Article
Chemistry, Physical
Mohammad Nikookar, Mohammad R. Omidkhah, Gholam R. Pazuki, Amir H. Mohammadi
Summary: The study investigated the molecular weight distributions of asphaltene and asphalt, finding that asphaltene has more aggregation at higher molecular weights compared to asphalt, and the molecular weight distribution of asphaltene is generally wider than that of asphalt.
JOURNAL OF MOLECULAR LIQUIDS
(2022)
Article
Energy & Fuels
Azadeh Karevan, Shadi Kheirollahi, Mohsen Zirrahi, Hassan Hassanzadeh
Summary: Solvents are injected with steam into oil sands to dilute and mobilize bitumen. However, measuring the solvent content in the produced streams is challenging due to component overlap and the presence of water. In this study, an analytical technique based on GPC and GC was developed to fully characterize complex mixtures of bitumen and solvent and accurately measure the solvent content in the production streams.
Article
Forestry
Muller de Souza Luana, Renato Queiroz Assis, Cristian Mauricio Barreto Pinilla, Rafaela Stange, Helena Cristina Vieira, Adriano Brandelli, Tania Maria Haas Costa, Alessandro de Oliveira Rios, Polliana D'Angelo Rios
Summary: This study aimed to obtain cellulose nanocrystals (CNC) through acid hydrolysis and evaluate their application potential in paper as a structural reinforcing agent. Papers incorporated with 12% and 18% CNC showed superior mechanical properties in tensile testing, improving paper quality. Optical properties remained unchanged after the addition of CNC.
WOOD SCIENCE AND TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Kaiyan Jin, Yanjun Tang, Jichun Liu, Junming Wang, Chunjie Ye
Summary: Nanofibrillated cellulose (NFC) prepared from microcrystalline cellulose (MCC) via high-pressure homogenization process can be used as a coating agent to enhance the properties of paper coatings and coated paper. The optimum NFC addition of 0.30-0.40% can lead to improved performance of coated paper, such as decreased water retention value and increased tensile strength, with a relatively uniform surface structure.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2021)
Article
Materials Science, Multidisciplinary
Xiao Wu, Hongyan Mou, Huiming Fan, Jiayuan Yin, Yibei Liu, Jianan Liu
Summary: This paper proposes the use of stable bacterial cellulose (BC) solutions in ultrasonic atomization for the restoration of ancient paper. It effectively strengthens the aged paper, improves its mechanical strength and chemical properties.
MATERIALS TODAY COMMUNICATIONS
(2022)
Article
Chemistry, Applied
Caroline E. P. Silva, Juliana S. Bernardes, Watson Loh
Summary: This study investigates the ability of nanocellulose to stabilize oil droplets and nanoparticles in the same colloidal system, finding that it can simultaneously stabilize oil droplets and titanium dioxide nanoparticles. This could potentially be used as a formulation tool for other complex systems.
CARBOHYDRATE POLYMERS
(2023)
Article
Multidisciplinary Sciences
Shancong Huang, Xiyun Wang, Yu Zhang, Yu Meng, Feiguo Hua, Xinxing Xia
Summary: The effect of cellulose nanofibers (CNFs)/polyvinyl alcohol (PVA) coating on the hydrophobic, oleophobic, and strength properties of paper were investigated. The increase of CNFs can effectively improve the lipophobicity, hydrophobicity, and tensile strength of the PVA coated paper.
SCIENTIFIC REPORTS
(2022)
Article
Polymer Science
Christina Elsaesser, Veronika Mayr, Peter Montag, Eva Mariasole Angelin, Harald Hilbig, Christian Ulrich Grosse, Marisa Pamplona
Summary: This work successfully prepares three-dimensional (3D) mock-ups made of celluloid using historical industrial production strategies and small-scale lab facilities. The best compression molding conditions for shaping celluloid sheets into mock-ups with 3D geometries are determined through visual inspection and ATR-FTIR spectroscopy. Artificial aging experiments confirm the degradation of celluloid mock-ups, making them representative of moderately aged artifacts. This study paves the way for further research on the conservation of moderately aged celluloid objects using 3D mock-ups.
Article
Materials Science, Paper & Wood
Ayhan Tozluoglu, Hakan Fidan, Ahmet Tutus, Recai Arslan, Selva Sertkaya, Bayram Poyraz, Sibel Dikmen Kucuk, Tamer Sozbir, Bekir Yemsen, Mehmet Onurhan Gucus
Summary: The study on the influence of nanofibrillated cellulose (NFC) as a reinforcing agent for recycled paper sheets showed that the addition of NFC can significantly improve the mechanical properties of the papers, but a high addition may lead to increased water retention, which is undesirable for papermaking. With optimum selection of NFC/NFC-OX and process conditions, higher mechanical properties could be acquired without increasing drainage rate.
Article
Materials Science, Paper & Wood
Jonas Simon, Lukas Fliri, Flavia Froehlich, Janak Sapkota, Matti Ristolainen, Michael Hummel, Thomas Rosenau, Antje Potthast
Summary: Borohydride reduction of dialdehyde cellulose is a promising strategy for producing bio-based dialcohol cellulose. However, degradation of the polymer backbone limits its practical applications. This study aimed to optimize the reduction process by adjusting reaction time, pH, and reagent stoichiometry to suppress degradation reactions. The degree of oxidation significantly affects the yields and molecular weights of the dialcohol cellulose products, with a leveling-off effect at higher oxidation degrees. Increasing the amount of sodium borohydride can minimize chain scissions, while lowering the pH slows down degradation but affects conversion of aldehyde functionalities. This study provides insights into side reactions during borohydride reduction of dialdehyde cellulose and the chemistry of the dialdehyde cellulose/dialcohol cellulose system.
Article
Agricultural Engineering
Areej Fathelrahman Abdallah, Mohammad Jawaid, Ainun Zuriyati Mohamed, Paridah Md. Tahir, Ummi Hani Abdullah
Summary: This study aims to evaluate the effect of incorporating nanofibrillated cellulose (NFC) and chitosan (CH) as dry additives during papermaking for unbleached bamboo alkaline sulfite anthraquinone methanol (ASAM). The results showed that the addition of nanofibrillated cellulose and chitosan significantly altered the physical and mechanical strength of the paper.
INDUSTRIAL CROPS AND PRODUCTS
(2023)
Article
Polymer Science
Mamoona Tariq, Rabia Khokhar, Arslan Javed, Muhammad Usman, Syed Muhammad Muneeb Anjum, Huma Rasheed, Nadeem Irfan Bukhari, Chao Yan, Hafiz Awais Nawaz
Summary: This study developed reactive anhydride-based oligomers and used them to fabricate gelatin-based crosslinked hydrogels with improved mechanical strengths. These hydrogels varied in their mechanical properties and degradation profiles, but exhibited good cytocompatibility with hADCs. Therefore, oligomer-crosslinked gelatin-based hydrogels hold promise as drug or cell carriers in various biomedical applications.
Article
Nanoscience & Nanotechnology
Hiroyuki Kono, Yoichiro Sogame, Uugan-Erdene Purevdorj, Makoto Ogata, Kenji Tajima
Summary: Nanofibrillated bacterial cellulose (NFBC) was modified with an aqueous alkaline solution of 2,3-epoxypropyltrimethylammonium chloride (EPTMAC) to confer it with antimicrobial properties. The modified NFBC showed similar fiber morphologies and crystal structures to pristine NFBC, indicating that EPTMAC selectively reacted with the surface hydroxyl groups of NFBC. The modified nanofibers demonstrated antibacterial activity against Klebsiella pneumoniae, likely due to the positive charge on the surface of the modified NFBC.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Mohit Sharma, Roberto Aguado, Dina Murtinho, Artur J. M. Valente, Paulo J. T. Ferreira
Summary: This study explores the use of micro-/nanofibrillated celluloses (M/NFCs) on the paper surface to enhance printing quality. Different pre-treatment methods were used to produce M/NFCs, and various components were added to the coating formulations. The presence of M/NFCs and increased cationic charge density improved the printing quality, while the addition of other components showed varying effects on paper whiteness and color properties.
Article
Chemistry, Multidisciplinary
Galen Yang, Edmond Lam, Audrey Moores
Summary: This study explores the use of mechanochemistry and aging as effective methods to control the molecular weight of commercial high molecular weight chitosan. Compared to conventional solution-based methods, this new mechanochemical method has improved process mass intensity and produces low molecular weight chitosan samples with a range of 200 to 19.5 kDa and a polydispersity of 1.8.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Matthias Guggenberger, Ivan Sumerskii, Thomas Rosenau, Stefan Boehmdorfer, Antje Potthast
Summary: In this study, the stability of volatile profiles in low-odor kraft lignins was investigated on both long and short term. It was found that the emitted amount of volatile compounds increased with temperature, while the types of volatiles remained unchanged. Chemical degradation processes were unlikely to contribute to the release of volatiles up to 100 degrees C. High humidity had a stronger effect on the release of volatiles than temperature, indicating a physical release mechanism possibly caused by water displacement.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Applied
Jonas Simon, Lukas Fliri, Felix Drexler, Markus Bacher, Janak Sapkota, Matti Ristolainen, Michael Hummel, Antje Potthast, Thomas Rosenau
Summary: Periodate oxidation of cellulose to produce dialdehyde cellulose (DAC) has attracted increasing attention in sustainable materials development. However, there is a large variation in the proposed preparation and work-up protocols, decreasing comparability and causing reproducibility problems. This study critically examined and compared two prevalent work-up protocols, glycol quenching and filtration/washing. The findings suggest that simple washing protocols are recommended instead of glycol quenching to prevent side reactions and organic contaminations.
CARBOHYDRATE POLYMERS
(2023)
Article
Materials Science, Paper & Wood
Yujin Hwang, Kyu-Young Kang, Bong Suk Yang, Antje Potthast, Myung-Joon Jeong
Summary: In this study, we analyzed aqueous extracts of cotton linter paper and Hanji to assess the deterioration of paper cultural heritage. Cello-oligosaccharides, water-soluble low-molecular-weight carbohydrates, were quantified in the paper extracts. The degree of polymerization of aged paper was evaluated based on the absolute molecular weight of cellulose. The content of water-soluble cello-oligosaccharides varied with cellulose degradation, and a linear relationship was found between cellulose hydrolysis rate and water-soluble cello-oligosaccharides content.
Article
Materials Science, Paper & Wood
Ivan Melikhov, Markus Bacher, Takashi Hosoya, Hubert Hettegger, Antje Potthast, Thomas Rosenau
Summary: Propyl gallate is commonly used as a stabilizer and antioxidant in food and material applications, as well as in the Lyocell process. However, it was found that propyl gallate hydrolyzes quickly under Lyocell conditions and generates discoloration. On the other hand, gallic acid morpholide and gallic amide, which have similar antioxidant activity but do not produce discoloration, are considered to be superior alternatives to propyl gallate.
Article
Materials Science, Paper & Wood
Takaaki Goto, Sara Zaccaron, Hubert Hettegger, Robert H. Bischof, Karin Fackler, Antje Potthast, Thomas Rosenau
Summary: In this study, an analytical method was developed to evaluate chelating agents and oxidative damage to cellulose during the chelation and bleaching process. This method utilized GPC and ICP-OES for analyzing the molar mass distribution, oxidative damage, and metal content of the pulp, enabling the assessment of new chelating agents and their impact on cellulose at a molecular level.
Article
Materials Science, Paper & Wood
Johanna Zieher, Markus Bacher, Irina Sulaeva, Ivan Sumerskii, Hubert Hettegger, Antje Potthast, Thomas Rosenau
Summary: This paper investigates the three key chromophores in cellulosic materials, which have special structures and high resonance stabilization, making them thermodynamically stable and resistant to bleaching. The study explores the derivatization of these hydroxyl groups by a phosphitylation agent and analyzes them using P-31 NMR, a commonly used method for quantitative analysis and differentiation of OH groups in lignins and lignin derivatives. The chemical shifts and structural characteristics of the chromophore derivatives are discussed. The P-31 NMR approach contributes to the analysis, bleaching, and aging studies of cellulose chromophores.
Article
Materials Science, Paper & Wood
Johanna Zieher, Ivan Melikhov, Markus Bacher, Hubert Hettegger, Antje Potthast, Thomas Rosenau
Summary: This study investigates the analysis of stabilizers and their major degradation products in Lyocell dopes. The stabilizer-derived compounds are easily extracted from the solution and analyzed using P-31 NMR after chemical derivatization of the hydroxyl groups.
Article
Materials Science, Paper & Wood
Paul Jusner, Irina Sulaeva, Sonja Schiehser, Karin Potthast, Alexander Tischer, Stefano Barbini, Antje Potthast, Thomas Rosenau
Summary: Beta-irradiation and swelling in ionic liquids are common pretreatments in biorefinery scenarios. When both processes are combined, covalent derivatization of cellulose and incorporation of nitrogen occur, with nitrogen uptake only happening in the presence of ionic liquids.
Article
Materials Science, Paper & Wood
Jonas Simon, Lukas Fliri, Flavia Froehlich, Janak Sapkota, Matti Ristolainen, Michael Hummel, Thomas Rosenau, Antje Potthast
Summary: Borohydride reduction of dialdehyde cellulose is a promising strategy for producing bio-based dialcohol cellulose. However, degradation of the polymer backbone limits its practical applications. This study aimed to optimize the reduction process by adjusting reaction time, pH, and reagent stoichiometry to suppress degradation reactions. The degree of oxidation significantly affects the yields and molecular weights of the dialcohol cellulose products, with a leveling-off effect at higher oxidation degrees. Increasing the amount of sodium borohydride can minimize chain scissions, while lowering the pH slows down degradation but affects conversion of aldehyde functionalities. This study provides insights into side reactions during borohydride reduction of dialdehyde cellulose and the chemistry of the dialdehyde cellulose/dialcohol cellulose system.
Article
Materials Science, Paper & Wood
Yuko Yoneda, Toshinari Kawada, Markus Bacher, Alexander Prado-Roller, Hubert Hettegger, Antje Potthast, Alfred D. French, Thomas Rosenau
Summary: Cellulose model compounds are widely used in cellulose research to study the polymer's properties. By synthesizing methyl 4-O-methyl beta-D-glucopyranoside derivatives with different substitution patterns, the solid-state structures of these compounds were determined using X-ray diffraction. Solid-state C-13 NMR measurements confirmed the influence of packing arrangement on the chemical shifts of the substituted carbons.
Article
Chemistry, Multidisciplinary
Jonas Simon, Inge Schlapp-Hackl, Janak Sapkota, Matti Ristolainen, Thomas Rosenau, Antje Potthast
Summary: In this study, the glass transition temperature (Tg) of dialdehyde cellulose derivatives was successfully tailored by adjusting the degree of oxidation and introducing different side chains, providing a strategy for developing sustainable thermoplastics.
Article
Chemistry, Multidisciplinary
Nadine Kohlhuber, Oliver Musl, Irina Sulaeva, Stefan Bohmdorfer, Ivan Sumerskii, Thomas Ters, Thomas Rosenau, Antje Potthast
Summary: This paper introduces a novel method for the direct analysis of diluted black liquor by size-exclusion chromatography, enabling simultaneous determination of lignin content and molar mass while avoiding tedious sample preparation. The method significantly reduces analysis time and provides an authentic molar mass distribution of lignin. The analytical system shows excellent column stability and is suitable for high-throughput characterization of complex lignin samples.
ACS SUSTAINABLE CHEMISTRY & ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Leonardo D. Antonino, Ivan Sumerskii, Antje Potthast, Thomas Rosenau, Maria Isabel Felisberti, Demetrio J. dos Santos
Summary: This study investigates the use of lignin as a precursor for polyurethanes through the blocked isocyanate approach. The hydroxypropylation of lignin enhances its reactivity and leads to the formation of hindered urea-terminated polyurethane prepolymers. Single-lap shear tests demonstrate the potential of these prepolymers as monocomponent adhesives.
Article
Chemistry, Multidisciplinary
Gerhild K. Wurzer, Markus Bacher, Oliver Musl, Nadine Kohlhuber, Irina Sulaeva, Theres Kelz, Karin Fackler, Robert H. Bischof, Hubert Hettegger, Antje Potthast, Thomas Rosenau
Summary: A new chemical modification protocol was developed to generate N-lignins using Indulin AT and Mg2+-lignosulfonate. The traditional liquid ammonoxidation reaction was optimized to a solid-state approach. Through comprehensive analysis and comparison, it was found that the N-lignins obtained with the new method showed similar properties as the traditional ammonoxidation products. The use of the urea-hydrogen peroxide complex (UHP) as a single chemical was sufficient to achieve satisfying N-content.
Article
Materials Science, Paper & Wood
Elisa Sponla, Simo Hannula, Taina Kamppuri, Ulla Holopainen-Mantila, Irina Sulaeva, Antje Potthast, Ali Harlin, Stina Gronqvist, Jenni Rahikainen
Summary: In this study, regenerated fibers were spun from hemicellulose-rich pulps using a superbase ionic liquid, and it was found that pulp pretreatment was critical for achieving good mechanical properties in the regenerated fibers.
