RESUMEN
Nowadays, flexible multifunctional composites are attracting much attention and are practically being used in various emerging electronic devices. However, most composites suffer from the disadvantages of high loadings of conductive fillers, complicated preparation processes, and low energy conversion efficiency. In this article, Caffeic acid-modified multiwalled carbon nanotubes (C-MWCNTs)/poly(3,4-ethylene dioxythiophene):polystyrene sulfonic acid (PEDOT:PSS)/polyimide (PI) composite films (CPFs) were prepared using a simple layer-by-layer deposition method. The "reinforced concrete" structure of the C-MWCNTs/PEDOT:PSS layer ensures high electrical conductivity of the film, while the PI layer provides excellent mechanical properties (72.69 MPa). The composite film exhibits excellent electrothermal response and thermal stability up to approximately 125 °C at 5 V. In addition, the good conductivity of the film provides its electromagnetic shielding effectiveness (32.69 dB). With these advantages, we expect that flexible CPFs will be widely utilized in wearable devices, electromagnetic interference (EMI) shielding applications, and thermal management of personal or electronic devices.
RESUMEN
With the popularization of 5G technology and the development of science and technology, flexible and transparent conductive films (TCF) are increasingly used in the preparation of optoelectronic devices such as electromagnetic shielding devices, transparent flexible heaters, and solar cells. Silver nanowires (AgNW) are considered the best material for replacing indium tin oxide to prepare TCFs due to their excellent comprehensive properties. However, the loose overlap between AgNWs is a significant reason for the high resistance. This article investigates a sandwich structured conductive network composed of AgNW and Ti3C2Tx MXene for high-performance EMI shielding and transparent electrical heaters. Polyethylene pyrrolidone (PVP) solution was used to hydrophilic modify PET substrate, and then MXene, AgNW, and MXene were assembled layer by layer using spin coating method to form a TCF with a sandwich structure. One-dimensional AgNW is used to provide electron transfer channels and improve light penetration, while two-dimensional MXene nanosheets are used for welding AgNWs and adding additional conductive channels. The flexible TCF has excellent transmittance (85.1 % at 550 nm) and EMI shielding efficiency (27.1 dB). At the voltage of 5 V, the TCF used as a heater can reach 85.6 °C. This work offers an innovative approach to creating TCFs for the future generation.
RESUMEN
Traditional conductive fabrics are prepared by the synthesis of conductive polymers and the coating modification of metals or carbon black conductive materials. However, the conductive fabrics cause a significant decline in performance after washing or mechanical wear, which limits their application. Moreover, the single function of the traditional conductive fabric is also the reason that limits its wide application. In order to prepare a wearable, stable, high-performance, washable, multifunctional conductive fabric, we have carried out related research. In this work, polydopamine was used as a bonding layer, an adsorption reduction layer, and a protective layer to improve the bonding between silver nanoparticles and carbon nanotubes (CNTs) on the polyester fabric surface so as to prepare a multifunctional conductive fabric with a high-stability "sandwich" structure, in which a Ag-NPS@CNT structure acting as an intermediate conductive layer formed on the inner layer PDA@CNT by electroless silver plating and the outermost layer PDA@CNT coated on the surface of the intermediate conductive layer by the impregnation-drying method. The sheet resistance of an E-Fabric can reach 2.11 Ω/â¡ due to the uniform and dense conductive path formed by the special structure Ag-NPs@CNT. At a low voltage of 1.5 V, the E-Fabric can reach 117 °C in 50 s and remain stable. The electrical conductivity and current heating properties of the E-Fabric remain good even after multiple washing or bending tests. Due to its stable and outstanding electrical conductivity, the E-Fabric has an electromagnetic shielding efficiency (SET) of 35.3 dB in the X-band (8.2-12.4 GHz). In addition, E-Fabric-based spin-coated poly(methyl methacrylate) or polydimethylsiloxane electrodes exhibit excellent performance in nanogenerators. Through the low-frequency friction of the human body, transient voltages up to 4 V can be generated from a 2 cm × 2 cm electrode sample. The output power of a single generator can reach about 12 nW/cm2. Therefore, an E-Fabric is considered to have great potential in the fields of electric heating, electromagnetic shielding, and smart wearable devices.
RESUMEN
Transparent conductive films with high stability were prepared by embedding silver nanowires in colorless polyimide and adding a protective layer of exfoliated graphene. The films exhibit great light transmission and conductivity with a sheet resistance of 22 Ω sq-1at transmittance of 83%. Due to its special embedded structure, the conductive layer can withstand several peeling experiments without falling off. In addition, the most outstanding advantage is the ultra-high stability of the films, including high mechanical robustness, strong chemical corrosion resistance and high operating voltage capacity. The organic light-emitting diode devices prepared based on this transparent conductive electrode exhibit comparable efficiency to indium tin oxide (ITO) based devices, withC.E.max= 2.78 cd A-1,P-1.E.max= 1.89 lm W-1,EQEmax= 0.89%. Moreover, the efficiencies were even higher than that of ITO devices when the operating voltage of the device exceeds 5 V. The above performances show that the transparent conductive electrode based on this structure has high potential for application in organic electronic devices.
RESUMEN
In this paper, we used tannic acid (TA) functionalized carbon nanotubes (TCNTs), and silver nanowires (AgNWs) to construct a new type of transparent conductive film (TCF) with a double-layered conductive network structure. The hybrid film exhibits excellent light transmittance, high electrical conductivity, ultra-flexibility, and strong adhesion. These outstanding performances benefit from the filling and adhesion of hydrophilic TCNT layers to the AgNW networks. Besides, we introduced the post-treatment process of mechanical pressing and covering polymer conductive polymer PEDOT:PSS, which obtained three layers of TCNT/AgNW/PEDOT hybrid film and greatly improved the comprehensive properties. The hybrid film can reach a sheet resistance of 9.2 Ω sq-1 with a transmittance of 83.4% at 550 nm wavelength, and a low root mean square (RMS) roughness (approximately 3.8 nm). After 10 000 bends and tape testing, the conductivity and transmittance of the hybrid film remain stable. The resistance of the film has no significant degradation after 14 d of exposure to high temperature of 85 °C and humidity of 85%, indicating excellent stability. The organic light-emitting diodes (OLEDs) with TCNT/AgNW/PEDOT hybrid film as anode exhibit high current density and luminosity, confirming this process has considerable potential application in photovoltaic devices.