The enhancement of the electromagnetic interference shielding efficiency (EMI SE) for conductive polymer composites (CPCs) has garnered increasing attention. The shielding performance is influenced by conductivity, which is dependent on the establishment of effective conductive pathways. In this review, Schelkunoff’s theory on outlining the mechanism of electromagnetic interference shielding was briefly described. Based on the mechanism, factors that influenced the electrical percolation threshold of CPCs were presented and three main kinds of efficient methods were discussed for establishing conductive pathways. Furthermore, examples were explored that highlighted the critical importance of such conductive pathways in attaining optimal shielding performance. Finally, we outlined the prospects for the future direction for advancing CPCs towards a balance of enhanced EMI SE and cost–performance.
Collecting ambient energy to power various wearable electronics is considered a prospective approach to addressing their energy consumption. Mechanical and thermal energies are abundantly available in the environment and can be efficiently converted into electricity based on different physical effects. Hydrogel-based energy harvesters have turned out to be a promising solution, owing to their unique properties including flexibility and biocompatibility. In this review, we provide a concise overview of the methods and achievements in hydrogel-based energy harvesters, including triboelectric nanogenerators, piezoelectric nanogenerators, and thermoelectric generators, demonstrating their applications in power generation, such as LED lighting and capacitor charging. Furthermore, we specifically focus on their applications in self-powered wearables, such as detecting human motion/respiration states, monitoring joint flexion, promoting wound healing, and recording temperature. In addition, we discuss the progress in the sensing applications of hydrogel-based self-powered electronics by hybridizing multiple energy conversion in the field of wearables. This review analyzes hydrogel-based energy harvesters and their applications in self-powered sensing for wearable devices, with the aim of stimulating ongoing advancements in the field of smart sensors and intelligent electronics.
In this paper, a novel resorcinol-formaldehyde-free and environmentally friendly adhesives for polyester (PET) fiber impregnation treatment were compounded successfully. First, a network structure was formed by reacting micromolecular and water-soluble glycerol triglycidyl ether (GLTE) and triethylenetetramine (TETA). Then, this was mixed with latex in order to prepare an impregnation solution glycerol triglycidyl ether-triethylenetetramine-butyropyridine latex system (GTL), which can replace the toxic components (resorcinol and formaldehyde) of the resorcinol-formaldehyde-latex (RFL) impregnation system. Similarly, the macromolecular epoxy resin E-51-triethylenetetramine-butyropyridine latex system (ETL) and the traditional RFL impregnation system were also prepared in order to compare with the GTL. Further, the reaction conditions of the impregnation system, the surface chemical composition and interfacial properties were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and peeling strength, respectively. The results showed that the peeling adhesion performance between the GTL-modified PET fabric and the rubber (38.5% higher than that of the ETL impregnation solution) was comparable to that of the RFL impregnation system because of micromolecular and more active GLTE. This study provides new insights into the interface design of PET/rubber composites and will facilitate the development of PET/rubber composites.