Murali, M.G.Udayakumar, U.Sridharan, K.2026-02-052012Journal of Materials Science, 2012, 47, 23, pp. 8022-8034222461https://doi.org/10.1007/s10853-012-6692-8https://idr.nitk.ac.in/handle/123456789/26929Two new donor-acceptor (D-A) conjugated polymers P1 and P2 containing 3,4-didodecyloxythiophene and 1,3,4-oxadiazole units are synthesized via Wittig reaction methodology. Cyclic voltammetry studies reveal that the polymers are both p and n dopable, and possess low-lying LUMO energy levels (-3.34 eV for P1 and -3.46 eV for P2) and high-lying HOMO energy levels (-5.34 eV for P1 and -5.27 eV for P2). The optical band gap of the polymers is in the range of 2.25-2.29 eV, calculated from the onset absorption edge. The polymers emit orange to yellow light in the film state when irradiated with a UV light. The synthesized polymers are used to prepare polymer nanocomposites with different wt% of silver nanoparticles. The polymer nanocomposites are characterized by UV-Vis absorption spectroscopy, field emission scanning electron microscopy, and thermogravimetric analysis. Both polymers and polymer/ Ag nanocomposites show good thermal stability with onset decomposition temperature around 300 °C under nitrogen atmosphere. The nonlinear optical properties of polymers and polymer/Ag nanocomposites are measured by Z-scan technique. Both polymers and polymer nanocomposites show a good optical limiting behavior. Nearly five times enhancement in the nonlinear optical properties is observed for polymer/Ag nanocomposites. The value of effective two-photon absorption coefficient (?) is in the order of 10 -10-10 -11 m/W. These results indicate that the synthesized polymers (P1 and P2) and their Ag nanocomposites are expected to be good candidates for application in photonic devices. © Springer Science+Business Media, LLC 2012.1 , 3 , 4-oxadiazoleAbsorption edgesDonor-acceptor conjugated polymersDonor-acceptorsField emission scanning electron microscopyFilm stateHOMO energy levelsLUMO energy levelsNitrogen atmospheresNon-linear optical propertiesOnset decomposition temperaturesOptical limiting behaviorPolymer nanocompositeSilver nanoparticlesSynthesized polymersTwo-photon absorptionsUV-Vis absorption spectroscopyWittig reactionYellow lightZ-scan techniqueCyclic voltammetryField emission microscopesSilverSynthesis (chemical)Thermogravimetric analysisTwo photon processesUltraviolet spectroscopyNanocomposites