Detection of intramolecular associations in hydrophobically modified pectin derivatives using fluorescent probes
| Autor: | A. Fischer, C. Geoffroy-Chapotot, M. C. Houzelle, Monique A. V. Axelos, M. L. Viriot, Edith Dellacherie, Marie-Christiane Carré, P. Hubert |
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| Přispěvatelé: | PhysicoChimie des Macromolécules (LPCM), Institut National de la Recherche Agronomique (INRA), ProdInra, Migration |
| Jazyk: | angličtina |
| Rok vydání: | 1998 |
| Předmět: |
Fluorophore
Ionic bonding 02 engineering and technology 010402 general chemistry Photochemistry 01 natural sciences Fluorescence spectroscopy chemistry.chemical_compound Electrochemistry Organic chemistry General Materials Science [SDV.BBM.BC]Life Sciences [q-bio]/Biochemistry Molecular Biology/Biochemistry [q-bio.BM] [SDV.BBM.BC] Life Sciences [q-bio]/Biochemistry Molecular Biology/Biochemistry [q-bio.BM] Spectroscopy ComputingMilieux_MISCELLANEOUS Chemistry Intermolecular force Surfaces and Interfaces 021001 nanoscience & nanotechnology Condensed Matter Physics Fluorescence Polyelectrolyte 0104 chemical sciences Covalent bond Pyrene 0210 nano-technology |
| Zdroj: | Langmuir Langmuir, American Chemical Society, 1998, 14, pp.4482-4488 |
| ISSN: | 0743-7463 1520-5827 |
| Popis: | Hydrophobically modified pectin derivatives were prepared byimmobilization of long alkyl chains (C 12 -C 18 ) at various substitution ratios, using two different synthetic pathways, one affording covalent fixation and the other one leading to a mere ionic association. These derivatives display an associative tendency in semidilute as well as in dilute aqueous solutions. This phenomenon, which stems from both intra- and intermolecular interactions between hydrophobic groups, results in the formation of hydrophobic microdomains. The latter can be characterized, especially in the dilute regime, thanks to fluorescence spectroscopy. Fluorescent molecular rotors, as well as pyrene, a classical fluorescence probe of widespread use, witness the variations of the medium polarity. In addition, they can also provide further information, particularly about the local cohesion of the microenvironment of the probe, without performing any complementary experiment, for example, the addition of quenchers together with the fluorescent probe in the polymer solutions. CAC values derived from polarity changes (CAC polarity ), using the molecular rotor as well as pyrene as the fluorescence probes, are significantly different from those determined from the cohesion of the microenvironment (CAC cohesion ), accessible only with the molecular rotor. This latter type of fluorophore may therefore enable us to determine more accurately the actual critical aggregation concentration. |
| Databáze: | OpenAIRE |
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