Huanxia Zhang

High-performance aerogels featuring exceptional thermal insulation and integrated motion-sensing capabilities are pivotal for the advancement of next-generation flexible electronics and protective systems in extreme environments. However, achieving a synergistic balance between multi-functional integration within a single lightweight framework remains a significant challenge due to the structural limitations of conventional isotropic materials. Inspired by the hierarchical porous structures of aquatic plants, we herein report an anisotropic polyimide/reduced graphene oxide aerogel (PI/rGOA) with a biomimetic architecture, fabricated via a synergistic strategy of directional freezing and interfacial regulation. This approach combines directional freezing with hydrogen-bonding-assisted interfacial regulation between polyimide nanofibers (PINF) and graphene oxide (GO), enabling the construction of highly ordered anisotropic channels. The resulting PI/rGOA demonstrates superior thermal regulation, maintaining substantial temperature gradients at both −190 and 200 °C, while exhibiting rapid self-extinguishing behavior and structural integrity under a 1300 °C flame. Furthermore, the simultaneous regulation of heat conduction and infrared radiation enables effective stealth performance. The sensor encapsulated with polydimethylsiloxane (PDMS) provides high sensitivity and stability over 500 cycles. Overall, this work provides a versatile paradigm for developing multifunctional and structurally ordered materials, offering a promising solution for aerospace, defense, and wearable electronic devices.

As a typical carbon-based material electrode, graphene fiber exhibits many advantages, such as good electrical conductivity, lightweight, and strong structural designability. Its demand is increasing in the wearable display field. With the help of fine denier fiber spinning combined with multistranded graphene fibers prepared via twisting and drafting, their petal-like twisted structure endows the fibers with a high specific surface area, enabling them to complete dye adsorption within 30 min. Simultaneously, compared with that of a single fiber with the same thickness, the volume specific resistance of a multistranded twisted graphene fiber is reduced by 2.4 times. During force sensing, the twisted structure of multistranded fibers exhibits varying simultaneity of fiber fracture with excellent resistance sensitivity reaching up to 55%. The multistranded twisted flexible graphene fibers demonstrate excellent robustness. Electroluminescent flexible devices prepared with graphene fibers and fiber braided fabrics with different organizational structures as electrodes emit highly saturated short-wave blue light during long-term multiple use. Therefore, multistranded twisted graphene fibers exhibit considerable potential for future applications in wearable multicolor smart displays and flexible optical signal electronics.

3D graphene-based flexible nanosponges have shown great application potential in areas such as human motion tracking, health monitoring, and electronic skin. However, previously reported graphene-based flexible sensors typically focus on simple pressure sensing, lacking the capability to simultaneously detect both pressure and physiological signals. This limitation restricts their application in the field of intelligent wearable technology. In this study, a pressure-flexible composite sponge sensor was prepared using polyvinylidene fluoride (PVDF), viscose nonwoven fabric, and graphene oxide (GO) in a simple and cost-effective manner. Results showed that high-pressure electrospun PVDF inhibited the α-crystalline phase while promoting the transformation of diffraction peaks into the β-crystalline phase. Furthermore, high-temperature oxidation–reduction improved the crystallinity of β-phase crystals, enhancing the conductivity of PVDF/reduced GO/viscose fiber/polydimethylsiloxane ( PV/rGO/VF/P )sponges. With the increase of GO mass ratio, the thermal stability of the flexible composite device improved while weight loss decreased and resistance sensitivity increased. When compressed to 40%, the piezoelectric effect is most sensitive, and the composite sponge can fully recover under 60% compression. The addition of viscose fiber with a high swelling effect enables the composite sponge to precisely and sensitively detect the amount of sweat or glucose. This three-dimensional nanosponge can be applied in the design of ergonomic, physiologically monitoring smart wearable devices.

α-NiS/g-C₃N₄ nanocomposites were synthesized and used for photocatalytic hydrogen (H₂) evolution and tetracycline hydrochloride (TC) degradation. The fabricated nanocomposites were characterized by XRD, XPS, SEM, TEM, UV-vis DRS, TRPL, and PEC measurements. Photocatalytic studies show that the hydrogen generation rate of the 15%-α-NiS/g-C₃N₄ nanocomposite reaches 4025 μmol·g⁻¹·h⁻¹ and TC degradation rate 64.6% within 120 min, both of which are higher than that of g-C₃N₄. The enhanced performance of the nanocomposite is attributed to the formation of a heterojunction between α-NiS and g-C₃N₄ that enhances visible light absorption, promotes the separation and transfer of charges, and inhibits the recombination of carriers. The photocatalytic mechanism of the α-NiS/g-C₃N₄ heterojunction nanocomposite is discussed in terms of relevant energy levels and charge transfer processes.

In this present study, we have successfully fabricated the cellulose fabric with excellent electrical conductivity by depositing the graphene oxide grafted with the modified ferroferric oxide (GOF) upon fabric substrate via layer-by-layer magnetic-field-induced self-assembly apporoach and followed by chemical reduction. The results indicated that the morphologies of graphene oxide nanosheets for three-layer deposited fabrics could form the highly oriented wrinkled structures, which resulted from the synergistic interactions of magnetic induction force on magnetic doublet, hydrogen bonds and van der Waals. The volume resistivity of the three-layer deposited fabric could reach to 64.8 Ω cm compared with that of pure RGO-coated viscose fabrics (137.94 Ω cm) in the previous work, which could be favorable for improving the electrical conductivity and decreasing the graphene oxide consumption. Furthermore, the three-layer deposited fabric possessed excellent washing durability even after twelve times water laundering. Our results suggested that the flexible GOF-coated fabric had great potential in conductive devices for wearable electronics, strain sensors, smart actuators and bioelectrodes and so on.