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Transport of solutes through calix[4]pyrrole-containing cellulose acetate films
Valente, A. J. M.; Jiménez, A.; Simões, A. C.; Burrows, H. D.; Polishchuk, A. Ya.; Lobo, V. M. M.Films of cellulose acetate containing different concentrations of meso-octamethyl-porphyrinogen (calix[4]pyrrole) were prepared and characterized using UV-vis and FTIR spectroscopy, DSC and SEM. Incorporation of calix[4]pyrrole into cellulose acetate leads to a decrease in the degree of hydrophilicity of the polymeric matrix. However, a slight increase in the percentage of water uptake of the polymer is found w...
Effect of terbium(III) chloride on the micellization properties of sodium decyl...
Neves, A. C. S.; Valente, A. J. M.; Burrows, H. D.; Ribeiro, A. C. F.; Lobo, V. M. M.The effect of TbCl3 on the aggregation processes of the anionic surfactants sodium decyl sulfate (SDeS) and sodium dodecyl sulfate (SDS) has been investigated. Electrical conductivity data, combined with Tb(III) luminescence measurements suggest that the formation of micelles involving TbCl3 and SDS occurs at concentrations below the critical micelle concentration (cmc) of the pure surfactants; the formation of...
Interactions of copper (II) chloride with sucrose, glucose, and fructose in aqu...
Ribeiro, A. C. F.; Esteso, M. A.; Lobo, V. M. M.; Valente, A. J. M.; Simões, S. M. N.; Sobral, A. J. F. N.; Burrows, H. D.The interaction between copper (II) chloride and the carbohydrates sucrose, glucose, and fructose has been studied in aqueous solutions at 298.15 and 310.15 K, using measurements of diffusion coefficients and electrical conductivity. Significant effects on the electrical conductivity were observed in the presence of these carbohydrates, suggesting interactions between them and copper chloride. Support for this ...
Effect of Europium(III) Chloride on the Aggregation Behavior of Sodium Dodecyl ...
Valente, A. J. M.; Burrows, H. D.; Pereira, R. F.; Ribeiro, A. C. F.; Pereira, J. L. G. Costa; Lobo, V. M. M.The effect of EuCl3 on the aggregation processes of sodium dodecyl sulfate was investigated. Electrical conductivity data, combined with Eu(III) luminescence measurements, suggest that the formation of micelles involving EuCl3 and SDS occurs at low SDS concentration; the formation of these mixed aggregates was also monitored by light scattering, which indicates that the addition of EuCl3 to SDS concentration at...
Interactions of Copper (II) Chloride with ß-Cyclodextrin in Aqueous Solutions
Ribeiro, A. C. F.; Esteso, M. A.; Lobo, V. M. M.; Valente, A. J. M.; Simões, S. M. N.; Sobral, A. J. F. N.; Ramos, L.; Burrows, H. D.; Amado, A. M.The interaction between copper (II) chloride and the carbohydrate ß-cyclodextrin (ß-CD) has been studied in aqueous solutions (298.15 K and 310.15 K) using measurements of diffusion coefficients and electrical conductivity. Significant effects on the electrical conductivity were observed in the presence of the ß-CD, suggesting interactions between this carbohydrate and copper chloride. Support for this came fro...
Interactions between surfactants and 1,4-phenylene-[9,9-bis(4-phenoxy-butylsulf...
Burrows, H. D.; Lobo, V. M. M.; Pina, J.; Ramos, M. L.; Melo, J. Seixas de; Valente, A. J. M.; Tapia, M. J.; Pradhan, S.; Scherf, U.; Hintschich, S. I.The interaction between the water-soluble anionic conjugated copolymer poly1,4-phenylene-[9,9-bis(4-phenoxy-butylsulfonate)]fluorene-2,7-diyl (PBS-PFP) and various surfactants has been studied in aqueous solution by UV-vis absorption spectra, fluorescence and electrical conductivity. It is suggested from the linear dependence of absorbance, fluorescence and electrical conductivity on concentration that in the a...
Permeation of sodium dodecyl sulfate through polyaniline-modified cellulose ace...
Valente, A. J. M.; Burrows, H. D.; Polishchuk, A. Ya.; Domingues, C. P.; Borges, O. M. F.; Eusébio, M. E. S.; Maria, T. M. R.; Lobo, V. M. M.The preparation of polyaniline (PANi)-cellulose acetate (CA) blends by casting films from a suspension, is reported. Two membranes were prepared from different solvents, one with a homogeneous and the other a heterogeneous dispersion of PANi in CA matrices. The membranes were characterized by X-ray diffraction, SEM, DSC, and FTIR, and the results were compared with those obtained for pure CA and PANi films. The...
Interaction between the Water Soluble Poly1,4-phenylene-[9,9-bis(4-phenoxy buty...
Tapia, M. J.; Burrows, H. D.; Valente, A. J. M.; Pradhan, S.; Scherf, U.; Lobo, V. M. M.; Pina, J.; Melo, J. Seixas deThe interaction has been studied in aqueous solutions between a negatively charged conjugated polyelectrolyte poly1,4-phenylene-[9,9-bis(4-phenoxybutylsulfonate)]fluorene-2,7-diyl copolymer (PBS-PFP) and several cationic tetraalkylammonium surfactants with different structures (alkyl chain length, counterion, or double alkyl chain), with tetramethylammonium cations and with the anionic surfactant sodium dodecyl...
Fluorescence Enhancement of the Water- Soluble Poly1,4-phenylene-[9,9-bis- (4-p...
Burrows, H. D.; Lobo, V. M. M.; Pina, J.; Ramos, M. L.; Melo, J. Seixas de; Valente, A. J. M.; Tapia, M. J.; Pradhan, S.; Scherf, U.http://dx.doi.org/10.1021/ma048780+
Sorption/diffusion behaviour of anionic surfactants in polyacrylamide hydrogels...
Valente, A. J. M.; Polishchuk, A. Ya.; Burrows, H. D.; Miguel, M. G.; Lobo, V. M. M.The sorption and diffusion processes of anionic surfactants with different chain length through polyacrylamide hydrogels with low swelling degree have been studied by electrical conductivity measurements. The multicomponent equilibrium equation has been used to model the sorption isotherms of different anionic surfactant in the hydrogels. Such isotherms show that initial rapid sorption of unimer surfactant into...
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