Faraday Discussions最新文献

{"title":"Molecular weight dependent water uptake and dynamics in lignin-based epoxy anticorrosive coatings.","authors":"Azade Kafashan, Timon Binger, Markus Schackmann, Kim Dam-Johansen, Narayanan Rajagopalan","doi":"10.1039/d5fd00065c","DOIUrl":"https://doi.org/10.1039/d5fd00065c","url":null,"abstract":"<p><p>While the challenges of incorporating raw softwood kraft lignin (KL) as particulate pigments in epoxy coatings were addressed using mechanically sieved, size-fractionated lignin, and its corrosion resistance was evaluated, a key question remains: does solvent fractionation, which yields lower molecular weight lignin, offer improved barrier performance? This study explores the use of lignin as a functional particulate pigment in an amine-cured epoxy-based anticorrosive coating (EP), with a particular focus on how its molecular weight influences water uptake and transport behavior. Three pigmented epoxy systems with well-defined particle size distributions were investigated: a high molecular weight (<i>M</i>_w) kraft lignin incorporated <i>via</i> mechanical sieving (KL-sieved-EP, 5-30 μm), a low <i>M</i>_w lignin fraction obtained through ethyl acetate solvent fractionation (KL-EtOAc-EP, 5-10 μm), and a conventional acicular-shaped iron oxide pigment (FeOOH-EP, ∼0.3 × 0.5 μm). To evaluate the barrier performance of these coatings, water uptake behavior was systematically analyzed using gravimetric mass gain and electrochemical impedance spectroscopy (EIS), enabling assessment of both surface and bulk water transport pathways. The results show that KL-sieved-EP had the highest equilibrium water uptake, compared to KL-EtOAc-EP, which exhibited the lowest water uptake and diffusion coefficients, indicating superior compatibility with the epoxy matrix and a more cohesive barrier. These differences can be linked to the extent of supramolecular aggregation in the lignin: high molecular weight lignin tends to retain strong supramolecular associations, which limit its interaction with the epoxy. In contrast, solvent-fractionated low molecular weight lignin disrupts this aggregation, allowing for enhanced dispersion and integration within the epoxy network. The conventional FeOOH-EP coating showed a similar equilibrium water uptake to KL-EtOAc-EP based on gravimetric analysis but exhibited the highest diffusion coefficient among the three systems, indicating faster water transport. Although both had comparable total water uptake, EIS measurements revealed higher overall water absorption in FeOOH-EP. In contrast, KL-EtOAc-EP maintained extremely low water uptake in both gravimetric and EIS measurements. This contrast highlights a key finding: lignin-based systems, particularly KL-EtOAc-EP, showed no clear pigment-binder interface under SEM, which may contribute to their more uniform, defect-free morphology and improved barrier performance.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"X-ray and neutron diffraction patterns of the AlCrTiV high-entropy alloy and quaternary Heusler structures.","authors":"Nedjma Kalliney, Michael Widom","doi":"10.1039/d5fd00079c","DOIUrl":"10.1039/d5fd00079c","url":null,"abstract":"<p><p>The quaternary alloy AlCrTiV has been proposed as both a lightweight high-entropy alloy and also a functional spin filter material based on the Heusler structure. Experimental investigations to-date, based on X-ray diffraction, offer conflicting interpretations of the structure. Here we simulate diffraction patterns of the various proposed structures to show that neutron diffraction, in particular, can reveal the nature of long-range chemical order and discriminate among distributions of the refractory transition metals. Magnetic contributions to the neutron diffraction are also discussed.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224637","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reactivity of high-entropy alloy nanoparticles under O₂ studied by <i>in situ</i> transmission electron microscopy.","authors":"Syrine Krouna, Nathaly Ortiz Peña, Christian Ricolleau, Guillaume Wang, Adrien Moncomble, Damien Alloyeau, Jaysen Nelayah","doi":"10.1039/d5fd00090d","DOIUrl":"https://doi.org/10.1039/d5fd00090d","url":null,"abstract":"<p><p>The gas reactivity of high-entropy nanoalloys (HENAs) is an emerging area of research with significant potential for applications in catalysis, gas sensing, hydrogen storage, and corrosion resistance. Insights into the structure-reactivity relationships that dictate the behavior of HENAs in reactive gas environments are critical for optimizing their performance across these applications. However, understanding the complex structural attributes of HENAs, such as size, shape and structure in response to a gas stimulus, remains challenging because of the limited accessibility to methods capable of probing these attributes under <i>in situ</i> or <i>operando</i> conditions. Here, we performed aberration-corrected environmental gas scanning transmission electron microscopy (STEM) observations to investigate the atomic and chemical structures of quinary CoNiCuPtAu HENAs in response to pure oxygen exposure at atmospheric pressure and elevated temperatures. The nanoparticles were fabricated by pulsed laser deposition with a high degree of control over both size and composition. Atomic-scale STEM imaging combined with energy dispersive X-ray (EDX) spectroscopy at the single particle level revealed a complex structural and chemical evolution pathway for CoNiCuPtAu HENAs under oxygen at atmospheric pressure during progressive heating up to 700 °C. Notably, we have identified substantial mass transfers between nanoparticles accompanied by oxygen-induced demixing of components, nanovoid formation and the stabilization of platelet-like nanostructures crystallizing as a Co-Ni oxide solid solution.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145224663","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is solvent-based dissolution and precipitation an effective substrate pretreatment for the enzymatic depolymerisation of poly(ethylene terephthalate)?","authors":"Brooke Wain, Gustavo P Borin, Elaine M Rudge, Benjamin Moore, Bruce R Lichtenstein, Andrew R Pickford, Victoria L Bemmer","doi":"10.1039/d5fd00061k","DOIUrl":"10.1039/d5fd00061k","url":null,"abstract":"<p><p>Plastics are ubiquitous in modern society; however, their disposal at end-of-life remains challenging. Enzymatic recycling offers a potential low-energy solution to recycling poly(ethylene terephthalate) (PET); however, high-crystallinity substrates such as polyester textiles are recalcitrant to enzymatic hydrolysis. Current amorphisation pretreatments yield substrates amenable to enzymatic digestion; however, they account for a significant percentage of all process electricity requirements. Here we investigate dissolution-reprecipitation with the green solvents gamma-valerolactone and 2-isopropylphenol as a lower-energy pretreatment regime. We find that whilst there is only a minimal decrease in substrate crystallinity, activity of the benchmark PET hydrolase LCC^ICCG is increased on all solvent-treated substrates. We show that GVL negatively impacts the thermostability of LCC^ICCG, and both solvents dramatically decrease enzyme activity, from concentrations as low as 4%, highlighting the need for effective solvent removal following pretreatment. Finally, we show that IPP and GVL are effective for the removal of synthetic dyes from polyester textiles, enabling new applications for these solvents in PET recycling.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12486811/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145197553","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"From dark to light: light-coloured lignin for cultural heritage conservation.","authors":"Felipe F Meneses, Camilla H M Camargos, Camila A Rezende","doi":"10.1039/d5fd00072f","DOIUrl":"https://doi.org/10.1039/d5fd00072f","url":null,"abstract":"<p><p>Lignin is a natural macromolecule with remarkable properties, such as UV-shielding and antioxidant capacity; however, its application is often limited by its intense, dark colour. In this paper, oxidation methods using hydrogen peroxide and peroxy-citric acid were employed to produce light-coloured lignins with tailored functional properties. The transition from the macroscale to the nanoscale enhanced both the UV-protective and antioxidant performance of bulk lignin, while further attenuating the visible coloration of the nanoparticle aqueous dispersions. Oxidized and unmodified lignin nanoparticles were incorporated into nanocellulosic films to develop protective coatings intended for the preservation of cellulosic cultural heritage artifacts, while safeguarding their aesthetic integrity. Nanoparticles derived from oxidized lignins imparted UV protection and antioxidant capacity to the films without significantly affecting their colorimetric properties. Therefore, the oxidized lignins presented herein offer a novel and environmentally friendly approach to lignin valorisation in colour-sensitive applications, including sophisticated uses such as the conservation of cultural heritage.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190436","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Efficient room-temperature synthesis of crosslinked polyhydroxyurethanes from 5-membered cyclic carbonates without solvent or catalyst.","authors":"P Helbling, C Desgoulières, F Hermant, M Petit, T Vidil, H Cramail","doi":"10.1039/d5fd00057b","DOIUrl":"https://doi.org/10.1039/d5fd00057b","url":null,"abstract":"<p><p>We report the first solvent- and catalyst-free synthesis of crosslinked polyhydroxyurethanes (PHUs) at room temperature from five-membered cyclic carbonates (5CC). A trifunctional carbonate (tri-5CC) combined with tetraethyleneglycol diamine (tDA) formed homogeneous, gelled networks within 24 h (carbonate conversion = 90%, gel time = 6 h). By blending tri-5CC with a tetrafunctional analogue (tetra-5CC), we achieved tunable gel times (1-6 h) and crosslink densities. All systems completed crosslinking under ambient conditions within one month and displayed robust thermal and mechanical properties. Ambient moisture enhanced network formation, confirming the practical relevance of these systems. This study repositions carbonate-amine chemistry as a promising route for the room-temperature synthesis of isocyanate-free thermosetting polyurethanes.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145190397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Telechelic all-<i>cis</i> polycyclooctene <i>via</i> catalytic stereoretentive ROMP for the synthesis of polylactide-based ABA triblock copolymers.","authors":"Jake L Nicholson, Antoine C Gravet, Quentin Michaudel","doi":"10.1039/d5fd00067j","DOIUrl":"https://doi.org/10.1039/d5fd00067j","url":null,"abstract":"<p><p>Polylactide (PLA) is a commercial and sustainably sourced aliphatic polyester but its applications have been limited by its low toughness. The insertion of a rubbery segment within the PLA backbone is among the promising strategies to enhance the mechanical properties of PLA while retaining sustainability. Herein, we disclose a catalytic stereoretentive ring-opening metathesis polymerization process to access high molar mass (<i>M</i>expn up to 127.9 kg mol^-1) all-<i>cis</i> telechelic polycyclooctene (PCOE) at low catalyst loadings. The use of <i>cis</i>-1,4-diacetoxy-2-butene as a chain-transfer agent in the presence of stereoretentive dithiolate Ru carbenes afforded precise control over the <i>cis</i> content, the molar mass, and the introduction of acetoxy chain ends. Subsequent hydrolysis of the acetoxy motifs followed by chain extension <i>via</i> ring-opening polymerization of D,L-lactide yielded high molar mass (<i>M</i>expn up to 105.0 kg mol^-1) all-<i>cis</i> PLA ABA triblock copolymers. The influence of the molar mass of the all-<i>cis</i> PCOE over the thermal and mechanical properties of the ABA triblock was investigated.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145147252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bond dissociation energies of lignin-carbohydrate complexes.","authors":"Thomas Elder, Martin Lawoko","doi":"10.1039/d5fd00045a","DOIUrl":"https://doi.org/10.1039/d5fd00045a","url":null,"abstract":"<p><p>Lignin-carbohydrate complexes, in which lignin and polysaccharides are directly connected, have been identified and extensively analyzed. To date, however, the origin of these structures has not been unequivocally established. That notwithstanding, it has been found that delignification, whether by conventional pulping and bleaching processes or in the biorefinery context, is effected by the presence of lignin-carbohydrate complexes. Using density functional theory calculations, the current work has evaluated the thermodynamics of bond dissociation as a function of structure and chemical composition. Among the lignin-carbohydrate complexes that have been identified, the homolytic bond dissociation energy is highest for the α-benzyl ethers and γ-ester, with phenyl glycosides being markedly less endothermic. This is consistent with observations on the recalcitrance of these compounds. Heterolytic cleavage reactions of the α-benzyl ethers are less endothermic, due to water solvation of the ions. The latter observation may provide support for the proposed homolytic cleavage reaction, since if heterolysis were operative, the α-benzyl ethers would not exhibit the level of recalcitrance that is observed experimentally.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135952","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved 2PP additive manufacturing build/process quality <i>via</i> the use of hyperbranched pre-polymer.","authors":"Andrea A Konta, Michelle Duong, Joseph Sefton, Valentina Cuzzucoli Crucitti, Amy Stimpson, Sophie Goodwin, Thomas Swift, Gustavo F Trindade, Yinfeng He, Mohamed Adam, Eleanor Binner, Laura Ruiz Cantu, Cameron Alexander, Ricky D Wildman, Derek J Irvine","doi":"10.1039/d5fd00097a","DOIUrl":"https://doi.org/10.1039/d5fd00097a","url":null,"abstract":"<p><p>This study reports the first systematic study investigating the potential of using hyperbranched (HB) polymers as novel materials for improving two photon polymerisation (2PP) processing. It demonstrated that HB polymer containing additive manufacturing resins can be successfully formulated and used to print: (a) mono-/multi-material structures, the latter containing monomers of different functionality (<i>i.e.</i>, hydrophilic/hydrophobic mixes), (b) with a broader range of printing conditions, (c) to high levels of cure and (d) at faster processing speeds than monomeric resins. A printed multi-material structure was confirmed to contain both feed materials and exhibit high cure by ToF-SIMS and Raman analysis, respectively. Thus, HB polymers were shown to improve mixing in multi-functional resins and overcome 2PP chemistry restrictions. When processing with selected HB polymers, both the polymerisation \"onset\" and \"burning\" thresholds were improved compared to monomeric resins. Processing more reactive HB polymers still increased the overall processing window compared to the 2PP processing of the equivalent monomer, but the \"burning\" threshold was in fact lowered, which was linked to depolymerisation events. Thus, a HB polymer was subject to degradation studies and shown to produced more residual material (<i>i.e.</i> \"char\") than linear materials, which delivers the decolourisation in 2PP \"burning\". This study confirms that using HB polymers can extend the viability and utility of 2PP processing, improvements that were delivered by understanding the reactivity of these pre-polymers toward both polymerisation and depolymerisation.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135943","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mass-resolved UV-Vis-GPC mapping diagnoses catalyst ageing in RCF lignin streams.","authors":"Siyuan Gao, Raul Rinken, Robert T Woodward, Jie Bao, Roberto Rinaldi","doi":"10.1039/d5fd00109a","DOIUrl":"10.1039/d5fd00109a","url":null,"abstract":"<p><p>Catalyst stability is central to the viability of lignin-first biorefineries, yet conventional characterisation often fails to detect the subtle deactivation processes that govern product quality. Here, we demonstrate that ultraviolet-visible (UV-Vis) spectroscopy, when combined with gel permeation chromatography (GPC), can serve as a sensitive diagnostic tool for detecting catalyst performance decline in Reductive Catalytic Fractionation (RCF). We introduce a concentration-independent spectral index (SI₃₂₀), derived from the absorbance ratio at 280 and 320 nm, given by SI₃₂₀ = 1 - <i>A</i>₃₂₀/<i>A</i>₂₈₀. Native-like lignins show negligible absorbance at 320 nm (SI₃₂₀ ≈ 1), whereas condensation, benzylic oxidation, and extended π-conjugation depress SI₃₂₀. As a ratio, SI₃₂₀ is concentration-independent within the Beer-Lambert regime and can be profiled across the chromatogram to yield SI₃₂₀(<i>M</i>) profiles, with <i>M</i> denoting apparent molar mass. SI₃₂₀(<i>M</i>) profiles report directly on the formation of chromophores associated with catalyst ageing across the lignin apparent-<i>M</i> distribution. Utilising post-consumer cardboard as a substrate, we tracked RCF over RANEY^® Ni across multiple recycling runs. A comparative analysis of fresh and recycled catalysts revealed systematic SI₃₂₀ downshifts in oligomer fractions, indicating chromophore accumulation well before changes in bulk yield of low <i>M</i> products become evident. Linear regression of SI₃₂₀(<i>M</i>) mean values (<i>r</i>² = 0.95) enables a practical estimate of catalyst life. Under our conditions, it is estimated that RANEY^® Ni can sustain lignin stabilisation for up to 15 runs of catalyst use (<i>ca.</i> 45 h operation), after which the chromophore density approaches that of organosolv lignin. Our findings reframe UV-Vis spectroscopy from a simple detection method for GPC analysis into a diagnostic platform of lignin-first catalysis. By funnelling apparent-<i>M</i>-resolved spectra into a simple index, GPC-UV-Vis enables rapid, non-destructive monitoring of catalyst performance, supports optimisation of RCF conditions and recycling protocols, and highlights the stabilising action of hydrogen-transfer catalysis. In the broader context, the approach is general to diverse feedstocks, catalysts, and lignin-first modalities, offering a practical route to correlate catalyst ageing with product quality and to guide development of durable, robust catalysts for circular economy and lignin valorisation.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12462285/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145135933","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}