Faraday Discussions最新文献

{"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":"https://doi.org/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":"","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":"","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}

{"title":"Determining the biodegradation of functionalised cellulose esters.","authors":"Katrina Entwistle, Sandhya Moise, Fatma Guler, Katherine A Smart, Matthew Crow, Christopher J Chuck","doi":"10.1039/d5fd00040h","DOIUrl":"https://doi.org/10.1039/d5fd00040h","url":null,"abstract":"<p><p>Recently, there has been an increased interest in developing functionalised carbohydrates, such as cellulose palmitate, as novel replacements for petroplastics. The functionalisation gives the materials excellent water barrier properties, as well as processability and mechanical properties akin to PET, while potentially having superior biodegradability to conventional first-generation biopolymers. However, the true biodegradability of these novel polymers is still unknown with some recent reports suggesting that it is limited. In this study, we investigated the potential of cellulose palmitate to biodegrade under controlled laboratory conditions, comparing the polymer to cellulose acetate. To this end, studies using specific enzymes, targeted whole cell fungal degradation and model edibility experiments were devised to study the biodegradability at end-of-life. On an enzymatic level, a combination of cellulase and lipase enzymes were found to hydrolyse the fatty acid linkages, allowing the cellulases to access the carbohydrate chain and release glucose. Under optimal conditions the biopolymer was completely hydrolysed within 6 hours. A soil fungi was then isolated from a compost heap that had been loaded with the functional material, to establish the most suitable species for whole cell degradation. This common soil fungi, <i>Mucor</i> sp., was then grown successfully under lab conditions on the functional material as a 95% carbon source. Finally, an edibility experiment was designed, using pepsin and pancreatic enzymes at precise pH concentrations found in the gastrointestinal tract to mimic real life conditions of ingestion by birds. While cellulose acetate broke down under just the acidic conditions, with no enzymes, the cellulose palmitate was found to be stable at the acidic conditions, but hydrolyse over 7 days when the enzymes were present. To the best of our knowledge this is the first study to confirm the biodegradability of functionalised cellulose highlighting the large promise of functionalised carbohydrates as a sustainable alternative to petrochemical plastics within the packaging industry.</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":"145135950","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":"An empirical assessment of the physicochemical properties of lignin solutions in aqueous sodium hydroxide - corroboration and demystification of some widely accepted statements.","authors":"Antonio L Alves, Veronica Calado","doi":"10.1039/d5fd00071h","DOIUrl":"https://doi.org/10.1039/d5fd00071h","url":null,"abstract":"<p><p>Lignin is one of the main byproducts of the pulp, paper, and cellulosic ethanol industries. For the past 35 years, it has received increased interest in applications other than its use as an energy source. Although much of this research requires the use of lignin solubilized in solvents such as alkalis, little is known about the impact of the main process conditions - initial lignin mass, alkali concentration, and temperature and time of dissolution - on key solution properties - density, mass fraction of lignin, and pH. A central composite design, with these process conditions as input variables and these key solution properties as output variables, was made by varying the temperature from 30 to 80 °C, the time from 1 to 3 h, the concentration from 0.1 to 0.5 M, and, instead of directly working with lignin mass, a ratio of added lignin to alkali concentration of 30 to 60 g L mol^-1. The hypothesis made by Sarkanen <i>et al.</i> (<i>Macromolecules</i>, 1984, <b>17</b>(12), 2588-2597) that lignin may aggregate under strong alkaline media and Lindströmn's (<i>Colloid Polym. Sci.</i>, 1979, <b>257</b>, 277-285) hypothesis that there are thermally induced processes that also cause aggregation - and further agglomeration - were attested and updated to indicate a joint action of both factors. Surprisingly, mass fraction displayed a maximum value using fixed ratio conditions instead of a saturation point. That shows lignin solubilization depends on more factors than simply the ratio of hydroxide anions <i>vs.</i> phenolic-OH groups and the pH. pH evolution was governed by slow aggregation and agglomeration reactions and conformational changes sensitive to time and temperature. The resulting polynomial models achieved adjusted <i>R</i>² > 0.996 for all responses, and ten validation experiments exhibited maximum relative errors ≤1.6%. These results furnish quantitative guidelines for tailoring lignin solution properties and suggest further studies into rheology, extended factor ranges, alternative lignin sources, and developing theoretical - and possibly more universal - models to predict lignin solution properties.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129609","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":"In-depth analysis of kraft lignin epoxy thermosets.","authors":"Saeid Nikafshar, Kevin Dunne, Sajad Nikafshar, Mojgan Nejad","doi":"10.1039/d5fd00047e","DOIUrl":"https://doi.org/10.1039/d5fd00047e","url":null,"abstract":"<p><p>In this study, epoxidized lignins were prepared by reacting softwood (SW) and hardwood (HW) technical (kraft) lignins with a biobased epichlorohydrin. The chemical structures, rheological behaviors, and thermomechanical properties of the epoxidized lignins were measured and compared with those of petroleum-based (DGEBA) epoxy resin. First, the chemical and physical properties of the lignin samples were assessed using Fourier-transform infrared spectroscopy (FTIR), gel permeation chromatography (GPC), quantitative phosphorus nuclear magnetic resonance spectroscopy (³¹P NMR), and 2D-heteronuclear single quantum coherence (HSQC) NMR analyses. Subsequently, the unmodified lignins were epoxidized over a short period (3 hours), using ethyl lactate as a biobased co-solvent. The ³¹P NMR and HSQC analysis of the epoxidized lignins confirmed that phenolic hydroxyl and carboxylic acid groups in lignin were selectively epoxidized without any other significant changes to the chemical structure of lignin. Rheological multi-wave curing studies of both lignin-based and bisphenol A-based (DGEBA) resins cured with a biobased curing agent revealed that the lignin-based systems exhibited significantly shorter gelation times and lower activation energies. Further analyses, including gel fraction, swelling ratio, thermal gravimetric analysis (TGA), and dynamic mechanical analysis (DMA) results, demonstrated that lignin-based thermosets had comparable properties to the petroleum-based epoxy system when both were prepared with solvent (40 wt%) inclusion. Notably, the thermoset resin made with kraft hardwood lignin exhibited superior thermomechanical properties compared to the softwood system.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2025-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145129567","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}