyelectrolytes affected the surface topography significantly, as well as the film thickness. In this work, we were able to control the surface topography and obtain both micro- and nanostructured surfaces.