Binary films composed of azobenzene-based amorphous molecular materials and p-toluene sulfonic acid were found to exhibit drastic and reversible colour change when we breathed onto their films.
Phase separation of the mixed film of an azobenzene-based photochromic amorphous molecular material, 4-[bis(9,9-dimethylfluoren-2-yl)amino]azobenzene, and a quaternary ammonium salt, tetrabutylammonium tetrafluoroborate, could be induced to form dissipative self-assembled microstructures not only by heating but also by photoirradiation. Fabrication of a micropattern and a relief grating composed of the quaternary ammonium salt by irradiation of the film followed by rinsing with hexane was demonstrated. The present study indicates that the mixed films of amorphous molecular materials and quaternary salts are novel candidates for micro- and nano-patterning materials.
In due course of our studies on photomechanical effects observed for azobenzene-based photochromic amorphous molecular materials, photoinduced change in phase-separated structure of an amorphous binary film composed of title materials has been investigated in the present study. When the phase-separated film was irradiated with a linearly polarized laser beam, the circular domains in the film extended in the direction parallel to the polarization direction of the incident laser beam. The rate of such photoinduced extension was found to increase with increasing temperature. The result seemed to be contrary to the results of the temperature dependences of other photomechanical effects observed for photochromic amorphous molecular materials we have previously reported.Azomolecules were suggested to exist both in the domains and in their surroundings and it is of importance to consider the both effects of azo-molecules existed in the domains and in their surroundings for phase-separated binary systems.
We have found that fluorescence emission of binary films composed of fluorescent amorphous molecular materials, 4-[bis(4methylphenylaryl)amino]benzaldehyde (BMABA) and 4-[bis(4methylphenylaryl)amino]acetophenone (BMAAP), with p-toluenesulfonic acid (TsOH) was quenched at ambient dry atmosphere but enhanced when we breathed onto their films. When pausing the breath, the emission was again quenched. Moisture in the exhaled breath was suggested to play a role for such phenomena. It was suggested that some BMABA and BMAAP molecules were protonated in their films as prepared at ambient dry atmosphere and that protonation and deprotonation took place corresponding to change in surrounding humidity, resulting in modulation of emission intensity.
Mixed films of the title aminoazobenzene with a few different conventional organic acids exhibited drastic and reversible colour changes when exposed to exhaled breath.
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