Studies on fluorescence of cellulosics
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Alain Castellan
Abstract
Steady-state fluorescence emission spectra of various celluloses were measured at an excitation wavelength of 320 nm. Various spectra recorded in the solid state were compared: (1) ECF bleached papers made of hardwood, the anhydroglucose units of which were chemically modified at C1 and C6 or C2 and C3 positions with carboxylic groups; (2) microcrystalline cellulose; (3) cotton linters; and (4) delignified sisal fibers (mercerized or not). Fluorescence emission was quite independent of the carboxylic acid content and average molecular weight (determined by viscosimetry) of the cellulose polymers. Microcrystalline cellulose (Avicel), cotton linters, and mercerized delignified sisal cellulose were acetylated in homogeneous medium (DMAc/LiCl as solvent system) to obtain soluble polymers in dichloromethane for comparison of spectra recorded in the solid and liquid states. Fluorescence of cellulose acetates in solution (CH2Cl2) and in the solid state was compared under similar experimental conditions to non-esterified celluloses in the solid state. The importance of the solid state for fluorescence emission could be demonstrated. Fluorophores are present in minute amounts in the polymer and their favorable energy transfer for excitation in the solid state likely enhances fluorescence emission. Among numerous fluorophores, dityrosine appeared to be a good candidate for fluorescence because it displayed emission in the fluorescence range of cellulose. Dityrosine is an amino acid involved in the lignification of non-woody plants. Mercerized sisal impregnated with tyrosine in the presence of peroxidase and hydrogen peroxide did not show enhanced emission, in contrast to para-hydroxycinnamic acid (coumaric acid), which is also involved in the lignification process at least for non-woody plants. The origin of cellulose fluorescence remains uncertain and appears to have several origins. This study clearly underlines the importance of the solid state for enhancing fluorophore emission.
©2007 by Walter de Gruyter Berlin New York
Articles in the same Issue
- Meetings
- Chemical composition of 36 Brazilian Amazon forest wood species
- Characterization of non-cellulosic glucans in Eucalyptus globulus Labill. wood and kraft pulp
- Study of the phenolic compounds formed during pretreatment of sugarcane bagasse by wet oxidation and steam explosion
- Determination of the accessible hydroxyl groups in heat-treated Styrax tonkinensis (Pierre) Craib ex Hartwich wood by hydrogen-deuterium exchange and 2H NMR spectroscopy
- Lignin modification in the initial phase of softwood kraft pulp delignification with polyoxometalates (POMs)
- Synthesis of light-colored rosin glycerol ester
- Studies on fluorescence of cellulosics
- Fluorescence spectroscopy for chromophore studies on bleached kraft pulps
- Influence of surface structure on wetting of coated offset papers
- Fundamental study of the interaction of Ti atoms with spruce surfaces
- Surface analysis of groundwood paper treated by diffuse coplanar surface barrier discharge (DCSBD) type atmospheric plasma in air and in nitrogen
- Ultrastructural aspects of fibre development during the stone groundwood process: New insights into derived pulp properties
- Stabilization of peracetic acid with aspartic acid diethoxy succinate (AES)
- Stabilization of H2O2 in the presence of Fe(II) and Mn(II) impurities under alkaline conditions
- Viscoelastic properties of green wood across the grain measured by harmonic tests in the range 0–95°C: Hardwood vs. softwood and normal wood vs. reaction wood
- Thermoforming of wood veneer composite sheets
- A revised multi-Fickian moisture transport model to describe non-Fickian effects in wood
- Novel experimental approach for longitudinal-radial stiffness characterisation of clear wood by a single test
- Fracture characterisation of yew (Taxus baccata L.) and spruce (Picea abies [L.] Karst.) in the radial-tangential and tangential-radial crack propagation system by a micro wedge splitting test
- Determination of Young's modulus and shear modulus by means of deflection curves for wood beams obtained in static bending tests
- Insecticidal activity of essential oil from Chamaecyparis formosensis Matsum
- Knotwood as a window to the indirect measurement of the decay resistance of Scots pine heartwood
- Field assessment of wood stake decomposition in forest soil
Articles in the same Issue
- Meetings
- Chemical composition of 36 Brazilian Amazon forest wood species
- Characterization of non-cellulosic glucans in Eucalyptus globulus Labill. wood and kraft pulp
- Study of the phenolic compounds formed during pretreatment of sugarcane bagasse by wet oxidation and steam explosion
- Determination of the accessible hydroxyl groups in heat-treated Styrax tonkinensis (Pierre) Craib ex Hartwich wood by hydrogen-deuterium exchange and 2H NMR spectroscopy
- Lignin modification in the initial phase of softwood kraft pulp delignification with polyoxometalates (POMs)
- Synthesis of light-colored rosin glycerol ester
- Studies on fluorescence of cellulosics
- Fluorescence spectroscopy for chromophore studies on bleached kraft pulps
- Influence of surface structure on wetting of coated offset papers
- Fundamental study of the interaction of Ti atoms with spruce surfaces
- Surface analysis of groundwood paper treated by diffuse coplanar surface barrier discharge (DCSBD) type atmospheric plasma in air and in nitrogen
- Ultrastructural aspects of fibre development during the stone groundwood process: New insights into derived pulp properties
- Stabilization of peracetic acid with aspartic acid diethoxy succinate (AES)
- Stabilization of H2O2 in the presence of Fe(II) and Mn(II) impurities under alkaline conditions
- Viscoelastic properties of green wood across the grain measured by harmonic tests in the range 0–95°C: Hardwood vs. softwood and normal wood vs. reaction wood
- Thermoforming of wood veneer composite sheets
- A revised multi-Fickian moisture transport model to describe non-Fickian effects in wood
- Novel experimental approach for longitudinal-radial stiffness characterisation of clear wood by a single test
- Fracture characterisation of yew (Taxus baccata L.) and spruce (Picea abies [L.] Karst.) in the radial-tangential and tangential-radial crack propagation system by a micro wedge splitting test
- Determination of Young's modulus and shear modulus by means of deflection curves for wood beams obtained in static bending tests
- Insecticidal activity of essential oil from Chamaecyparis formosensis Matsum
- Knotwood as a window to the indirect measurement of the decay resistance of Scots pine heartwood
- Field assessment of wood stake decomposition in forest soil
