Mussel-inspired UV protective organic coatings via layer-by-layer assembly

Abstract

Layer-by-layer (LbL) deposition technique has been employed to design mussel-inspired UV protective organic coating using polyethylenimine-polydopamine (PEI-PDA) and poly (acrylic acid) (PAA) pairs. The photocatalytic decomposition of RhB (Rhodamine B) is studied inside the multilayer coated glass vials and a 10 BLs (Bilayers) coatings with a thickness of 1 µm reduces the degradation efficiency of the dye by a factor of 7. The nanocomposite films remain stable under a broad range of pH (pH 4 to pH 10) and temperature (250 °C). The presence of PDA in the nanocomposite films offers a substrate independent adhesion and the film has grown conformally on diverse substrates like cotton and poly(ethylene terephthalate) (PET) using spray assisted LbL coating. Moreover, a study has shown that LbL deposited films have better UV protection efficiency compared to traditional “one pot” PDA deposited films. Finally, these environmental friendly multilayer films are able to protect the degradation of conducting poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films from long UV exposure.