Luminescent solar concentrators (LSCs) are attractive for building-integrated photovoltaics but require host matrices combining high transparency, stability, and sustainability. Here, half bio-based, isocyanate-free polyhydroxyurethanes (PHUs) are introduced as covalently functional host materials for transparent LSCs. Two aromatic fluorescent aldehydes based on fluorene and 8-hydroxycoumarin were synthesized and grafted onto a tailor-made PHU backbone via a facile post-synthetic modification strategy, yielding PHU1-Flu and PHU1-Coum with high degrees of functionalization (up to 80%). The resulting polymers were directly processed into thin-film LSCs by spin coating, acting simultaneously as host matrix and photoactive component. The devices exhibited excellent optical transparency and colour neutrality, with an average visible transmittance of similar to 90%, comparable to clear glass. Among the two systems, PHU1-Flu showed superior performance, achieving external and internal photon efficiencies of 2.19% and 37.27%, respectively, a device efficiency of 0.34%, and a light utilization efficiency of 0.30%. By covalently immobilizing the luminophores, PHU-based LSCs inherently suppress dye migration and phase separation, addressing key stability limitations of conventional systems. These results demonstrate that bio-based PHUs represent not only sustainable but also functionally superior host matrices for durable and transparent LSCs.

Despite the progress achieved in ionic-based sensors, the growing demand for soft and flexible devices has highlighted several key requirements for the next generation of materials: (1) complete elimination of liquid phases that may evaporate or leak; (2) sufficient mechanical robustness for stable operation over repeated loading cycles; (3) facile device assembly; (4) high voltage output and sensitivity; and (5) a broad operational pressure range. To address these challenges, two complementary ionic liquid-like monomers (ILMs) were designed and synthesized: a cationic (M-BIM) and an anionic (M-TFSI) monomer, each incorporating a butylimidazolium (BIM+) or bis(trifluoromethylsulfonyl)imide (TFSI-) fragment covalently bonded to a methacrylate group together with their complementary counterions (respectively, TFSI- or BMIM+). Their copolymerization with poly(ethylene glycol) monomethacrylate (PEGM) and dimethacrylate (PEGDM) and optimization of the composition afforded flexible, self-standing, highly ion-conductive films combining good mechanical properties (E' = 0.4-1.0 MPa) with high ionic conductivities (up to 2.3 × 10-6 S cm-1 at 25 °C). Systematic optimization of film thickness, interfacial electrode layer (IEL) geometry, and IEL metal type revealed that sputtered gold IELs effectively suppressed signal drift and shortened response times, while platinum IELs markedly enhanced voltage generation. Comparison among sensors with mobile anions, mobile cations, and mixed carriers demonstrated that the charge-carrier type critically governs both sensitivity and voltage amplitude. The optimized sensor, based on the anionic M-TFSI formulation, featuring a 0.35 mm-thick film and rectangular Pt IEL exhibited a linear potential-pressure dependence across the entire range (0-80 kPa), an ultrafast recovery time of 0.2 s, and an exceptional output voltage of 190 mV, maintaining stable operation over 1000 loading cycles.

Conventional methods for synthesizing thermoplastic polyurethanes (TPUs) typically rely on isocyanates and tin-based catalysts, both of which pose significant environmental and safety risks. To mitigate these issues, alternative routes for synthesizing nonisocyanate polyurethanes (NIPUs) have been explored since the 1980s. However, most reported approaches yield polymers with molecular weights below 35 kg/mol and only a few exceptions reaching 50-70 kg/mol, often requiring oligomeric monomers or postmodification. This limitation has been a major barrier to the broader application and production of NIPUs. In this study, we demonstrate a direct polyaddition strategy for synthesizing high-molecular-weight poly-(hydroxyurethane)-s (PHUs, a subclass of NIPUs) from low-mass difunctional monomers without relying on macromonomers, oligomers, catalysts, or postcondensation/modification steps. The key to this achievement was the rational design of the monomers. The reactivity of cyclic carbonates was enhanced by incorporating aromatic rings into the structure of 7,7,7',7'-tetramethyl-6,6',7,7'-tetrahydro-5,5'-spirobi-[indeno-[5,6-d]-[1,3]-dioxole]-2,2'-dione. Model reactions of this bis-(cyclic carbonate) with secondary amines revealed that steric and electronic effects are decisive with alicyclic secondary amines markedly outperforming their linear analogues. Further pairing of activated aromatic bis-(cyclic carbonate) with alicyclic secondary diamines enabled nearly quantitative monomer conversion under mild, catalyst-free conditions (at 50 °C), yielding linear PHUs with a record-high degree of polymerization (DPn) of up to 220 and a number-average molecular weight (M n) of 105 kg/mol. This strategy was further extended to another aromatic cyclic carbonate, 5,5'-(9H-fluorene-9,9-diyl)-bis-(benzo-[d]-[1,3]-dioxol-2-one), producing PHUs with M n values of up to 100 kg/mol.

Lignin, a renewable biopolymer, presents significant potential for sustainable materials development, particularly in the synthesis of porous adsorbents for water treatment. This study introduces a tailored approach for synthesizing lignin-based xerogels (LBX) via a sol-gel process combined with polymerization-induced phase separation (PIPS), enabling a controlled pore morphology and hierarchy. Data on lignin structure and molecular weight are used to effectively predict the outcome of the sol-gel process prior to the incorporation of polyethylene glycol (PEG) as an additive polymer. By systematically varying the molecular weight and concentration of PEG, the influence of these factors on phase separation dynamics, drying behavior, and the structure of the resulting porous bodies is revealed. The synthesized xerogels exhibited tunable pore structures, with average pore sizes ranging from 10 to 90 μm, porosities between 19 and 73 vol %, specific surface areas (SSAs) from 0.7 to 13.2 m2/g, and permeability values spanning 1.3 to 5.6 darcys. This study highlights a tunable strategy for lignin valorization, offering insights into the development of biobased porous materials with potential relevance to heavy metal adsorption.

Dynamic ion gels (DIGs) obtained via complex coacervation of oppositely charged poly-(ionic liquid)-s (PILs) address the inherent trade-off between ionic conductivity (σDC) and mechanical strength (G') of PILs by providing both enhanced ion transport and robust viscoelastic properties. In order to tune the strength of ionic cross-links through charge delocalization of ion pairs, we study a series of four DIGs obtained from the combination of a cationic PIL (PIL + ) containing pendant imidazolium groups and free bis-(trifluoromethylsulfonyl)-imide (TFSI) counteranions with four anionic PILs (PIL - ) bearing pendant sulfonate anions and various free counter cations (i.e., 1-methyl-3-butylimidazolium, trimethylpropylammonium, tetrabutylammonium, and tetrabutylphosphonium). These new DIGs are produced via the formation of ionic cross-links with ion pairs having more localized charges (i.e., cations paired with sulfonate instead of TFSI). This results in stronger electrostatic interactions with counterions, reducing their mobility and significantly increasing the enthalpic driving force for ion exchange-induced coacervation. As a consequence, the four resulting DIGs release different free ionic liquids (ILs) consisting of TFSI anions associated with imidazolium, ammonium or phosphonium cations. The physical, ion-conducting, and viscoelastic properties of the resulting DIGs are systematically investigated by differential scanning calorimetry, broadband dielectric spectroscopy and rheology. The DIG having sulfonate-imidazolium ionic cross-links and releasing EMIM-TFSI ILs exhibits the best compromise between G' = 62 kPa (at 25 °C, 1 rad s-1) and σDC = 6.5 × 10-6 S cm-1 (at 25 °C), significantly outperforming the parent PILs. These results highlight DIGs as a highly promising class of materials with enhanced processability and mechanical integrity, making them ideal candidates for electrochemical applications such as supercapacitors, soft robotics, electrochromic devices, sensors, and solar cells.

We demonstrate the first application of dynamic ion gels (DIGs) from the coacervation of two oppositely charged poly(ionic-liquid)s in the fabrication of quasi-solid-state supercapacitor devices, able to operate at high temperature without liquid leakage. The formation of the DIG enables the spontaneous in situ release of free ionic liquid (IL) avoiding the need to boost the ionic conductivity by the addition of exogeneous IL. Remarkably, the DIG maintains its solid-like behavior at elevated temperatures, enabling safe operation across a wide temperature range (25-80 degrees C) without leakage. Used as quasi-solid-state electrolyte, binder, separator and ionic-conducting filler for the rGO-based electrodes, various parameters are optimized, including the use of single cationic/ anionic poly(ionic-liquid), their association modes and DIG content. Combined with rGO-MWCNTs, DIG made from poly(1-butyl-3-[oxiran-2-ylmethyl]-1-imidazole-3-ium-s-ethylene oxide) bis (trifluoromethyl sulfonyl) imide and poly[(1-butyl-3-methylimidazolium 1-[3-(methacryl oyloxy)propylsulfonyl]-1-(trifluoromethane sulfonyl)imide)-r-(poly(ethyleneglycol) methyl ether methacrylate) yields optimal electrochemical performance of 27.2 F g- 1 at 1 mV s- 1 (at 25 degrees C) with device's excellent stability, maintaining 80% of capacitance after 4700 cycles and 60.1 F g- 1 (at 80 degrees C) in open air conditions. Accordingly, the maximum energy/power densities of 17 Wh kg-1/137 W kg- 1 at 25 degrees C and 31.4 Wh kg- 1/366 W kg- 1 at 80 degrees C are obtained.

While polyhydroxyurethanes (PHUs) have been offered as "greener" alternatives to conventional polyurethanes (PUs) for ∼15 years, their low molecular weights, high hydrophilicity, and water uptake limit practical utility. In this study, we directly address these limitations by coupling pendant hydroxyl groups in tailored thermoplastic PHUs with 1,4-phenylenediboronic acid to form tough, robust PHU vitrimers, whose enhanced viscoelastic properties and reduced moisture sensitivity significantly differentiate them from existing linear and vitrimeric PHUs. Three families of PHU vitrimers incorporate either dioxaborolane or dioxazaborocane moieties based on aromatic or aliphatic amines. A fundamental comparison of structure-property relationships confirmed that dioxazaborocanes stabilized by aliphatic nitrogen atoms improve thermal and hydrolytic stability, as demonstrated through direct observations via solid-state NMR. In contrast to aromatic nitrogens, aliphatic nitrogens form N→B dative bonds, reducing chain mobility and increasing T g. This significantly enhances mechanical performance (+65-170% tensile strength, +125-300% break strain, ∼4-11× increase in tensile toughness) vs the parent PHUs and allows the resulting vitrimers to maintain their viscoelastic properties even at elevated humidity levels. Moreover, these N-stabilized dioxazaborocane PHU vitrimers are readily recyclable, both mechanically (up to at least 3×) and chemically (using ethanol/NaOHaq), without loss of performance.

Single-ion conducting polyelectrolytes transport only lithium ions, thereby increasing the lithium transference number and reducing concentration polarization in batteries. While this improves the electrochemical performance and safety, it remains challenging to balance ionic conductivity and mechanical strength (viscoelastic properties). A promising solution can be ionic block copolymers (BCPs), in which one charged block enables ion conduction while the neutral block with a high glass transition temperature provides mechanical reinforcement. Ionic conductivity in these BCPs is strongly dependent on their microphase-separated morphology. Although bicontinuous structures were believed to offer optimal ion conduction, synthesizing such morphologies is difficult, because they form in a narrow phase-space window requiring precise control of block volume fractions, molecular weights, and interaction parameters. To address this, we combined theoretical and experimental approaches to study a series of poly[(LiM n -r-PEGM m )-b-PhEtM k ] block copolymers, where the ion-conducting block comprises lithium 1-[3-(methacryloyloxy)propylsulfonyl]-1-(trifluoromethanesulfonyl)imide (LiM) and poly(ethylene glycol)methyl ether methacrylate (PEGM), and the neutral block is poly(2-phenylethyl methacrylate) (PhEtM k ). The length of the LiM n -r-PEGM m block was fixed at n = 20 and m = 80, while k was varied from 70 to 140. Dissipative particle dynamics simulations, coupled with a 3D scattering-diagram analysis, revealed stability regions for hexagonally packed cylinders, lamellae, and bicontinuous phases, predicting that bicontinuous phases emerge at k = 110 divided by 120. To validate this, a series of poly[(LiM n -r-PEGM m )-b-PhEtM k ] block copolymers with k ranging from 79 to 174 was synthesized. In keeping with predictions, morphologies consistent with the existence of a (disordered) bicontinuous structure were observed via AFM at k = 96 and 110. At the same time, while the storage modulus (G ') increased with rising k, the ionic conductivity decreased monotonically. The polymers with (disordered) bicontinuous structures demonstrated an optimal balance of viscoelastic properties and ionic conductivity, highlighting their potential, despite the absence of a significant conductivity enhancement in this series of BCPs.

Fibre-reinforced vitrimers are an emerging class of recyclable composites, but the influence of fibre type and stacking sequence on performance remains underexplored. This study examines benzoxazine vitrimer composites with flax and/or carbon fibres, focusing on flexural strength, interlaminar shear strength (ILSS), and healing efficiency (property recovery after damage and reprocessing). Composites were fabricated using vacuum-assisted compression resin transfer moulding, with morphology analysed via X-ray microtomography. Among hybrid configurations, sandwich structures with carbon fibre skins showed higher flexural strength (up to 580 +/- 50 MPa) compared to those with carbon fibre cores (180 +/- 6 MPa). Increasing flax content reduced both flexural strength (from 580 +/- 50 MPa to 500 +/- 7 MPa) and ILSS (from 27.5 +/- 0.7 MPa to 18.4 +/- 1.5 MPa) for similar sandwich structures. Alternating structures exhibited intermediate performance, lower than composites with carbon fibre skins but higher than composites with flax fibre skins. Significantly higher flexural strength and modulus recovery was observed in composites with flax fibre skins (>87 %) vs. carbon fibre skins (<45 %), while ILSS recovery ranged from 78 % to 90 % regardless of structure. These findings highlight the role of stacking sequence and fibre selection in optimising the damage-repair performance of vitrimer composites.

Nanofibrillated cellulose (NFC) has diverse applications, but economical large-scale production with minimized ecological footprint remains challenging. A Masuko Supermasscolloider was modified for continuous processing using a pump-controlled circulating system, an in-line viscosimeter, and power consumption meters. Utilizing the upgraded system, we investigated NFC production from Miscanthus biomass under various conditions: different initial cellulose concentrations (1, 1.5, and 2 wt%), process volumes (15 and 25 L) and different grinding times (15–120 min, 15 min intervals). Particle size analysis showed equivalent hydrodynamic diameters of 200–300 nm regardless of processing conditions. Notably, our approach demonstrated 70 % reduction in specific energy consumption by simultaneously increasing process volume from 15 L to 25 L and initial cellulose concentration from 1 wt% to 2 wt%. Additionally, NFC produced at different grinding times was used to prepare carboxymethyl cellulose nanocomposites. Tensile testing demonstrated the same level of mechanical reinforcement regardless of NFC grinding time, highlighting a clear opportunity to reduce the footprint of NFC production while maintaining performance.

The additive manufacturing of a bio-based, UV active, recyclable and reshapable polybenzoxazine is demonstrated.

Nonisocyanate polyurethanes (NIPUs) are broadly investigated as a potential replacement for conventional polyurethanes (PUs) to eliminate the use of toxic isocyanates and reduce occupational hazards. One of the most popular approaches to NIPU synthesis is the polyaddition of cyclic bis(carbonate)s and diamines to form poly(hydroxyurethane)s (PHUs). However, such PHUs are highly hydrophilic due to the presence of two hydroxyl groups per repeat unit, and the resulting moisture absorption significantly degrades their thermomechanical performance and physical stability upon exposure to humidity, thus limiting their utility. Here, we introduce a simple and scalable approach for the modification of PHUs to increase hydrophobicity and adjust their properties. The proposed reaction between aldehydes and appropriately spaced hydroxyl groups in the polymer backbone resulted in high degrees of modification (up to 84%) and up to 3-fold reductions in water uptake at 85% RH. Furthermore, the use of aromatic aldehydes in particular enabled the retention of mechanical properties over a wide range of humidity levels, resulting in performance comparable to conventional PUs. Finally, we note that this approach is not limited to reducing moisture sensitivity alone and provides ample opportunities for imparting a broad range of novel properties to PHUs through an appropriate selection of functional aldehydes.

The increasing amount of electronic waste, predicted to reach 60 million tons by 2029, is one of the big health concerns for our society. This issue, together with plastic waste, represents the main environmental concern when dealing with large-area electronic devices and systems. The solution for this growing problem is to realize sustainable and green electronics, using new classes of recyclable and eco-friendly electronic materials and substrates. Innovative polymers, such as vitrimers, are promising candidates, thanks to their recyclability and biodegradability. In this work, vitrimers were synthesized and implemented for the first time as green substrate for transient thin-film temperature sensors using vacuum deposition. Here, Silver- and Zinc-based resistance temperature detectors (RTDs), as well as semiconductive thermistor exhibiting sensitivities of 0.21%degrees C-1, 0.18%degrees C-1 and -0.22%degrees C-1, are reported. All temperature sensors exhibit good linearity and stability over 10 heatingcooling cycles between 25 degrees C and 70 degrees C. Finally, to demonstrate the chemical degradability of a Zn RTD, the sensor was dissolved in water, which leads to a loss of functionality after 30 min and its complete dissolution after 1 h. Overall, the combination of recyclable vitrimers and green dissolvable electronics represents an innovative route towards a fully sustainable technological platform.

A cationic poly(ionic liquid) (PIL) with pendent butyl imidazolium cations and free bis(trifluoromethylsulfonyl)imide (TFSI) anions and an anionic PIL with pendent TFSI anions and free 1-butyl-3-methylimidazolium cations are synthesized by postpolymerization chemical modification and reversible addition-fragmentation chain-transfer radical copolymerization, respectively. Upon mixing solutions of these two PILs in acetone with stoichiometric amounts of ion pairs, ionic exchanges induce coacervation and, after solvent evaporation, lead to the formation of a dynamic ion gel (DIG) and the concomitant release of free [1-methyl-3-butyl imidazolium]TFSI ionic liquid (IL). A comparison of thermal (T g), ion conducting (sigma DC), and viscoelastic (elastic moduli (G ')) properties for DIGs and their parent polyelectrolytes, as well as extracted and IL-doped DIGs, demonstrates the formation of ionic cross-links and the ability to easily produce polymer electrolytes with enhanced ionic conductivity (sigma DC up to 4.5 x 10(-5) S cm(-1) at 30 degrees C) and higher elastic moduli (G ' up to 4 kPa at 25 degrees C and 1 rad s(-1)), making them highly desirable in many electrochemical applications, including supercapacitors, soft robotics, electrochromic devices, sensors, and solar cells.

Polyurethanes (PUs) are common commodity plastics that cover a wide range of applications. However, PUs are based on isocyanates, the toxic compounds that pose respiratory and dermal hazards. As a more sustainable alternative, polyhydroxyurethanes (PHUs) have gained attention as PU substitutes. Nevertheless, their utility is often limited by low molecular weights and inferior properties. To overcome these shortcomings, the present study focuses on the application of reactive extrusion (REx) to the synthesis of thermoplastic PHUs, allowing rapid production without compromising molecular weight. First, a series of cyclic carbonate monomers were synthesized; in particular, a BPA-based bis(cyclic carbonate) was prepared from the commercial bis(epoxide), while two additional bis(cyclic carbonates) were prepared from the relevant bisphenols via sequential epoxidation and carbonation with CO2. Spectroscopic analyses confirm the successful synthesis of high-purity monomers. Second, PHUs were prepared via REx of the synthesized bis(cyclic carbonates) with various diamines following optimization of the process using a model system with the aim of maximizing the molecular weight and yield. The resulting series of linear PHUs possessed molecular weights of up to 21800 g/mol (as assessed via GPC), high strengths (up to 60 MPa as determined by quasi-static tensile testing), and attractive thermal properties (T g up to 110 degree celsius via DSC; T onset > 195 degree celsius via TGA). The viscoelastic and rheological behavior of selected PHUs is also reported. Finally, PHUs with comparable properties to traditional PUs were foamed, and the resulting foams were shown to possess densities and compressive and thermal properties comparable to conventional rigid PU foams.

High ionic conductivity poly(ionic liquid)s (PILs) are of growing interest for their thermal and electrochemical stability, processability, and potential in safe, flexible all-solid-state electrochemical devices. While various approaches to enhance the ionic conductivity are reported, the influence of cation substituents is rarely addressed. Moreover, some of the asymmetric anions recently developed for high-conductivity ionic liquids were never tested in PILs. We report the design and synthesis of twelve novel cationic PILs prepared via quaternization of N-substituted imidazoles by commercially available poly(epichlorohydrin-co-ethylene oxide) (poly(EPCH-r-EO)) with subsequent ion metathesis. They differ by imidazolium side chain length (C-1-C(6 )alkyl) and presence of heteroatoms (silyl, siloxane, and fluoroalkyl) and by anion type (bis(trifluoromethylsulfonyl)imide (TFSI), 2,2,2-trifluoromethylsulfonyl-N-cyanoamide (TFSAM), tetrafluoroborate (BF4), trifluoro(trifluoromethyl)borate (BF3CF3), and tricyanofluoroborate (BF(CN)(3))). TFSI-based PILs with alkyl side chains gave lower glass transition temperatures (T (g)) and higher ionic conductivities than those bearing heteroatomic substituents, with n-butyl side chains providing a conductivity of 4.7 x 10(-6) S cm(-1) at 25 degrees C under anhydrous conditions. This increased to 1.0 x 10(-5) and 4.5 x 10(-4) S cm(-1 )at 25 and 70 degrees C, respectively, when the TFSI anion was replaced with BF(CN)3. All PILs showed good electrochemical (>3.2 V vs Ag+/Ag) and thermal (>185 degrees C) stability, making them excellent candidates for solid-state electrolytes in electrochemical devices.

Due to its amphiphilic structure, lignin has the potential to stabilize emulsions via adsorption at the oil/water interface. By converting lignin into nanoparticles, we can significantly enhance its emulsion-stabilizing capabilities through a Pickering-type stabilization mechanism. Two essential elements may be modified to fine-tune emulsion stability: the size of the lignin nanoparticles (LNPs) and the physicochemical nature of the lipid phase. In this context, we highlight the behavior and utility of unmodified LNPs in the preparation of Pickering emulsions made up of water and a complex bio-based pharmaceutical-grade wax that can be used for the formulation of lipid carriers. As a proof-of-concept, we employ the developed Pickering emulsions to encapsulate indocyanine green (ICG), an FDA-approved dye commonly used in medical imaging applications. We demonstrate that ultra-small LNPs are well-suited for the colloidal stabilization of pharmaceutical wax ester micro beads. This stabilization does not require any lignin modification. Additionally, we present evidence that our new lipid/lignin hybrid carrier has potential as a new drug delivery system.

Covalent adaptable networks and vitrimers are novel polymers with dynamic reversible bond exchange reactions for crosslinks, enabling them to modulate their properties between those of thermoplastics and thermosets. They have been gathering interest as materials for their recycling and self-healing properties. In this review, we discuss different molecular simulation efforts that have been used over the last decade to investigate and understand the nanoscale and molecular behaviors of covalent adaptable networks and vitrimers. In particular, molecular dynamics, Monte Carlo, and a hybrid of molecular dynamics and Monte Carlo approaches have been used to model the dynamic bond exchange reaction, which is the main mechanism of interest since it controls both the mechanical and rheological behaviors. The molecular simulation techniques presented yield sufficient results to investigate the structure and dynamics as well as the mechanical and rheological responses of such dynamic networks. The benefits of each method have been highlighted. The use of other tools such as theoretical models and machine learning has been included. We noticed, amongst the most prominent results, that stress relaxes as the bond exchange reaction happens, and that at temperatures higher than the glass transition temperature, the self-healing properties are better since more bond BERs are observed. The lifetime of dynamic covalent crosslinks follows, at moderate to high temperatures, an Arrhenius-like temperature dependence. We note the modeling of certain properties like the melt viscosity with glass transition temperature and the topology freezing transition temperature according to a behavior ruled by either the Williams–Landel–Ferry equation or the Arrhenius equation. Discrepancies between the behavior in dissociative and associative covalent adaptable networks are discussed. We conclude by stating which material parameters and atomistic factors, at the nanoscale, have not yet been taken into account and are lacking in the current literature.