A novel surface modifier was developed by a simple method, in which n-octadecanethiol (OT) and divinyltetramethyldisilazane (DVTS) reacted via a one-step thiol-ene click chemistry. The prepared surface modifier OT-DVTS could be easily applied onto the surface of various substrates via dip-coating technique. After the cotton fabric was modified by OTDVTS, the Fourier transform infrared and X-ray photoelectron spectra confirmed that OT-DVTS had been successfully grafted onto fabric surface. The resultant OT-DVTS@fabric surface exhibited a significant change from a smooth to a rough structure. Benefiting from synergistic effect of increased roughness and decreased surface energy, the OTDVTS@fabric achieved superhydrophobic performance with a water contact angle of 154 degrees and oil contact angle nearly 0 degrees. When the OT-DVTS@fabric was used for separating oil-water mixture, even after 30 reuse cycles, the separation efficiency for water and oil remained above 99% and 91%, respectively. The measurement results revealed that OTDVTS@fabric exhibited outstanding durability against irradiation, chemical solvents, high temperature, tape peelingoff, and abrasion, which should be attributed to the strong covalent bonding interaction between OT-DVTS and substrates. Therefore, this work provided a UV-induced, highly efficient strategy to prepare OT-DVTS surface modifier, which could endow substrates surface with durable hydrophobic performance.

Cellulose is an important natural carbohydrate polymer, and natural or regenerated cellulose fibers are widely used in many fields, but the flammability of cellulose fibers limits their further development. To address the issue, an in situ growth of P and N flame retardant chelates (IGPN) was employed in a LiCl/N, N-dimethylacetamide (DMAc) solvent system to produce flame retardant cellulose fibers (Cellulose-IGPN@Li). X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) proved the successful synthesis of Li-containing IGPN (IGPN@Li) as well as the effective introduction of IGPN@Li into the fibers. The limiting oxygen index (LOI) value of Cellulose-IGPN@Li achieved 29.6% and remained at 28.7% even after 30 laundering cycles (LCs). In addition, the peak heat release rate (PHRR) and total heat release (THR) were reduced by 65% and 41%, respectively. Thermogravimetric-infrared (TG-IR) and cone calorimetry (CC) tests confirmed that IGPN@Li played an important role in the gas and condensed phases. Moreover, Cellulose-IGPN@Li had good antibacterial properties and moisture-dependent conductivity. This work provides a novel production method of durable flame retardant cellulose fibers with integrated potential greenness and economy.

Developing high-performance epoxy resins (EP) that integrate outstanding flame retardancy, mechanical reinforcement and optical transparency is a persistent challenge, often hindered by the detrimental effects of conventional additives. Herein, a novel hyperbranched polymeric flame retardant (HPBAE) containing phosphorus and borate ester moieties was synthesized from boric acid, ethanolamine and phenylphosphonic dichloride. Remarkably, incorporation of merely 2 wt% HPBAE substantially boosted the flammability resistance of resin to the UL-94 V-0 rating with 32.9% limiting oxygen index (LOI) and a 23.4% suppression in the peak heat release rate (PHRR). The superior flame retardancy arises from dual-phase action: condensed-phase formation of a P/Brich thermal barrier char and gas-phase release of phosphorus radicals that quench H center dot/HO center dot combustion intermediates. Relative to pure EP, the EP/HPBAE-2 exhibited a 57.9% enhancement in tensile strength while retaining the optical transparency. The synergistic effects imparted by HPBAE not only provide a balanced property profile but also offer a viable design paradigm for developing high-performance, transparent and flameretardant epoxy composites.

Triggered by heightened public safety concerns and the imperative of sustainable chemistry, an urgent demand has emerged for the development of eco-friendly and durable flame retardant Lyocell fibers. However, reconciling high flame retardancy, washing durability, mechanical strength, and formaldehyde-free processing within an environmentally benign and feasible approach remains a significant challenge. To address the issue, a novel co-coordination system of biomass tea polyphenols, L-lysine and Fe3+, cooperating with covalent linking of 3-epoxypropyl trimethoxysilane was constructed. Compared with Lyocell fabric, the treated Lyocell fabric exhibited substantial reductions of 70.35 % for total heat release (THR) and 61.82 % for peak heat release rate (PHRR), alongside a limiting oxygen index (LOI) value of 26.8 % even after 50 laundering cycles. Meanwhile, the modified fabric had excellent UV resistance, antibacterial and hydrophobic properties. Encouragingly, the proposed modification process basically retained the high mechanical properties of the Lyocell fabrics, providing a sustainable, green route toward multifunctional, durable Lyocell textiles for protective and technical apparel applications.

The inherent flammability and insufficient ultraviolet (UV) protection of regenerated cellulose fibers limit their functional applications. Inspired by the natural polyphenol-polysaccharide synergy in plants, a lignin-derived boron-containing phenolic network (Lig-BPF) was incorporated into a cellulose spinning system and then coordinated with Zn2+ to fabricate Cellulose/Lig-BPF@Zn fibers. Compared with pristine cellulose fibers, Cellulose/Lig-BPF@Zn increased the char residue at 800 °C from 13.72% to 30.35% under N2 atmosphere, and reduced the peak heat release rate by 43.03%. The limiting oxygen index increased from 17.2% to 31.5%, and still remained 29.1% after 20 laundering cycles. TG-FTIR analysis showed an 88.56% reduction in total volatile release intensity, while Raman analysis confirmed an increased degree of graphitization, as evidenced by a decreased ID/IG value from 3.59 to 2.55. Furthermore, the UV protection factor increased from 11.42 to 128.82, and remained 109.74 after durability testing. Mechanistic analyses demonstrate that lignin-derived aromatic domains, boron-containing structures and Zn-coordinated species regulate cellulose pyrolysis and promote the char formation. This work develops a sustainable strategy for converting natural lignin into a bio-based flame retardant that simultaneously improves the flame retardancy and UV protection performance of regenerated cellulose fibers, providing a phosphorus-free and eco-friendly approach for preparing multifunctional carbohydrate-based fibers.

To mitigate ecological pollution and fossil-resource depletion caused by traditional petroleum-based materials, biomass-derived functional materials have emerged as promising sustainable alternatives. Herein, a fully biomass-derived phenolic resin (TA-PPF) was developed from renewable feedstocks, which integrated intrinsic flame retardancy, robust adhesion, and value-added reuse capability. TA-PPF exhibited an exceptionally high limiting oxygen index (LOI) of 64.5% and maintained its structural integrity without macroscopic collapse after continuous exposure to a butane flame for 240 s, outperforming many previously reported bio-based and petrochemical flame-retardant materials. Additionally, TA-PPF exhibited robust adhesion to diverse substrates, achieving an adhesion strength of 3.65 MPa on wood and retaining favorable environmental stability in organic solvents, acidic and alkaline media, and under extreme temperatures. Benefiting from its intrinsic flame retardancy and adhesion capability, TA-PPF was further applied as an eco-friendly fire-safety coating for wood, increasing its LOI from 22.3% to 45.4%. Furthermore, inspired by the natural synergy between polyphenols and carbohydrates in plants, waste TA-PPF was repurposed as a functional additive for regenerated cellulose fibers, producing multifunctional composite fibers with excellent flame retardancy and ultraviolet protection, as evidenced by an LOI of 33.5% and an ultraviolet protection factor (UPF) of 136.63. This work provides a sustainable strategy for developing high-performance bio-based resins, fire-safety coatings, and multifunctional regenerated cellulose fibers.

To improve the flame retardancy of lyocell fabrics, in this paper, an eco-friendly flame retardant and antibacterial lyocell fabric (FR@Si-lyocell) was fabricated by surface grafting modification. The surface morphology, combustion properties and antibacterial rate of FR@Si-lyocell were investigated. FR@Si-lyocell exhibited excellent char-forming ability with residual char of up to 40.24 wt% and 11.78 wt% at 800oC in N2 and air, respectively. Its limiting oxygen index (LOI) value increased from 17.6% to 32.3%, and the peak heat release rate (PHRR) and total heat release (THR) decreased significantly by 94.4% and 74.5% compared to the control sample. The synergistic flame retardant mechanism of gas and condensed phases was proposed by analyzing the volatile pyrolysis products and char residue generated during the combustion process. In addition, FR@Si-lyocell showed excellent antibacterial properties, with inhibition efficiencies as high as 99.9% and 99.7% against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work provided an efficient and eco-friendly method to prepare multifunctional lyocell fabrics with potential application fields.

Sustainability limitations, inherent flammability, and poor adhesion durability of conventional petroleum-derived resins have given rise to a great demand for renewable bio-based materials with integrated fire safety and interfacial robustness.

Waterborne polyurethane (WPU) is a highly flammable polymer that is unsuitable for use in fire-prone environments. To address this limitation, an innovative biomass-derived intrinsic flame retardant containing phosphorus, nitrogen, and silicon (hereafter referred to as DETS) was synthesized via a one-pot reaction involving 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane, protocatechualdehyde, and diethyl phosphite. Because its molecular structure includes four terminal hydroxyl groups, DETS enables covalent cross-linking with WPU during curing to construct an internally cross-linked network. The resulting WPU/DETS composites exhibited outstanding flame retardancy. Notably, the limiting oxygen index increased up to 27.7%, and vertical burning tests demonstrated self-extinguishing behavior. Cone calorimetry tests revealed reductions of 46.6% and 57.1% in peak heat release rate and smoke production rate, respectively. Furthermore, thermogravimetric analyses confirmed enhanced char yield, and TG-IR analyses showed suppressed emission of toxic volatiles. The tensile strength and elongation at break of WPU/DETS-5 were significantly improved relative to pristine WPU. The study provides a promising strategy for developing sustainable and intrinsically flame-retardant WPU materials based on renewable chemistry.

A facile in situ grafting strategy was elaborately designed to fabricate flame-retardant lyocell fabrics. Acrylamide first immobilized to the surface of lyocell fabrics via an additional reaction between carbon-carbon double bonds and oxygen-free radicals derived from the activated cellulose chain. Diphenylphosphinyl chloride was grafted through the intermediate bridge acrylamide. The combination of acrylamide and diphenylphosphinyl chloride significantly retarded the heat release rate and total heat release and efficiently promoted the formation of rigid and swollen carbonaceous structures. The obtained fire-resistant lyocell fabrics (C-g-AD) with an LOI value (30.6 %) were immediately extinguished after exposed flame for more than 30 s with only 48 mm char length. Besides, the thermal degradation rate of C-g-AD sharply decreased by 17.1 % and 14.7 % in nitrogen and air, respectively. Herein, C-g-AD fabricated by the present strategy exhibited outstanding flame retardancy.

With the depletion of petrochemical resources and the escalating severity of white pollution, replacing petrochemical resources with bio-based resources aligns with sustainable development strategy. In this work, a novel biomass flame retardant (PCDAC) derived from curcumin was intercalated into expandable graphite (EG) to construct an intrinsically intumescent flame retardant system (EG@PCDAC), which was then melt blended with polylactic acid (PLA) to fabricate flame retardant, anti-dripping and smoke suppressive PLA composite (PLA/ EG@PCDAC). The residual char of PLA/EG@PCDAC was 14.27 wt% under N2 atmosphere, while reaching UL-94 V-0 rating. Furthermore, the peak heat release rate and total heat release of PLA/EG@PCDAC were reduced by 46.95 % and 19.02 % compared with original PLA, and the total smoke production and peak smoke production rate also decreased by 20.74 % and 72.09 %, respectively. This work offered green and feasible inspiration for exploring biomass flame retardants and renewable PLA-based functional materials.

Although surface-enhanced Raman spectroscopy (SERS) substrates exhibit high sensitivity, their diverse application scenarios are often limited by specific fine structures. This study proposed a synergistic strategy of photolithography and in-situ generation to form isostereo-resonant interfaces on multidimensional substrates with different flexibility for urine detection and printing anti-counterfeiting. The interface utilizes the hydroxyl group of tannic acid (TA) for in situ reduction of metal ion nucleation on the substrate surface, forming a stable nanogold interface. UV-induced generation of free radicals at the interface leads to the destruction of hydroxyl (-OH) groups, thereby effectively modulating the spatial distribution through the inhibition of the gold nanocrystal reduction process. This interface exhibits excellent SERS activity for detecting sub-nanomolar concentrations of probes, with high biocompatibility. Through combined deep learning algorithms, it enables the detection of uric acid from clinical urine samples with an accuracy of 98.6%. This interface construction strategy with SERS function is compatible with versatility and accuracy, offering the possibility of optimizing the limitations of traditional interfaces in a single application scenario.

Despite being the earliest and most extensively studied class of vitrimers, transesterification epoxy (EP) vitrimers still face some large limitations in thermomechanical stability and flammability. Unlike the preparation of functional composite materials using ordinary curing agent compounds and nano fillers, this paper proposed a new strategy of using carbon dots to design nano-curing agents and dynamically crosslink active sites for constructing epoxy vitrimers with excellent thermomechanical stability and flame retardancy. Herein carboxylic acid type carbon dots (C-CDs) was synthesized via glutamate pyrolysis, subsequently grafting with organophosphorus compounds via the Kabachnik-Fields reaction to achieve the phosphorus doping (P-CDs). It is interesting that the synthesized P-CDs played a quadruple role as flame retardants, curing agents, dynamically exchangeable bonds, and nano-reinforcement effect. The results showed that this new kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers was firstly reported, which exhibited good thermomechanical stability, flame retardancy and fast stress relaxation time. When the molar ratio of P-CDs to epoxy was about 1:1, the peak heat release rate (PHRR) and CO2 production (CO2P) of the EP/P-CDs could be reduced by 53.4 %, and 65.1 %. The limiting oxygen index (LOI) was 31.3 % and the UL-94 grade reached V-0 rating, which benefitted from the dual-phase flame-retardant mechanisms. Furthermore, the stress relaxation time of EP/P-CDs was significantly shortened to be 90 s, which was important for the reprocessing of epoxy thermosets. Notably, EP/P-CDs maintained up to 98 % of its thermo-mechanical properties even after twice reprocessing. This kind of organic-inorganic hybrid flame-retardant EP/CDs vitrimers will have imposing potential applications in many fields.

Polyamide 66 (PA66) fabric has attracted significant attention due to its excellent overall performance. However, its flammability and melt droplet defects severely restricted its wide application. In this work, we successfully developed a bio-based multifunctional intumescent flame retardant (MIFR) coating for PA66 fabric via the interactions between quaternary chitosan (QC), tannins (TA), 9,10-Dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and 4-Formylphenylboronic acid (4-FB). The results indicated that the coated polyamide 66 (PA66) fabric (P-PA66@TA@QC) achieved a limiting oxygen index (LOI) of 30.1 % and no molten droplets generated during the combustion. Additionally, the peak heat release rate (pHRR) and total heat release rate (THR) of P-PA66@TA@QC were reduced by 50.3 % and 55.7 %, while the total smoke production (TSP) was decreased by 80 % compared to the control sample, exhibiting a lower fire risk and excellent smoke suppression performances. Furthermore, P-PA66@TA@QC exhibited good hydrophilicity, high UV protection factor (UPF > 180), and high inhibition rate against E. coli (> 99.9 %) and S. aureus (> 99.9 %), indicating outstanding UV resistance and excellent antibacterial properties. This study successfully developed a bio-based multifunctional flame retardant coating, providing significant guidance for preparing eco-friendly and multifunctional PA66 fabrics.

Traditional epoxy resins are manufactured from non-renewable fossil resources and suffer from several drawbacks, including poor flame retardancy, non-reprocessability and recycling difficulties, greatly affecting their wider applications. To address these issues, an inherent flame-retardant epoxy resin (L-Trp@PA/TPEP) was synthesized from biomass tea polyphenols, L-tryptophan, phytic acid and epichlorohydrin. L-Trp@PA/TPEP achieved a limiting oxygen index (LOI) value of 36.4%, with excellent anti-dripping, self-healing and reprocessability. Additionally, due to the limited number of reprocessable cycles, a versatile durable Lyocell fabric (L-Trp@PA/TPEP/Lyocell) was fabricated by finishing with the recycling of non-reprocessable L-Trp@PA/TPEP. L-Trp@PA/TPEP/Lyocell showed an LOI value of 34.5% and ultraviolet protection factor of 137.29. The elongation at break and tensile strength of modified Lyocell fabric increased by 19.2% and 33.6%. In addition, the modified fabric had favorable chemical resistance without mechanical deterioration within the pH range of 1 to 13. Besides, L-Trp@PA/TPEP/Lyocell displayed remarkable anti-fouling and self-cleaning capabilities. This work proposed a comprehensive and eco-friendly approach in terms of raw materials, application and recycling, which was significant for the development of sustainable novel materials and multifunctional textiles.

Addressing the dual challenges of diminishing fossil reserves and proliferating plastic waste accumulation, harnessing renewable cellulose resources offers a promising solution. Guided by the principles of intumescent flame retardant system, the eco-friendly hyperbranched phosphonitrile networks integrating acid, carbon and gas sources was prepared and covalently anchored onto Lyocell fabrics. Further, the hyperbranched phosphonitrile networks induced the interfacial assembly of zirconium phosphate (ZrP) to construct flame retardant Lyocell fabrics (Lyocell-TCHNs@ZrP) with low-temperature multiphase catalytic carbonization and hightemperature physical shielding effects. The char residue of Lyocell-TCHNs@ZrP under N2 atmosphere was increased from 13.63 % of original sample to 39.12 % at 800 degrees C, while the thermo-oxidative behavior was also suppressed in air conditions. Meanwhile, the peak heat release rate (PHRR) and total heat release (THR) of Lyocell-TCHNs@ZrP were reduced by 66.10 % and 80.90 %, which showed great self-extinguishing ability in combustion test. In addition, the tensile strength of Lyocell-TCHNs@ZrP was slightly improved, while the hand feel and whiteness were well remained. This work provided fundamental insights into the molecular design of hyperbranched intumescent flame retardants and the synergistic interaction between solid catalysts, along with an effective strategy for the fire safety performance of cellulose derived textiles.

Epoxy resins (EP) with excellent mechanical properties, adhesive properties and heat resistance are favored in high-end fields. In this study, a silicone-containing phosphoramidite (DPATS) was synthesized through the nucleophilic substitution between diphenylphosphine chloride (DPPC) and 1,3-bis(3-aminopropyl)-1,1,3,3-tetramethyldisiloxane (PATS). DPATS markedly improved the flame retardancy of EP due to the synergy of phosphorous, nitrogen and silicon elements. The results demonstrated that, with only 2 wt% of DPATS, the EP/DDM/ DPATS-2 sample achieved a UL-94 V-0 classification along with a limiting oxygen index (LOI) of 31.4 %. Meanwhile, the peak heat release rate (PHRR) and total heat release (THR) of EP/DDM/DPATS-2 sample reduced by 16.4 % and 8.7 % when compared to virgin EP. The possible flame-retardant mechanism of DPATS on EP during combustion was studied. It was determined that the primary mechanism responsible for the flameretardant behavior of DPATS may be achieved by the promoting char-formation effect from P and Si elements in the condensed phase, and quenching effect from P-containing radicals as well as the dilution effect of Ncontaining gases in the gas phase. Additionally, the flexible silicon-oxygen (Si-O) chain segments from DPATS contributed to the toughness of EP. Compared with neat EP, those containing 2 wt% DPATS showed an increment in tensile strength by 23.8 % and elongation at break by 21.9 %. Moreover, high transparency was maintained thanks to excellent compatibility between DPATS and EP. Hence, our work provides an effective approach for producing flame-retardant EP that is simultaneously tough and transparent.

Aluminum (Al) batteries are promising for sustainable and large-scale energy storage due to the inherent safety, low cost, and attractive metrics of the Al anode. However, the development of high-voltage and high-capacity cathodes remains a key challenge. Herein, we achieve the reversible iodine redox-amphoteric conversion (i.e., I − /I 0 /I + ) in Al batteries, wherein AlCl 4 − -deficient eutectic electrolytes are identified critical for stabilizing the conversion process. In contrast to ionic liquid electrolytes prone to parasitic Cl 2 evolution, eutectic systems facilitate the I − /I 0 /I + conversion process with high reversibility and significantly suppressed Cl 2 generation. Spectroscopic and theoretical investigations reveal AlCl 4 − as the dominant species limiting anodic stability of the electrolyte, and its reduced presence in eutectic electrolytes directly enhances iodine conversion reversibility. The optimized electrolyte allows the I 2 electrode to deliver a specific capacity of 358 mAh g −1 and an energy density of 490 Wh kg −1 (based on I 2 mass), along with excellent cycling stability (83.8% retention over 1000 cycles). High-loading I 2 electrodes (8.52 mg cm −2 ) achieve a high areal capacity of 2.25 mAh cm −2 and demonstrate practical feasibility in a single-layer pouch cell. This work establishes a new design framework for high-energy-density Al batteries and opens avenues for advancing conversion chemistries in multivalent systems.

Polyethylene terephthalate (PET) fibers are widely used in many fields, but their flammability and molten droplet characteristics during combustion pose a significant safety risk. To address the issue, a novel approach was developed to enhance the flame retardant and anti-dripping performances of PET fabric through a combination of dyeing and mussel-inspired strategy. First, PET fabric was directly dyed with heme chloride (HC) to produce dyed PET fabric (HC-PET), which was then treated by a mussel-inspired tannic acid-based flame retardant (TAPP) and an impregnation-drying-curing process to prepare flame retardant PET fabric (FR-PET). The results indicated that the total heat release (THR) and peak smoke production rate (PSPR) of FR-PET were decreased by 22.8 % and 49.7 %, respectively, and the limiting oxygen index (LOI) was increased from 21 % to 29.8 %, showing good flame retardant properties. Additionally, the UV resistance and antibacterial performances of FR-PET were also significantly improved. In summary, this study provided a feasible approach for the preparation of multifunctional PET textiles with dyeing, flame retardant, anti-dripping, UV resistance and antibacterial performances.

Aluminium-based aqueous batteries hold promises for next-generation sustainable and large-scale energy storage due to the favorable metrics of Al and water-based electrolytes. However, the performance of current aluminium-based aqueous batteries falls significantly below theoretical expectations, with a critical bottleneck of realizing cathodes with high areal capacities. Herein, we present a hydrate-melt electrolyte design utilizing cost-effective AlCl3 and organic halide salts, which enables the demonstration of aqueous Al-Br batteries with enhanced energy-power characteristics. The optimal electrolyte features suppressed water activity and loosely bound halogen anions, attributed to its unique electrolyte structure, where the majority of water molecules engage in robust ion solvation (>98% as suggested by simulations) and halogen anions reside in the outer solvation sheath of cations. These distinctive features ensure good compatibility of the electrolyte with the reversible Br-/Br0/Br+ conversion, enabling cathodes with a high areal capacity of 5 mAh cm-2. Besides, the electrolyte allows for Zn-Al alloying/de-alloying with minimal polarization (around 100 mV at 5 mA cm-2) and a smooth alloy surface. The assembled Al-Br cell delivers an energy density (267 Wh L-1, based on the volume of anode, cathode and separator) comparable to commercial Li-ion batteries and a substantial power density (1069 W L-1) approaching electrochemical capacitors.