Search

The key challenge in the practical application of electrochromic energy storage devices (EESDs) is the fabrication of high-performance electrode materials. Herein, we deposited K7[La(H2O)x(α2-P2W17O61)] (P2W17La) onto TiO2 nanowires (NW) to construct an NW–P2W17La nanocomposite using a layer-by-layer self-assembly method. In contrast to the pure P2W17La films, the nanocomposite exhibits enhanced electrochromic and electrochemical performance owing to the 3D sea-cucumber-like microstructure. An EESD using the NW–P2W17La film as the cathode exhibited outstanding electrochromic and energy storage properties, with high optical modulation (48.6% at 605 nm), high switching speeds (tcoloring = 15 s, tbleaching = 4 s), and high area capacitance (5.72 mF cm−2 at 0.15 mA cm−2). The device can reversibly switch between transparent and dark blue during the charge/discharge process, indicating that electrochromic contrast can be used as a quantitative indicator of the energy storage status. [ABSTRACT FROM AUTHOR]

Textile‐substrate electromagnetic interference (EMI) shielding materials show great promise for next‐generation electronic communication technology challenges. A new strategy based on structure optimization is highly desired for wearable electronic devices to improve EMI shielding performance. Here, the enhancement effect of fabric structure on the shielding effectiveness (SE) of conductive nanocomposite coating is demonstrated. Plain fabrics with different fabric densities are weaved and used as the substrate to be layer‐by‐layer assembled by graphite oxide and polypyrrole. The resulting conductive nanocomposite coating endows common cotton fabrics with electrical conductivity and EMI shielding ability. In comparison, the EMI SE of the conductive coated fabrics is depended on the fabric density, that is, the pore size. Specifically, the EMI SE of the coated fabric can be increased by ≈71% through the control of fabric structure. Interestingly, the EMI SE is always the maximum at the fabric density of 100 × 100 picks/ 10 cm, different from the electrical conductivity. Moreover, the sueding treatment was proven to be useful to further improve the EMI SE of the conductive coated fabrics. This work presents the significance of substrate structures in EMI shielding, offering new opportunities for the development of high efficiency EMI shielding fabrics. [ABSTRACT FROM AUTHOR]

Surface potential decay on negative corona charged epoxy/Al2O3 nanocomposites irradiated with high-energy electron beam has been investigated in this paper. 2-mm-thick laminate nanocomposite samples were irradiated with electron beam at an average energy of 7.5 MeV, and the total accumulated dose was up to 500 kGy. After the irradiation, the nanocomposites were corona charged with dc voltage at −10 kV through a pair of needle to plate electrode. Surface potential of the sample was then measured by means of an electrostatic voltmeter through which trap distribution and carrier mobility were calculated. Differential scanning calorimetry curve for the each sample was measured to understand the change in chemical and physical structures induced by the irradiation. Results obtained indicated that the presence of nanofiller in the nanocomposites played a role in limiting the charge transportation both before and after the irradiation, and the charge transportation behavior was remarkably dependent upon the total irradiation dose. It is found that when irradiated with a certain total dose of electron beam, electron migration within epoxy and its nanocomposites is restricted, which should be attributed to the high-energy irradiation-induced structural change of the material. [ABSTRACT FROM AUTHOR]

Tough swelling nanocomposite hydrogels have been fabricated via introducing graphene oxide (GO) and in situ synthesis. Upon addition of GO, the swelling properties of a calcium alginate/polyacrylamide (CA/PAAm) double network (DN) are considerably suppressed. Moreover, the mechanical properties of CA/PAAm DN gels and GO reinforced DN gels in swelling and as-prepared states have been systematically explored. The results affirm that the swelling largely damages the mechanical properties of gels, due to the osmotic pressure introducing solvents into the gaps between polymer chains and cross-linkers, thereby leading to weak spots in the gels. GO demonstrates the ability to improve the mechanical properties of pristine DN gels in both swelling and as-prepared states by offering large numbers of physical interpenetrations and chemical bindings between long polymeric chains and GO nanosheets, and building a Ca2+ coordination-induced GO network. The toughness of swelling nanocomposite gels is around 106 kJ m−3 that is comparable to that of cartilage in large animal joints. Furthermore, the consecutive loading–unloading tests and cytotoxicity tests show that the swelling nanocomposite gels, respectively, obtain superior fatigue resistance and high biocompatibility. Therefore, these swelling nanocomposite gels are promising as substitutes for load-bearing tissues. [ABSTRACT FROM AUTHOR]