Fei Wan

With the increasing demand for low-carbon and integrated energy-storage systems, cement-based structural supercapacitors (CSSCs) have attracted growing attention because they combine energy-storage capability with structural load-bearing functions. However, limited ion transport within the cement matrix remains a key challenge. In this study, ceramic fibers were incorporated into a LiOTf/PAA-containing cement-based electrolyte to regulate ion transport while maintaining mechanical performance. Fiber−matrix interfacial regions formed during hydration provide additional electrolyte-containing transport pathways, while well-dispersed fibers help connect spatially separated transport regions and facilitate ion migration. At a ceramic fiber content of 0.8 wt %, the cement-based electrolyte exhibits the highest ionic conductivity of 2.62 mS cm−1. The corresponding CSSC delivers an areal capacitance of 834.67 mF cm−2, representing a 151.9% increase over the fiber-free system, and a maximum areal energy density of 260.83 μ Wh cm−2. Meanwhile, compressive and flexural strengths of 20.37 and 5.04 MPa are retained, respectively. Under compressive loading, the assembled device maintains stable charge−discharge behavior and retains 92.3% of its initial areal capacitance at an applied load of 4 kg. These results indicate that appropriate ceramic-fiber incorporation can improve ion transport and energy-storage performance while preserving mechanical functionality, supporting the potential of this strategy for integrated structural energy-storage applications.

Structural adhesives used in wet–cold environments are vulnerable to moisture ingress, ice expansion, and thermal mismatch. Here, a low‐loading ferric‐ion (Fe ³⁺ )‐coordinated polydopamine (PDA)‐coated geopolymer (GP), denoted Fe ³⁺ ‐PDA@GP, was introduced into an epoxy/polyurethane (EP/PU) adhesive to construct a multiscale hybrid interphase. The geopolymer core provides physical reinforcement and crack‐pinning effects, the PDA shell improves organic–inorganic interfacial compatibility, and Fe ³⁺ –catechol coordination introduces additional coordination‐mediated interfacial interactions that are associated with improved stress redistribution and fracture resistance. At an optimized loading of only 0.75 wt%, the adhesive achieved a lap‐shear strength of 29.2 MPa and a work of debonding of 14.5 kN m ⁻¹ , representing increases of 47.5% and 202.1% over neat EP/PU, respectively. Strong adhesion was maintained across multiple metallic substrates. After 100 freeze–thaw cycles between −40°C and 20°C, the adhesive retained 20.8 MPa, while two‐dimensional correlation analysis of Fourier transform infrared spectra indicated reduced molecular rearrangement. The modified adhesive also exhibited improved storage modulus and slightly increased glass‐transition temperature without compromising insulation. This work demonstrates a bioinspired, low‐filler strategy for developing strong, tough, and freeze–thaw‐resistant structural adhesives.

Simultaneously strengthening and toughening epoxy/polyurethane (EPU) structural adhesives while ensuring long‐term corrosion resistance remains challenging. Here, we develop a functionality‐tailored silane modification strategy that reinforces EPU with alkali‐activated metakaolin‐based geopolymer (GP). Amino‐functional KH550 and epoxy‐functional KH560 are grafted onto the GP framework via Si–O–M (M = Si, Al) bonds, while –NH₂ or epoxy groups further react with the EPU network, constructing chemically bonded organic–inorganic interfacial layers. At an optimal GP loading of 0.75 wt%, the KH560‐GP/EPU composite exhibits a ~21.6% increase in tensile strength, a 64.2% increase in elongation at break, and a lap‐shear strength of 13.5 MPa, achieving a favorable strength–ductility synergy. Flexural and compressive tests, together with scanning electron microscopy (SEM)/energy‐dispersive spectroscopy (EDS), reveal that silane modification—especially KH560—suppresses GP agglomeration and forms a continuous, compact interfacial transition zone, markedly enhancing flexural load‐bearing capacity with minimal impact on compressive strength. TGA/DSC and contact angle measurements further demonstrate higher thermal stability and pronounced surface hydrophobicity (water contact angle up to ~118°). Electrochemical impedance spectroscopy confirms superior long‐term barrier performance, with |Z|(0.01 Hz) remaining as high as 6.0 × 10 ⁸ Ω·cm ² after 14 days in 3.5 wt% NaCl. These results establish silane‐modified GP as a powerful platform for designing high‐performance EPU‐based structural adhesives and protective coatings.

Epoxy resins often require toughening to broaden their engineering applications, such as in durable concrete repair. This study addresses this need by developing high-performance polyurethane/epoxy (PU/EP) interpenetrating polymer networks (IPNs). The composites were synthesized via prepolymer and stepwise methods using polyether polyol (PPG-1000), isocyanate (MDI-50), and E51 epoxy. At an optimal PU prepolymer content of 15 wt%, the polyether-based IPNs achieved a balanced mechanical profile (tensile strength: 59.90 MPa; elongation at break: 6.46%; compressive strength: 69.99 MPa). Further tuning of the soft segment by introducing polyester polyol (PS-2412) yielded superior performance at a PS-2412/PPG-1000 ratio of 30/70. This formulation increased tensile and compressive strengths by 11.4% and 6.07% (to 66.74 MPa and 74.24 MPa), and dry and wet bond strengths by 12.1% and 36.3% (to 5.68 MPa and 4.62 MPa), respectively. The enhancement is attributed to the increased crosslinking density and more uniform network structure imparted by PS-2412, which improves stress distribution and interfacial adhesion. This work provides an effective soft-segment design strategy for fabricating toughened epoxy composites with robust mechanical and adhesive properties.

A combination of surface wettability and antibacterial performance is highly imperative for construction of antibacterial coatings. In this study, motivated by the antibacterial properties of zwitterionic polymer, mussel-inspired adhesion, and the “grafting to”, a novel DOMA-SBMA copolymer with adhesion and wettability is developed for constructing a bacteriostatic surface. Specifically, the antibacterial coating is prepared via free radical polymerization and grafting to methods on the surface of stainless steel, and characterized by SCA, FTIR, XPS, SEM, and AFM to confirm the modification process. Antibacterial activity evaluation using Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) shows that the coating presents satisfactory antibacterial performance. The results showed that DOMA-SBMA coating is enough for antibacterial application, with high antibacterial efficiency against E. coli (92.2%) and S. aureus (95.0%). In summary, the bioinspired coating developed here may improve the stability of zwitterionic coatings and provides a simple preparation strategy for constructing antibacterial coatings.