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Hexagonal boron nitride (hBN), as one of the two-dimensional (2D) materials, possesses many excellent properties like others. Herein, we report a novel self-healing epoxy filled with hBN. High compatibility between hBN and the epoxy matrix was obtained by the modification of hBN with silane coupling agent (Mi-Si). At the meantime, excellent self-healing behavior was achieved by retro Diels–Alder (r-DA) reaction between the maleimide functional group in the modified hBN (m-hBN-OH) and the added furfurylamine. Besides, the inadequate curing of epoxy led to the glass transition temperature (Tg), which is also seemed as the transition temperature for the shape memory of the epoxy, below the r-DA reaction temperature, and endowed the system with the shape memory-assisted self-healing properties. The m-hBN-OH was characterized by Fourier transform infrared spectra, nuclear magnetic resonance (1H-NMR) spectra, X-ray diffraction experiments, X-ray photoelectron spectroscopy measurements and so on. The new m-hBN-OH modifier was prepared with the optimized Mi-Si/hBN-OH weight ratio of 3.0, which could both improve the thermal property and achieve better thermal conductivity. This designed m-hBN-OH/epoxy could actually show ideal self-healing properties due to the shape memory-assisted self-healing effect. The thermal conductivity of the neat epoxy resin and the m-hBN-OH/epoxy was 0.2156 W m−1 K−1 and 0.4358 W m−1 K−1, respectively. As a novel material with efficient thermal conductivity, hBN made great contribution to the thermally induced shape memory and self-healing property. Systematic researches reveal that the composites are promising as long durable thermal interface materials, anti-scratch materials and so on.

Highlights A transparent and ceramizable coating was developed by incorporating nano-layered double hydroxide nanosheets into hierarchical hydrogen bonding polymer networks. The resulting coating composites demonstrated excellent high-temperature stability and fire resistance, effectively withstanding the direct exposure to a butane flame (~ 1100 °C) in air atmosphere. The mechanisms behind the flame-retardant behavior and ceramicization behaviors were thoroughly investigated and explained. In recent decades, annual urban fire incidents, including those involving ancient wooden buildings burned, transportation, and solar panels, have increased, leading to significant loss of human life and property. Addressing this issue without altering the surface morphology or interfering with optical behavior of flammable materials poses a substantial challenge. Herein, we present a transparent, low thickness, ceramifiable nanosystem coating composed of a highly adhesive base (poly(SSS 1 -co-HEMA 1 )), nanoscale layered double hydroxide sheets as ceramic precursors, and supramolecular melamine di-borate as an accelerator. We demonstrate that this hybrid coating can transform into a porous, fire-resistant protective layer with a highly thermostable vitreous phase upon exposure to flame/heat source. A nanosystem coating of just ~ 100 μm thickness can significantly increase the limiting oxygen index of wood (Pine) to 37.3%, dramatically reduce total heat release by 78.6%, and maintain low smoke toxicity (CIT G  = 0.016). Detailed molecular force analysis, combined with a comprehensive examination of the underlying flame-retardant mechanisms, underscores the effectiveness of this coating. This work offers a strategy for creating efficient, environmentally friendly coatings with fire safety applications across various industries.

Despite enormous efforts, copper corrosion remains a key inducement causing huge economic losses in electrical, construction, and military industries, and deteriorates the performance of semiconductor devices. Here we show that a set of ligands functionalized with both catechol and aromatic amine groups achieves environmentally-adaptive copper passivation and fully preserves the intrinsic electrical and thermal conductivities of copper and its alloys. The oxidation of ligands in corrosive environments causes the structure-adaptation of the passivation layer, further enhancing the corrosion resistance to harsh environments including alkali and salt solutions, thermal treatment, and UV-light- and oxygen-enriched conditions. Simply adsorbing these ligands on the surface of copper, brass, copper powder, copper-based flexible printed circuits, and copper inks for flexible electronics results in strong liquid and air anticorrosion performances. Our copper passivation technique only requires a room temperature soaking procedure, providing a high industrialization possibility for copper protection, particularly in semiconductor electronics and flexible electronics. A ligand oxidation structure-adaptive strategy creates an ultra-thin passivation nanolayer that enables copper and its alloys to resist corrosion and oxidation in harsh environments while retaining intrinsic electrical and thermal conductivities.

Stimuli‐responsive supercapacitors have attracted broad interest in constructing self‐powered smart devices. However, due to the demand for high cyclic stability, supercapacitors usually utilize stable or inert electrode materials, which are difficult to exhibit dynamic or stimuli‐responsive behavior. Herein, this issue is addressed by designing a MoS2@carbon core‐shell structure with ultrathin MoS2 nanosheets incorporated in the carbon matrix. In the three‐electrode system, MoS2@carbon delivers a specific capacitance of 1302 F g−1 at a current density of 1.0 A g−1 and shows a 90% capacitance retention after 10 000 charging‐discharging cycles. The MoS2@carbon‐based asymmetric supercapacitor displays an energy density of 75.1 Wh kg−1 at the power density of 900 W kg−1. Because the photo‐generated electrons can efficiently migrate from MoS2 nanosheets to the carbon matrix, the assembled photo‐responsive supercapacitor can answer the stimulation of ultraviolet‐visible‐near infrared illumination by increasing the capacitance. Particularly, under the stimulation of UV light (365 nm, 0.08 W cm−2), the device exhibits a ≈4.50% (≈13.9 F g−1) increase in capacitance after each charging‐discharging cycle. The study provides a guideline for designing multi‐functional supercapacitors that serve as both the energy supplier and the photo‐detector. An in situ approach based on the coordination between boronate ester polymers and metal ions has been developed to generate ultrathin MoS2 nanosheets in the carbon matrix, affording MoS2@carbon core‐shell particles. Due to the synergistic effect between the semiconductor MoS2 and the multi‐element co‐doped carbon matrix, MoS2@carbon exhibits outstanding capacitive performance and light‐triggered reversible capacitance evolution.

Octa-N-phenylaminopropyl-POSS (Octa-NAPA-POSS), DOPO and paraformaldehyde were used to synthesize Octa-DOPO-POSS through the Kabachnik-Fields reaction. It was added into epoxy resin with different ratio to prepare a series of modified epoxy resin composites. The results proved that the addition of flame retardant Octa-DOPO-POSS significantly improved the thermal property, flame retardant performance and moisture resistance of epoxy resin without weakening the mechanical properties. When the addition amount of Octa-DOPO-POSS was 5 wt%, the LOI value of the cured EP/Octa-DOPO-POSS composite increased to 33.9%. Its UL-94 level reached V-0 rating, and the THR and PHRR were significantly reduced. Meanwhile, the flexural modulus and breaking elongation were improved. Moreover, as the adding amount increased the residual char yield of EP/Octa-DOPO-POSS composites also increased, while the maximum thermal weight loss rate gradually decreased. The real-time FTIR and SEM analysis of the char residue after high temperature pyrolysis proved that Octa-DOPO-POSS could promote the char formation and produce a denser char layer. Overall, the combination of POSS and DOPO at a molecular level rather than physical mixing has a positive and significant effect on the flame retardancy of epoxy resin.

α-FeOOH nanocrystals were grown on the surface of polymeric spheres through in situ hydrothermal synthesis. The polymer with the surface amine groups was composed of styrene, divinylbenzene and 2-(dimethylamino)ethyl methacrylate via emulsion polymerization, which abbreviated it as PSDM. The structure and component of PSDM@α-FeOOH composites were investigated by Fourier transform infrared, thermogravimetric analysis, X-ray diffraction, X-ray photoelectron spectroscopy, scanning electron microscope and transmission electron microscopy. It was observed that the crystal structure, morphology and dispersion of α-FeOOH depended on different factors, i.e., temperature, reactant concentration and ferric salt types. A plausible formation mechanism of PSDM@α-FeOOH composites was revealed based on the systematic investigations of the assembly process. Additionally, it was possible for this method to be extended to synthesis the composite particles for other metal ions. The photocatalytic activity of the composites had been discussed by testing the degradation of rhodamine B as well as methylene blue and neutral red in the presence of H 2 O 2 . The measurements demonstrated that PSDM@α-FeOOH composites catalyst exhibited excellent photocatalytic ability and superior stability.

It is still extremely challenging to endow epoxy resins (EPs) with excellent flame retardancy and high toughness. In this work, we propose a facile strategy of combining rigid–flexible groups, promoting groups and polar phosphorus groups with the vanillin compound, which implements a dual functional modification for EPs. With only 0.22% phosphorus loading, the modified EPs obtain a limiting oxygen index (LOI) value of 31.5% and reach V-0 grade in UL-94 vertical burning tests. Particularly, the introduction of P/N/Si-containing vanillin-based flame retardant (DPBSi) improves the mechanical properties of EPs, including toughness and strength. Compared with EPs, the storage modulus and impact strength of EP composites can increase by 61.1% and 240%, respectively. Therefore, this work introduces a novel molecular design strategy for constructing an epoxy system with high-efficiency fire safety and excellent mechanical properties, giving it immense potential for broadening the application fields of EPs.

Due to unique chelating and macrocyclic effects, crown ether compounds exhibit wide application prospects. They could be introduced into amphiphilic copolymers to provide new trigger mode for drug delivery. In this work, new amphiphilic random polymers of poly(lipoic acid-methacrylate-co-poly(ethylene glycol) methyl ether methacrylate-co-N-isopropylacrylamide-co-benzo-18-crown-6-methacrylamide (abbrev. PLENB) containing a crown ether ring and disulphide bond were synthesized via RAFT polymerization. Using the solvent evaporation method, the PLENB micelles were formed and then used to load substances, such as doxorubicin hydrochloride (DOX) and gold nanoparticles. The results showed that PLENB exhibited a variety of lowest critical solution temperature (LCST) in response to the presence of different ions, such as K+, Na+ and Mg2+. In particular, the addition of 150 mM K+ increased the LCST of PLENB from 31 to 37 °C and induced the release of DOX from the PLENB@DOX assemblies with a release rate of 99.84% within 12 h under 37 °C. However, Na+ and Mg2+ ions could not initiate the same response. Furthermore, K+ ions drove the disassembly of gold aggregates from the PLENB-SH@Au assemblies to achieve the transport of Au NPs, which is helpful to construct a K+-triggered carrier system.

As a promising nanofiller, layered double hydroxides (LDHs) can advance the fire safety of epoxy resin (EP), but so far, due to the problems of dispersion and low efficiency, it has still been a challenge to incorporate the flame retardancy and mechanical properties of EP nanocomposites effectively under the circumstance of a low additive amount. In this work, we take LDHs as the template, via the adsorption of a catechol group and the condensation polymerization between catechol groups and phenylboric acid groups, to prepare a core–shell structured nanoparticle LDH@BP, which contains rich flame-retardant elements. EP/LDH@BP nanocomposites were prepared by introducing LDH@BP into EP. The experimental results indicate that, compared with the original LDH, LDH@BP disperses uniformly in the EP matrix, and the flame retardancy and mechanical properties of EP/LDH@BP are significantly improved. At a relatively low content (5 wt%), EP/LDH@BP reached the rating of V-0 in the UL-94 test, LOI was increased to 29.1%, and peak heat release rate (PHRR) was reduced by 35.9% in cone calorimeter tests, which effectively inhibited the release of heat and toxic smoke during the combustion process of EP. Simultaneously, the mechanical properties of EP/LDH@BP have been improved satisfactorily. The above results derive from the reasonable architectural design of organic–inorganic nano-hybrid flame retardants and provide a novel method for the construction of efficient and balanced EP nanocomposite system with LDHs.

In this paper, the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO)-containing diblock copolymer poly[(p-hydroxybenzaldehyde methacrylate)m-b-(2-((6-oxidodibenzo[c,e][1,2]oxaphosphinin-6-yl)oxy)ethyl methacrylate)n] (abbrev. poly(HAMAm-b-HEPOMAn)) was synthesized by reversible addition fragmentation chain transfer (RAFT) polymerization. When it was continued to react with titanium-hybridized aminopropyl-polyhedral oligomeric silsesquioxane (Ti-POSS) through a Schiff-base reaction, new grafted copolymers poly[(Ti-POSS-HAMA)m-b-HEPOMAn] (abbrev. PolyTi) were obtained. Then, they were used as macromolecular flame retardant to modify epoxy resin materials. The thermal, flame retardant and mechanical properties of the prepared EP/PolyTi composites were tested by TGA, DSC, LOI, UL-94, SEM, Raman, DMA, etc. The migration of phosphorus moiety from epoxy resin composites was analyzed by immersing the composites into ethanol/H2O solution and recording the extraction solution by UV-Vis spectroscopy. The results showed that the added PolyTi enhanced the glass transition temperature, the carbon residue, the graphitization of char, LOI, and mechanical properties of the EP/PolyTi composites when compared to pure cured EP. Furthermore, the phosphorus moieties were more likely to migrate from EP/DOPO composites than that from EP/PolyTi composites. Obviously, compared with small molecular flame retardant modified EP, the macromolecular flame retardant modified EP/PolyTi composites exhibited better thermal stability, flame retardancy, and resistance to migration.