A novel water-soluble anionic conjugated copolymer containing poly(p-phenylene vinylene) segments:Copolymer synthesis and multilayer construction by assembling poly(diallyl dimethyl ammonium chloride)

This paper reports the synthesis of a water soluble conjugated polymer poly(p-phenylene vinyleneco-sodium methacrylate) (ws-P(PV-co-SMA)) and the multilayer of the derived copolymer assembling poly(diallyl dimethyl ammanium chloride) (PDDA). The self-assembling process of the multilayer was monitored by UV-vis absorption spectroscopy, and the data indicated a linear increase in film thick- ness with a number of ws-P(PV-co-SMA)/PDDA bilayers. The alternative deposition of ws-P (PV-co-SMA) and PDDA allowed the insertion of a non-conjugated layer between the conjugated layers, thus the migration of the photogenerated polarons was effectively confined in the isolated ws-P (PV-co-SMA) chains. Consequently, the photoluminescence quantum yield reached 0.68, 30 times higher than that of pure poly(p-phenylen vinylene). The distinct electronic interactions between conjugated segments were confirmed by comparative analyses of the excitation spectra and time-resolved photoluminescence spectra of ws-P(PV-co-SMA) solid film and the assembled multilayers. The confinement effect of the PDDA layer on the photogenerated carriers was verified by the surface photovoltage spectroscopic measurement on both ws-P(PV-co-SMA) solid film and self-assembled multilayers.