Encontrados 7 documentos, a visualizar página 1 de 1
Interplay of Electrostatic and Hydrophobic Effects with Binding of Cationic Gem...
Burrows, Hugh D.; Tapia, María J.; Silva, Cláudia L.; Pais, Alberto A. C. C.; Fonseca, Sofia M.; Pina, João; Melo, J. Seixas de; Wang, YujieUnderstanding factors responsible for the fluorescence behavior of conjugated polyelectrolytes and modulation of their behavior are important for their application as functional materials. The interaction between the anionic poly1,4-phenylene-[9,9-bis(4-phenoxy-butylsulfonate)]fluorene-2,7-diylcopolymer (PBS−PFP) and cationic gemini surfactants α,ω-(CmH2m+1N+(CH3)2)2(CH2)s(Br-)2 (m-s-m; m = 12, s = 2, 3, 5, 6, ...
Solubilization of Polyelectrolytic Hairy-Rod Polyfluorene in Aqueous Solutions ...
Knaapila, Matti; Almásy, László; Garamus, Vasil M.; Pearson, Christopher; Pradhan, Swapna; Petty, Michael C.; Scherf, Ullrich; Burrows, Hugh D.We report on the solubilization, phase behavior, and self-organized colloidal structure of a ternary water−polyfluorene−surfactant (amphiphile) system comprised of polyelectrolytic poly1,4-phenylene[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl (PBS−PFP) in nonionic pentaethylene glycol monododecyl ether (C12E5) at 20 °C. We show in particular how a high amount (milligrams per milliliter) of polyfluorene c...
Fast and Slow Time Regimes of Fluorescence Quenching in Conjugated Polyfluorene...
Dias, Fernando B.; Knaapila, Matti; Monkman, Andrew P.; Burrows, Hugh D.The luminescence decay kinetics of polyfluorene copolymers containing fluorenone units randomly distributed along the polymer chain have been studied by steady-state and time-resolved fluorescence techniques in toluene solution. The typical green emission from polyfluorenes containing 9-fluorenone moieties is only observed if the 9-fluorenone group is covalently attached to the polymer. Small-angle neutron scat...
Interaction between the Conjugated Polyelectrolyte Poly1,4-phenylene[9,9-bis(4-...
Tapia, María J.; Burrows, Hugh D.; Knaapila, Matti; Monkman, Andrew P.; Arroyo, Antonio; Pradhan, Swapna; Scherf, Ullrich; Pinazo, AuroraIn this paper, the interaction between the water-soluble conjugated polyelectrolyte poly1,4-phenylene[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl copolymer and the amino acid glyceride conjugate 1-O-(l-arginyl)-2,3-O-dilauroyl-sn-glycerol dichlorohydrate (a mimic for the phospholipid lecithin) has been studied in aqueous solution by electronic spectroscopy (absorption and fluorescence) and small-angle ne...
Kinetics and Thermodynamics of Poly(9,9-dioctylfluorene) β-Phase Formation in D...
Dias, Fernando B.; Morgado, Jorge; Maçanita, António L.; Costa, Fernando P. da; Burrows, Hugh D.; Monkman, Andrew P.Poly(9,9-dioctylfluorene) (PFO) adopts a particular type of conformation in dilute solutions of the poor solvent methylcyclohexane (MCH) below 273 K, which is revealed by the appearance of a red-shifted absorption peak at 437−438 nm. The formation of this ordered conformation depends on the temperature but is independent of polymer concentration over the range studied (3−25 μg/mL). On the basis of absorption, s...
Kinetics and thermodynamics of poly (9,9-dioctylfluorene) beta-phase formation ...
Costa, Fernando Pestana da; Maçanita, António L.; Morgado, Jorge; Dias, Fernando B.; Burrows, Hugh D.; Monkman, Andrew P.Poly(9,9-dioctylfluorene) (PFO) adopts a particular type of conformation in dilute solutions of the poor solvent methylcyclohexane (MCH) below 273 K, which is revealed by the appearance of a red-shifted absorption peak at 437−438 nm. The formation of this ordered conformation depends on the temperature but is independent of polymer concentration over the range studied (3−25 μg/mL). On the basis of absorption, s...
Characterization of the Triplet State of Tris(8-hydroxyquinoline)aluminium(III)...
Burrows, Hugh D.; Fernandes, Mariana; Melo, J. Seixas de; Monkman, Andrew P.; Navaratnam, SuppiahThe lowest triplet state of tris(8-hydroxyquinoline)aluminium(III) (Alq3) has been prepared by pulse radiolysis/energy transfer from appropriate donors in benzene solutions and has an absorption maximum around 510 nm with a lifetime of about 50 μs. It is quenched by molecular oxygen, leading to singlet oxygen formation. From flash photolysis and singlet oxygen formation measurements, a quantum yield of triplet ...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||