Hydrophobic polymer-incorporated hybrid 1D photonic crystals with brilliant structural colors via aqueous-based layer-by-layer dip-coating

Abstract

Preparation and application of photonic crystal (PC) films with structural colors have received extensive attention in recent years. Aqueous-based layer-by-layer (LbL) dip-coating is an environmentally friendly and versatile method to prepare functional films. This work focuses on using the method to prepare a kind of hydrophobic polymer-containing 1D PCs with brilliant structural colors. High and low refractive index stacks are produced by electrostatic assembly of nano TiO2/poly (styrene sulfonate) (PSS) and poly (diallyldimethyl ammonium chloride) (PDAC)/nano poly (methyl methacrylate) (PMMA) multilayers, respectively. Hydrophobic PMMA was introduced for the first time in this aqueous-based electrostatically-assisted assembly for expanding the applicable materials. The zeta potential and particle size of the PMMA and TiO2 nanoparticles are measured under different pHs, and the effects of the bilayer number on both film thickness and refractive index are investigated. The structural colors of the heterostructure 1D PCs can be regulated in the visible range by variation of bilayer number, incident angle and stack number. This hydrophobic polymer incorporated 1D PCs can achieve colorful coatings on flat and curved glass substrates. In addition, upon exposure to organic solvent vapors, the PC film shows color change. Thereby, the obtained multilayered PCs exhibit potential applications in coating, decoration and sensing.