Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.1/3191
Título: On the binding of calcium by micelles composed of carboxy-modified pluronics measured by means of differential potentiometric titration and modeled with a self-consistent-field theory
Autor: Lauw, Y.
Leermakers, F. A. M.
Cohen Stuart, M. A.
Pinheiro, J. P.
Custers, J. P. A.
Van Den Broeke, L. J. P.
Keurentjes, J. T. F.
Data: 2006
Editora: American Chemical Society
Citação: Lauw, Y.; Leermakers, F. A. M.; Cohen Stuart, M. A.; Pinheiro, J. P.; Custers, J. P. A.; Van Den Broeke, L.J . P.; Keurentjes, J. T. F. On the binding of calcium by micelles composed of carboxy-modified pluronics measured by means of differential potentiometric titration and modeled with a self-consistent-field theory, Langmuir, 22, 26, 10932-10, 2006.
Resumo: We perform differential potentiometric titration measurements for the binding of Ca2+ ions to micelles composed of the carboxylic acid end-standing Pluronic P85 block copolymer (i.e., CAE-85 (COOH-(EO)26-(PO)39-(EO)26-COOH)). Two different ion-selective electrodes (ISEs) are used to detect the free calcium concentration; the first ISE is an indicator electrode, and the second is a reference electrode. The titration is done by adding the block copolymers to a known solution of Ca2+ at neutral pH and high enough temperature (above the critical micellization temperature CMT) and various amount of added monovalent salt. By measuring the difference in the electromotive force between the two ISEs, the amount of Ca2+ that is bound by the micelles is calculated. This is then used to determine the binding constant of Ca2+ with the micelles, which is a missing parameter needed to perform molecular realistic self-consistentfield (SCF) calculations. It turns out that the micelles from block copolymer CAE-85 bind Ca2+ ions both electrostatically and specifically. The specific binding between Ca2+ and carboxylic groups in the corona of the micelles is modeled through the reaction equilibrium -COOCa+ h -COO- + Ca2+ with pKCa ) 1.7 ( 0.06.
Peer review: yes
URI: http://hdl.handle.net/10400.1/3191
ISSN: 1520-5827
Aparece nas colecções:FCT2-Artigos (em revistas ou actas indexadas)

Ficheiros deste registo:
Ficheiro Descrição TamanhoFormato 
n33_Langmuir 22 (2006) 10932.pdf152,68 kBAdobe PDFVer/Abrir    Acesso Restrito. Solicitar cópia ao autor!


FacebookTwitterDeliciousLinkedInDiggGoogle BookmarksMySpace
Formato BibTex MendeleyEndnote Degois 

Todos os registos no repositório estão protegidos por leis de copyright, com todos os direitos reservados.