Phloxine B as a probe for entrapment in microcrystalline cellulose

The photophysical behaviour of phloxine B adsorbed onto microcrystalline cellulose was evaluated by reflectance spectroscopy and laser induced time-resolved luminescence in the picosecond-nanosecond and microsecond- millisecond ranges. Analysis of the absorption spectral changes with concentration p...

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Autor principal: Rodríguez, Hernán Bernardo
Publicado: 2012
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Acceso en línea:https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14203049_v17_n2_p1602_Duarte
http://hdl.handle.net/20.500.12110/paper_14203049_v17_n2_p1602_Duarte
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spelling paper:paper_14203049_v17_n2_p1602_Duarte2023-06-08T16:13:34Z Phloxine B as a probe for entrapment in microcrystalline cellulose Rodríguez, Hernán Bernardo Delayed fluorescence Heterogeneous systems prompt fluorescence Microenvironmental effects Phloxine B Phosphorescence cellulose eosine blue article chemistry luminescence molecular probe spectrofluorometry Cellulose Eosine I Bluish Luminescence Molecular Probes Spectrometry, Fluorescence The photophysical behaviour of phloxine B adsorbed onto microcrystalline cellulose was evaluated by reflectance spectroscopy and laser induced time-resolved luminescence in the picosecond-nanosecond and microsecond- millisecond ranges. Analysis of the absorption spectral changes with concentration points to a small tendency of the dye to aggregate in the range of concentrations under study. Prompt fluorescence, phosphorescence and delayed fluorescence spectral decays were measured at room temperature and 77 K, without the need of sample degassing because cellulose protects triplet states from oxygen quenching. In all cases, spectral changes with time and lifetime distribution analysis were consistent with the dye coexisting in two different environments: dyes tightly entrapped between polymer chains in crystalline regions of cellulose showed longer fluorescence and phosphorescence lifetimes and more energetic triplet states, while dyes adsorbed in more amorphous regions of the support showed shorter lifetimes and less energetic triplet states. This behaviour is discussed in terms of the different dye-support interactions in both kinds of adsorption sites. Fil:Rodríguez, H.B. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2012 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14203049_v17_n2_p1602_Duarte http://hdl.handle.net/20.500.12110/paper_14203049_v17_n2_p1602_Duarte
institution Universidad de Buenos Aires
institution_str I-28
repository_str R-134
collection Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic Delayed fluorescence
Heterogeneous systems prompt fluorescence
Microenvironmental effects
Phloxine B
Phosphorescence
cellulose
eosine blue
article
chemistry
luminescence
molecular probe
spectrofluorometry
Cellulose
Eosine I Bluish
Luminescence
Molecular Probes
Spectrometry, Fluorescence
spellingShingle Delayed fluorescence
Heterogeneous systems prompt fluorescence
Microenvironmental effects
Phloxine B
Phosphorescence
cellulose
eosine blue
article
chemistry
luminescence
molecular probe
spectrofluorometry
Cellulose
Eosine I Bluish
Luminescence
Molecular Probes
Spectrometry, Fluorescence
Rodríguez, Hernán Bernardo
Phloxine B as a probe for entrapment in microcrystalline cellulose
topic_facet Delayed fluorescence
Heterogeneous systems prompt fluorescence
Microenvironmental effects
Phloxine B
Phosphorescence
cellulose
eosine blue
article
chemistry
luminescence
molecular probe
spectrofluorometry
Cellulose
Eosine I Bluish
Luminescence
Molecular Probes
Spectrometry, Fluorescence
description The photophysical behaviour of phloxine B adsorbed onto microcrystalline cellulose was evaluated by reflectance spectroscopy and laser induced time-resolved luminescence in the picosecond-nanosecond and microsecond- millisecond ranges. Analysis of the absorption spectral changes with concentration points to a small tendency of the dye to aggregate in the range of concentrations under study. Prompt fluorescence, phosphorescence and delayed fluorescence spectral decays were measured at room temperature and 77 K, without the need of sample degassing because cellulose protects triplet states from oxygen quenching. In all cases, spectral changes with time and lifetime distribution analysis were consistent with the dye coexisting in two different environments: dyes tightly entrapped between polymer chains in crystalline regions of cellulose showed longer fluorescence and phosphorescence lifetimes and more energetic triplet states, while dyes adsorbed in more amorphous regions of the support showed shorter lifetimes and less energetic triplet states. This behaviour is discussed in terms of the different dye-support interactions in both kinds of adsorption sites.
author Rodríguez, Hernán Bernardo
author_facet Rodríguez, Hernán Bernardo
author_sort Rodríguez, Hernán Bernardo
title Phloxine B as a probe for entrapment in microcrystalline cellulose
title_short Phloxine B as a probe for entrapment in microcrystalline cellulose
title_full Phloxine B as a probe for entrapment in microcrystalline cellulose
title_fullStr Phloxine B as a probe for entrapment in microcrystalline cellulose
title_full_unstemmed Phloxine B as a probe for entrapment in microcrystalline cellulose
title_sort phloxine b as a probe for entrapment in microcrystalline cellulose
publishDate 2012
url https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_14203049_v17_n2_p1602_Duarte
http://hdl.handle.net/20.500.12110/paper_14203049_v17_n2_p1602_Duarte
work_keys_str_mv AT rodriguezhernanbernardo phloxinebasaprobeforentrapmentinmicrocrystallinecellulose
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