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Ku TH, Yano H, Abe K. High temperatures and pressures during cooking hinder the nanofibrillation of purified pulp. Carbohydr Polym 2022; 298:120078. [DOI: 10.1016/j.carbpol.2022.120078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 11/15/2022]
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Chemical Structure and Mechanical Properties of Wood Cell Walls Treated with Acid and Alkali Solution. FORESTS 2020. [DOI: 10.3390/f11010087] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The mechanical properties of individual fibers are related to the production and performance of papers and fiberboards. This paper examines the behavior of the microstructure constituents of wood subjected to acid and alkali treatments. The chemical structure and mechanical properties of wood cell walls with different acid or alkali treatments was analyzed. The results show that, compared with acid treatment, the crystal size and crystallinity index of cellulose increased after alkali treatment, resulting in an increase in the cell wall elastic modulus. The mechanical properties of the wood cell wall S2 region were higher than those of the compound middle lamella (CML) region. There was a topochemical effect between the CML and the S2 region in acid and alkali-treated samples, which provided a major threshold that facilitates the production/separation of wood fibers for better strength fiber properties.
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Birch wood pre-hydrolysis vs pulp post-hydrolysis for the production of xylan-based compounds and cellulose for viscose application. Carbohydr Polym 2018; 190:212-221. [PMID: 29628240 DOI: 10.1016/j.carbpol.2018.02.064] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 01/26/2018] [Accepted: 02/21/2018] [Indexed: 12/16/2022]
Abstract
Hydrothermal treatments of birch wood and kraft pulp were compared for their ability to extract the xylan and produce viscose-grade pulp. Water post-hydrolysis of kraft pulp produced a high-purity cellulosic pulp with lower viscosity but higher cellulose yield than traditional pre-hydrolysis kraft pulping of wood. Post-hydrolysis of pulp also increased the crystallite dimensions and degree of crystallinity in cellulose, and promoted a higher extent of fibril aggregation. The lower specific surface area in post-hydrolyzed pulps, derived from their larger fibril aggregates, decreased the accessibility of OH groups. However, this lower accessibility did not seem to decrease the pulp reactivity to derivatizing chemicals. In the aqueous side-stream, the xylose yield was similar in both pre- and post-hydrolysates, although conducting post-hydrolysis of pulp in a flow-through system enabled the recovery of high purity and molar mass (∼10 kDa) xylan for high-value applications.
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Sun Q, Foston M, Meng X, Sawada D, Pingali SV, O’Neill HM, Li H, Wyman CE, Langan P, Ragauskas AJ, Kumar R. Effect of lignin content on changes occurring in poplar cellulose ultrastructure during dilute acid pretreatment. BIOTECHNOLOGY FOR BIOFUELS 2014; 7:150. [PMID: 25342973 PMCID: PMC4205766 DOI: 10.1186/s13068-014-0150-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/17/2014] [Accepted: 09/25/2014] [Indexed: 05/02/2023]
Abstract
BACKGROUND Obtaining a better understanding of the complex mechanisms occurring during lignocellulosic deconstruction is critical to the continued growth of renewable biofuel production. A key step in bioethanol production is thermochemical pretreatment to reduce plant cell wall recalcitrance for downstream processes. Previous studies of dilute acid pretreatment (DAP) have shown significant changes in cellulose ultrastructure that occur during pretreatment, but there is still a substantial knowledge gap with respect to the influence of lignin on these cellulose ultrastructural changes. This study was designed to assess how the presence of lignin influences DAP-induced changes in cellulose ultrastructure, which might ultimately have large implications with respect to enzymatic deconstruction efforts. RESULTS Native, untreated hybrid poplar (Populus trichocarpa x Populus deltoids) samples and a partially delignified poplar sample (facilitated by acidic sodium chlorite pulping) were separately pretreated with dilute sulfuric acid (0.10 M) at 160°C for 15 minutes and 35 minutes, respectively . Following extensive characterization, the partially delignified biomass displayed more significant changes in cellulose ultrastructure following DAP than the native untreated biomass. With respect to the native untreated poplar, delignified poplar after DAP (in which approximately 40% lignin removal occurred) experienced: increased cellulose accessibility indicated by increased Simons' stain (orange dye) adsorption from 21.8 to 72.5 mg/g, decreased cellulose weight-average degree of polymerization (DPw) from 3087 to 294 units, and increased cellulose crystallite size from 2.9 to 4.2 nm. These changes following DAP ultimately increased enzymatic sugar yield from 10 to 80%. CONCLUSIONS Overall, the results indicate a strong influence of lignin content on cellulose ultrastructural changes occurring during DAP. With the reduction of lignin content during DAP, the enlargement of cellulose microfibril dimensions and crystallite size becomes more apparent. Further, this enlargement of cellulose microfibril dimensions is attributed to specific processes, including the co-crystallization of crystalline cellulose driven by irreversible inter-chain hydrogen bonding (similar to hornification) and/or cellulose annealing that converts amorphous cellulose to paracrystalline and crystalline cellulose. Essentially, lignin acts as a barrier to prevent cellulose crystallinity increase and cellulose fibril coalescence during DAP.
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Affiliation(s)
- Qining Sun
- />School of Chemistry and Biochemistry, Renewable Bioproducts Institute,
Georgia Institute of Technology, 500 10th Street, N.W. Atlanta, GA 30332-0620 USA
| | - Marcus Foston
- />Department of Energy, Environmental and Chemical
Engineering, Washington University, 1 Brookings Drive, Saint Louis, MO 63130 USA
| | - Xianzhi Meng
- />School of Chemistry and Biochemistry, Renewable Bioproducts Institute,
Georgia Institute of Technology, 500 10th Street, N.W. Atlanta, GA 30332-0620 USA
| | - Daisuke Sawada
- />Center for Structural Molecular Biology and the Biology and Soft Matter
Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Sai Venkatesh Pingali
- />Center for Structural Molecular Biology and the Biology and Soft Matter
Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Hugh M O’Neill
- />Center for Structural Molecular Biology and the Biology and Soft Matter
Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Hongjia Li
- />Center for Environmental Research and Technology
(CE-CERT), Bourns College of Engineering, University of California, 1084 Columbia Avenue, Riverside, CA 92507 USA
| | - Charles E Wyman
- />Center for Environmental Research and Technology
(CE-CERT), Bourns College of Engineering, University of California, 1084 Columbia Avenue, Riverside, CA 92507 USA
- />Department of Chemical and Environmental Engineering, Bourns College of Engineering, University of California, 900 University Avenue, Riverside, CA 92521 USA
- />BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831 USA
| | - Paul Langan
- />Center for Structural Molecular Biology and the Biology and Soft Matter
Division, Oak Ridge National Laboratory, Oak Ridge, TN 37831 USA
| | - Art J Ragauskas
- />School of Chemistry and Biochemistry, Renewable Bioproducts Institute,
Georgia Institute of Technology, 500 10th Street, N.W. Atlanta, GA 30332-0620 USA
- />BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831 USA
- />Department of Chemical and Biomolecular Engineering, Department of
Forestry, Wildlife, and Fisheries, Center for Renewable Carbon, University of Tennessee, Knoxville, TN 37996-2200 USA
| | - Rajeev Kumar
- />Center for Environmental Research and Technology
(CE-CERT), Bourns College of Engineering, University of California, 1084 Columbia Avenue, Riverside, CA 92507 USA
- />BioEnergy Science Center (BESC), Oak Ridge National Laboratory (ORNL), Oak Ridge, TN 37831 USA
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Cozzolino CA, Nilsson F, Iotti M, Sacchi B, Piga A, Farris S. Exploiting the nano-sized features of microfibrillated cellulose (MFC) for the development of controlled-release packaging. Colloids Surf B Biointerfaces 2013; 110:208-16. [DOI: 10.1016/j.colsurfb.2013.04.046] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Revised: 04/03/2013] [Accepted: 04/28/2013] [Indexed: 01/17/2023]
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Foston M, Katahira R, Gjersing E, Davis MF, Ragauskas AJ. Solid-state selective (13)C excitation and spin diffusion NMR to resolve spatial dimensions in plant cell walls. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2012; 60:1419-1427. [PMID: 22295909 DOI: 10.1021/jf204853b] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The average spatial dimensions between major biopolymers within the plant cell wall can be resolved using a solid-state NMR technique referred to as a (13)C cross-polarization (CP) SELDOM (selectively by destruction of magnetization) with a mixing time delay for spin diffusion. Selective excitation of specific aromatic lignin carbons indicates that lignin is in close proximity to hemicellulose followed by amorphous and finally crystalline cellulose. (13)C spin diffusion time constants (T(SD)) were extracted using a two-site spin diffusion theory developed for (13)C nuclei under magic angle spinning (MAS) conditions. These time constants were then used to calculate an average lower-limit spin diffusion length between chemical groups within the plant cell wall. The results on untreated (13)C enriched corn stover stem reveal that the lignin carbons are, on average, located at distances ∼0.7-2.0 nm from the carbons in hemicellulose and cellulose, whereas the pretreated material had larger separations.
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Affiliation(s)
- Marcus Foston
- BioEnergy Science Center, School of Chemistry and Biochemistry, Institute of Paper Science and Technology, Georgia Institute of Technology, 500 10th Street, Atlanta, Georgia 30332, USA
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