Ultrathin film fabricated from PDDAC/DSB and NDR/DSB

Two kinds of ultrathin films were successfully fabricated by the self-assem bly deposition technique from poly(diallyldimethylammonium chloride) (PDDAC ) or nitro-containing diazoresin (NDR) as the polycation and 4,4'-di(sodium styryl-2-sulfonate) biphenyl (DSB) as the dianion. This stepwise fabricati on process was monitored by UV-vis spectrometry. The regularity of the film and the morphology of the film surface were examined by X-ray diffraction (XRD) and atom force microscopy (AFM), respectively. The results show that these kinds of films are composed of well arranged molecules, and have a ve ry flat surface. Among them, the PDDAC/DSB film emits fluorescence when exc ited with UV light at 354 nm. The NDR/DSB film does not emit fluorescence, because the NDR quenches the fluorescence of DSB; however, the NDR/DSB film possesses more stability against solvent etching (such as DMF), compared w ith the PDDAC/DSB film. (C) 2001 Elsevier Science Ltd. All rights reserved.