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Papp D, Carlström G, Nylander T, Sandahl M, Turner C. A Complementary Multitechnique Approach to Assess the Bias in Molecular Weight Determination of Lignin by Derivatization-Free Gel Permeation Chromatography. Anal Chem 2024; 96:10612-10619. [PMID: 38888104 PMCID: PMC11223100 DOI: 10.1021/acs.analchem.4c01187] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 05/29/2024] [Accepted: 05/30/2024] [Indexed: 06/20/2024]
Abstract
The growing interest in lignin valorization in the past decades calls for analytical techniques for lignin characterization, ranging from wet chemistry techniques to highly sophisticated chromatographic and spectroscopic methods. One of the key parameters to consider is the molecular weight profile of lignin, which is routinely determined by size-exclusion chromatography; however, this is by no means straightforward and is prone to being hampered by considerable errors. Our study expands the fundamental understanding of the bias-inducing mechanisms in gel permeation chromatography (GPC), the magnitude of error originating from using polystyrene standards for mass calibration, and an evaluation of the effects of the solvent and type of lignin on the observed bias. The developed partial least-squares (PLS) regression model for lignin-related monomers revealed that lignin is prone to association mainly via hydrogen bonding. This hypothesis was supported by functional group-based analysis of the bias as well as pulse field gradient (pfg) diffusion NMR spectroscopy of model compounds in THF-d8. Furthermore, although the lack of standards hindered drawing conclusions based on functionalities, direct infusion electrospray ionization mass spectrometry indicated that the relative bias decreases considerably for higher molecular weight species. The results from pfg-diffusion NMR spectroscopy on whole lignin samples were comparable when the same solvents were used in both experiments; in addition, the comparison between results obtained by pfg-diffusion NMR in different solvents gives some additional insights into the aggregation.
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Affiliation(s)
- Daniel Papp
- Department
of Chemistry, Centre for Analysis and Synthesis, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Göran Carlström
- Department
of Chemistry, Centre for Analysis and Synthesis, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Tommy Nylander
- Department
of Chemistry, Physical Chemistry, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Margareta Sandahl
- Department
of Chemistry, Centre for Analysis and Synthesis, Lund University, P.O. Box 124, Lund SE-22100, Sweden
| | - Charlotta Turner
- Department
of Chemistry, Centre for Analysis and Synthesis, Lund University, P.O. Box 124, Lund SE-22100, Sweden
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2
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Riddell LA, de Peinder P, Polizzi V, Vanbroekhoven K, Meirer F, Bruijnincx PCA. Predicting Molecular Weight Characteristics of Reductively Depolymerized Lignins by ATR-FTIR and Chemometrics. ACS SUSTAINABLE CHEMISTRY & ENGINEERING 2024; 12:8968-8977. [PMID: 38872958 PMCID: PMC11167637 DOI: 10.1021/acssuschemeng.4c03100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2024] [Revised: 05/14/2024] [Accepted: 05/16/2024] [Indexed: 06/15/2024]
Abstract
Recent scientific advances in the valorization of lignin, through e.g., (partial-)catalytic depolymerization, require equally state-of-the-art approaches for the analysis of the obtained depolymerized lignins (DLs) or lignin bio-oils. The use of chemometrics in combination with infrared (IR) spectroscopy is one avenue to provide rapid access to pertinent lignin parameters, such as molecular weight (MW) characteristics, which typically require analysis via time-consuming size-exclusion methods, or diffusion-ordered NMR spectroscopy. Importantly, MW serves as a marker for the degree of depolymerization (or recondensation) that the lignin has undergone, and thus probing this parameter is essential for the optimization of depolymerization conditions to achieve DLs with desired properties. Here, we show that our ATR-IR-based chemometrics approach used previously for technical lignin analysis can be extended to analyze these more processed, lignin-derived samples as well. Remarkably, also at this lower end of the MW scale, the use of partial least-squares (PLS) regression models well-predicted the MW parameters for a sample set of 57 depolymerized lignins, with relative errors of 9.9-11.2%. Furthermore, principal component analysis (PCA) showed good correspondence with features in the regression vectors for each of the biomass classes (hardwood, herbaceous/grass, and softwood) obtained from PLS-discriminant analysis (PLS-DA). Overall, we show that the IR spectra of DLs are still amenable to chemometric analysis and specifically to rapid, predictive characterization of their MW, circumventing the time-consuming, tedious, and not generally accessible methods typically employed.
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Affiliation(s)
- Luke A. Riddell
- Faculty
of Science, Organic Chemistry & Catalysis, Institute for Sustainable
and Circular Chemistry, Utrecht University
institution, Utrecht 3584CG, The Netherlands
| | - Peter de Peinder
- Faculty
of Science, Inorganic Chemistry & Catalysis, Institute for Sustainable
and Circular Chemistry, Utrecht University, Utrecht 3584CG, The Netherlands
- VibSpec, Haaftenlaan 28, Tiel 4006
XL, The Netherlands
| | - Viviana Polizzi
- Sustainable
Polymer Technologies team, Materials & Chemistry unit, Flemish Institute for Technological Research (VITO), Mol 2400, Belgium
| | - Karolien Vanbroekhoven
- Sustainable
Polymer Technologies team, Materials & Chemistry unit, Flemish Institute for Technological Research (VITO), Mol 2400, Belgium
| | - Florian Meirer
- Faculty
of Science, Inorganic Chemistry & Catalysis, Institute for Sustainable
and Circular Chemistry, Utrecht University, Utrecht 3584CG, The Netherlands
| | - Pieter C. A. Bruijnincx
- Faculty
of Science, Organic Chemistry & Catalysis, Institute for Sustainable
and Circular Chemistry, Utrecht University
institution, Utrecht 3584CG, The Netherlands
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3
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Ghahri S, Park BD. Amination and crosslinking of acetone-fractionated hardwood kraft lignin using different amines and aldehydes for sustainable bio-based wood adhesives. BIORESOURCE TECHNOLOGY 2024; 399:130645. [PMID: 38554759 DOI: 10.1016/j.biortech.2024.130645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/19/2024] [Accepted: 03/27/2024] [Indexed: 04/02/2024]
Abstract
Hardwood kraft lignin from the pulping industry is burned or discarded. Its valorization was conducted by subjecting fractionation, amination with ethylenediamine, diethylenetriamine, and monoethanolamine, and crosslinking with formaldehyde or glyoxal to obtain bio-based wood adhesives. Acetone-soluble and insoluble hardwood kraft lignin were prepared and subjected to amination and then crosslinking. Fourier transform infrared, 13C NMR, 15N NMR, and X-ray photoelectron spectroscopy results revealed successful amination with amide, imine, and ether bonds and crosslinking of all samples. Hardwood kraft lignin aminated with diethylenetriamine/ethylenediamine and crosslinked using glyoxal exhibited excellent results in comparison with samples crosslinked using formaldehyde. Acetone-insoluble hardwood kraft lignin aminated and crosslinked using diethylenetriamine and formaldehyde, respectively, exhibited excellent adhesion strength with plywood, satisfying the requirements of the Korean standards. The amination and crosslinking of industrial waste hardwood kraft lignin constitute a beneficial valorization method.
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Affiliation(s)
- Saman Ghahri
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Byung-Dae Park
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea.
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Clobes ML, Kozliak EI, Kubátová A. Advancing Molecular Weight Determination of Lignin by Multi-Angle Light Scattering. Polymers (Basel) 2024; 16:477. [PMID: 38399853 PMCID: PMC10892000 DOI: 10.3390/polym16040477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2024] [Revised: 02/01/2024] [Accepted: 02/05/2024] [Indexed: 02/25/2024] Open
Abstract
Due to the complexity and recalcitrance of lignin, its chemical characterization is a key factor preventing the valorization of this abundant material. Multi-angle light scattering (MALS) is becoming a sought-after technique for absolute molecular weight (MW) determination of polymers and proteins. Lignin is a suitable candidate for MW determination via MALS, yet further investigation is required to confirm its absolute MW values and molecular size. Studies aiming to break down lignin into a variety of renewable products will benefit greatly from a simple and reliable determination method like MALS. Recent pioneering studies, discussed in this review, addressed several key challenges in lignin's MW characterization. Nevertheless, some lignin-specific issues still need to be considered for in-depth characterization. This study explores how MALS instrumentation manages the complexities of determining lignin's MW, e.g., with simultaneous fractionation and fluorescence interference mitigation. Additionally, we rationalize the importance of a more detailed light scattering analysis for lignin characterization, including aspects like the second virial coefficient and radius of gyration.
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Affiliation(s)
| | - Evguenii I. Kozliak
- Department of Chemistry, University of North Dakota, 151 Cornell St., Stop 9024, Grand Forks, ND 58202, USA;
| | - Alena Kubátová
- Department of Chemistry, University of North Dakota, 151 Cornell St., Stop 9024, Grand Forks, ND 58202, USA;
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Johnson AM, Karaaslan MA, Cho M, Ogawa Y, Renneckar S. Exploring the impact of water on the morphology and crystallinity of xylan hydrate nanotiles. Carbohydr Polym 2023; 319:121165. [PMID: 37567708 DOI: 10.1016/j.carbpol.2023.121165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 06/18/2023] [Accepted: 06/28/2023] [Indexed: 08/13/2023]
Abstract
There has been a resurgence of studies on xylan particles describing various properties and exploring new applications. The aim of this study was to analyze xylan hydrate crystals in the wet state and after air-drying using state-of-art imaging techniques in order to assess the impact of water on both crystallinity and particle morphology. Xylan from esparto grass (Stipa tenacissima) was crystallized and formed convex platelets, termed 'nanotiles'. Fully hydrated xylan crystals were examined in a layer of vitreous ice by cryogenic electron microscopy. Selected area electron diffraction of the xylan hydrate crystals revealed an oriented crystalline core, unlike the dried crystals that showed no orientation. The surface topographies and thickness of wet and air-dried xylan nanotiles were observed using atomic force microscopy imaging in both liquid and in air. X-ray diffraction was used to assess the crystallinity of xylan nanotiles after drying to varying levels. Air-dried crystals gave diffraction maxima corresponding to xylan hydrate, while wet crystals gave diffraction maxima corresponding to xylan dihydrate. This study offers new insight into xylan hydrate particles, focusing on the role of water on their crystallinity, ultrastructure, and orientation of the crystalline layers.
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Affiliation(s)
- Amanda M Johnson
- Advanced Renewable Materials Laboratory, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Muzaffer A Karaaslan
- Advanced Renewable Materials Laboratory, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - MiJung Cho
- Advanced Renewable Materials Laboratory, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada; Department of Bioproducts and Biosystems, Alto University, Espoo, Finland
| | - Yu Ogawa
- Univ. Grenoble Alpes, CNRS, CERMAV, 38000 Grenoble, France
| | - Scott Renneckar
- Advanced Renewable Materials Laboratory, Department of Wood Science, Faculty of Forestry, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada.
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Wibowo ES, Park BD. Chemical and Thermal Characteristics of Ion-Exchanged Lignosulfonate. Molecules 2023; 28:molecules28062755. [PMID: 36985727 PMCID: PMC10052178 DOI: 10.3390/molecules28062755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 03/30/2023] Open
Abstract
Lignosulfonate features sulfonate groups, which makes it soluble in water and hence, suitable for a wide range of applications. However, its characterization is challenging because of its limited solubility in organic solvents. Thus, this study investigated the chemical and thermal characteristics of ion-exchanged sodium lignosulfonate (Na-LS) and compared it with those of industrial kraft lignin derived from softwood and hardwood. The results demonstrated that the ion exchange successfully converted Na-LS to lignosulfonic acid (H-LS), as proven by the Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and elemental analysis. H-LS has a greater apparent molecular weight than those of Na-LS and softwood and hardwood kraft lignin (SKL and HKL). According to 31P nuclear magnetic resonance (NMR) analysis, H-LS has less phenolic OH than SKL and HKL, indicating that it has more polymeric chains. Furthermore, H-LS has substantially more native side chains, such as β-O-4 units, than SKL and HKL. Thermal analysis revealed that H-LS has a greater glass temperature (Tg) than SKL and HKL, although Na-LS has a lower Tg than SKL and HKL. In addition, H-LS degraded faster than Na-LS did because the acid condition accelerated degradation reaction.
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Affiliation(s)
- Eko Setio Wibowo
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea
- Research Center for Biomass and Bioproducts, National Research and Innovation Agency, Bogor 16911, Indonesia
| | - Byung-Dae Park
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea
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Hua Q, Liu LY, Cho M, Karaaslan MA, Zhang H, Kim CS, Renneckar S. Functional Lignin Building Blocks: Reactive Vinyl Esters with Acrylic Acid. Biomacromolecules 2023; 24:592-603. [PMID: 36705942 DOI: 10.1021/acs.biomac.2c00806] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Introducing vinyl groups onto the backbone of technical lignin provides an opportunity to create highly reactive renewable polymers suitable for radical polymerization. In this work, the chemical modification of softwood kraft lignin was pursued with etherification, followed by direct esterification with acrylic acid (AA). In the first step, phenolic hydroxyl and carboxylic acid groups were derivatized into aliphatic hydroxyl groups using ethylene carbonate and an alkaline catalyst. The lignin was subsequently fractionated using a downward precipitation method to recover lignin of defined molar mass and solubility. After recovery, the resulting material was then esterified with AA, resulting in lignin with vinyl functional groups. The first step resulted in approximately 90% of phenolic hydroxyl groups being converted into aliphatic hydroxyls, while the downward fractionation resulted in three samples of lignin with defined molar masses. For the esterification reaction, the weight ratio of reagents, reaction temperature, and reaction time were evaluated as factors that would influence the modification efficacy. 13C NMR spectroscopy analysis of lignin samples before and after esterification showed that the optimized reaction conditions could reach approximately 40% substitution of aliphatic hydroxyl groups. Both steps only used lignin and the modifying reagent (no solvent), with the possibility of recovery and reuse of the reagent by dilution and distillation. An additional second esterification step of the resulting lignin sample with acetic acid or propionic acid converted 90% of remaining hydroxyl groups into short-chain carbon aliphatic esters, making a hydrophobic material suitable for further copolymerization with synthetic hydrophobic monomers.
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Affiliation(s)
- Qi Hua
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Li-Yang Liu
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Mijung Cho
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Muzaffer A Karaaslan
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Huaiyu Zhang
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
| | - Chang Soo Kim
- Clean Energy Research Center, Korea Institute of Science and Technology, Seoul 02792, Republic of Korea.,Department of Chemical and Biological Engineering, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada.,Division of Energy & Environment Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea
| | - Scott Renneckar
- Advanced Renewable Materials Lab, Department of Wood Science, Faculty of Forestry, The University of British Columbia, Vancouver, British Columbia V6T 1Z4, Canada
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Wibowo ES, Park BD. The role of acetone-fractionated Kraft lignin molecular structure on surface adhesion to formaldehyde-based resins. Int J Biol Macromol 2023; 225:1449-1461. [PMID: 36436598 DOI: 10.1016/j.ijbiomac.2022.11.202] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Revised: 11/02/2022] [Accepted: 11/20/2022] [Indexed: 11/26/2022]
Abstract
One of the key strategies for valorizing kraft lignin (KL) into value-added products such as bio-based adhesives is to perform solvent fractionation of KL to produce lignin with improved homogeneity. Understanding the structure and properties of fractionated KL will aid in the selection of the best samples for certain applications. In this study, acetone-fractionated KL from softwood and hardwood was characterized to understand its chemical structure, elemental composition, molecular weight, and thermal properties. The results revealed that acetone-insoluble KL (AIKL) fractions from softwood and hardwood have greater molecular weight, polydispersity, glass temperature, carbohydrate content, aliphatic hydroxyl groups, and a variety of native wood lignin side chains. In contrast, acetone-soluble KL (ASKL) fractions have a significantly lower molecular weight and polydispersity, a lower glass-transition temperature, a more condensed structure, more aromatic hydroxyl groups, and fewer native wood lignin side chains. In addition, the ASKL samples demonstrated stronger adhesive force and work of adhesion toward phenol-formaldehyde (PF) and urea-formaldehyde (UF) resins than the AIKL samples, regardless of the lignin source. These findings suggest that ASKL has great potential as a substitute for phenol in PF resins and as a green additive to reinforce UF resins.
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Affiliation(s)
- Eko Setio Wibowo
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea
| | - Byung-Dae Park
- Department of Wood and Paper Science, Kyungpook National University, Daegu 41566, Republic of Korea.
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Zhang X, Zhang J, Yang H, He C, Ke Y, Singh S, Cheng G. Determination of the Structures of Lignin Subunits and Nanoparticles in Solution by Small-Angle Neutron Scattering: Towards Improving Lignin Valorization. CHEMSUSCHEM 2022; 15:e202201230. [PMID: 35916324 DOI: 10.1002/cssc.202201230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/01/2022] [Indexed: 06/15/2023]
Abstract
Lignin nanoparticles (LNPs) are usually produced from lignin solution through supersaturation. The structure of the lignin in solution is still poorly understood due to structural variability of isolated lignins. Here, lignins were extracted from different plants to establish a general pattern of their structure in several lignin solvents. Lignin molecules (lignin subunits) and larger aggregates were observed in dimethyl sulfoxide (DMSO), ethylene glycol (EG) and 0.1 N NaOD solutions by small-angle neutron scattering (SANS). It was proposed that the aggregates were composed of lignin subunits with a higher molecular weight and a higher ratio of the aliphatic to phenolic hydroxyl groups. The size, shape, and compactness are important factors that affect the uses of the LNPs, which were obtained from the SANS data for the first time. A discrepancy in the radius between SANS and DLS was discovered, pointing to a large hydration shell around the LNPs in aqueous solutions. The cytotoxicity of the corncob lignin, kraft lignin, and their LNPs were measured and compared.
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Affiliation(s)
- Xin Zhang
- State Key Laboratory of Organic-Inorganic Composites and College of Life Science and Technology, Beijing University of Chemical Technology, North 3rd Ring East, # 15, 100029, Beijing, P. R. China
- State Key Laboratory of Tribology, Tsinghua University, 100084, Beijing, P. R. China
| | - Jinxu Zhang
- State Key Laboratory of Organic-Inorganic Composites and College of Life Science and Technology, Beijing University of Chemical Technology, North 3rd Ring East, # 15, 100029, Beijing, P. R. China
| | - Hua Yang
- Dongguan Neutron Source Science Center, 523803, Dongguan, P. R. China
- Institute of High Energy Physics, Chinese Academy of Science, 100049, Beijing, P. R. China
| | - Chunyong He
- Dongguan Neutron Source Science Center, 523803, Dongguan, P. R. China
- Institute of High Energy Physics, Chinese Academy of Science, 100049, Beijing, P. R. China
| | - Yubin Ke
- Dongguan Neutron Source Science Center, 523803, Dongguan, P. R. China
- Institute of High Energy Physics, Chinese Academy of Science, 100049, Beijing, P. R. China
| | - Seema Singh
- Deconstruction Division, Joint BioEnergy Institute (JBEI), 5885 Hollis Street, 94608, Emeryville, CA, USA
- Sandia National Laboratories, 7011 East Ave, 94551, Livermore, CA, USA
| | - Gang Cheng
- State Key Laboratory of Organic-Inorganic Composites and College of Life Science and Technology, Beijing University of Chemical Technology, North 3rd Ring East, # 15, 100029, Beijing, P. R. China
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