It is well accepted that the microwave absorption performance (MAP) of carbon nanotubes (CNTs) can be enhanced via coating magnetic nanoparticles on their surfaces. However, it is still unclear if the magnetic coating structure has a significant influence on the microwave absorption behavior. In this work, nano-FeO compact-coated CNTs (FCCs) and FeO loose-coated CNTs (FLCs) are prepared using a simple solvothermal method. The MAP of the FeO-coated CNTs is shown to be adjustable via controlling the FeO nanocoating structure. The results reveal that the overall MAP of coated CNTs strongly depends on the magnetic coating structure. In addition, the FCCs show a much better MAP than the FLCs. It is shown that the microwave absorption difference between the FLCs and FCCs is due to the disparate complementarities between the dielectric loss and the magnetic loss, which are related to the coverage density of FeO nanoparticles on the surfaces of CNTs. For FCCs, the mass ratio of CNTs to Fe is then optimized to maximize the effective complementarities between the dielectric loss and the magnetic loss. Finally, a comparison is made with the literature on FeO-carbon-based composites. The FCCs at the optimized CNT to Fe ratio in the present work show the most effective specific RL (28.7 dB·mm) and the widest effective bandwidth (RL < -10 dB) (8.3 GHz). The excellent MAP of the as-prepared FCC sample is demonstrated to result from the consequent dielectric relaxation process and the improved magnetic loss. Consequently, the structure-property relationship revealed is significant for the design and preparation of CNT-based materials with effective microwave absorption.

Novel three-dimensional (3D) urchin-like a-Fe 2 O 3 superstructures were successfully prepared by a template-free hydrothermal synthetic route using FeSO 4 ?7H 2 O and NaClO 3 as reagents. The as-obtained products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis and vibrating sample magnetometry. It is shown that the superstructures consisted of well-aligned a-Fe 2 O 3 nanorods growing radially from the cores of the superstructures. The a-Fe 2 O 3 nanorods have an average length of about 800 nm and a mean diameter of about 80 nm. Magnetic hysteresis measurement reveal that the urchin-like a-Fe 2 O 3 superstructures display weak ferromagnetic behavior with a remanence of 4.6783 6 10 23 emu g 21 and a coercivity of 92.235 Oe at room temperature. The formation mechanism of the 3D urchin-like a-Fe 2 O 3 superstructures was also discussed.

Uniform-sized, monodisperse, and single-crystal magnetite hollow spheres with a diameter of 200-300 nm and a shell thickness of ∼50 nm have been successfully synthesized in high yield using a template-free solvothermal route. The reaction duration and the ethylenediamine amount are shown to play important roles in the formation of the magnetite hollow spheres. X-ray diffraction, X-ray photoelectron spectroscopy, Fourier tranform IR, scanning electron microscopy, transmission electron microscopy (TEM), and high-resolution TEM were used to characterize the products. The results show that the prepared single-crystalline hollow spheres are composed of well-aligned magnetite and have a cubic structure. The magnetite hollow spheres show a high saturation magnetization of ca. 68 emu/g, a remnant magnetization of ca. 13 emu/g, and a coercivity of ca. 94 Oe at room temperature. A possible mechanism for the formation of magnetite hollow spherical structures is proposed based on the experimental observations. The prepared magnetite hollow spheres have promising applications in biomedical fields due to their above characteristics.

Wearable electronics used in smart clothing for healthcare monitoring or personalized identification is a new and fast-growing research topic. The challenge is that the electronics has to be simultaneously highly stretchable, mechanically robust and water-washable, which is unreachable for traditional electronics or previously reported stretchable electronics. Herein we report the wearable electronics of sliver nanowire (Ag-NW)/poly(dimethylsiloxane) (PDMS) nanocomposite which can meet the above multiple requirements. The electronics of Ag-NW/PDMS nanocomposite films is successfully fabricated by an original pre-straining and post-embedding (PSPE) process. The composite film shows a very high conductivity of 1.52 × 104 S cm−1 and an excellent electrical stability with a small resistance fluctuation under a large stretching strain. Meanwhile, it shows a robust adhesion between the Ag-NWs and the PDMS substrate and can be directly machine-washed. These advantages make it a competitive candidate as wearable electronics for smart clothing applications.

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Surface modified ZnO quantum dots (QDs) with ultrastable, strong and tunable luminescence have been successfully prepared via silanization during the growth process by (3-(2,3-epoxypropoxy)propyl)trimethoxysilane. The as-prepared ZnO QDs are demonstrated to be promising for anti-counterfeit applications in expensive high-end liquors, etc.

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Here a facile, green and efficient printing-filtration-press (PFP) technique is reported for room-temperature (RT) mass-production of low-cost, environmentally friendly, high performance paper-based electronic circuits. The as-prepared silver nanowires (Ag-NWs) are uniformly deposited at RT on a pre-printed paper substrate to form high quality circuits via vacuum filtration and pressing. The PFP circuit exhibits more excellent electrical property and bending stability compared with other flexible circuits made by existing techniques. Furthermore, practical applications of the PFP circuits are demonstrated.