Abstract Ternary organic solar cells (T-OSCs) can mitigate the spectral and morphological limitations of binary blends, but the molecular requirements for effective polymeric guest donors remain insufficiently defined. Here, three composition-tuned, benzo[d][1,2,3]thiadiazole-containing wide-band gap terpolymers (F1–F3) were synthesized and evaluated as guest donors in PM6:Y6 devices. Varying the relative contents of the benzo[d][1,2,3]thiadiazole- and benzodithiophene-dione-derived segments modulates the absorption, frontier molecular orbitals (FMO), and blend compatibility. Among the series, F2 provides the most favorable combination of a deep highest occupied molecular orbital (HOMO) level, efficient exciton dissociation (98.8%), and balanced hole/electron transport (mobility ratio = 1.15). Its surface energy (22.7 mN m–1) lies between those of PM6 (20.6 mN m–1) and Y6 (27.4 mN m–1), while its comparatively low Flory–Huggins interaction parameter with Y6 (χ = 0.221) is consistent with improved interfacial mixing. Transmission electron microscopy and atomic force microscopy reveal a finer and more uniform blend morphology, supporting reduced recombination and improved charge collection. Consequently, PM6:Y6:F2 devices deliver a power conversion efficiency of 17.45%, compared with 16.19% for the binary PM6:Y6 control, through simultaneous increases in open-circuit voltage, short-circuit current density, and fill factor. These results demonstrate that terpolymer composition can be used to co-optimize electronic structure and interfacial compatibility, providing a practical route to polymeric guest donors for multicomponent organic solar cells (OSCs).
Abstract The practical application of self-assembled monolayers (SAMs) in inverted perovskite solar cells (PSCs) is severely hindered by insufficient substrate binding, inhomogeneous coverage, and limited defect passivation at the buried interface. Herein, we report the synthesis of poly{(2-(4,8-bis(3-(dimethylamino)propoxy)-6-(thiophen-2-yl)benzo [1,2-b:4,5-b′]dithiophen-2-yl)-7-(thiophen-2-yl)-9H-fluorene-9,9-diyl)[bis(hexane-6,1-diyl)]bis(phosphonic acid)}, a bisphosphonic acid–functionalized polymer, which was co-assembled with 4-phenyl-4-(4-(dicyanomethylene)-2-methyl-6-(pyridin-4-yl)-4H-pyran-4-ylidene)cyclohexanone, a conventional small molecule forming SAMs to fabricate a synergistic composite hole-transport layer. Based on a synergistic dual-site anchoring mechanism, the multidentate bisphosphonic acid groups strongly bind with the transparent conductive oxide substrate, while the sulfur atoms in the polymer backbone coordinate with undercoordinated Pb2+, mitigating interfacial ionic defects. The conjugated backbone facilitates rapid hole transport along the polymer chain, while co-assembly suppresses molecular aggregation, yielding a uniform, pinhole-free buried interface with enhanced wettability. Consequently, the optimized inverted PSCs exhibit a remarkable power conversion efficiency (PCE) of 24.23%, with a short-circuit current density of 24.85 mA cm–2 and high fill factor of 84.26%. The unencapsulated device maintains ∼80% of its initial PCE after 600 h of thermal aging at 80°C under a nitrogen atmosphere. This polymer-small-molecule co-assembly strategy offers a versatile route for developing efficient and stable inverted perovskite photovoltaics.
Abstract The rapid growth of modern electronics and 5G communication has created a strong demand for flexible electromagnetic interference (EMI) shielding materials; however, achieving high shielding effectiveness in polymer composites typically requires large amounts of conductive fillers, often at the severe cost of mechanical performance. To address this trade-off, a highly stretchable and self-healable polyurethane urea (PUU) composite film was developed by introducing amino-modified, silver-plated tetrapod zinc oxide whiskers (T-ZnO@Ag-NH2) as conductive fillers. The PUU matrix was deliberately constructed with dynamic disulfide bonds, reversible imine bonds, and multiple hydrogen-bonding interactions, which together imparted excellent toughness and intrinsic self-healing ability. Meanwhile, the T-ZnO fillers were modified through electroless silver plating followed by amino functionalization, thereby improving their electrical conductivity, dispersibility, and interfacial compatibility with the polymer matrix. The optimized composite containing 25 wt % T-ZnO@Ag-NH2 exhibited stable tensile performance, with a tensile strength of 8.7 MPa, while still maintaining effective self-healing behavior, reaching a healing efficiency of up to 70% at 60 °C. In addition, the composite film delivered an outstanding EMI shielding effectiveness of 49.57 dB in the X-band at a thickness of only 0.5 mm. Overall, this work provides an effective route for designing flexible, durable, and multifunctional EMI shielding materials, and also highlights their considerable potential in flexible electronics and wearable sensing devices.
Abstract The demand for flexible polyvinylidene fluoride (PVDF) sensors in underwater and wearable technologies is increasing due to their ability to maintain stable performance by adapting complex geometries and withstanding mechanical deformation. This study reports the use of a predictive model based on Machine Learning (ML) to develop highly piezoelectric thick PVDF sheets for hydrophone applications. A sustainable and scalable three-stage process comprising extrusion, controlled stretching, and high-voltage contact poling was used for preparing thin piezoelectric PVDF sheets. To identify the structure correlation with the stretching process, these were characterized using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and quantification of the β-phase was performed using FTIR spectroscopy. In this study, five different machine learning models, viz., Gaussian process regression (GPR), support vector regression (SVR), random forest regression (RFR), artificial neural network (ANN), and genetic algorithm-optimized artificial neural network (GA-ANN) were developed using the outcome from the FTIR analysis of the stretched PVDF sheets. These models were used to predict the optimal stretching conditions to achieve the optimum β-phase content for thick PVDF sheets, which are required for specific applications. The statistical error analysis showed that the GA-ANN model had a higher generalization capability than the other models. The predicted conditions were experimentally validated and employed to develop thick PVDF sheets with high β-phase content. The highly piezoelectric form of the stretched PVDF sheet was obtained by high-voltage contact poling, with a high voltage coefficient (g33) of −300 ± 10 mVm/N. Finally, a prototype PVDF hydrophone was fabricated using the sheets developed with GA-ANN predicted conditions, and its underwater acoustic receiving sensitivity was tested. The hydrophone exhibited a flat frequency response of −204 ± 0.8 dB ref V/μPa in the frequency range of 1–10 kHz. This work demonstrates a promising method for integrating GA-ANN modeling with scalable PVDF processing for tailoring the piezoelectric properties and fabricating flexible underwater acoustic sensing systems.
Abstract Additive manufacturing of soft conductive materials enables flexible electronics, sensors, and robotic systems, yet is often constrained by high-temperature melt processing, postprint activation, or rigid conductive inclusions that reduce compliance. Here, we introduce a cold-extrusion strategy to create feedstock for liquid metal (LM)/thermoplastic elastomer composites that overcomes these limitations, enabling additive manufacturing of intrinsically conductive soft structures. By lightly solvating the polymer matrix, the composite enters a transient, putty-like processing state that enables extrusion without elevated temperature while preserving high LM loading (>60 vol %) and uniform droplet dispersion. Crucially, we leverage the high shear forces inherent to the extrusion process to drive droplet coalescence within the putty, directly forming a feedstock with a percolated, electrically conductive network. The continuously extruded LM/thermoplastic polyurethane feedstock is then pelletized and directly fabricated into multidimensional, conductive architectures using elevated-temperature extrusion-based 3D printing, without the need for thermal sintering, mechanical embossing, or secondary conductive inclusions. The printed composites reach notable conductivities of 0.4–1.8 × 104 S/m while retaining extensibility above 200% strain, demonstrating an additive manufacturing workflow that enables simultaneous printability, conductivity, and mechanical compliance. These results establish a general strategy for additive manufacturing of conductive thermoplastic elastomer composites for scalable fabrication of soft electronic and robotic systems.
Abstract Conventional transparent paper suffers from limited optical transmittance, poor water resistance, and low mechanical strength, and its fabrication typically depends on organic solvents, which cannot meet the long-term requirements of high-end packaging. In this work, we fabricated a biodegradable, highly transparent Carnauba wax/Waterborne Polyurethane (CW/WPU) composite paper via a green, solvent-free aqueous emulsion impregnation process using cellulose paper as the substrate, and systematically elucidated the synergistic mechanism among cellulose, CW, and WPU. The aqueous CW/WPU system uniformly disperses and infiltrates the paper pores, forming a dense, continuous structure (RMS = 7.31 nm) that suppresses interfacial light scattering and thus achieves a high transmittance of 87.79% at 550 nm. The continuous WPU network establishes strong interfacial adhesion and hydrogen bonds with the cellulose substrate, imparting excellent mechanical strength and toughness (tensile strength = 37.6 MPa). Meanwhile, the composite exhibits enhanced water vapor barrier performance (WVTR = 125.5 g/(m2·d)) while retaining biodegradability in natural soil. This entirely green, solvent-free strategy overcomes the optical, mechanical, and barrier limitations of conventional cellulose paper, providing a pathway to replace plastics in packaging for consumer electronics displays and protective equipment.
Abstract Adverse friction and wear between moving mechanical parts create safety risks by dissipating substantial energy and causing mechanical failure. The most common method for reducing friction and wear and improving energy efficiency is the lubrication of mechanical parts. However, conventional sulfur- and phosphorus-based lubricant additives have raised serious toxicological and ecological issues, which are incompatible with contemporary sustainable development goals. In this work, diethanolamine phenylborate (DEAB)-containing polymer micelles have been constructed in situ in a lubricating base oil via dative interactions (B–N) between diethanolamine-functionalized block copolymers and phenylboronic acid derivatives. The resulting polymer micelles have a poly(stearyl methacrylate) corona and a DEAB core, conferring long-term colloidal stability in the base oil. Ball-on-disc reciprocating tribological studies showed that the polymer micelles achieved a 52% reduction in friction coefficient (from 0.25 to 0.12) and an 89% decrease in wear volume (from 1.02 × 106 to 1.12 × 105 μm3) compared to the unmodified base oil. Moreover, the micelles exhibited high load-bearing capacity up to 1200 N, which was much higher than those of diethanolamine- (450–650 N) and boron-containing block or random copolymers (700–900 N) alone. This enhanced load-carrying capability was attributed to the in situ formation of B2O3 and h-BN at the rubbing steel interfaces via tribochemical reactions. This work provides a platform for developing environmentally friendly lubricant additives through rational combination of functionalized block copolymers and triboactive molecular units.
Abstract Photovoltaic (PV) encapsulants play a pivotal role in ensuring the long-term reliability of solar modules by protecting sensitive cells from moisture ingress, mechanical stress, and ultraviolet (UV) degradation. However, conventional encapsulant materials, such as ethylene-vinyl acetate, polyolefin elastomer, and polyvinyl butyral, exhibit several inherent limitations, including a high water vapor transmission rate, poor delamination resistance, and easy formation of optical haze under long-term UV irradiation in hygrothermal conditions. To address these challenges, we herein design a CO2-derived aliphatic polycarbonate-based thermoplastic polyurethane (TPU) as a PV encapsulant, which combines high transmittance (>90.5%), flexibility, superior water vapor barrier properties (WVP < 12.42 g·mm m–2 day–1), moisture insensitivity, and strong adhesion to PV glass and backsheet substrates. More specifically, the multiblock TPU is synthesized via the polyaddition of poly(propylene carbonate)diol, polyether diol, hexamethylene diisocyanate, and 1,4-butanediol. Upon optimizing the chemical composition and incorporating proper additives (e.g., silicone coupling agents, UV absorbers, antioxidants), the encapsulant achieves enhanced interfacial adhesion with a peel strength of 87.2 N cm–1 and maintains a residual peel strength of 73.4 N cm–1 following accelerated UV aging. Additionally, the adhesion mechanism based on TPU is proposed and preliminarily elucidated. This study tackles key challenges in photovoltaic module encapsulation by developing this high-performance alternative material, demonstrating significant potential for large-scale industrial applications.
Abstract The valorization of whey, the main byproduct of cheese manufacture, is hindered for small and medium-sized dairy enterprises (SMEs) by the high cost of conventional separation technologies such as membrane filtration and chromatography. In this work, complex coacervation between whey proteins and carboxymethylcellulose (CMC) was scaled from 5 to 100 L to develop a simple, low-cost process for recovering a protein- and lipid-enriched product. Five commercial CMCs with molecular weights ranging from 18 to 780 kDa were first evaluated at laboratory scale. Intermediate-Mw CMC (400 kDa) provided the best balance between electrostatic complexation and sedimentation, removing 99% of the initial protein from the supernatant, as confirmed by residual protein quantification and turbidity. Using the selected CMC, the process was successfully scaled to 100 L in a conical-bottom tank with an off-centered 45° four-blade turbine. Geometric similarity (H/Dt = 2.0–2.5, Da/Dt = 0.26–0.33) was applied, achieving fully turbulent flow at both scales (Re = 3.56 × 104 and 1.41 × 105). Protein recovery reached 76%, with a 3.4-fold concentration of proteins and nearly complete fat recovery in the coacervate. The freeze-dried coacervate was readily redispersible up to 20% (w/v). Its ζ-potential shifted from near-zero at pH 3 to −40 mV above pH 6, reflecting the combined contribution of whey proteins and residual CMC. Thermal gelation of the coacervate (3.1% protein) was strongly pH-dependent: weak gels formed at acidic pH (G′ = 6–23 Pa), while strong, cohesive gels developed at alkaline pH (G′ = 325 Pa at pH 9). The lactose-rich supernatant showed reduced COD and BOD loads (12% and 28% reduction, respectively) and was successfully fermented by kefir grains without nutrient supplementation. This scalable, food-grade coacervation process offers an accessible alternative for dairy SMEs to transform whey from an environmental burden into a functional ingredient.
Abstract Addressing the critical issues of inevitable agglomeration and unsatisfactory photocatalytic efficiency inherent to powdered photocatalysts during water treatment, the idea to develop a robust nanofiber membrane carrier that can achieve uniform loading of photocatalysts and enhance their activity is valuable. The modified polyacrylonitrile (P-CPAN) was synthesized first by pomegranate peel carbon dots (PCDs) with acrylonitrile (AN) and acrylic acid (AA) through the in situ polymerization, then the hierarchical composite membrane, i.e., TP/CT@P-CPAN, was fabricated via electrospinning followed by a subsequent preimpregnation/solvothermal synthesis method. Compared with the reference sample, i.e., titanium dioxide (CT) powder, the heterojunctional TiO2@PCDs (TP) powder formed by the combination of TiO2 and PCDs has better photocatalytic ability, as TP could significantly expand the light absorption range to the visible-light region and reduce the recombination of photoinduced electron–hole pairs. Both PCDs and −COOH groups on the surface of P-CPAN nanofibers were suitable anchor points for amorphous CT during preimpregnation, TP and CT crystals through solvothermal synthesis could then attach firmly on the membrane. Hence, the TP/CT@P-CPAN membrane demonstrated good photocatalytic performance and durability. Even after 4 h of ultrasonic treatment, no significant shedding of the supported photocatalyst was observed. It can remain relatively stable even under acidic (pH = 2), alkaline (pH = 12), and high-salinity (10 g·L–1) conditions. Research on this kind of TP/CT@P-CPAN material that can be applied to complex usage environments has certain reference value for the development of fiber membrane-based photocatalyst materials.
Abstract Organ-on-a-chip (OOC) systems rely on membrane-supported tissue interfaces to replicate organ-level barrier functions in vitro. However, conventional porous membranes often provide limited biological cues for cell adhesion and may require an extracellular matrix coating. Here, we developed core–shell nanofibrous porous membranes via coaxial electrospinning, using polycaprolactone (PCL) as the structural core and gelatin as the bioactive shell. These membranes were integrated as replaceable inserts into a commercial dual-channel intestinal chip. Using identical chip geometry and membrane material, we compared three culture regimens: static culture, gravity-driven oscillatory flow, and continuous low-shear perfusion. The C-PCL/Gel membrane exhibited suitable mechanical stability, hydrophilicity, cytocompatibility, and cell-adhesion performance for epithelial–endothelial coculture. In the intestinal barrier model, continuous low-flow perfusion yielded the most favorable outcomes, including transepithelial electrical resistance (TEER) values exceeding 500 Ω·cm2, reduced tracer permeability, more continuous zonula occludens-1 (ZO-1) junctional staining, denser F-actin networks, and altered mucin 2 (MUC2) distribution. These improvements likely arise from combined effects of continuous medium renewal, enhanced mass transport, waste removal, and low-level hydrodynamic stimulation. This membrane-integrated chip provides a practical platform for studying intestinal barrier formation under different fluidic regimens, offering a biomimetic alternative to conventional membrane interfaces.
Abstract All-polymer photodetectors, owing to their remarkable advantages of flexibility and mechanical durability, exhibit demonstrated potential for application in the field of wearable technology. Nevertheless, the frequently employed double-component active layer structure is susceptible to performance degradation during long-term use. Consequently, a copolymer PM6-co-TTY6 possessing both donor and acceptor properties was designed and synthesized. The single-component active layer devices based on PM6-co-TTY6 exhibit pronounced photomultiplication characteristics. The maximum external quantum efficiency (EQEmax) of PM6-co-TTY6 device with thin active layer reaches 365% or 336% under a bias voltage of +5 V or −5 V, respectively. Remarkably, the device shows bias-tunable spectral response with increasing active layer thickness: a narrowband response (800–900 nm) with a EQEmax of 25% and a narrow full width at half maximum (FWHM) of 30 nm under negative bias, while a broadband response (300–900 nm) under positive bias. At this stage, the device can be switched between broadband and narrowband detection modes by reversing the polarity of the applied bias.
Abstract To enhance the gas separation performance of polyimide membranes, the synergy of thermal rearrangement (TR) and in situ decarboxylation crosslinking represents a distinctive fabrication strategy. Herein, a diamine monomer functionalized with both carboxyl and hydroxyl groups, namely 2-(3,6-bis(4-amino-3-hydroxyphenoxy)-9H-xanthen-9-yl)benzoic acid (BAHXBA), was synthesized. This diamine was then copolymerized with 2,2-bis(3-amino-4-hydroxyphenyl)hexafluoropropane (6FAP) and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) at varying molar ratios. A set of polyimide (PI) membranes, designated as PI(BAHXBA-6FAP), were fabricated via thermal imidization at 300 °C, followed by annealing at 450 °C to construct thermally rearranged membranes, TR(BAHXBA-6FAP). The high-temperature thermal treatment induces in situ benzoxazole cyclization and moderate crosslinking derived from side-chain carboxyl decarboxylation. The copolymer composition effectively tunes chain-stacking distance and thermal properties: elevated 6FAP content increases d-spacing, and higher thermal treatment temperature also leads to a noticeable increase in d-spacing. For the TR(BAHXBA-6FAP) membrane with a BAHXBA-to-6FAP molar ratio of 5:5, gas permeability coefficients reach 1177 (H2), 341 (O2), 1116 (CO2), 51 (CH4) and 43 (N2) Barrer. Its ideal H2/N2 selectivity exceeds the 2008 Robeson upper bound, and the O2/N2 selectivity surpasses the corresponding 2015 upper bound. This work provides a facile structural tailoring strategy via coupled thermal rearrangement and decarboxylation crosslinking for high-performance polyimide separation membranes.
Abstract Hydrogels have been widely used in tissue engineering, soft robotics, and wearable electronics. However, developing hydrogels that simultaneously possess high strength, high stretchability, and good conductivity to meet diverse application requirements remains a significant challenge. In this study, a strategy involving glycerol substitution, liquid metal (LM) coordination, and sodium lignosulfonate (LS) immersion was proposed to enhance the polymer network by adjusting the molecular arrangement and coordination of poly(vinyl alcohol) (PVA), thereby enabling the preparation of high-performance PVA/LM5.0@LS24 hydrogels. The PVA/LM5.0@LS24 hydrogels exhibited a tensile strength of up to 10.7 MPa and a high fracture strain of 833.1%. Additionally, the Young’s modulus and toughness reached 186.4 MPa and 69.9 MJ/m3, respectively. The outstanding mechanical properties demonstrated clear advantages compared to those of other tough hydrogels. Moreover, the incorporation of LM combined with LS immersion endowed the PVA/LM5.0@LS24 hydrogels with excellent electrical conductivity (6.20 S/m). Interestingly, the hydrogel also demonstrated good biocompatibility and excellent coagulation properties, making it suitable for human-sensing applications. The effective method for fabricating highly tough, fatigue-resistant, and stretchable hydrogels shows promising potential for use in artificial ligaments and sensing technologies.
Abstract Against the backdrop of global warming and energy shortages, passive personal thermal management textiles have gradually become a highly attractive alternative to traditional high-energy-consumption refrigeration systems. However, traditional radiative cooling textiles generally suffer from poor sweat management and complex manufacturing processes, which greatly limit their practical application. In this study, a continuous layered electrospinning technique was used to prepare an advanced hierarchical textile (PCAS) using polylactic acid (PLA) as the polymer matrix and alumina (Al2O3)/silica (SiO2) as nanofillers. Inspired by plant transpiration, PCAS has a hydrophilic top layer and a hydrophobic bottom layer, with markedly different fiber diameters between the two layers. This biomimetic Janus double-layer structure possesses a transpiration-like gradient wettability and gradient pore size characteristics, enabling biomimetic unidirectional sweat transport and excellent antireflux performance. Benefiting from the synergistic optical effect of Al2O3 and SiO2 (i.e., enhancing solar light scattering and mid-infrared radiation capabilities), the optimized PCAS exhibits a high solar reflectivity of 95.2% and an excellent mid-infrared emissivity of 96.9%, achieving a maximum subambient cooling effect of 13.7 °C under an average solar radiation of 1008 W/m2. Meanwhile, the PCAS textile also demonstrates excellent mechanical flexibility, good air permeability, and an ultrahigh water vapor transmission rate of up to 6174 g m–2 day–1. In conclusion, this study provides a green, scalable, and efficient strategy for the development of high-performance sustainable personal thermal management textiles, which hold broad application prospects in the fields of wearable cooling, outdoor protection, and building energy conservation.
Abstract Poly(vinylidene fluoride) (PVDF) membranes suffer from severe fouling because of their intrinsic hydrophobicity, while the random distribution of functional nanofillers in conventional blend membranes often limits their modification efficiency. In this work, a magnetically responsive nanocomposite, consisting of Fe3O4 nanoparticles anchored onto carboxylated multiwalled carbon nanotubes (c-MWCNTs@Fe3O4), was developed and incorporated into a PVDF matrix. During the nonsolvent induced phase separation process, an external magnetic field was employed to direct the migration of the c-MWCNTs@Fe3O4 nanocomposite toward the membrane surface, promoting its preferential localization at the membrane interface and thereby enhancing the interfacial exposure of hydrophilic functional groups. Consequently, the membrane surface hydrophilicity and pore structure were simultaneously improved, leading to a reduction in the water contact angle from 131° to 50.93° and an approximately 6-fold increase in pure water flux (518.55 L·m–2·h–1) while maintaining high rejection toward bovine serum albumin (BSA), humic acid (HA), and sodium alginate (SA). Moreover, the magnetically regulated membrane exhibited excellent antifouling performance, with flux recovery ratios of 88.30% for SA and above 92% for both BSA and HA, together with markedly reduced irreversible fouling and filtration resistance. Resistance and adsorption analyses further demonstrated that the interfacially enriched c-MWCNTs@Fe3O4 effectively alleviated pore blocking and cake-layer formation by weakening foulant–membrane interactions. This work demonstrates that magnetic-field-induced interfacial regulation provides an effective strategy for controlling the spatial localization of functional nanofillers in blended membranes, thereby maximizing their interfacial functionality and simultaneously enhancing membrane permeability and antifouling performance.
Abstract The direct transesterification of cellulose with vinyl laurate (VL) was investigated in the DMSO–DBU–CO2 switchable solvent system and subsequently translated to reactive extrusion (R-EX) under high-solid conditions, offering a simple and catalyst-free route for the preparation of long-chain cellulose esters. In a homogeneous medium, degree of substitution (DS) was tuned by varying the anhydroglucose unit (AGU):VL molar ratio (1:1–1:5). FTIR and NMR confirmed progressive hydroxyl substitution, with DS increasing with VL feed. The resulting cellulose laurates showed enhanced thermal stability and hydrophobicity, while higher DS reduced stiffness and increased flexibility due to internal plasticization by lauryl side chains. To overcome the inherent limitations of batch processes─namely, low cellulose concentration and long reaction times─the system was successfully extended to R-EX up to 22 wt % cellulose. Under these conditions, transesterification proceeded rapidly at moderate temperatures, yielding transparent, ductile, and hydrophobic films with DS comparable to those obtained in solution. A DOZN green-chemistry assessment of the esterification step showed that R-EX reduced the DOZN score by nearly 60% compared with the batch protocol. This study demonstrates that the DMSO–DBU–CO2 medium constitutes a solvent-lean platform for the sustainable preparation of cellulose esters. Its integration with R-EX provides a process-intensified route toward high-performance, biobased materials with tunable mechanical and surface properties.
Abstract Developing reactive flame-retardant strategies that improve fire safety while preserving mechanical flexibility is important for expanding the practical applications of polyurethane elastomers (PUEs). Herein, a cyano-bearing P–N reactive flame retardant (CPD) was synthesized through Schiff-base condensation and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) addition and then introduced into PUE as a cochain extender. This molecular design allowed CPD-derived flame-retardant segments to be covalently integrated into the PUE backbone during the chain extension. The resulting PUE/CPD elastomers exhibited significantly improved fire safety and antidripping performance. The limiting oxygen index (LOI) value of PUE/CPD15 reached 28.3%, compared to 21.6% for PUE, while its peak heat release rate (pHRR) and total heat release (THR) were reduced by 58.3 and 33.0%, respectively. Moreover, PUE/CPD10 and PUE/CPD15 achieved a UL-94 V-0 rating without ignition of the cotton indicator. Thermal degradation and evolved gas analyses showed that CPD promoted early char-forming reactions and suppressed the release of combustible and isocyanate-containing volatile products. Char residue analyses further revealed the formation of a compact P/N-rich protective layer, which contributed to a reduced heat release and combustion intensity. Importantly, PUE/CPD15 retained a high elongation at a break of 819.39%, despite a slight decrease in tensile strength. This work demonstrates a cyano-bearing P–N reactive chain-extension strategy for constructing fire-safe PUEs with balanced flame retardancy, antidripping performance, and mechanical toughness.
Abstract Selenium nanoparticles (SeNPs) exhibit promising antitumor activity and drug-loading capacity. However, their high instability and tendency to aggregate often lead to a loss of bioactivity. To address this issue, bioactive tea polysaccharides (TP) were employed as a template to synthesize stable TP@SeNPs (TPS), which were then loaded with the antitumor drug doxorubicin hydrochloride (DOX). Subsequently, the DOX@TP@SeNPs (DTPS) complex was encapsulated within a zeolitic imidazolate framework (ZIF-8), resulting in an antitumor drug delivery system (DOX@TP@SeNPs@ZIF-8, DTPSZ) that combines the targeted release capability of ZIF-8 with the synergistic chemotherapeutic effects of SeNPs and DOX. In this work, the synthesized DTPSZ was characterized, and its anti-HepG2 cell activity, targeting effect, and biosafety were investigated both in vitro and in vivo. The successful synthesis of DTPSZ was confirmed by mapping analysis and spectroscopic characterization. The DTPSZ particles measured approximately 166 nm in diameter with a ζ-potential of +23 mV and exhibited favorable sustained-release characteristics along with good stability in aqueous solution. DTPSZ showed significant efficacy in killing HepG2 cells, inhibiting their migration, and displayed strong HepG2 tumor-targeting capability in mice, leading to pronounced suppression of HepG2 tumor growth. Further analysis revealed that DTPSZ treatment upregulated Caspase-3 expression and reduced the proportion of Ki67-positive cells, demonstrating its capacity to inhibit the proliferation of HepG2 cells and induce their apoptosis. Additionally, DTPSZ demonstrated low cytotoxicity, minimal hemolytic activity, and negligible toxicity to the heart, liver, spleen, lungs, and kidneys. Consequently, DTPSZ holds promise as a potential therapeutic agent for the treatment of hepatocellular carcinoma.
Abstract The use of environment friendly and sustainable biobased materials to synthesize high-performance silicon carbide (SiC) aerogel electromagnetic wave-absorbing (EMW) materials is an important trend, which helps to promote their development and application. However, due to the inherent pore structure of biobased templates, the structural design of SiC aerogels is limited. Here, a salt-induced sol–gel strategy is proposed to fabricate high-performance SiC aerogels by crushing the biobased material and then cleverly using the DLVO colloid stability theory to restructure the biobased template. This strategy gets rid of the shackles of the inherent pore structure of biobased materials and designs aerogels composed of oriented SiC nanowire bundles. Benefiting from the unique structure, the obtained aerogel has a porosity of ∼98%, while enhancing the multiple reflection absorption effect of the aerogel on EMWs (effective absorption bandwidth = 4.2 GHz) and extending the thermal performance of the aerogel transmission path (thermal conductivity reduced to 0.019 W·m–1·K–1). The salt-induced sol–gel strategy paves the way for the structural design of high-performance ceramic aerogel electromagnetic absorbers.
