Alcohols responsive photonic crystals prepared by self-assembly of dendronized block copolymers

Abstract

Photonic crystals are widely used in chemical sensing for their visually color change. In this work, by proper design of the dendronized brush block copolymers, one dimensional photonic crystals (1D PCs) films that turned to different colors with different alkyl alcohols, alcohols isomers and alcohols mixtures were reported. Specifically, dendronized block copolymer (P(NAM-r-NDMA)-b-PNBM) with alcohols soluble PNAM block and alcohols insoluble PNBM block was prepared by sequential ring-opening metathesis polymerization of the corresponding monomers. The 1D PCs films with lamellar structures were prepared by self-assembly of P(NAM-r-NDMA)-b-PNBM. By swollen in alcohols and alcohol isomers with carbon numbers less than 8, the domain size of the 1D PCs changed, and the reflected wavelength red shifted to show different color as a result. Furthermore, in the binary alcohols mixtures and the alcohol aqueous solution, the color of the film changes with variation of the component, which can be used in semi-quantitative analyses. The alcohols responsive 1D PCs are very promising in visual, portable and reusable detection of alkyl alcohols.