Electrochemical, pulsed-field-gradient spin-echo NMR spectroscopic, and ESR spectroscopic study of the diffusivity of molecular probes inside gel-type cross-linked polymers.
Chemistry
; 13(8): 2392-401, 2007.
Article
in En
| MEDLINE
| ID: mdl-17167802
ABSTRACT
The permeability of five gel-type synthetic resins, obtained by polymerization of 1-vinylpyrrolidin-2-one cross-linked with N,N'-methylenebisacrylamide (1, 2, 3, 4, and 5 wt %) and swollen by N,N-dimethylformamide (DMF), has been analyzed. The diffusion of 2,2,6,6-tetramethyl-4-oxo-1-piperidinyloxyl (TEMPONE) was studied by ultramicroelectrode voltammetry. Similar measurements were performed for solutions of non-cross-linked poly(vinylpyrrolidone) in DMF. To provide information on the rotational mobility of TEMPONE and the translational mobility of DMF, electron spin resonance (ESR) spectroscopic and pulsed-field-gradient spin-echo nuclear magnetic resonance (PGSE-NMR) spectroscopic experiments, respectively, were carried out. Comparative analysis of the results obtained by electrochemical, ESR spectroscopic, and PGSE-NMR spectroscopic measurements showed that diffusivity inside the polymer framework is significantly affected by the extent of cross-linking, the size of the diffusing probe, and the presence of electrolytes.
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Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Chemistry
Journal subject:
QUIMICA
Year:
2007
Document type:
Article
Affiliation country: