A novel multiplayer film was assembled from poly[(4 carboxyphenyl)acetylene](PCPA) and diazoresin(DR) in aqueous solution via electrostatic attraction. Under UV irradiation, following the decomposition of diazonium group between the adjacent interfaces of the multiplayers, the ionic bonds of the self assembly film convert to covalent bonds and the film becomes very stable toward electrolyte solutions. Thus the photoelectric conversion property of poly[(4 carboxyphenyl)acetylene] containing film can be measured in conventional three electrode photoelectrochemical cell, and 0.5 mol/L KCl solution can be used as the supporting electrolyte. The photocurrent spectroscopy responses coincide with the absorption spectrum of the irradiated self assembly film, which indicates that the irradiated DR/PCPA film is responsible for the photocurrent generation.
On the substrate of modified quartz, two kinds of self assembled ultra thin films were fabricated through layer by layer electrostatic deposition with diazoresin′s sulfonate(DRS) as the polyanion, and chitosan(CS) as the polycation. The self assembly process was monitored by UV Vis spectra and confirmed that the layer by layer deposition takes place regularly. The films obtained both from DRS, CS(CS/DRS film) and from DR, DRS, CS(DR/DRS/CS/DRS film) were photo sensitive. Under irradiation of ultraviolet light, the stability of the films towards polar solvents increases significantly. The kinetic study shows that the rate of the photodecomposition reaction of DR/DRS/CS/DRS films is higher than that of CS/DRS films and doesnt show the first order reaction for both films.
Through self assembly technique, a new type of layer by layer ultra thin film was fabricated based on water soluble substituted polyaniline and photosensitive diazoresin through electrostatic attraction. Under UV irradiation, the bond nature between layers turns from ionic to covalent following the decomposition of diazonium group, and the film gets very stable. The photoelectric conversion property of substituted polyaniline containing self assembled film has also been investigated in this article.