Self-assembly multi-layer of 1,3-bisdicyanovinylindane and its spectral sensing properties

The multi-layer dye film as an acid-alkali reversible sensing material has been fabricated using poly(diallyldimethylammonium chloride) (PDDAC) and 1,3-bisdicyanovinylindane dye compound by electrostatic forces and layer-by-layer self-assembly attractions. These dye layers show reversible color switchable properties. The dye shows blue colored characteristic in alkaline condition. However, when strong acidic atmospheres are subjected to colored dye structure, it converts to the colorless form of the dye structure within the multi film layers. These results were characterized using absorbance measurement and Atomic Force Microscopy (AFM). UV-vis absorption spectra of the multi-layer films increased linearly at 583 nm, which indicated that fabrication of the dye layer as a sensing moiety proceeded regularly. The dye fabrication films also clearly showed the hydrochloric gas sensing properties with reversible color changes.