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547.913This study concentrates on the extraction of eugenol, menthol, and genistein, and the synthesis, antimicrobial activity, and structure-activity relationships of their ester derivatives. The esters were tested for antimicrobial activity against several bacteria and yeast, and the correlation between biological properties and various physicochemical properties was examined. The ester derivatives gave intense emissions upon irradiation by UV light and have photoluminescence quantum yields of 39, 35, and 36% and long excited-state lifetimes of 3.62, 3.23, and 3.40 ns, respectively. These esters may be used in herbal medicinal therapy, and additionally as a base for the development of new drugs for phytomedicine.

Silver (Ag) nanoparticles are known to hold an important place in nanotechnology, and studies herein present the preparation and characterization of Ag metallic nanoparticles bearing antibacterial properties. In situ polymerization was used to prepare the conductive polymer polyaniline (PANI) and polyaniline/silver (PANI/Ag) nanocomposites. Increases in electrical conductivities of the nanocomposite films were observed compared to neat PANI, whereby these increases may be a result of the Ag doping effect or its complex formation. Spectroscopic techniques, such as, UV–Vis, FTIR, and photoluminescence were used for the characterizations of PANI and PANI/Ag nanocomposites. UV–Vis and FTIR data showed the quinoid units along the polymer chain being affected, such that strong interactions between Ag nanoparticles and quinoidal sites of PANI were presumed. The PANI/Ag nanocomposites showed higher photoluminescence intensities than neat PANI. TGA analyzes were used to determine weight losses and thermostabilities of PANI and PANI/Ag nanocomposites. Scanning electron microscopy was used for morphological evaluations of the nanoparticles and films, where the micrographs revealed that Ag nanoparticles were well dispersed and isolated in nanocomposite films. The presence and distribution of the Ag nanoparticles in PANI film matrix were analyzed by EDX. Antimicrobial properties of the nanocomposite films obtained were also explored. POLYM. ENG. SCI., 59:E182–E194, 2019. © 2018 Society of Plastics Engineers

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This study focuses on the preparation, polymerization, characterization, and optical properties of a new bis‐(4‐trifluoromethanesulfonyloxyphenyl)phenylamine monomer. This is the first nitrogen‐containing monomer having nitrogen atoms as bridges between phenyl rings, and it was synthesized in three steps. The polymerization was carried out through the Ni(0)‐catalyzed homocoupling reaction of the bis‐(4‐trifluoromethanesulfonyloxyphenyl)phenylamine compound. The resulting polymer, polybis(paraphenyl)phenylamine, emitted an intense blue color (where λ = 415 nm) upon irradiation by ultraviolet light. The photoluminescence quantum yield was found to be 36% with a long excited‐state lifetime of 3.3 ns. Electrical conductivity data for an HCl‐doped film of the polymer were also examined. This novel polymer is of interest as an organic emitting material for electroluminescent devices. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1860–1867, 2007