TY - JOUR
T1 - Fluorescence-labeled pyrenesulfonamide response for characterizing polymeric interfaces in composite materials
AU - Lima, João Carlos dos Santos Silva E Pereira de
AU - ITQB Group Author
PY - 2000/1/1
Y1 - 2000/1/1
N2 - E-glass fibers were silanized using a 1% (v/v) aqueous solution of gamma-aminopropyltriethoxysilane (APES). Pyrene-sulfonamide conjugates were formed by reaction of 1-pyrenesulfonyl chloride (PSC) in acetonitrile (AcN), with the amine groups immobilized on the glass fiber surface. These pyrene-sulfonamide conjugates were used as fluorescence probes, being a relatively simple analytical method to study the coating microstructure of polyorganosiloxane layer on glass fibers. The first aim of this work was to estimate possible interactions of the polyaminosiloxane coating with surrounding molecules of different solvents (solvent accessibility to the chromophore). For this study, the fluorescence response of pyrene-sulfonamide dye (PSA) was correlated with solvent polarity parameters. It was concluded that all the studied solvents were accessible to the chromophore, and they can gather in two groups, depending on their ability to swell the polioganosiloxane layer. The second objective was to estimate the rigidity of the coating polymer from the temperature dependence of PSA emission. At about 180 K, a sudden change in the behavior of different photophysical parameters of PSA were observed. This phenomenon was interpreted as a density change in the polyaminosiloxane attached to the glass fibers.
AB - E-glass fibers were silanized using a 1% (v/v) aqueous solution of gamma-aminopropyltriethoxysilane (APES). Pyrene-sulfonamide conjugates were formed by reaction of 1-pyrenesulfonyl chloride (PSC) in acetonitrile (AcN), with the amine groups immobilized on the glass fiber surface. These pyrene-sulfonamide conjugates were used as fluorescence probes, being a relatively simple analytical method to study the coating microstructure of polyorganosiloxane layer on glass fibers. The first aim of this work was to estimate possible interactions of the polyaminosiloxane coating with surrounding molecules of different solvents (solvent accessibility to the chromophore). For this study, the fluorescence response of pyrene-sulfonamide dye (PSA) was correlated with solvent polarity parameters. It was concluded that all the studied solvents were accessible to the chromophore, and they can gather in two groups, depending on their ability to swell the polioganosiloxane layer. The second objective was to estimate the rigidity of the coating polymer from the temperature dependence of PSA emission. At about 180 K, a sudden change in the behavior of different photophysical parameters of PSA were observed. This phenomenon was interpreted as a density change in the polyaminosiloxane attached to the glass fibers.
U2 - 10.1023/A:1009491009039
DO - 10.1023/A:1009491009039
M3 - Article
VL - 10
SP - 141
EP - 146
JO - Journal Of Fluorescence
JF - Journal Of Fluorescence
SN - 1053-0509
IS - 2
ER -