[article-cris] Kemian tekniikan korkeakoulu / CHEM

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  • Atomistic Mechanism in Sodium-Ion Storage Revealed by Experiment and Simulation
    (2026-03-19) Luong, Hieu Trung; Front, Alexis; Zarrouk, Tigani; Mousavihashemi, Seyedabolfazl; Durairaj, Vasuki; Kontturi, Katri S.; Tammelin, Tekla; Caro, Miguel A.; Laurila, Tomi
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Unlike lithium-ion batteries (LIBs), sodium-ion battery (SIB) technology is still in an early stage of development, where the pursuit of cost-effective and sustainable active materials is critical. Hard carbon (HC) is the most extensively studied anode material thanks to its compatibility with sodium-ion insertion. In this study, several cellulose-derived HCs were further evaluated as potential SIB anodes by using experimental and computational methods. Among them, the HC prepared from cellulose nanofibers delivers outstanding rate capability and cycling stability (∼210 mAh g–1 at 1000 mA g–1), exceeding the performance of its commercial counterpart. The excellent electrochemical performance is attributed to multiple merits: enlarged interplanar spacing, a hierarchical porous architecture, abundant defective sites, and enhanced conductivity arising from graphitic ribbon-like networks throughout the carbon matrix. Atomistic simulations using machine learning interatomic potentials further support these findings. Overall, this work offers new insights into the fundamental sodium-ion storage mechanisms in high-performance HC electrodes and highlights a sustainable route to next-generation SIB anodes.
  • Furanoate thermoplastic elastomer copolymers with tunable Hard–Soft segment ratios for extrusion-based 3D rapid prototyping
    (2026-03-23) Ponkratenkova, Alisa; Välinen, Lauri; Baniasadi, Hossein; Tropa, Anete; Starkova, Olesja; Gaidukovs, Sergejs; Niskanen, Jukka
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Poly (ethylene 2,5-furandicarboxylate) (PEF) is a prospective substitute for its fossil-fuel counterpart poly (ethylene terephthalate). However, its high melting temperature and poor toughness have limited its industrial applications. The properties of PEF can be improved by copolymerization with long-chain aliphatic diols, 1,6-hexanediol (HD), 1,8-octanediol (OD), and 1,10-decanediol (DD). A two-step polycondensation yielded in copolymers with molecular weights ranging from 17 to 66 kg/mol. The thermal and mechanical properties of the copolymers could be tuned by adjusting the ratio of ethylene glycol (EG) to the long-chain diols (1:9, 3:7, 5:5, 7:3, 9:1). The melting temperatures (Tm) ranged from 94 to 139 °C for copolymers with 70 and 90 wt% of long-chain diols; and the glass transition (Tg) temperature from −3 to 64 °C with increasing of EG content. Mechanical testing demonstrated a tunable stiffness affected by the hard (FDCA) vs soft (long-chain diols) segments ratios of the obtained copolymers. A copolymer with 70 wt% decanediol exhibited ductile deformation with a strain of 420%, Tg = 2 °C, and Tm = 94 °C. While a copolymer with 70 wt% hexanediol has a Tg = 36 °C and Tm = 139 °C, and exhibits a high degree of rubbery elasticity with elongation of 500% at room temperature. A copolymer with 70 wt% hexanediol was 3D printed via Fused Granular Fabrication (FGF) into a dimensionally stable rubber spring with good layer adhesion, without delamination between the layers. Hence, the synthesized copolymers can form a bio-based and sustainable platform for next-generation engineering plastics used in additive manufacturing materials, replacing fossil-based thermoplastic polyurethanes.
  • Engineering Chiroptical Interactions through Integrating Plasmonic Arrays with Cholesteric Nanocellulose
    (2026-03-17) Tao, Han; Jo, Sunghwan; Chu, Guang; Qi, Xiaoyu; Estévez, Irene; Lizana, Angel; Xu, Wenyang; Deng, Shengwei; Mihi, Agustin; Kontturi, Eero
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Achieving scalable fabrication with precise control of chiroptical properties in chiral plasmonic materials remains challenging. We present a new family of engineered chiroptical composites comprising linearly assembled gold nanoparticle arrays integrated with cholesteric self-assembled cellulose nanocrystals (CNCs). Aqueous CNC suspensions are cast onto pre-assembled achiral plasmonic nanoparticle arrays via evaporation-induced transfer imprinting lithography, yielding centimeter-scale hybrid films with custom-tailored chiroptical responses. During drying, CNCs co-assemble with the gold nanoparticles at the interface, preserving the array's linear arrangement and keeping it isolated from the overlying cholesteric CNC layers. This configuration combines the linear dichroism of the plasmonic array with the linear birefringence of the CNC matrix, producing strong and tunable plasmonic circular dichroism at the surface lattice resonance, reaching 1217 ± 51 mdeg with a dissymmetry factor of –0.19 ± 0.02. Our approach provides a sustainable platform for engineering multifunctional chiral plasmonic materials with potential applications in optical sensing, photonic devices, and chiral biointerfaces.
  • A digital twin for real-time biodiversity forecasting with citizen science data
    (2026-03) Ovaskainen, Otso; Winter, Steven; Tikhonov, Gleb; Lauha, Patrik; Lehtiö, Ari; Nokelainen, Ossi; Abrego, Nerea; Aroluoma, Anni; Harrison, Jesse Patrick; Heikkinen, Mikko; Kallio, Aleksi; Koliseva, Anniina; Lehikoinen, Aleksi; Roslin, Tomas; Somervuo, Panu; Souza, Allan Tainá; Tahir, Jemal; Talaskivi, Jussi; Turunen, Alpo; Vancraeyenest, Aurélie; Zuquim, Gabriela; Autto, Hannu; Hänninen, Jari; Inkinen, Jasmin; Kalttopää, Outa; Koskinen, Janne; Kotakorpi, Matti; Kuntze, Kim; Loehr, John; Mutanen, Marko; Oranen, Mikko; Paavola, Riku; Renkonen, Risto; Schiestl-Aalto, Pauliina; Sipilä, Mikko; Sujala, Maija; Sundell, Janne; Tepsa, Saana; Tuominen, Esa-Pekka; Uusitalo, Joni; Vallinmäki, Mikko; Vatka, Emma; Veikkolainen, Silja; Watts, Phillip C.; Dunson, David
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Citizen science provides large amounts of biodiversity data. Key challenges in unlocking its full potential include engaging citizens with limited species identification skills and accelerating the transition from data collection to research and monitoring outputs. Here we use a large dataset from Finland to show how even citizens who cannot identify birds themselves can contribute to real-time predictions of avian distributions. This is achieved through a digital twin that combines smartphone-based citizen science with long-term knowledge in a continuously updating model. The app submits raw audio to a backend that classifies birds with machine learning, reducing variation in data quality and enabling validation and reclassification by continuously improving classifiers. We counteracted spatiotemporal sampling biases by interval recordings and permanent point count networks. Over 2 years, the app generated 15 million bird detections. Independent test data show that the digital-twin-informed models are more accurate at predicting bird spatiotemporal distributions. Because our approach is highly scalable and has the potential to generate biomonitoring data even in understudied areas, it could accelerate the flow of reliable biodiversity information and increase inclusivity in citizen science projects.
  • Species-specific structural adaptation of the potyviral coat protein in virions and virus-like particles
    (2026-02-12) Koritnik, Neža; Kežar, Andreja; Kavčič, Luka; Žnidarič, Magda Tušek; Leonardi, Adrijana; De, Swarnalok; Pollari, Maija; Mäkinen, Kristiina; Podobnik, Marjetka
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Potyviruses are the largest group of plant positive-sense single-stranded RNA viruses and represent a major economic burden worldwide. Their coat protein (CP) forms a filamentous, flexible capsid around the genomic RNA. However, information is still lacking on the mechanisms of virion assembly, disassembly and stability, which is central to understanding virus biology and control. Here, we investigate the role of CP in these processes using structural, biochemical and biophysical studies of five potyviral CPs from three phylogenetic clades combined with bioinformatics and in planta experiments. Our results suggest that, while potyviruses have a conserved virion structure, the amino acids forming the CP-CP and CP-RNA interactions leading to this structure are species-specific. We show that the species-specific CP sequence also determines the architecture of RNA-free virus-like particles (VLPs) and the degree of their structural polymorphism. We identify the residues that determine this specificity at distinct S1-S4 interaction sites. In contrast, a highly conserved charged amino acid triad at the CP-CP interface is essential for the stability of virions and RNA-free VLPs. These results contribute to understanding the molecular mechanism of potyviral virion assembly and highlight the significance of the amino acid sequence of selected CPs in potential biotechnological or biomedical applications.
  • Toxicological Evaluation of Ionic Liquids: QSAR Approach for Acetylcholinesterase Enzyme Inhibition
    (2026-03-16) Ebrahimpoor Gorji, Ali; Uusi-Kyyny, Petri; Alopaeus, Ville
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    A “quantitative structure–activity relationship” (QSAR) model is developed to predict the toxicity of ionic liquids (ILs) based on the effect on the acetylcholinesterase (AChE) enzyme. A data set of 243 ILs was compiled and randomly divided into training (183 ILs) and test (60 ILs) sets to enable both internal and external validations. To optimize the model performance, a breaking point analysis was performed to identify the most relevant molecular descriptors. The analysis revealed that a set of 11 COSMO-RS quantum chemical descriptors provided near-optimal predictive power, with additional descriptors offering minimal improvement. A multiple linear regression (MLR) model was developed by using these descriptors, incorporating both cationic and anionic molecular features. Internal validation using Leave-One-Out and Leave-Many-Out cross-validation (Q2LOO = 0.79, Q2LMO = 0.78) as well as Y-scrambling confirmed the robustness of the model. External validation on the test set yielded acceptable R2 = 0.75 and low RMSE = 0.35 values, indicating strong predictive performance. The developed model outperformed previous models, particularly by accounting for the influence of anion structures, which have been largely neglected in earlier works. The final MLR-QSAR model not only demonstrated statistical reliability but also provided mechanistic insights into the structural contributions of both ionic components to IL’s toxicity. Predicted toxicity values (Log 1/EC50) for novel ILs are also presented, expanding our understanding of IL safety profiles.
  • Platinum-Based Bimetallic Electrocatalyst for Hydrogen Evolution and Oxidation Reactions in Alkaline Media
    (2026-02-03) Hammouali, Mohammed Amine; Vikberg, Milla; Moumaneix, Lilian; Ali, Farhan S.M.; Jiang, Hua; Laasonen, Kari; Kallio, Tanja
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Achieving sustainable green hydrogen economy requires overcoming the challenges associated with hydrogen production and utilization, one of them being the sluggish kinetics of hydrogen evolution and oxidation reactions (HER/HOR) in alkaline media. Utilizing Pt-based bimetallic catalysts enhances the HER/HOR reaction rate by exploiting the different properties of each metal. However, the lack of detailed understanding of the mechanism driving alkaline HER/HOR limits further advancement. This work establishes the co-adsorption of hydrogen and hydroxide as a dual activity descriptor for alkaline HER/HOR. By integrating electrochemical analyses (CV, LSV, EIS) with density functional theory trends across a series of Pt-based bimetallic alloys, we show that balancing H and OH affinities is critical for optimal activity. Rather than relying on a single descriptor, this study proposes a dual-descriptor framework for rational catalyst selection, highlighting PtRu and PtIr as examples for optimal binding balance.
  • Experimental and Modeling Investigation of Vapor–Liquid Equilibria and Excess Enthalpies in Binary Mixtures Containing γ-Valerolactone (GVL), Ethylbenzene, and Cyclohexene
    (2026-02-12) Wibowo, Agung Ari; Asadi, Ehsan; Ossama, Muhammad; Uusi-Kyyny, Petri; Pokki, Juha Pekka; Alopaeus, Ville
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    In this work, the vapor–liquid equilibrium (VLE) and excess molar enthalpy (HE) of three binary mixtures, namely, ethylbenzene + γ-valerolactone (GVL), cyclohexene + GVL, and cyclohexene + ethylbenzene, were measured. VLE data were measured at 35.0 and 70.0 kPa for the GVL-containing mixtures and at 70.0 and 101.3 kPa for the ethylbenzene + cyclohexene mixture. Vapor pressures of the pure components were measured and correlated using an extended Antoine equation, which aligned well with the literature data. The HE values were experimentally determined at 298.15 K. All the binary mixtures exhibited positive HE, indicating endothermic mixing. Including HE data in the regression of binary interaction parameters (BIPs) was essential for accurate modeling; omitting these data led to inaccurate results, such as an incorrectly negative calculated HE. All three studied mixtures showed no azeotrope formation. Correlative models such as Wilson, NRTL, and UNIQUAC accurately represented the experimental VLE and HE data. In contrast, predictive group-contribution models UNIFAC and UNIFAC-Dortmund did not adequately reproduce the VLE and HE of the GVL-containing mixtures, mainly due to insufficient group parameters for GVL’s structure. COSMO-RS predictions improved when experimental vapor pressure data were included in compound properties. The VLE data were confirmed to be thermodynamically consistent upon verification using the Van Ness and L–W tests.
  • Acoustic performance optimization of natural-fiber micro-perforated panels backed by an optimized polyurethane–fibrogranule composite
    (2026-02-09) Nakhaeipour, Mojtaba; Forouharmajd, Farhad; Habibi, Ehsanollah; Soltani, Parham; Tehrani, Ali
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Noise pollution poses a major threat to public health and urban sustainability, necessitating effective and environmentally compatible acoustic solutions. Here we report a high-performance hybrid absorber that integrates a natural-fiber micro-perforated panel (MPP) fabricated from alkali-treated flax and rice husks with an optimized polyurethane–fibrogranule (PU-FG) composite backing reinforced by the same renewable fillers. Using response surface methodology based on central composite design, we systematically optimized composite formulation, panel porosity, and air-gap geometry to achieve superior broadband absorption. The resulting system, a 1.61% porosity MPP, 28.5 mm front air gap, 40 mm PU-FG backing, and a 30 mm rear air gap, achieves a sound absorption average (SAA) of 0.82 and a noise reduction coefficient (NRC) of 0.85 across the frequency range 100–2500 Hz. This configuration provides effective broadband absorption through the combined action of Helmholtz resonance from the MPP and visco-thermal losses in the porous backing. Morphological analysis via field-emission scanning electron microscopy confirms hierarchical pore structures enhancing tortuosity and interfacial adhesion. By substantially increasing the renewable content of both the MPP and the porous backing, this lightweight, high-efficiency hybrid offers a practical and scalable pathway toward more sustainable noise-control materials for architectural, transportation, and urban applications.
  • Engineered phytic acid-lignin networks: one-pot strategy toward stable, multifunctional bio-based materials
    (2026-03) Bagheri, Marzieh; Farooq, Muhammad; Nousiainen, Paula; Hyväkkö, Uula; Österberg, Monika
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    This study introduces a one-pot approach that covalently links phytic acid into the lignin network while preserving lignin's ability to self-assemble into nanoparticles. Using diepoxy reagent and ethyl levulinate as crosslinkers, covalent bonding was achieved and confirmed via lignin model compounds experiments. The resulting phytic acid-modified lignin exhibited promising self-extinguishing behavior, retained lignin's antioxidant activity (IC50 of 0.1 g/l), and could be converted into stable nanoparticles via solvent shifting, thus broadening the application portfolio. These self-assembled spherical phytic acid-modified lignin nanoparticles (P-LNPs) with an average size of 140 ± 5 nm demonstrated high surface charge of -64.5 mV at pH 7, efficient cationic pollutant adsorption (62.9 mg/g adsorption capacity achieved instantly), and antifogging properties. This work presents a stable lignin-phytic acid system that can be used directly or as aqueous dispersion of nanoparticles, enabling a variety of applications and establishing a scalable framework to transform lignin into a high-value platform material.
  • Demonstrating the Performance of Aspartic-Acid Functionalized Naphthalene Diimide in a Near-Neutral Flow Battery
    (2026-02-08) Shahsavan, Mahsa; Wiberg, Cedrik; Hamza, Andrea; Poskela, Aapo; Hjelm, Johan; Peljo, Pekka
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The performance of the negatively charged aspartic acid-functionalized naphthalene diimide (ASP-NDI) in a flow battery is investigated in this article. The high concentration ASP-NDI/ferrocyanide flow battery presented cycled for 79.8 days with an average coulombic efficiency of 99.9% and an energy efficiency of 87.5% at 20 mA cm−2 while accessing an over 90% of the theoretical capacity of ASP-NDI with a capacity fade rate of 0.0275% per day that is the lowest reported for the NDI-based flow batteries to date.
  • Improved capabilities of the TurboGAP code for radiation induced cascade simulations : An illustration with silicon
    (2026-03-10) Saha, Uttiyoarnab; Hamedani, Ali; Caro, Miguel A.; Sand, Andrea E.
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    TurboGAP is a software package designed for efficient molecular dynamics simulations using Gaussian approximation potential (GAP) machine-learning interatomic potentials (MLIP). In this work, we enhance the capabilities of TurboGAP for radiation damage simulations by implementing a two-temperature molecular dynamics model, based on electron density-dependent coupling of electronic and atomic subsystems. Additionally, we implement adaptive calculation of the timestep and grouping of atoms for cell-border cooling. Our implementation incorporates electronic stopping power either through a traditional friction-based model or a more realistic first-principles-derived model. By combining the computational efficiency of TurboGAP with the accuracy of GAP MLIP, we perform cascade simulations in silicon with primary knock-on atom (PKA) energies up to 10 keV. Our simulations scale to systems containing up to 1 million atoms. We study the generation and clustering of radiation-induced defects. We also calculate ion-beam mixing and compare our results with the experimental data, discussing how the GAP-MLIP along with the inclusion of a realistic electronic stopping model affects the prediction of experimental mixing values.
  • Lithium-ion batteries recycling: Review of reactor and process design, scalability, cost, and environmental performance
    (2026-04-01) Benaabidate, Safae; El Mounafia, Nabil; Rahimpour, Saeed; Fogarasi, Szabolcs; Lasri, Karima; Wilson, Benjamin P.; Cormos, Ana-Maria; Taha, Yassine; Hakkou, Rachid; Saadoune, Ismael; Zaabout, Abdelghafour
    A2 Katsausartikkeli tieteellisessä aikakauslehdessä
    Various methods are being explored to recover valuable metals from spent lithium-ion batteries (SLIBs), particularly those with LiNixCoyMnzO2 (x + y + z = 1) (NMC) cathode materials composed of critical metals Ni, Co, and Li. Methods being investigated are primarily based on hydrometallurgy, pyrometallurgy, hybrid, and direct cathode regeneration. Key studies focus primarily on increased recovery rates and maximized selectivity towards targeted products. However, such methods involve complex reactive multiphase flow phenomena requiring perfect understanding and adaptation of existing knowledge to the battery recycling context beyond lab scale experiments and associated performance. This work reviews and analyzes various recycling methods, focusing on the chemical engineering aspects, targeting accelerated upscaling of promising ones towards an industry with maximized cost-effectiveness and minimized environmental impacts. The analyses revealed very scattered technical, economic, and environmental data, with a lack of standardized assessment frameworks, making it difficult to make any clear judgment on the performance of the different proposed methods. Guidelines for streamlined technological maturation are presented and discussed. The proposal includes holistic, integrated assessment approaches in standardized frameworks that align the interplaying aspects of chemical engineering, such as thermodynamics, kinetics, and multiphase flow dynamics, with targeted techno-economic and life cycle performance. Such an approach can be used as an effective tool for screening promising technology at an early stage of development to identify the one to prioritize for faster scale-up. This can guarantee reducing research and development costs and ultimately de-risking investments to drive the scale-up and industrial deployment.
  • Mining metal from waste
    (2026-02-16) Pirrie, Duncan; Donnelly, Laurance J.; Power, Matthew R.; Butcher, Alan R.; Menzies, Andrew; Jolis, Ester M.; Wilson, Ben P.
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    With the transition to a low carbon future and increasing technological applications, the global demand for metals will continue to rise into the foreseeable future. However, primary ore deposits are finite, and to continue production, lower grade and more complex ore deposits need to be discovered, evaluated and exploited, with increasing exploration and production costs. Additionally, there are significant geopolitical constraints on global resources for some critical raw materials and metals, along with ethical constraints of ‘off-shoring’ minerals supply to areas of the world with poor records in terms of legal mineral production, human rights violations, health and safety, and the long-term environmental impact of mining. Whilst it is unlikely at present to be able to fully meet supply needs, one source of metals for the future is through recycling of both domestic and industrial waste. Modern waste streams such as end-of-life lithium-ion batteries and electrical waste commonly contain significantly more metals than primary ore deposits before processing. However, these waste materials are complex, and through two case studies in this article, we focus on how methods commonly used in modern mining and mineral processing can be used to assist the processing and recovery of metals from waste. Perhaps it is time to reclassify waste as valuable resources for the future.
  • Resolving DNA origami structural integrity and pharmacokinetics in vivo
    (2026-02) Wang, Yang; Rocamonde-Lago, Iris; Waldvogel, Janine; Shen, Boxuan; Wu, Yi-Chia; Zhu, Junke; Zang, Shuya; Jia, Yingbo; Baars, Igor; Kloosterman, Alexander; Hoffecker, Ian T.; Wu, Ming-Ru; He, Qin; Högberg, Björn
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    DNA origami holds great potential for advancing therapeutics, but the lack of methods for the precise assessment of structural integrity in vivo prevents its translation. Here we introduce proximity ligation assay for structural tracking and integrity quantification (PLASTIQ) for resolving origami structural integrity with only 1 µl of blood sample and with a detection limit of 0.01 fM. Through PLASTIQ, we could observe and quantify the dynamics of DNA origami degradation during blood circulation and evaluate the effectiveness of PEGylation for slowing this process in a murine model. Additionally, by using a double-layered barrel-like origami structure, we found distinct degradation kinetics of DNA helices depending on their specific location, revealing the slower degradation of internal helices compared with the outer ones. Our results suggest that PLASTIQ offers a quantitative approach for assessing DNA origami integrity in vivo by longitudinal sampling, providing dynamic pharmaceutical-level insights for accelerating the development of DNA-nanostructure-based therapeutic molecules and drugs.
  • Atomic layer deposition of zinc oxide films on lateral high-aspect-ratio test structures using diethylzinc and water as precursors
    (2026-03-04) Haimi, Eero; Philip, Anish; Velasco, Jorge A.; Gao, Feng; Karppinen, Maarit; Puurunen, Riikka L.
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Zinc oxide is a wide bandgap semiconductor with a variety of applications as a thin film material. In this work, a set of zinc oxide thin films were grown on lateral high-aspect-ratio test structures using atomic layer deposition. Diethylzinc and water were used as precursors, and several processing conditions were examined. The grown films were characterized for conformality using energy-dispersive electron probe x-ray microanalysis supported by x-ray reflectometry studies of additional reference samples. To analyze growth kinetics and film thickness profiles, diffusion-reaction simulations were made. Most importantly, it was found that at the 200 °C growth temperature, the film thickness profile followed nearly perfectly the ideal saturation profile expected for self-terminating reactions. The obtained result, thus, establishes an excellent reference case for process optimization.
  • Liquid–Liquid Extraction of Acetic Acid with 2-Methyltetrahydrofuran: Experiments, Process Modeling, and Economics
    (2026-02-04) Laitinen, Antero T.; Parsana, Vyomesh M.; Khirsariya, Priyank; Jauhiainen, Olli; Huotari, Marco; Pokki, Juha-Pekka; Vlugt, Thijs J.H.; Ramdin, Mahinder
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Acetic acid production from renewable processes such as biomass hydrolysis and electrochemical reduction of CO2 exhibits low concentrations, which make downstream separation challenging. We measured the vapor–liquid equilibria of the binary systems acetic acid + 2-methyltetrahydrofuran (2-MTHF), methyl-t-butyl ether (MTBE) + acetic acid, and the ternary liquid–liquid equilibria of the system 2-MTHF + AA + water, fitted the data to the UNIQUAC-HOC and NRTL models, designed a hybrid extraction-distillation process for acetic acid separation with 2-MTHF, and evaluated its economics and compared with that of three other commonly used solvents (i.e., ethyl acetate, MTBE, and methyl propyl ketone). The lowest and highest costs of separation were observed for MTBE and MPK, while 2-MTHF and EA showed similar performance. The cost of separation increased exponentially as the feed concentration decreased, and renewable processes should aim for at least 5 wt % acetic acid in the feed to allow economically feasible separation.
  • A Machine Learning-Guided Study of Structure-Reactivity Relationships in Diels-Alder Cycloadditions
    (2026-01-23) Mahdian, Amir; Farshadfar, Kaveh; Laasonen, Kari
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    The Diels-Alder cycloaddition is a cornerstone transformation in organic synthesis and has been extensively studied in both experimental and theoretical contexts. In this work, we present a complementary computational approach that combines density functional theory (DFT) and machine learning to further elucidate the role of steric and electronic effects in determining the reactivity and activation barriers. A diverse dataset of 1000 uncatalyzed hydrocarbon Diels-Alder reactions was used to train predictive models that relate activation energies to chemically meaningful molecular descriptors. SHAP analysis of the machine learning models highlights the dominant influence of steric effects, particularly those associated with substituent volume at the internal diene carbons, which can impose conformational strain and lead to significantly elevated barriers. In contrast, substituents at the terminal positions have a more limited impact. We introduced the minimum energy gap between LUMOdiene-HOMOdienophile and LUMOdienophile-HOMOdiene as a key predictive descriptor. This feature shows a strong correlation with the activation energy across the dataset, although steric interactions can lead to notable deviations from the overall trend. The resulting models provide insights for rationalizing selectivity and designing more efficient cycloadditions based on steric and electronic complementarity.
  • Synthesis and characterisation of bio-derived furan-based polyamides copolymers from dimethyl furan-2,5-dicarboxylate
    (2026) Paganelli, Zoe; Välinen, Lauri; Hanafi, Onsi; Hirvonen, Sami-Pekka; Baniasadi, Hossein; Niskanen, Jukka
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Polymers and plastics play integral roles in everyday life due to their versatility and durability. Among them, polyamides are particularly valued for their excellent properties and broad range of applications. The study explores the synthesis and characterisation of bio-derived polymers copolymers. Specifically, polyamides and copolyamides have been successfully synthesised from dimethyl furan-2,5-dicarboxylate and two diamines, hexamethylene diamine and 1,10-decanediamine, by employing a new three-step method. Key findings include the successful polymerisation of polyamides and copolyamides with a molecular weight up to 26 900 g mol−1 while demonstrating robust thermal stability, withstanding up to 403.7 °C. In addition, the mechanical properties, such as elastic modulus, of these amorphous polyamides and copolyamides were found to be comparable to commercial polyamides. Notably, the variation of molar ratios of diamines greatly influences the final properties of the polyamides and copolyamides, offering insight into customising mechanical, thermal, and physical qualities of the polymer. This research contributes significantly to the advancement of sustainable polymer solutions, positioning bio-derived polyamides as viable substitutes to mitigate reliance on fossil fuels while enhancing environmental sustainability.
  • Decoupling H-Release and OH– Management at Pd@TiO2 Interfaces for Efficient Alkaline Hydrogen Oxidation Reaction
    (2026-02-20) Jin, Benjin; Kallio, Antti Jussi; Rieger, Nils; Marchuk, Vasyl; Schiwek, Cedric; Shi, Junjie; Sainio, Jani; Jiang, Hua; Hammouali, Amine; Koivuniemi, Jefina A.S.; Han, Nana; Wickman, Björn; Huotari, Simo; Kallio, Tanja
    A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä
    Operando-level insight into catalyst degradation and reaction mechanisms is essential for progress in the alkaline hydrogen oxidation reaction (HOR). Herein, these aspects are investigated using a core–shell Pd@TiO2/C catalyst synthesized by thermal reduction followed by atomic layer deposition. The obtained catalyst exhibits high stability and delivers a mass exchange current density (j0,m) of 97.5 mA mgPd–1, more than three times that of uncoated Pd/C (27.5 mA mgPd–1). Identical location transmission electron microscopy reveals a growth–detachment degradation pathway for Pd/C during accelerated durability testing, whereas the TiO2 shell in Pd@TiO2/C effectively suppresses this degradation, resulting in enhanced structural stability. Operando X-ray absorption spectroscopy under device-relevant conditions demonstrates the complementary functions of the two components: hydrogen dissociates and forms PdHx on the Pd core, lowering its Fermi level and driving electron transfer from TiO2 to Pd, while the TiO2 shell facilitates hydrogen desorption and provides OH– adsorption sites, thereby accelerating the reaction kinetics. These findings elucidate the dual stabilizing and catalytic roles of TiO2 and suggest a promising strategy for the design of durable and efficient alkaline HOR catalysts.