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Akira Isogai - One of the best experts on this subject based on the ideXlab platform.
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Analysis of celluloses, plant Holocelluloses, and wood pulps by size-exclusion chromatography/multi-angle laser-light scattering.
Carbohydrate polymers, 2020Co-Authors: Yuko Ono, Akira IsogaiAbstract:Abstract Size-exclusion chromatography with multi-angle laser-light scattering and refractive index detection (SEC/MALLS/RI) provides the number- and weight-average molar masses, molar mass distributions, conformations, and linear/branched structures of polymers. In the case of pure celluloses including highly crystalline tunicate and alga celluloses, and hemicellulose-rich plant Holocelluloses, soaking in ethylene diamine (EDA) and subsequent solvent exchange to N,N-dimethylacetamide (DMAc) though methanol is effective for complete dissolution in ∼8% (w/w) LiCl/DMAc. SEC/MALLS/RI analysis can, therefore, be applied to pure celluloses, chemical wood pulps, and plant Holocelluloses after dissolution in ∼8% (w/w) LiCl/DMAc, dilution to 1% (w/v) LiCl/DMAc and membrane filtration. All pure celluloses and the high-molar-mass cellulose fractions of hardwood and grass Holocelluloses have linear and random-coil conformations and various average molar masses and molar mass distributions depending on the cellulose and Holocellulose resources. In contrast, Japanese cedar (i.e., softwood) Holocellulose and softwood bleached kraft pulp have alkali-stable cellulose/glucomannan branched structures in the high-molar-mass fractions.
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characterization of cellulose microfibrils cellulose molecules and hemicelluloses in buckwheat and rice husks
Cellulose, 2019Co-Authors: Yasutaka Nakamura, Tsuguyuki Saito, Akira IsogaiAbstract:Holocelluloses, TEMPO-oxidized Holocelluloses, and TEMPO-oxidized cellulose nanofibrils were prepared from buckwheat and rice husks to characterize the cellulose microfibril morphologies and Holocellulose molar masses. The buckwheat and rice husks had ash contents of 0.8% and 23%, respectively. All TEMPO-oxidized Holocelluloses had cellulose I crystal structures. TEMPO-oxidized cellulose nanofibrils prepared from the two husks were both ~ 3 nm wide. As significant amounts of xylan remained in the TEMPO-oxidized buckwheat and rice husk Holocelluloses, the TEMPO-oxidized cellulose nanofibrils prepared from them by mechanical disintegration in water gave yields as low as 14–17% (based on dry weight of dewaxed husk samples). Atomic force microscopy images of TEMPO-oxidized cellulose nanofibrils prepared from buckwheat husks showed that individual nanofibrils with widths of ~ 3 nm were quite flexible, while nanofibril bundles had rigid and needle-like morphologies. Rice husks had a high ash content, with part of the ash remaining in the corresponding Holocellulose, TEMPO-oxidized Holocellulose, and TEMPO-oxidized cellulose nanofibrils. Never-dried buckwheat husk cellulose (prepared by removal of hemicelluloses from Holocellulose) and oven-dried buckwheat husk Holocellulose containing a significant amount of hemicelluloses had leveling-off degrees of polymerization (DPs) of 650 and 810, respectively, after dilute acid hydrolysis. In contrast, oven-dried buckwheat husk cellulose had a leveling-off DP of 270.
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SEC–MALLS analysis of wood Holocelluloses dissolved in 8 % LiCl/1,3-dimethyl-2-imidazolidinone: challenges and suitable analytical conditions
Cellulose, 2015Co-Authors: Yuko Ono, Tsuguyuki Saito, Shuji Fujisawa, Ryoya Hiraoki, Akira IsogaiAbstract:The use of size-exclusion chromatography in combination with multi-angle laser-light scattering analysis (SEC–MALLS) can provide useful information pertaining to the molecular mass parameters of wood celluloses and hemicelluloses. When wood Holocelluloses containing significant amounts of hemicelluloses were soaked in ethylenediamine (EDA) and subjected to sequential EDA-removal and solvent-exchange processes into 1,3-dimethyl-2-imidazolidinone (DMI) under suitable conditions, the resulting materials provided much more reliable molecular mass parameters when they were dissolved in LiCl/DMI and subjecting to SEC–MALLS analysis. Furthermore, the residual EDA molecules trapped in the EDA-treated Holocelluloses could be removed by simply washing with methanol following the solvent-exchange process. The effect of the stirring time for the EDA-treated and solvent-exchanged eucalyptus Holocellulose in 8 % (w/v) LiCl/DMI was investigated in terms of its impact on the molecular mass parameters of the high-molecular-mass cellulose fractions and found to have no impact for up to 5 months. The optimal EDA treatment and solvent-exchange conditions obtained for eucalyptus Holocellulose were subsequently applied to various other wood Holocelluloses, including Japanese cedar, ginkgo and birch, which gave characteristic SEC elution patterns together with the corresponding molecular mass parameters, depending on their hemicellulose contents and the number of cellulose/lignin/hemicellulose chemical linkages present in their high-molecular-mass cellulose fractions. The weight-average degrees of polymerization of the high-molecular-mass cellulose fractions in the wood Holocelluloses ranged from 4400 to 6400, which were higher than those of cotton cellulose (2700) and bacterial cellulose (3100).
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tempo oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive & Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
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TEMPO-oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive and Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
Ryota Kuramae - One of the best experts on this subject based on the ideXlab platform.
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tempo oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive & Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
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TEMPO-oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive and Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
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TEMPO-Mediated Oxidation of Hemp Bast Holocellulose to Prepare Cellulose Nanofibrils Dispersed in Water
Journal of Polymers and The Environment, 2012Co-Authors: Buapan Puangsin, Ryota Kuramae, Tsuguyuki Saito, Shuji Fujisawa, Akira IsogaiAbstract:Hemp bast Holocellulose fiber (Cannabis sativa L. Subsp. Sativa) was oxidized by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation at various NaClO addition levels in water at pH 10. When carboxylate contents of the oxidized products were 1.5–1.7 mmol/g, TEMPO-oxidized cellulose nanofibrils almost completely dispersed at the individual nanofibril were obtained by mechanical disintegration of the TEMPO-oxidized hemp bast Holocelluloses in water, where the nanofibrillation yields were 98–100 %. The sugar composition analysis revealed that most of hemicelluloses originally present in the hemp bast Holocellulose were degraded and removed from the solid oxidized products, providing almost pure TEMPO-oxidized celluloses. X-ray diffraction patterns of all TEMPO-oxidized hemp bast Holocelluloses had the same cellulose I crystal structure and similar crystallinity indices and crystal widths, indicating that carboxylate groups formed by the oxidation were selectively present on the crystalline cellulose microfibril surfaces in the Holocellulose. However, the weight recovery ratios and viscosity-average degrees of polymerization of the TEMPO-oxidized hemp bast Holocelluloses decreased to 69–59 % and 470–380, respectively, when their carboxylate contents increased to 1.5–1.7 mmol/g by the TEMPO-mediated oxidation. Atomic force microscopy height images showed that the nanofibril widths were 2.7–2.9 nm, and the average nanofibril lengths decreased from 590 to 400 nm as the NaClO addition level was increased from 7.5 to 12.5 mmol/g in the TEMPO-mediated oxidation.
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TEMPO-Mediated Oxidation of Hemp Bast Holocellulose to Prepare Cellulose Nanofibrils Dispersed in Water
Journal of Polymers and The Environment, 2012Co-Authors: Buapan Puangsin, Ryota Kuramae, Tsuguyuki Saito, Shuji Fujisawa, Akira IsogaiAbstract:Hemp bast Holocellulose fiber (Cannabis sativa L. Subsp. Sativa) was oxidized by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation at various NaClO addition levels in water at pH 10. When carboxylate contents of the oxidized products were 1.5–1.7 mmol/g, TEMPO-oxidized cellulose nanofibrils almost completely dispersed at the individual nanofibril were obtained by mechanical disintegration of the TEMPO-oxidized hemp bast Holocelluloses in water, where the nanofibrillation yields were 98–100 %. The sugar composition analysis revealed that most of hemicelluloses originally present in the hemp bast Holocellulose were degraded and removed from the solid oxidized products, providing almost pure TEMPO-oxidized celluloses. X-ray diffraction patterns of all TEMPO-oxidized hemp bast Holocelluloses had the same cellulose I crystal structure and similar crystallinity indices and crystal widths, indicating that carboxylate groups formed by the oxidation were selectively present on the crystalline cellulose microfibril surfaces in the Holocellulose. However, the weight recovery ratios and viscosity-average degrees of polymerization of the TEMPO-oxidized hemp bast Holocelluloses decreased to 69–59 % and 470–380, respectively, when their carboxylate contents increased to 1.5–1.7 mmol/g by the TEMPO-mediated oxidation. Atomic force microscopy height images showed that the nanofibril widths were 2.7–2.9 nm, and the average nanofibril lengths decreased from 590 to 400 nm as the NaClO addition level was increased from 7.5 to 12.5 mmol/g in the TEMPO-mediated oxidation.
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light scattering analysis of native wood Holocelluloses totally dissolved in licl dmi solutions high probability of branched structures in inherent cellulose
Biomacromolecules, 2011Co-Authors: Mako Yamamoto, Ryota Kuramae, Masahiro Yanagisawa, Daisuke Ishii, Akira IsogaiAbstract:Three Holocelluloses (i.e., cellulose and hemicellulose fractions) are prepared from softwood and hardwood by the Wise method. These Holocelluloses completely dissolve in 8% lithium chloride/1,3-dimethyl-2-imidazolidinone (LiCl/DMI) after an ethylenediamine (EDA) pretreatment. After diluting the Holocellulose solutions to 1% LiCl/DMI, they are subjected to size-exclusion chromatography/multiangle laser-light scattering/photodiode array (SEC-MALLS-PDA) analysis. All Holocelluloses exhibit bimodal molecular weight distributions primarily due to high-molecular-weight (HMW) cellulose and low-molecular-weight hemicellulose fractions. Plots of molecular weight vs root-mean-square radius obtained by SEC-MALLS analysis revealed that all the wood celluloses comprise dense conformations in 1% LiCl/DMI. In contrast, bacterial cellulose, which was used as a pure cellulose model, has a random coil conformation as a linear polymer. These results show that both softwood and hardwood HMW celluloses contain branched struc...
Tsuguyuki Saito - One of the best experts on this subject based on the ideXlab platform.
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characterization of cellulose microfibrils cellulose molecules and hemicelluloses in buckwheat and rice husks
Cellulose, 2019Co-Authors: Yasutaka Nakamura, Tsuguyuki Saito, Akira IsogaiAbstract:Holocelluloses, TEMPO-oxidized Holocelluloses, and TEMPO-oxidized cellulose nanofibrils were prepared from buckwheat and rice husks to characterize the cellulose microfibril morphologies and Holocellulose molar masses. The buckwheat and rice husks had ash contents of 0.8% and 23%, respectively. All TEMPO-oxidized Holocelluloses had cellulose I crystal structures. TEMPO-oxidized cellulose nanofibrils prepared from the two husks were both ~ 3 nm wide. As significant amounts of xylan remained in the TEMPO-oxidized buckwheat and rice husk Holocelluloses, the TEMPO-oxidized cellulose nanofibrils prepared from them by mechanical disintegration in water gave yields as low as 14–17% (based on dry weight of dewaxed husk samples). Atomic force microscopy images of TEMPO-oxidized cellulose nanofibrils prepared from buckwheat husks showed that individual nanofibrils with widths of ~ 3 nm were quite flexible, while nanofibril bundles had rigid and needle-like morphologies. Rice husks had a high ash content, with part of the ash remaining in the corresponding Holocellulose, TEMPO-oxidized Holocellulose, and TEMPO-oxidized cellulose nanofibrils. Never-dried buckwheat husk cellulose (prepared by removal of hemicelluloses from Holocellulose) and oven-dried buckwheat husk Holocellulose containing a significant amount of hemicelluloses had leveling-off degrees of polymerization (DPs) of 650 and 810, respectively, after dilute acid hydrolysis. In contrast, oven-dried buckwheat husk cellulose had a leveling-off DP of 270.
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SEC–MALLS analysis of wood Holocelluloses dissolved in 8 % LiCl/1,3-dimethyl-2-imidazolidinone: challenges and suitable analytical conditions
Cellulose, 2015Co-Authors: Yuko Ono, Tsuguyuki Saito, Shuji Fujisawa, Ryoya Hiraoki, Akira IsogaiAbstract:The use of size-exclusion chromatography in combination with multi-angle laser-light scattering analysis (SEC–MALLS) can provide useful information pertaining to the molecular mass parameters of wood celluloses and hemicelluloses. When wood Holocelluloses containing significant amounts of hemicelluloses were soaked in ethylenediamine (EDA) and subjected to sequential EDA-removal and solvent-exchange processes into 1,3-dimethyl-2-imidazolidinone (DMI) under suitable conditions, the resulting materials provided much more reliable molecular mass parameters when they were dissolved in LiCl/DMI and subjecting to SEC–MALLS analysis. Furthermore, the residual EDA molecules trapped in the EDA-treated Holocelluloses could be removed by simply washing with methanol following the solvent-exchange process. The effect of the stirring time for the EDA-treated and solvent-exchanged eucalyptus Holocellulose in 8 % (w/v) LiCl/DMI was investigated in terms of its impact on the molecular mass parameters of the high-molecular-mass cellulose fractions and found to have no impact for up to 5 months. The optimal EDA treatment and solvent-exchange conditions obtained for eucalyptus Holocellulose were subsequently applied to various other wood Holocelluloses, including Japanese cedar, ginkgo and birch, which gave characteristic SEC elution patterns together with the corresponding molecular mass parameters, depending on their hemicellulose contents and the number of cellulose/lignin/hemicellulose chemical linkages present in their high-molecular-mass cellulose fractions. The weight-average degrees of polymerization of the high-molecular-mass cellulose fractions in the wood Holocelluloses ranged from 4400 to 6400, which were higher than those of cotton cellulose (2700) and bacterial cellulose (3100).
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tempo oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive & Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
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TEMPO-oxidized cellulose nanofibrils prepared from various plant Holocelluloses
Reactive and Functional Polymers, 2014Co-Authors: Ryota Kuramae, Tsuguyuki Saito, Akira IsogaiAbstract:Abstract Plant Holocelluloses were prepared from softwood, gymnosperm, hardwood, and herbaceous species, and subjected to TEMPO-mediated oxidation using the TEMPO/NaBr/NaOCl and TEMPO/NaOCl/NaO2Cl systems in water at pH 10 and 6.8, respectively. Weight recovery ratios of the water-insoluble TEMPO-oxidized Holocellulose (TOH) fractions and their carboxylate contents, sugar compositions, and X-ray diffraction patterns were measured. When the oxidation at pH 10 was used, the carboxylate content of the TOHs increased up to 1.4–1.7 mmol g−1. The oxidation at pH 6.8 resulted in higher weight recovery ratios of TOHs and their lower carboxylate contents (0.8–1.2 mmol g−1) than those prepared by the oxidation at pH 10. Hemicelluloses in plant Holocelluloses are preferentially degraded to water-soluble fractions and removed from TOHs in the oxidation at pH 10. In contrast, the TEMPO-mediated oxidation at pH 6.8 provides hemicellulose-rich TOHs in high weight recovery ratios, although their nanofibrillation yields were low. All TEMPO-oxidized Holocellulose nanofibrils (TOHNs) obtained by mechanical disintegration treatment of TOHs in water had the same average widths of ∼3 nm, when measured by atomic force microscopy in water, which were consistent with those of TOHs determined from X-ray diffraction patterns. The number-average lengths of TOHNs were 500–600 nm.
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TEMPO-Mediated Oxidation of Hemp Bast Holocellulose to Prepare Cellulose Nanofibrils Dispersed in Water
Journal of Polymers and The Environment, 2012Co-Authors: Buapan Puangsin, Ryota Kuramae, Tsuguyuki Saito, Shuji Fujisawa, Akira IsogaiAbstract:Hemp bast Holocellulose fiber (Cannabis sativa L. Subsp. Sativa) was oxidized by TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical)-mediated oxidation at various NaClO addition levels in water at pH 10. When carboxylate contents of the oxidized products were 1.5–1.7 mmol/g, TEMPO-oxidized cellulose nanofibrils almost completely dispersed at the individual nanofibril were obtained by mechanical disintegration of the TEMPO-oxidized hemp bast Holocelluloses in water, where the nanofibrillation yields were 98–100 %. The sugar composition analysis revealed that most of hemicelluloses originally present in the hemp bast Holocellulose were degraded and removed from the solid oxidized products, providing almost pure TEMPO-oxidized celluloses. X-ray diffraction patterns of all TEMPO-oxidized hemp bast Holocelluloses had the same cellulose I crystal structure and similar crystallinity indices and crystal widths, indicating that carboxylate groups formed by the oxidation were selectively present on the crystalline cellulose microfibril surfaces in the Holocellulose. However, the weight recovery ratios and viscosity-average degrees of polymerization of the TEMPO-oxidized hemp bast Holocelluloses decreased to 69–59 % and 470–380, respectively, when their carboxylate contents increased to 1.5–1.7 mmol/g by the TEMPO-mediated oxidation. Atomic force microscopy height images showed that the nanofibril widths were 2.7–2.9 nm, and the average nanofibril lengths decreased from 590 to 400 nm as the NaClO addition level was increased from 7.5 to 12.5 mmol/g in the TEMPO-mediated oxidation.
Michel Mench - One of the best experts on this subject based on the ideXlab platform.
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degradation pathways of Holocellulose lignin and α cellulose from pteris vittata fronds in sub and super critical conditions
Biomass & Bioenergy, 2012Co-Authors: Marion Carrier, Anne Loppinetserani, Christelle Absalon, Cyril Aymonier, Michel MenchAbstract:Abstract Fern (Pteris vittata L.) fronds were collected in the Reppel small-scale field experiment aiming at arsenic phytoextraction. Three organic fractions, i.e. Holocellulose, hemicelluloses, and lignin, were extracted from the fronds. The frond biomass as well as the Holocellulose, hemicelluloses, and lignin fractions were converted by sub- and super critical water treatments at low temperatures, 300 °C and 400 °C with 25 MPa, and organic products were identified. This study highlighted that hemicelluloses and lignin are reported as the major sources of cyclopentenones and furfurals, 5 carbons-containing products. The degradation of carbohydrates part (Holocellulose and α-cellulose) provided the largest range of by-products due to the thermal resistance of the lignin. The control of biochemical families's content and temperature should determine the presence of required by-products. The fact that no ‘synthetic’ materials but original materials, i.e. Holocellulose, α-cellulose and lignin directly extracted from control fern fronds have been converted revealed the presence of benzenes and cyclopentenones, by-products which have not been reported by the literature.
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Degradation pathways of Holocellulose, lignin and a-cellulose from Pteris vittata fronds in sub- and super critical conditions
Biomass and Bioenergy, 2012Co-Authors: Marion Carrier, Christelle Absalon, Cyril Aymonier, Anne Loppinet-serani, Michel MenchAbstract:Fern (Pterisvittata L.) fronds were collected in the Reppel small-scale field experiment aiming at arsenic phytoextraction. Three organic fractions, i.e. Holocellulose, hemicelluloses, and lignin, were extracted from the fronds. The frond biomass as well as the Holocellulose, hemicelluloses, and lignin fractions were converted by sub- and supercritical water treatments at low temperatures, 300 °C and 400 °C with 25 MPa, and organic products were identified. This study highlighted that hemicelluloses and lignin are reported as the major sources of cyclopentenones and furfurals, 5 carbons-containing products. The degradation of carbohydrates part (Holocellulose and α-cellulose) provided the largest range of by-products due to the thermal resistance of the lignin. The control of biochemical families's content and temperature should determine the presence of required by-products. The fact that no 'synthetic' materials but original materials, i.e. Holocellulose, α-cellulose and lignin directly extracted from control fern fronds have been converted revealed the presence of benzenes and cyclopentenones, by-products which have not been reported by the literature.
Marion Carrier - One of the best experts on this subject based on the ideXlab platform.
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degradation pathways of Holocellulose lignin and α cellulose from pteris vittata fronds in sub and super critical conditions
Biomass & Bioenergy, 2012Co-Authors: Marion Carrier, Anne Loppinetserani, Christelle Absalon, Cyril Aymonier, Michel MenchAbstract:Abstract Fern (Pteris vittata L.) fronds were collected in the Reppel small-scale field experiment aiming at arsenic phytoextraction. Three organic fractions, i.e. Holocellulose, hemicelluloses, and lignin, were extracted from the fronds. The frond biomass as well as the Holocellulose, hemicelluloses, and lignin fractions were converted by sub- and super critical water treatments at low temperatures, 300 °C and 400 °C with 25 MPa, and organic products were identified. This study highlighted that hemicelluloses and lignin are reported as the major sources of cyclopentenones and furfurals, 5 carbons-containing products. The degradation of carbohydrates part (Holocellulose and α-cellulose) provided the largest range of by-products due to the thermal resistance of the lignin. The control of biochemical families's content and temperature should determine the presence of required by-products. The fact that no ‘synthetic’ materials but original materials, i.e. Holocellulose, α-cellulose and lignin directly extracted from control fern fronds have been converted revealed the presence of benzenes and cyclopentenones, by-products which have not been reported by the literature.
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Degradation pathways of Holocellulose, lignin and a-cellulose from Pteris vittata fronds in sub- and super critical conditions
Biomass and Bioenergy, 2012Co-Authors: Marion Carrier, Christelle Absalon, Cyril Aymonier, Anne Loppinet-serani, Michel MenchAbstract:Fern (Pterisvittata L.) fronds were collected in the Reppel small-scale field experiment aiming at arsenic phytoextraction. Three organic fractions, i.e. Holocellulose, hemicelluloses, and lignin, were extracted from the fronds. The frond biomass as well as the Holocellulose, hemicelluloses, and lignin fractions were converted by sub- and supercritical water treatments at low temperatures, 300 °C and 400 °C with 25 MPa, and organic products were identified. This study highlighted that hemicelluloses and lignin are reported as the major sources of cyclopentenones and furfurals, 5 carbons-containing products. The degradation of carbohydrates part (Holocellulose and α-cellulose) provided the largest range of by-products due to the thermal resistance of the lignin. The control of biochemical families's content and temperature should determine the presence of required by-products. The fact that no 'synthetic' materials but original materials, i.e. Holocellulose, α-cellulose and lignin directly extracted from control fern fronds have been converted revealed the presence of benzenes and cyclopentenones, by-products which have not been reported by the literature.