Preparation of a structural color forming system by polypeptide-based LB films

To prepare novel display systems like chameleon which change the color by s timuli, we prepared a structural color forming system by use of LB films co nsisting of polypeptide multilayers. We think this system change its color depending on the molecular structure like photochemical systems. Poly(gamma -hexyl-L-glutamate) (PHeLG) was used as the multilayer component and silic on was used as the substrate for reflection of incident light. PHeLG monola yers were transferred onto substrates hydrophobized with octadecyl trimetho xy silane (OTS). LB films with various layer numbers up to 160 layers were prepared and they showed different colors depending on the thickness of pol ypeptide layer due to interference of light. The structures of LB films wer e estimated by using AFM and Fr-IR spectroscopy. Interference colors were c haracterized by reflective visible spectra and compared with theoretical on es. Silicon wafer pre-colored by excessive oxidization was also used, and i t was confirmed that only 10 or 20 layers of PHeLG could show the structura l color. In this study, the base for preparation of chameleon-type display system was established. We will introduce photochemical moiety (azobenzene moiety, etc.) into this system and produce display systems which change the ir colors by optical stimuli. (C) 2001 Elsevier Science BN. All rights rese rved.