Search Results (3)

Engineering carbon nanostructures directly on carbon fiber fabrics offers an effective route to constructing hierarchical multifunctional coating systems. In this study, methane-based chemical vapor deposition (CVD) was employed to investigate nanocarbon coating formation on woven carbon fabrics supported by electrodeposited Ni catalysts. Catalyst morphology was systematically engineered through surface pretreatment, electric-field configuration, and pulse electrodeposition. At 700 °C, methane activation was insufficient to sustain continuous nanocarbon growth, indicating a temperature-dependent activation threshold. Raising the growth temperature to 900 °C enabled sustained methane decomposition and produced dense nanocarbon coatings; hydrogen assistance suppressed amorphous deposition and promoted more ordered nanofilament features. Pulse electrodeposition refined Ni catalyst dispersion and nucleation density, improving coating uniformity compared with direct-current deposition. Structural ordering was further supported by Raman spectroscopy (D and G bands with an average ID/IG of 0.678 ± 0.068 for methane-grown samples versus 0.798 ± 0.011 for electrodeposition-only controls) and by HRTEM revealing multi-layer graphitic walls (~0.34 nm interlayer spacing). Together, the results support a methane-derived dissolution–diffusion–precipitation growth pathway governed by catalyst morphology, temperature, and gas composition. This controllable, textile-compatible catalyst engineering approach provides a scalable route to hierarchical graphitic coatings for carbon-fabric-based composites, electromagnetic interference shielding, and thermal management applications. Full article

Shape memory polymers (SMPs) are a class of smart materials that exhibit unique shape-fixing and recovery abilities, attracting wide attention for applications in electronics, aerospace, and biomedical engineering. Chitosan (CS) as a renewable biopolymer, possessing good biocompatibility, biodegradability, and antimicrobial properties; its use as a matrix enhances the environmental compatibility and bio-adaptability of SMPs. MXene, as a novel two-dimensional material, is characterized by high electrical conductivity, abundant surface functional groups and good hydrophilicity, showing potential in energy storage, electromagnetic shielding and sensing. In this work, CS and poly (vinyl alcohol) (PVA) were used as the polymer matrix, and carbon nanotubes (CNTs) together with MXene were introduced as co-fillers to construct multifunctional composites. The effect of the CNTs/MXene hybrid fillers on mechanical properties, electromagnetic shielding and multi-stimuli-responsive shape memory behavior was systematically investigated. After ratio optimization, the composites showed excellent comprehensive performance: tensile strength reached up to 20.0 MPa, Young’s modulus up to 292.2 MPa, and maximum elongation at break of 23.2%; electromagnetic interference shielding effectiveness (SE_T) in the X-band (8.2–12.4 GHz) reached a maximum of 10.6 dB; shape fixation rates exceeded 90%; under thermal stimulation, a shape recovery ratio of 98.3% was achieved within 41.7 s; light-driven recovery rate reached 86.5% with a minimal recovery time of 82.3 s; under electrical stimulation the highest recovery rate was 94.1% with a shortest recovery time of 30 s. This study successfully prepared functional multi-stimuli-responsive shape memory composite films and provided a new strategy for the design of green smart materials. Full article

Microwave and infrared–thermal radiation-compatible shielding fabrics represent an important direction in the development of wearable protective fabrics. Nevertheless, effectively and conveniently integrating compatible shielding functions into fabrics while maintaining breathability and moisture permeability remains a significant challenge. Here, we take hydrophilic PVA-co-PE nanofibrous film-coated PET fabric (NFs/PET) as a flexible substrate and deposit a dielectric/conductive (SiO₂/Al) bilayer film via magnetron sputtering. This strategy endows the fabric surface with high electrical conductivity, nanoscale roughness comparable to visible and infrared waves, and a dielectric–metal contact interface possessing localized plasmon resonance and Mie scattering effects. The results demonstrate that the optimized SiO₂/Al/NFs/PET composite conductive fabric (referred to as S4-1) possesses favorable X-band electromagnetic interference (EMI) shielding effectiveness (50 dB) as well as excellent long-wave infrared (LWIR) shielding or IR stealth performance (IR emissivity of 0.60). Notably, the S4-1 fabric has a cooling effect of about 12.4 °C for a heat source (80 °C) and an insulating effect of about 17.2 °C for a cold source (−20 °C), showing excellent shielding capability for heat conduction and heat radiations. Moreover, the moisture permeability of the S4-1 fabric is about 300 g/(m²·h), which is better than the requirement concerning moisture permeability for wearable fabrics (≥2500–5000 g/(m²·24 h)), indicating excellent heat and moisture comfort. In short, our fabrics have lightweight, thin, moisture-permeable and excellent shielding performance, which provides novel ideas for the development of wearable multi-band shielding fabrics applied to complex electromagnetic environments. Full article