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Molecular dynamics of 2-, 4- and 6-arm star-shaped poly(ɛ-caprolactone)s (PCLs) functionalized with pyrene at all chain ends followed by excimer formation were investigated in THF as a solvent. Dilute solutions (10 −8 to 10 −6 molL −1 ) of these polymers revealed excimer emission due to the intramolecular cyclization, proceeding via chain end interaction. Time-resolved fluorescence...
A meta-phenylene-containing poly(phenylenevinylene) (PPV) with pendant terdentate terpyridine ligand 2b was synthesized and its fluorescence properties were compared with its isomeric PPV. The meta-phenylene bridge interrupts the resonance connection between the PPV backbone and the metal-chelation sites, while jointing the structurally defined chromophores together. The fluorescence of the polymer,...
The crystallinity of poly(butylene terephthalate) (PBT) films was investigated by comparing measurements of fluorescence and density. It was found that the ratio of the fluorescence intensity at 320nm to that at 365nm can be an effective indicator of crystallinity. The dynamic process of cold crystallization was directly observed for PBT films prepared using a spin-casting method on quartz disks by...
The present paper reports on the syntheses and association behavior of two random copolymers of sodium N-acryloyl-l-valinate and N-dodecylacrylamide in buffered (pH 8.0) aqueous solution containing 0.1M NaCl. Surface tension and viscosity results showed pronounced amphiphilic nature of the copolymers in aqueous solution at pH 8.0. Steady-state fluorescence studies using pyrene and N-phenyl-1-naphthylamine...
Geometries, ionization potentials (IPs), electron affinities (EAs) and optical properties of two series of π-conjugated oligomers (2,6-(4,4-bis(2-ethylthexyl)-4H-cyclopenta-[def]-phenanthrene)) n CPPn (2,6-(4,4-bis(2-ethylthexyl)-8,9-dihydro-4H-cyclopenta-[def]-phenanthrene)) n HCPPn (n=1–4) were studied theoretically. The ground and the excited state geometries were optimized by B3LYP...
Fluorescence spectroscopic techniques, and time-resolved anisotropy measurements (TRAMS) in particular, have provided valuable information regarding micelle formation in luminescently labelled pH-responsive diblock copolymers of 2-(diethylamino)ethyl methacrylate (DEA) and 2-(dimethylamino)ethyl methacrylate (DMA). A pyrenyl derivative, located at the DEA block, allowed motion of this site to be monitored...
The interaction between poly(di-n-hexylsilane) (PDHS) and TiO 2 nanoparticle was studied based on the temperature dependence of the fluorescence of a PDHS/TiO 2 nanoparticle hybrid film. The polysilane is a suitable probe to investigate a guest polymer–host matrix interaction because the photophysical properties of polysilanes remarkably depend on the conformation of the σ-conjugated...
Non-conjugated polyelectrolytes were used to quench oppositely charged fluorescent dye–ligand conjugate (DLC) molecules by bringing them to the vicinity of the polyelectrolyte backbone to form aggregates and hence quench the dye fluorescence. As target protein molecules are added to the solution, the specific interaction between the DLC and the protein disrupts the aggregate structure, thus recovering...
Pyrene-functionalized chiral methylpropargyl esters, (R)-3-butyn-2-yl-1-pyrenebutyrate [(R)-1], (S)-3-butyn-2-yl-1-pyrenebutyrate [(S)-1], (R)-3-butyn-2-yl-1-pyrenecarboxylate [(R)-2], and 3-butyn-2-yl-1-pyrenecarboxylate [(R,S)-2] were polymerized with (nbd)Rh + [η 6 -C 6 H 5 B − (C 6 H 5 ) 3 ] to obtain the corresponding polymers with...
Structural, electronic, and optical properties of a series of π-conjugated chain type oligomers composed of the bipyridyl, ethynyl and thiophenyl fragments are studied by advanced quantum chemical methods. The properties of the P-oligomers (P1–P4, with 1–4 repeating units, respectively) and the corresponding DP-oligomers (DP2–DP4, with 2–4 repeating units, respectively, but without the terminal thiophenyl...
A novel cationic fluorene-containing water-soluble poly(p-phenyleneethynylene) (PPE) derivative, poly[(9,9-bis{6′-[(N,N-diethyl)-N-methylammonium]hexyl}-2,7-fluorenyleneethynylene)-alt-co-(2,5-bis{3′-[(N,N-diethyl)-N-methylammonium]-1′-oxapropyl}-1,4-phenylene)] tetraiodide (P1′), was synthesized through Sonogashira reaction and a post-polymerization treatment. P1′ emits bright blue fluorescence in...
The pH mediated intra-molecular association and inter-molecular aggregation of a range of amphiphilic poly(l-lysine iso-phthalamide) polymers have been investigated in aqueous solution over a range of pH values and concentrations. The desired functionality of these novel bioresponsive amphiphilic polymers was achieved by incorporating pendant hydrophilic carboxyl groups along the polymer backbone,...
Fluorescence spectroscopy, together with a conventional gravimetric method, were employed to study the mechanism and kinetics of water diffusion in UV-cured polyurethane-acrylate based adhesive films doped with organic fluorescent sensors. The diffusion of water through the films followed Fick's law during almost the whole mass sorption curve. Whilst the fluorescence data showed that boundary conditions...
A vesicle-forming amino acid derivatized surfactant, sodium N-(11-acrylamidoundecanoyl)-l-alaninate was polymerized to obtain a polysoap. The average molecular weight of the polysoap was determined by gel permeation chromatography. Rheological measurements suggested that the aqueous solution of the polysoap behaves as a non-Newtonian fluid. Fluorescence probe studies using pyrene as probe molecule...
Nanocomposites of benzo 15-crown-5 ether substituted oligo phenylene vinylene (CE–OPV) were prepared by solution intercalation into a surface treated bentone clay, B34, in both the presence and absence of Eu 3+ ions, and were characterized using X-ray diffraction (XRD) and fluorescence techniques. The intercalation of B34 by CE-OPV increases the d-spacing (gallery height) of B34, the increase...
In this work, thermal transitions of polystyrene, PS, were studied as a function of molecular weight (M w ) and thermal history using the fluorescence response of anthracene chemically bonded to the polymer chain ends. For each PS sample the fluorescence spectra of the anthracene were collected as a function of temperature in cycles of heating and cooling. Two photophysical parameters were...
The fluorescence and aggregation behavior of poly(amidoamine) (PAMAM) dendrimers modified with phenyl groups at the periphery (PAMAM-P) were investigated. For comparison, the third generation (G3) PAMAM dendrimer with a shell of positive charge (PAMAM-PA) was also synthesized. PAMAM-P G3, G4 and G5 show dual fluorescence emission due to the fluorescence emission of phenyl ring and its excimer. By...
Changes in the static and dynamic fluorescence from two covalently attached lumophores, 1-pyrenyl and 9-anthrylmethyl, induced by the diffusion of two N,N-dialkylanilines, N,N-dimethylaniline and N,N-dioctadecylaniline, within polyethylene films of 42% crystallinity have been examined. The longer lived excited singlet state of 1-pyrenyl is found to report on events occurring within a larger surrounding...
Sorption and drying processes were monitored in situ in polymer films by a fluorescence rotor probe, 4-tricyanovinyl-[N-(2-hydroxyethyl)-N-ethyl]aniline (TC1), a solvatochromatic fluorescence probe, 4-(N,N-dimethylamino)-4'-nitrostilbene (DANS), and pyrene. Taking advantage of an intensity ratio to monitor sorption, these fluorescence probes were found to serve as self-referencing sensors of water...
The synthesis and fluorescence behaviour of a range of amphiphilic poly(l-lysine co-bis-amine-Cy-3 iso-phthalamide) polymers that incorporate low levels of Cy-3 dye co-monomer (0.5-2.1% (w/w)) in their backbone have been investigated in aqueous solution over a range of pH values. The desired functionality of these biocompatible, hydrophobically modified polyelectrolytes was achieved by incorporating...
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