480 results match your criteria: "Wallenberg Wood Science Center[Affiliation]"

Passerini three-component reaction for the synthesis of saccharide branched cellulose.

Int J Biol Macromol

December 2023

State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, 510641 Guangzhou, China. Electronic address:

In this work, we investigate a multicomponent synthetic method for combining saccharides with cellulose to produce saccharide branched cellulose (b-Cel). First, cellulose is modified conventionally using carboxymethyl to create carboxyl functional groups for multicomponent reactions. The Passerini three-component reaction (Passerini-3CR) is then used to synthesize the saccharide b-Cel, with particular attention paid to the scope of the substrate and reaction process optimization.

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Integration of fiber modification step with a modern pulp mill is a resource efficient way to produce functional fibers. Motivated by the need to integrate polymer adsorption with the current pulping system, anion-specific effects in carboxymethylcellulose (CMC) adsorption have been studied. The QCM-D adsorption experiments revealed that CMC adsorption to the cellulose model surface is prone to anion-specific effects.

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Specific ion effects on lignin adsorption and transport through cellulose confinements.

J Colloid Interface Sci

January 2024

Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden; Wallenberg Wood Science Center, Chalmers University of Technology, Gothenburg, Sweden; FibRe - Centre for Lignocellulose-based Thermoplastics, Department of Chemistry and Chemical Engineering, Chalmers University of Technology, Gothenburg, Sweden. Electronic address:

The presence of ions in a solution is anticipated to induce distinct effects on macromolecules. Consequently, the tuning of adsorption and mass transfer of lignin molecules can be achieved by incorporating ions with chaotropic or kosmotropic characteristics. This study examines the adsorption and mass transfer behavior of lignin molecules across model cellulose membranes in presence of ions from the Hofmeister series.

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Herein, a binary cathode interface layer (CIL) strategy based on the industrial solvent fractionated LignoBoost kraft lignin (KL) is adopted for fabrication of organic solar cells (OSCs). The uniformly distributed phenol moieties in KL enable it to easily form hydrogen bonds with commonly used CIL materials, i.e.

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Phospholipase D Immobilization on Lignin Nanoparticles for Enzymatic Transformation of Phospholipids.

ChemSusChem

February 2024

Department of Materials and Environmental Chemistry, Stockholm University, Svante Arrhenius väg 16C, SE-10691, Stockholm, Sweden.

Lignin nanoparticles (LNPs) are promising components for various materials, given their controllable particle size and spherical shape. However, their origin from supramolecular aggregation has limited the applicability of LNPs as recoverable templates for immobilization of enzymes. In this study, we show that stabilized LNPs are highly promising for the immobilization of phospholipase D (PLD), the enzyme involved in the biocatalytic production of high-value polar head modified phospholipids of commercial interest, phosphatidylglycerol, phosphatidylserine and phosphatidylethanolamine.

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Biopolymers, especially cellulose, are vital to transitioning to a circular economy and reducing our reliance on fossil fuels. However, for many applications a high degree of cellulose hydroxyl modification is necessary. The challenge is that the chemical features of the hydroxyls of cellulose and water are similar.

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The quest for eco-friendly materials with anticipated positive impact for sustainability is crucial to achieve the UN sustainable development goals. Classical strategies of composite materials can be applied on novel nanomaterials and green materials. Besides the actual technology and applications also processing and manufacturing methods should be further advanced to make entire technology concepts sustainable.

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Lignin nanoparticles as co-stabilizers and modifiers of nanocellulose-based Pickering emulsions and foams.

Cellulose (Lond)

July 2023

Department of Food and Nutrition, Faculty of Agriculture and Forestry, University of Helsinki, P.O. Box 66, FI-00014 Helsinki, Finland.

Unlabelled: Nanocellulose is very hydrophilic, preventing interactions with the oil phase in Pickering emulsions. This limitation is herein addressed by incorporating lignin nanoparticles (LNPs) as co-stabilizers of nanocellulose-based Pickering emulsions. LNP addition decreases the oil droplet size and slows creaming at pH 5 and 8 and with increasing LNP content.

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Low-density foams and aerogels based on upcycled and bio-based nanofibers and additives are promising alternatives to fossil-based thermal insulation materials. Super-insulating foams are prepared from upcycled acid-treated aramid nanofibers (upANF ) obtained from Kevlar yarn and tempo-oxidized cellulose nanofibers (CNF) from wood. The ice-templated hybrid upANF /CNF-based foams with an upANF content of up to 40 wt% display high thermal stability and a very low thermal conductivity of 18-23 mW m K perpendicular to the aligned nanofibrils over a wide relative humidity (RH) range of 20% to 80%.

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Arabinoxylan source and xylanase specificity influence the production of oligosaccharides with prebiotic potential.

Carbohydr Polym

November 2023

Division of Glycoscience, Department of Chemistry, KTH Royal Institute of Technology, AlbaNova University Centre, SE-106 91 Stockholm, Sweden; Wallenberg Wood Science Centre, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden. Electronic address:

Cereal arabinoxylans (AXs) are complex polysaccharides in terms of their pattern of arabinose and ferulic acid substitutions, which influence their properties in structural and nutritional applications. We have evaluated the influence of the molecular structure of three AXs from wheat and rye with distinct substitutions on the activity of β-xylanases from different glycosyl hydrolase families (GH 5_34, 8, 10 and 11). The arabinose and ferulic acid substitutions influence the accessibility of the xylanases, resulting in specific profiles of arabinoxylan-oligosaccharides (AXOS).

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A flexible physical protection process for lignin extraction.

iScience

September 2023

Wallenberg Wood Science Center, Department of Fiber and Polymer Technology, School of Chemistry, Biotechnology and Health, KTH Royal Institute of Technology, Teknikringen 56-58, 100 44 Stockholm, Sweden.

Research on lignin valorization has gained ground, driven by its potential to replace fossil-based phenolics in bio-based applications. Technical lignins are structurally complex and still poorly characterized, prompting the need for novel extraction processes for lignin of high analytical quality. In this context, a two-step cyclic extraction process for lignin was contrasted with a one-step cyclic extraction.

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We demonstrate a framework of interpreting data from x-ray photon correlation spectroscopy experiments with the aid of numerical simulations to describe nanoscale dynamics in soft matter. This is exemplified with the transport of passive tracer gold nanoparticles in networks of charge-stabilized cellulose nanofibers. The main structure of dynamic modes in reciprocal space could be replicated with a simulated system of confined Brownian motion, a digital twin, allowing for a direct measurement of important effective material properties describing the local environment of the tracers.

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Gradience Free Nanoinsertion of FeO into Wood for Enhanced Hydrovoltaic Energy Harvesting.

ACS Sustain Chem Eng

July 2023

Wallenberg Wood Science Center, Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Stockholm SE-10044, Sweden.

Hydrovoltaic energy harvesting offers the potential to utilize enormous water energy for sustainable energy systems. Here, we report the utilization and tailoring of an intrinsic anisotropic 3D continuous microchannel structure from native wood for efficient hydrovoltaic energy harvesting by FeO nanoparticle insertion. Acetone-assisted precursor infiltration ensures the homogenous distribution of Fe ions for gradience-free FeO nanoparticle formation in wood.

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Cellulose nanofibrils (CNF) with 2D silicate nanoplatelet reinforcement readily form multifunctional composites by vacuum-assisted self-assembly from hydrocolloidal mixtures. The final nanostructure is formed during drying. The crystalline nature of CNF and montmorillonite (MTM) made it possible to use synchrotron X-ray scattering (WAXS, SAXS) to monitor structural development during drying from water and from ethanol.

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Formation and stability of studtite in bicarbonate-containing waters.

Ecotoxicol Environ Saf

September 2023

Department of Chemistry, School of Engineering Sciences in Chemistry, Biotechnology and Health, KTH Royal institute of Technology, SE-10044 Stockholm, Sweden.

Studtite and meta-studtite are the only two uranyl peroxides found in nature. Sparsely soluble studtite has been found in natural uranium deposits, on the surface of spent nuclear fuel in contact with water and on core material from major nuclear accidents such as Chernobyl. The formation of studtite on the surface of nuclear fuel can have an impact on the release of radionuclides to the biosphere.

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Electrical signals in plants are mediators of long-distance signaling and correlate with plant movements and responses to stress. These signals are studied with single surface electrodes that cannot resolve signal propagation and integration, thus impeding their decoding and link to function. Here, we developed a conformable multielectrode array based on organic electronics for large-scale and high-resolution plant electrophysiology.

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In nature, complex carbohydrates are rarely found as pure isolated polysaccharides. Instead, bacteria in competitive environments are presented with glycans embedded in heterogeneous matrices such as plant or microbial cell walls. Members of the Bacteroidota phylum thrive in such ecosystems because they are efficient at extracting nutrients from complex substrates, secreting consortia of synergistic enzymes to release metabolizable sugars.

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Kraft lignin, a by-product from the production of pulp, is currently incinerated in the recovery boiler during the chemical recovery cycle, generating valuable bioenergy and recycling inorganic chemicals to the pulping process operation. Removing lignin from the black liquor or its gasification lowers the recovery boiler load enabling increased pulp production. During the past ten years, lignin separation technologies have emerged and the interest of the research community to valorize this underutilized resource has been invigorated.

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Ultrastrong Ionotronic Films Showing Electrochemical Osmotic Actuation.

Adv Mater

November 2023

Department of Fibre and Polymer Technology, Wallenberg Wood Science Center, KTH Royal Institute of Technology, Stockholm, SE-100 44, Sweden.

A multifunctional soft material with high ionic and electrical conductivity, combined with high mechanical properties and the ability to change shape can enable bioinspired responsive devices and systems. The incorporation of all these characteristics in a single material is very challenging, as the improvement of one property tends to reduce other properties. Here, a nanocomposite film based on charged, high-aspect-ratio 1D flexible nanocellulose fibrils, and 2D Ti C T MXene is presented.

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Effect of Molecular Organization on the Properties of Fractionated Lignin-Based Thiol-Ene Thermoset Materials.

ACS Omega

July 2023

Wallenberg Wood Science Center (WWSC), Department of Fibre and Polymer Technology, KTH Royal Institute of Technology, Teknikringen 56-58, SE-100 44 Stockholm, Sweden.

In this study, the combination of sequential solvent fractionation of technical Kraft lignin was followed by allylation of most OH functionalities to give highly functional thermoset resins. All lignin fractions were highly functionalized on the phenolic (≥95%) and carboxylic acid OH (≥85%) and to a significant extent on the aliphatic OH moieties (between 43 and 75%). The resins were subsequently cross-linked using thiol-ene chemistry.

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Hornification of cellulose-rich materials - A kinetically trapped state.

Carbohydr Polym

October 2023

KTH Royal Institute of Technology, Department of Fiber and Polymer Technology, 11428 Stockholm, Sweden; KTH Royal Institute of Technology, Department of Fiber and Polymer Technology, Wallenberg Wood Science Center (WWSC), 11428 Stockholm, Sweden. Electronic address:

The fundamental understanding concerning cellulose-cellulose interactions under wet and dry conditions remains unclear. This is especially true regarding the drying-induced association of cellulose, commonly described as an irreversible phenomenon called hornification. A fundamental understanding of the mechanisms behind hornification would contribute to new drying techniques for cellulose-based materials in the pulp and paper industry while at the same time enhancing material properties and facilitating the recyclability of cellulose-rich materials.

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Multiscale X-ray imaging and characterisation of pharmaceutical dosage forms.

Int J Pharm

July 2023

Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; Photon Science Division, Paul Scherrer Institut, Villigen PSI, 5232, Switzerland; Institute of Materials, École Polytechnique Fédérale de Lausanne (EPFL), Lausanne 1015 Switzerland. Electronic address:

A correlative, multiscale imaging methodology for visualising and quantifying the morphology of solid dosage forms by combining ptychographic X-ray computed nanotomography (PXCT) and scanning small- and wide-angle X-ray scattering (S/WAXS) is presented. The methodology presents a workflow for multiscale analysis, where structures are characterised from the nanometre to millimetre regime. Here, the method is demonstrated by characterising a hot-melt extruded, partly crystalline, solid dispersion of carbamazepine in ethyl cellulose.

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

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Soft Electromagnetic Vibrotactile Actuators with Integrated Vibration Amplitude Sensing.

ACS Appl Mater Interfaces

June 2023

Laboratory of Organic Electronics, Department of Science and Technology, Linköping University, 602 21 Norrköping, Sweden.

Soft vibrotactile devices have the potential to expand the functionality of emerging electronic skin technologies. However, those devices often lack the necessary overall performance, sensing-actuation feedback and control, and mechanical compliance for seamless integration on the skin. Here, we present soft haptic electromagnetic actuators that consist of intrinsically stretchable conductors, pressure-sensitive conductive foams, and soft magnetic composites.

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In order to develop more economic uses of lignin, greater knowledge regarding its native structure is required. This can inform the development of optimized extraction methods that preserve desired structural properties. Current extraction methods alter the polymeric structure of lignin, leading to a loss of valuable structural groups or the formation of new non-native ones.

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