The surface of cellulose nanocrystals, prepared by sulfuric acid hydrolysis cotton, was rendered cationic through a reaction with epoxypropyltrimethylammonium chloride. resultant nanocrystal suspensions were characterized ζ-potential, conductometric titration and polarized light microscopy. Atomic force microscopy (AFM) showed no change in the size or shape but functionalization process reversed charge led to reduction total density. These modifications stable aqueous nanocrystalline...

The irradiation of pulp is interest from different perspectives. Mainly it required when a modification cellulose needed. Irradiation could bring many advantages, such as chemical savings and, therefore, cost and reduction in environmental pollutants. In this account, dissociated celluloses were analyzed before after by electron beaming. focus the analysis was oxidation hydroxyl groups to carbonyl carboxyl degradation causing decrease molar mass. For that purpose, samples labeled with...

Tannins are secondary metabolites that enriched in the bark, roots, and knots trees known to hinder microbial attack. The biological degradation of water-soluble gallotannins, such as tannic acid, is initiated by tannase enzymes (EC 3.1.1.20), which esterases able liberate gallic acid from aromatic-sugar complexes. However, only few tannases have previously been studied detail. Here, for first time, we biochemically structurally characterize three a single organism, anaerobic bacterium...

Cellulose carbonate as an intermediate for carbon dioxide capture in NaOH(aq).

Abstract Cationization of cellulose under aqueous alkaline conditions was studied. Two new epoxy reagents, N ‐oxiranylmethyl‐ ‐methylmorpolinium chloride and 2‐oxiranylpyridine, were used for preparation cationic ethers. Using the first agent, ethers obtained in one step, whereas latter yielded a reactive intermediate as precursor two different cationizations. Etherification with commonly 2,3‐epoxypropyltrimethylammonium also performed reference reaction. By changing water content reaction...

Abstract Wood meal was submitted to kraft cooking in a small-scale flow-through reactor and the structural changes of lignin have been investigated. The rate determining steps were focus. Based on two-dimensional nuclear magnetic resonance (2D-NMR) measurements fractions extracted at different times from black liquor, it observed that main reactions occur within 10–20 min thus kinetics chemical reaction cannot be rate-determining step. On other hand, molecular weight (MW) is shifted towards...

The adsorption of carboxymethylcellulose (CMC) on cellulose surfaces is relevance from both academic and industrial perspectives as it facilitates resource-efficient modification fibres that allows them to carry negative charges. It known that, compared monovalent ions, Ca2+ ions are superior in facilitating CMC the subsequent introduction charge fibres. However, formation deposition calcium oxide involved this process necessitates search for alternative cations. Magnesium form one more...

Abstract Lignin is an abundant polymer found in wood and grasses, but due to its heterogeneity complex macromolecular structure it has been less utilized than cellulose. While the building blocks are known, way they linked understood. Here, Molecular Dynamics simulations were used systematically characterize seven linkages native lignin. Their influence on lignin water structure, their interactions analyzed. The study limited guaiacyl (G-G) dimers connected by following common softwood...

Abstract In order to further understand the role of cation when dissolving cellulose in aqueous solutions hydroxide bases, different bases were combined solution. Up 5 wt.% microcrystalline was dissolved using a combination NaOH and organic base tetramethylammonium (TMAH) water at low temperatures. Thermoscans containing both NaOH(aq) TMAH(aq) indicated that interaction with TMAH seems be favoured over NaOH. Dynamic rheology measurements revealed combining two delayed gelation significantly...

The bark is the outermost defense of trees against microbial attack, largely thanks to toxicity and prevalence extractive compounds. Nevertheless, decomposes in nature, though by which species mechanisms remains unknown. Here, we have followed development enrichments growing on spruce over six months, monitoring both chemical changes material performing community metagenomic analyses. Carbohydrate metabolism was unexpectedly limited, instead a key activity extractives. Resin acid degradation...

Metal-organic frameworks have attracted a great deal of attention for future applications in numerous areas, including gas adsorption. However, order them to reach their full potential substrate provide an anchor may be needed. Ideally, this should environmentally friendly and renewable. Cellulose nanofibrils show area. Here we present hybrid material created from the self-assembly zeolitic imidazolate framework (ZIF-8) nanocrystals on cellulose (CNF) aqueous medium. The CNF/ZIF-8 was freeze...

Abstract Alkaline delignification of wood tissue is the core global pulping technology and most prominent large-scale separation main components. This work aims at improved understanding interplay between topochemistry alkaline associated morphological changes. Morphology chemical structure partially soda-delignified chips were studied combining X-ray tomography (XRT), diffraction analysis compositional characterization (lignin carbohydrate content). The XRT studies wet samples (providing 3D...

The adsorption of carboxymethylcellulose (CMC) on cellulose surfaces is one the most studied examples an anionic polyelectrolyte a like-charged surface. It has been suggested that divalent ions can act as bridge between CMC chains and surface enhance adsorption: they can, however, also alter structure CMCs in solution. In previous investigations, influence cations solution properties largely overlooked. This study investigates effect Ca2+ solutions well nanofibers (CNFs), which was by...

Abstract Autohydrolysis-based pretreatments enable extraction of hemicellulose from wood tissue prior to the paper pulp cooking processes enabling their further use as platform chemicals and in material applications. In this study, hot water birch meal was conducted a small flow-through system. The combination high surface area milled with increased driving force induced by constant flow freshwater, together fast evacuation extract, enabled detailed study dissolution process. Based on...

A series of N-methylmorpholinium salts with varying N-alkyl chains and Cl-, OAc- OH- as counter ions have been synthesized investigated for their ability to dissolve cellulose, aiming at elucidating solvent structural features affecting cellulose dissolution. Synthesis procedures developed to, a high extent, rely on conversions in water microwave-assisted reactions employing reduced number work-up steps ion-exchange resins that can be regenerated. Water solutions morpholinium hydroxides...

To further understand cellulose-solvent interactions in aqueous hydroxide solutions, cellulose behavior solutions of NaOH combined with tetramethylammonium (TMAH) or benzyltrimethylammonium (Triton B), as well urea, was investigated. The rheological properties the were assessed through flow sweeps at different temperatures, and intermolecular probed using solvatochromic dyes. results showed that TMAH had synergistic effects on dissolution a better solvent for than combination Triton B, spite...

A natural abundance of the air CO2 in NaOH(aq) at low temperature was investigated terms cellulose-CO2 interactions upon cellulose dissolution this system. An organic superbase, namely 1,8-diazabicyclo[5.4.0]undec-7-ene, DBU, known for its ability to incorporate carbohydrates, employed order shed light on previously overlooked feature temperature. The chemisorption onto using spectroscopic methods combination with suitable regeneration procedures. ATR-IR and NMR characterisation regenerated...

Abstract Wood is a heterogeneous material with significant variation among species. This inherent complexity poses challenge to the continuous expansion of our understanding kraft process; yet previous pulping research has mainly been limited few study investigates variations some less studied species and their cell wall level delignification behaviour during pulping. Ground wood birch, beech, aspen, alder were pulped at near-constant composition temperature conditions. Minor, significant,...