[article-cris] Kemian tekniikan korkeakoulu / CHEM
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Item Upgrading AquaSolv Omni (AqSO) biorefinery: access to highly ethoxylated lignins in high yields through reactive extraction (REx)(Royal Society of Chemistry, 2024-01-24) Rigo, Davide; Kohlhuber, Nadine; Fliri, Lukas; Diment, Daryna; Cho, Mijung; Sumerskii, Ivan; Hummel, Michael; Potthast, Antje; Balakshin, Mikhail; Department of Bioproducts and Biosystems; Bioproduct Chemistry; Biopolymer Chemistry and Engineering; Lignin Chemistry; University of Natural Resources and Life Sciences, ViennaChemical modification of lignin (i.e., ethoxylation) improves its properties for specific applications. Reactive extraction (REx)—the simultaneous functionalization and extraction of lignin from biomass—is a green, simple, and powerful solution to minimize subsequent steps in biorefinery operations, while upgrading the isolated products (i.e., lignin or lignin-carbohydrate hybrids). In this work, we successfully introduced REx into our recently reported AquaSolv Omni (AqSO) integrated biorefinery. Here, hydrothermally treated wood solids were refluxed with various EtOH : H2O mixtures (70-99 v/v%) in the presence of catalytic amounts of H2SO4 (c = 0.15-1.2 M). The effects of the process variables on the structures and properties of the obtained lignins and residual solids were elucidated by comprehensive NMR analyses (HSQC, quantitative 13C and 31P), differential scanning calorimetry (DSC), and gel permeation chromatography (GPC). In addition, we discuss different analytical approaches—NMR vs. chromatographic methods for the quantification of ethoxy groups in lignin. Implementing REx allowed the isolation of ethoxylated lignins in 27-52% yields (based on the initial lignin content) and to tune the degree of substitution (DS) up to 40.8 EtO-groups/100 Ar (based on quantitative 13C NMR)—which is approximately five times higher compared to other established organosolv processes (i.e., Alcell). Moreover, solution state NMR analysis of residual solids after REx showed that ethoxylation also occurs in the cellulose-rich fraction. REx highly ethoxylated lignins produced through a simple and green process enhanced the performance of polyurethane (PU) adhesive formulations compared to formulations using non-ethoxylated lignins.Item Pretreatment to Retrieve Xylose and Xylooligosaccharides by HCl Gas Directly from Biomass(American Chemical Society, 2024-02-12) Kilpinen, A. Topias; Nieminen, Kaarlo; Kontturi, Eero; Department of Bioproducts and Biosystems; Materials Chemistry of Cellulose; Biopolymer Chemistry and EngineeringIn this study, anhydrous hydrogen chloride gas was employed to selectively hydrolyze hemicellulose from aspen wood flour utilizing a gas-solid system. Selectivity toward hemicellulose was achieved by adjusting the acid concentration inside wood flour to 36% during gas hydrolysis, so only hemicellulose and disordered cellulose would be degraded during hydrolysis. Process parameters included the moisture content of the aspen wood flour (20%, 40%, and 60%) and reaction times from 30 min to 24 h. The optimal reaction conditions for the production of xylose and xylooligosaccharides was achieved with 40% moisture content and 6 h reaction time. Under these parameters, it was possible to retrieve 84% of the available xylan from aspen wood flour with only 1% glucan degradation.Item Cellulose modified to host functionalities via facile cation exchange approach(Elsevier Science Ltd., 2024-05-15) Spiliopoulos, Panagiotis; Navarro, Saül Llàcer; Orzan, Eliott; Ghanbari, Reza; Pietschnig, Rudolf; Stilianu, Clemens; Spirk, Stefan; Schaefer, Andreas; Kádár, Roland; Nypelö, Tiina; Department of Bioproducts and Biosystems; Lignocellulosic Chemistry; Chalmers University of Technology; University of Kassel; Graz University of TechnologyProperties of cellulose are typically functionalized by organic chemistry means. We progress an alternative facile way to functionalize cellulose by functional group counter-cation exchange. While ion-exchange is established for cellulose, it is far from exploited and understood beyond the most common cation, sodium. We build on our work that established the cation exchange for go-to alkali metal cations. We expand and further demonstrate the introduction of functional cations, namely, lanthanides. We show that cellulose nanocrystals (CNCs) carrying sulfate-half ester groups can acquire properties through the counter-cation exchange. Trivalent lanthanide cations europium (Eu3+), dysprosium (Dy3+) and gadolinium (Gd3+) were employed. The respective ions showed distinct differences in their ability of being coordinated by the sulfate groups; with Eu3+ fully saturating the sulfate groups while for Gd3+ and Dy3+, values of 82 and 41 % were determined by compositional analysis. CNCs functionalized with Eu3+ displayed red emission, those containing Dy3+ exhibited no optical functionality, while those with Gd3+ revealed significantly altered magnetic relaxation times. Using cation exchange to alter cellulose properties in various ways is a tremendous opportunity for modification of the abundant cellulose raw materials for a renewable future.Item Experimental study of the effect of the concentration of water/polyalkylene glycol solutions on heat transfer in steels subjected to quenching(Institute of Physics Publishing, 2024-01-24) Buenrostro, Brandon Farrera; Bocanegra, Constantin Alberto Hernández; Banderas, José Angel Ramos; Valdovinos, Luis Enrique Molina; López Granados, Nancy Margarita; Vapalahti, Sami; Department of Chemical and Metallurgical Engineering; Morelia Institute of Technology; Consejo Nacional de Ciencia y Tecnologia MexicoIn this work, the heat transfer coefficients were determined utilizing an experimental study for cooling a 15B35H boron steel, using aqueous solutions of polyalkylene glycol (PAG) as a cooling fluid. A cooling tank was designed and built to allow the fluid recirculation, where the effect of agitation and the PAG content in a concentration range of 2%-6% vol. were analyzed. The thermal histories of cylindrical probes instrumented with K-type thermocouples were obtained, and the heat transfer coefficients associated with the types of refrigeration were calculated, solving the IHCP. The results show the presence of two maximum surface heat flux denominated q1max for the low-temperature range and q2max for the high-temperature range. Getting higher q1max and low q2max is desirable to avoid distortion and cracking. It was found that 4% PAG exhibits a slight variation of heat flux values in both low and high-temperature regions, regardless of the degree of agitation, maintaining values of about 3 MW·m−2 for q1max and 5.5 MW·m−2 for q2max. In this case, q2max is higher than q1max, leading to higher cooling rates in the martensitic transformation zone, increasing the risk of distortion and cracking. In the cases of 2 y 6% PAG, agitation affects q1max ranging from 2.5 to 6 MW·m−2, and for q2max from 4 to 6 MW·m−2, where q1max is always higher than q2max, providing better conditions for quenching.Item Ignition and combustion of synthetic nickel mattes in simulated flash smelting conditions(Elsevier Ltd, 2024-02) Chen, Min; Sukhomlinov, Dmitry; Taskinen, Pekka; Grimsey, David; Rich, Anthony; Jokilaakso, Ari; Department of Chemical and Metallurgical Engineering; Metallurgy (MTG); Metallurgical Thermodynamics and Modelling; BHP Group LtdThe ignition and oxidation behavior of synthesized sulfur-lean nickel mattes was investigated using a laminar flow furnace simulating the conditions in the flash smelting reaction shaft to explore the ignition and oxidation processes of sulfur-lean electric furnace mattes obtained from slag cleaning. The experiments were conducted at 800–1100 °C with 40–85 vol% O2 in the reaction gas. Scanning electron microscopy equipped with energy-dispersive X-ray spectrometry was used to analyze the surface morphology and mineralogical compositions of the samples. Chemical analysis was employed to determine the sulfur remaining in the samples. The ignition temperature of the sulfur-lean nickel mattes was found to be below 800 °C. The highest sulfur removal from mattes was achieved under the most oxidizing conditions. The oxidation of the metallized nickel mattes started with preferential oxidation of iron and sulfur, forming sulfur dioxide and a porous iron oxide-rich rim. Particles were observed to melt completely and even to fragment due to fast combustion reactions and the formation of sulfur dioxide inside. The present results provide valuable insights into the mechanism of sulfur-lean nickel matte smelting in flash smelting furnaces.Item The potential of different hemicelluloses extraction methods in conversion of environmentally friendly ECF and TCF bleached paper-grade bagasse soda pulp to dissolving-grade pulp(Springer, 2023-10-16) Gilan, Kajal Moradian; Hedjazi, Sahab; Lê, Huy Quang; Abdulkhani, Ali; Sixta, Herbert; Department of Bioproducts and Biosystems; Biopolymer Chemistry and Engineering; Biorefineries; Gorgan University of Agricultural Sciences and Natural Resources; University of TehranDissolving pulp as a purified chemical pulp with high cellulose content, is an important raw material for many applications such as cellulose derivatives and regenerated cellulose, hence paper-grade bagasse pulp as a cheap alternative non-wood raw material can be used to produce dissolving-grade pulp. In this work, the potential of ECF and TCF bleached paper-grade soda bagasse pulp in the production of dissolving pulp was studied. To find an effective method, bleaching sequences followed by the different hemicellulose extraction processes including CCE, xylanase treatment, IONCELL-P, combination of xylanase treatment and IONCELL-P were investigated. The unbleached bagasse pulp was subjected to the IONCELL-P process using mixtures of 1-ethyl-3-methylimidazolium acetate/water for the extraction of xylan from an initial of 30.5 to 7.0%. The ECF (ODEpQP1.5%) sequence resulted in the optimum bleached pulp in terms of physical and chemical properties and the consumption of bleaching chemicals, which was selected for subsequent treatments to remove xylan to produce dissolving pulp. In the IONCELL-P treatment of bleached pulp, the xylan content could even be reduced to 5.9% (80% removal) and in X-IONCELL-P to 3.3% (90% removal). All the extraction methods investigated in this study removed xylan with differences in the selectivity and efficiency successfully.Item Controlling aggregation-induced emission by supramolecular interactions and colloidal stability in ionic emitters for light-emitting electrochemical cells(Royal Society of Chemistry, 2024-02-28) Sanz-Velasco, Alba; Amargós-Reyes, Olivia; Kähäri, Aya; Lipinski, Sophia; Cavinato, Luca M.; Costa, Rubén D.; Kostiainen, Mauri A.; Anaya-Plaza, Eduardo; Department of Bioproducts and Biosystems; Biohybrid Materials; Biohybrid Materials; Technical University of Munich; Aalto UniversityChromophores face applicability limitations due to their natural tendency to aggregate, with a subsequent deactivation of their emission features. Hence, there has been a fast development of aggregation induced emission (AIE) emitters, in which non-radiative motional deactivation is inhibited. However, a fine control of their colloidal properties governing the emitting performance is fundamental for their application in thin film optoelectronics. In addition, ion-based lighting devices, such as light emitting electrochemical cells (LECs), requires the design of ionic AIE emitters, whose structure allows (i) an easy ion polarizability to assist charge injection and (ii) a reversible electrochemical behavior. To date, these fundamental questions have not been addressed. Herein, the hydrophilic/hydrophobic balance of a family of cationic tetraphenyl ethene (TPE) derivatives is finely tuned by chemical design. The hydrophilic yet repulsive effect of pyridinium-based cationic moieties is balanced with hydrophobic variables (long alkyl chains or counterion chemistry), leading to (i) a control between monomeric/aggregate state ruling photoluminescence, (ii) redox behavior, and (iii) enhanced ion conductivity in thin films. This resulted in a LEC enhancement with the first ionic AIE emitters, reaching values of 0.19 lm W−1 at ca. 50 cd m−2. Overall, this design rule will be key to advance ionic active species for optoelectronics.Item Sweet Side Streams: Sugar Beet Pulp as Source for High-Performance Supercapacitor Electrodes(American Chemical Society, 2024-01-30) Selinger, Julian; Meinander, Kristoffer; Wilson, Benjamin P.; Abbas, Qamar; Hummel, Michael; Spirk, Stefan; Department of Bioproducts and Biosystems; Department of Chemical and Metallurgical Engineering; Biopolymer Chemistry and Engineering; Hydrometallurgy and Corrosion; Graz University of TechnologyValorization of the lignocellulosic side and waste streams is key to making industrial processes more efficient from both an economic and ecological perspective. Currently, the production of sugars from beets results in pulps in large quantities. However, there is a lack of promising opportunities for upcycling these materials despite their promising properties. Here, we investigate beet pulps from two different stages of the sugar manufacturing process as raw materials for supercapacitor electrodes. We demonstrate that these materials can be efficiently converted to activated, highly porous carbons. The carbons exhibit pore dimensions approaching the size of the desolvated K+ and SO42- ions with surface areas up to 2600 m2 g-1. These carbons were subsequently manufactured into electrodes, assembled in supercapacitors, and tested with environmentally friendly aqueous electrolytes (6 M KOH and 1 M H2SO4). Further analysis demonstrated the presence of capacitance-enhancing functionalities, and up to 193 and 177 F g-1 in H2SO4 and KOH, respectively, were achieved, which outperformed supercapacitors prepared from commercial YP80 F. Overall, our study suggests that side streams from sugar manufacturing offer a hidden potential for use in high-performance energy storage devices.Item Direct ink writing of biocompatible chitosan/non-isocyanate polyurethane/cellulose nanofiber hydrogels for wound-healing applications(Elsevier, 2024-02) Laurén, Isabella; Farzan, Afsoon; Teotia, Arun; Lindfors, Nina C.; Seppälä, Jukka; Department of Chemical and Metallurgical Engineering; Polymer technology; Helsinki University Central HospitalThe demand for new biocompatible and 3D printable materials for biomedical applications is on the rise. Ideally, such materials should exhibit either biodegradability or recyclability, possess antibacterial properties, and demonstrate remarkable biocompatibility with no cytotoxic effects. In this research, we synthesized biocompatible and 3D printable hydrogels tailored for biomedical applications, such as wound healing films, by combining antibacterial double-quaternized chitosan (DQC) with cystamine-based non-isocyanate polyurethane (NIPU-Cys) - a material renowned for enhancing both the flexibility and mechanical properties of the hydrogels. To improve the rheological behavior, swelling attributes, and printability, cellulose nanofibrils were introduced into the matrix. We investigated the impact of DQC on degradability, swelling capacity, rheological behavior, printability, and cell biocompatibility. The slightly cytotoxic nature associated with quaternary chitosan was evaluated, and the optimal concentration of DQC in the hydrogel was determined to ensure biocompatibility. The resulting hydrogels were found to be suitable materials for 3D printing via a direct ink writing technique (DIW), producing porous, biocompatible hydrogels endowed with valuable attributes suitable for various wound-healing applications.Item Regenerated cellulose properties tailored for optimized triboelectric output and the effect of counter-tribolayers(Springer, 2024-02-02) Dahlström, Christina; Eivazi, Alireza; Nejström, Malin; Zhang, Renyun; Pettersson, Torbjörn; Iftikhar, Haider; Rojas, Orlando J.; Medronho, Bruno; Norgren, Magnus; Department of Bioproducts and Biosystems; Bio-based Colloids and Materials; Mid Sweden University; KTH Royal Institute of TechnologyCellulose has shown great potential in the development of green triboelectric nanogenerators. Particularly, regenerated cellulose (R-cellulose) has shown remarkably high output power density but the structural features and key parameters that explain such superior performance remain unexplored. In this work, wood cellulose fibers were dissolved in a LiOH(aq)-based solvent to produce a series of R-cellulose films. Regeneration in different alcohols (from methanol to n-pentanol) was performed and the films’ structural features and triboelectric performance were assessed. Nonsolvents of increased hydrophobicity led to R-cellulose films with a more pronounced (1–10) diffraction peak. An open-circuit voltage (VOC) of up to ca. 260 V and a short-circuit current (ISC) of up to ca. 150 µA were measured for R-cellulose against polytetrafluoroethylene (as negative counter-layer). However, R-cellulose showed an increased VOC of 175% (from 88.1 V) against polydimethylsiloxane when increasing the alcohol hydrocarbon chain length from methanol to n-pentanol. The corresponding ISC and output power also increased by 76% (from 89.9 µA) and by 382% (from 8.8 W m–2), respectively. The higher R-cellulose hydrophilicity, combined with soft counter-tribolayer that follow the surface structures increasing the effective contact area, are the leading reasons for a superior triboelectric performance. Graphic abstract: (Figure presented.).Item Direct conversion of enzymatic hydrolysis lignin to cycloalkane fuel with hydrotalcite-derived Ni catalyst(Elsevier Science B.V., 2024-03-15) Jiao, Hairui; Xu, Guifeng; Sang, Yushuai; Chen, Hong; Li, Yongdan; Department of Chemical and Metallurgical Engineering; Industrial chemistry; Tianjin UniversityHerein, we reported a one-pot method that directly converting enzymatic hydrolysis lignin (EHL) into cycloalkane fuels using a Ni catalyst derived from Ni-Al hydrotalcite (NiAl-LDH). The effects of Ni/Al ratio and reduction condition on the catalytic activity have been examined. The catalyst obtained from the reduction of NiAl-LDH at 460 °C (Ni2Al1-re460) shows the highest activity among the catalyst samples examined, attributed to its abundant Lewis acidic sites, small-sized Ni metal particles, and large specific surface area. At optimized reaction conditions (320 °C, 3 MPa H2, 6 h), this catalyst achieves 100% EHL conversion and complete oxygen removal and improves the calorific value of the products from 25.0 MJ kg−1 to 42.5 MJ kg−1. The detected products are cycloalkane dimers and monomers with their carbon numbers within the range suitable for gasoline and diesel, and other large molecules with uncertain structures also predominantly consist of cycloalkane rings.Item Processing factors affecting roughness, optical and mechanical properties of nanocellulose films for optoelectronics(Elsevier Science Ltd., 2024-05-15) Kaschuk, Joice Jaqueline; Al Haj, Yazan; Valdez Garcia, Joaquin; Kamppinen, Aleksi; Rojas, Orlando J.; Abitbol, Tiffany; Miettunen, Kati; Vapaavuori, Jaana; Department of Bioproducts and Biosystems; Department of Chemistry and Materials Science; Bio-based Colloids and Materials; Multifunctional Materials Design; University of Turku; Swiss Federal Institute of Technology LausanneThis work aims to understand how nanocellulose (NC) processing can modify the key characteristics of NC films to align with the main requirements for high-performance optoelectronics. The performance of these devices relies heavily on the light transmittance of the substrate, which serves as a mechanical support and optimizes light interactions with the photoactive component. Critical variables that determine the optical and mechanical properties of the films include the morphology of cellulose nanofibrils (CNF), as well as the concentration and turbidity of the respective aqueous suspensions. This study demonstrates that achieving high transparency was possible by reducing the grammage and adjusting the drying temperature through hot pressing. Furthermore, the use of modified CNF, specifically carboxylated CNF, resulted in more transparent films due to a higher nanosized fraction and lower turbidity. The mechanical properties of the films depended on their structure, homogeneity (spatial uniformity of local grammage), and electrokinetic factors, such as the presence of electrostatic charges on CNF. Additionally, we investigated the angle-dependent transmittance of the CNF films, since solar devices usually operate under indirect light. This work demonstrates the importance of a systematic approach to the optimization of cellulose films, providing valuable insight into the optoelectronic field.Item Improving the inflammatory-associated corrosion behavior of magnesium alloys by Mn3O4 incorporated plasma electrolytic oxidation coatings(Elsevier Science Inc., 2024-03-01) Bahrampour, Sara; Bordbar-Khiabani, Aydin; Hossein Siadati, M.; Gasik, Michael; Mozafari, Masoud; Department of Chemical and Metallurgical Engineering; Materials Processing and Powder Metallurgy; K.N. Toosi University of Technology; University of OuluBiodegradable magnesium alloys for orthopedic bone fixation have been introduced for various fields of application. The corrosion resistance of magnesium implants weakens in physicochemical environments and is further compromised during post-implantation inflammation. In this study, Mn3O4-incorporated plasma electrolyte oxidation (PEO) coatings were developed on Mg-Zn-Ca substrate through two approaches: the addition of KMnO4 salt and the inclusion of Mn3O4 nanoparticles into the electrolyte composition. Incorporating additives into electrolytes led to a reduction in surface porosity and an increase in coating thickness in both synthesis approaches. The electrochemical and immersion corrosion tests were conducted under simulated normal conditions and inflammatory conditions, where inflammatory solutions were prepared with the addition of hydrogen peroxide (H2O2) and hydrochloric (HCl) acid. Both corrosion studies revealed that inflammation significantly increased the corrosion rate of the uncoated Mg-Zn-Ca biomaterial, escalating from approximately 2 mm·y-1 to 16 mm·y-1. Moreover, corrosion studies showed that the composite PEO coatings, incorporating Mn3O4 nanoparticles (MnPR-PEO), demonstrated superior corrosion performance among all coated samples. Potentiodynamic polarization results indicated a substantial reduction in corrosion current density, decreasing from 73.9 μA·cm- 2 for basic PEO coatings to 5.5 μA·cm- 2 for MnPR-PEO coatings. The improved performance of Mn3O4-incorporated PEO coatings, attributed to their catalytic H2O2 scavenging, suggests promise for magnesium implants, offering enhanced corrosion resistance and potential biomedical application benefits.Item Bio-based materials for solar cells(John Wiley & Sons, 2024-01-01) Miettunen, Kati; Hadadian, Mahboubeh; García, Joaquín Valdez; Lawrynowicz, Alicja; Akulenko, Elena; Rojas, Orlando J.; Hummel, Michael; Vapaavuori, Jaana; Department of Bioproducts and Biosystems; Department of Chemistry and Materials Science; Biopolymer Chemistry and Engineering; Multifunctional Materials Design; University of Turku; University of British ColumbiaPlant-based materials are emerging as an alternative to conventional components in advanced energy applications. Among these, energy harvesting from sunlight is highly attractive and, in fact, represents the fastest growing energy technology. This review addresses the broad field of solar cell science since plant-based components can be utilized in almost all solar technologies, and in certain photovoltaic technologies, they can fulfill most of the roles in photovoltaic devices. There is strengthened recent interest in developing sustainable materials options as well as new functionalities being developed for bio-based materials. This contribution describes the different options for plant-derived materials in photovoltaics and discusses their deployment feasibility. We focus on performance, lifetime, and embedded energy, all of which are critical to achieve—economically and sustainably–competitive photovoltaic devices. We address the tendency in the current literature for greenwashing, given that not all plant-based solutions are environmentally-sound at the device level. On the other hand, plant-based materials can offer functionalities that cannot be reached with currently used materials. This article is categorized under: Sustainable Energy > Solar Energy Emerging Technologies > Materials Sustainable Energy > Bioenergy.Item Efficient photocatalytic CO2 reduction coupled with selective styrene oxidation over a modified g-C3N4/BiOBr composite with high atom economy(Royal Society of Chemistry, 2024-02-21) Bai, Peng; Zhao, Yicheng; Li, Yongdan; Department of Chemical and Metallurgical Engineering; Industrial chemistry; Tianjin UniversityConventional photocatalytic CO2 reduction is usually combined with the oxidation of H2O or sacrificial agents, which faces problems such as low catalytic activity and inefficient atom economy. In this work, a photocatalytic CO2 reduction and selective styrene oxidation synergetic system is developed with an NH4Cl-modified g-C3N4/BiOBr composite photocatalyst. The interfacial heterostructure promotes the formation of surface amino groups and oxygen vacancies, which facilitates the adsorption and chemical reduction of CO2. The heterostructure also improves the separation of photogenerated electron-hole pairs and enhances the photocatalytic activity. The simultaneous consumption of electrons and holes is beneficial for both CO2 reduction and styrene oxidation processes. Meanwhile, the oxygen atoms removed during CO2 reduction are utilized efficiently for styrene oxidation in this synergistic system, and thus the atom economy is improved significantly. The generation rates of CO, CH4, benzaldehyde and styrene oxide are 802, 8, 684 and 139 μmol g−1 h−1, respectively. This study provides a novel strategy for designing a green photocatalytic CO2 reduction system.Item Oxidation of cellulose fibers using LPMOs with varying allomorphic substrate preferences, oxidative regioselectivities, and domain structures(Elsevier Science Ltd., 2024-04-15) Støpamo, Fredrik G.; Sulaeva, Irina; Budischowsky, David; Rahikainen, Jenni; Marjamaa, Kaisa; Potthast, Antje; Kruus, Kristiina; Eijsink, Vincent G.H.; Várnai, Anikó; School services, CHEM; Norwegian University of Life Sciences; University of Natural Resources and Life Sciences, Vienna; VTT Technical Research Centre of FinlandLytic polysaccharide monooxygenases (LPMOs) are excellent candidates for enzymatic functionalization of natural polysaccharides, such as cellulose or chitin, and are gaining relevance in the search for renewable biomaterials. Here, we assessed the cellulose fiber modification potential and catalytic performance of eleven cellulose-active fungal AA9-type LPMOs, including C1-, C4-, and C1/C4-oxidizing LPMOs with and without CBM1 carbohydrate-binding modules, on cellulosic substrates with different degrees of crystallinity and polymer chain arrangement, namely, Cellulose I, Cellulose II, and amorphous cellulose. The potential of LPMOs for cellulose fiber modification varied among the LPMOs and depended primarily on operational stability and substrate binding, and, to some extent, also on regioselectivity and domain structure. While all tested LPMOs were active on natural Cellulose I-type fibers, activity on the Cellulose II allomorph was almost exclusively detected for LPMOs containing a CBM1 and LPMOs with activity on soluble hemicelluloses and cello-oligosaccharides, for example NcAA9C from Neurospora crassa. The single-domain variant of NcAA9C oxidized the cellulose fibers to a higher extent than its CBM-containing natural variant and released less soluble products, indicating a more dispersed oxidation pattern without a CBM. Our findings reveal great functional variation among cellulose-active LPMOs, laying the groundwork for further LPMO-based cellulose engineering.Item Soluble and multivalent Jag1 DNA origami nanopatterns activate Notch without pulling force(Nature Publishing Group, 2024-01-18) Smyrlaki, Ioanna; Fördős, Ferenc; Rocamonde-Lago, Iris; Wang, Yang; Shen, Boxuan; Lentini, Antonio; Luca, Vincent C.; Reinius, Björn; Teixeira, Ana I.; Högberg, Björn; Department of Bioproducts and Biosystems; Biohybrid Materials; Karolinska Institutet; Moffitt Cancer CenterThe Notch signaling pathway has fundamental roles in embryonic development and in the nervous system. The current model of receptor activation involves initiation via a force-induced conformational change. Here, we define conditions that reveal pulling force-independent Notch activation using soluble multivalent constructs. We treat neuroepithelial stem-like cells with molecularly precise ligand nanopatterns displayed from solution using DNA origami. Notch signaling follows with clusters of Jag1, and with chimeric structures where most Jag1 proteins are replaced by other binders not targeting Notch. Our data rule out several confounding factors and suggest a model where Jag1 activates Notch upon prolonged binding without appearing to need a pulling force. These findings reveal a distinct mode of activation of Notch and lay the foundation for the development of soluble agonists.Item Graphite recovery from waste Li-ion battery black mass for direct re-use(Elsevier Ltd, 2024-03) Chernyaev, Alexander; Kobets, Anna; Liivand, Kerli; Tesfaye, Fiseha; Hannula, Pyry-Mikko; Kallio, Tanja; Hupa, Leena; Lundström, Mari; Department of Chemical and Metallurgical Engineering; Department of Chemistry and Materials Science; Hydrometallurgy and Corrosion; Electrochemical Energy Conversion; Åbo Akademi University; National Institute of Chemical Physics and Biophysics; Finnish Minerals GroupGraphite was recovered from two leached (H2SO4 = 2 M, 60 °C, t = 3 h, Fe3+ = 2 g/L) Li-ion battery black mass concentrates with minimized energy consumption. One black mass originated from a mixture of mobile device and power tool batteries, and another from a single electric vehicle battery. The leach residues were pyrolyzed (800 °C, t = 1 h, Ar atmosphere) to remove the polyvinylidene fluoride (PVDF) binder and other non-metallic fractions. The black mass, its leach residue, and pyrolyzed residue were characterized using inductively coupled plasma-optical emission spectrometry (ICP-OES), ion chromatography (IC), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDS), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Raman spectroscopy, and N2 adsorption/desorption. After hydrometallurgical recycling and pyrolysis, the main post-metallurgical black mass impurities were cobalt oxide, iron, acid-resistant boehmite (AlO(OH)), and silicon dioxide. The pyrolysis resulted in electrolyte and binder removal, affected the crystallinity of the remaining boehmite. The recovered graphite-rich residue with impurities identified was tested as an anode in half-cells vs. metal Li. The average specific capacities of recovered graphite-rich residues from both sources were 350 and 250 mAh/g at 0.1C and their capacity retention after 100 cycles was high (80 %) suggesting rather slow deterioration and hence the proposed recycling route being promising for the graphite reuse in new Li-ion batteries.Item Innovations in hydrogel-based manufacturing: A comprehensive review of direct ink writing technique for biomedical applications(Elsevier, 2024-02) Baniasadi, Hossein; Abidnejad, Roozbeh; Fazeli, Mahyar; Lipponen, Juha; Niskanen, Jukka; Kontturi, Eero; Seppälä, Jukka; Rojas, Orlando J.; Department of Chemical and Metallurgical Engineering; Department of Bioproducts and Biosystems; Polymer Synthesis Technology; Materials Chemistry of Cellulose; Bioproduct Technology; Polymer technology; Bio-based Colloids and MaterialsDirect ink writing (DIW) stands as a pioneering additive manufacturing technique that holds transformative potential in the field of hydrogel fabrication. This innovative approach allows for the precise deposition of hydrogel inks layer by layer, creating complex three-dimensional structures with tailored shapes, sizes, and functionalities. By harnessing the versatility of hydrogels, DIW opens up possibilities for applications spanning from tissue engineering to soft robotics and wearable devices. This comprehensive review investigates DIW as applied to hydrogels and its multifaceted applications. The paper introduces a diverse range of printing techniques while providing a thorough exploration of DIW for hydrogel-based printing. The investigation aims to explain the progress made, challenges faced, and potential trajectories that lie ahead for DIW in hydrogel-based manufacturing. The fundamental principles underlying DIW are carefully examined, specifically focusing on rheological attributes and printing parameters, prompting a comprehensive survey of the wide variety of hydrogel materials. These encompass both natural and synthetic variations, all of which can be effectively harnessed for this purpose. Furthermore, the review explores the latest applications of DIW for hydrogels in biomedical areas, with a primary focus on tissue engineering, wound dressing, and drug delivery systems. The document not only consolidates the existing state of DIW within the context of hydrogel-based manufacturing but also charts potential avenues for further research and innovative breakthroughs.Item A Low-Cost and Do-It-Yourself Pressure Sensor Enable Human Motion Detection and Human–Machine Interface Applications(Wiley-VCH Verlag, 2024-02-22) Heikkinen, Mari; Basarir, Fevzihan; Miikki, Kim; Al Haj, Yazan; Mohan, Mithila; Vapaavuori, Jaana; Department of Chemistry and Materials Science; School common, CHEM; Inorganic Materials Chemistry; Multifunctional Materials DesignAbstract In this work, cost-effective and do-it-yourself capacitive pressure sensors are fabricated using readily available commercial components. The sensors are created in a single-step process -by simply applying electrically conductive paint onto both sides of a porous melamine sponge. These sensors exhibit a wide-range pressure sensing capability, spanning from 10 Pa to 100 kPa. The sensors showcase an impressively low limit of detection, detecting pressures as low as 10 Pa, and exhibit a moderate response time of 123 ms. Moreover, the sensors display remarkable repeatability and stability over 10 000 loading and unloading cycles without experiencing fatigue. Notably, these exceptional qualities come at an exceptionally low material cost, with the sensor measuring 20 × 20 × 2 mm. To showcase their potential applications, the fabricated sensors are successfully employed in real-time human motion detection, proximity detection, and wearable keyboard applications.