Porous Graphene Produced by Carbothermal Shock for Green Electromagnetic Interference Shielding in Both Microwave and Terahertz Bands.

The prospect of graphene-based shielding materials in the form of fillers is limited by the cumbersome preparation of graphene. Herein, defect-tunable porous graphene prepared by carbothermal shock using low-value sucrose as a precursor is proposed as an effective shielding filler. The resultant porous graphene exhibits 32.5 dB shielding efficiency (SE) and 2.5-18 GHz effective bandwidth at a mass loading of 20 wt%, competing with the shielding performance of graphene fillers prepared by other methods. Particularly, defect-rich graphene synthesized by increasing voltage and prolonging time shows increased electromagnetic (EM) wave absorption, echoing the current concept of green shielding. In addition, the strategy of controlling the discharge conditions to improve the absorption by the shield is developed in the terahertz band. The average SE and reflection loss of the samples in the THz band (0.2-1.2 THz) exhibit 40.7 and 15.9 dB at filler loading of 5 wt%, respectively, achieving effective shielding and absorption of THz waves. This work paves a new way for low-cost preparation of graphene for EM interference shielding fillers. Meanwhile, it supplies a reference for the shielding research of the upcoming applications integrating multiple EM bands (such as sixth-generation based integrated sensing and communication).

Design of Superhydrophobic CoFe2O4 Solar Seawater Desalination Device and Its Application in Organic Solvent Removal.

Environmental pollution and clean water production are challenges to the development of human society. In this paper, devices consisting of a superhydrophobic Ni-CoFe2O4 foam layer (floating layer), a hydrophilic channel and a superhydrophilic Ni-CoFe2O4 foam layer (photothermal conversion layer) were designed. The light energy was converted into heat on the photothermal layer, for which the hydrophilic channel provided a small amount of water. The superhydrophobic layer ensured the floating and selective adsorption of organic solvents on the water surface, whose contact angle reached 157°, and the steam production rate reached 1.68 kg·m-2·h-1. Finally, the LSV curve demonstrated that the Ni-CoFe2O4 foam prepared had a minimum starting potential, achieving the multifunctionality of the Ni foam.

Effect of zinc content on the microstructure, in vitro bioactivity, and corrosion behavior of the microarc oxidized Mg-xZn-0.6Ca (x = 3.0, 4.5, 6.0) alloy.

Bioceramic calcium phosphorus (CaP) coatings were prepared on self-designed Mg-xZn-0.6Ca (x = 3.0, 4.5, 6.0 wt. %) alloy by microarc oxidation (MAO). The corrosion resistance, bioactivity, and biodegradability of the CaP coatings prepared on alloys with different zinc (Zn) contents were systematically studied and discussed by potentiodynamic polarization and in vitro immersion tests in the simulated body fluid solution. The CaP coatings and corrosion products were characterized by scanning electron microscopy, energy dispersive spectrometry, x-ray diffraction, and Fourier transform infrared spectroscopy. Based on the difference of microstructure caused by zinc content, the effect of microstructure on the properties of MAO coatings was analyzed by taking grain boundary and second phase defects as examples. Results showed that the CaP coatings could be prepared on the surface of the self-designed Mg-Zn-0.6Ca alloy by MAO. The CaP coatings have good bioactivity. Meanwhile, the Zn content has a significant effect on the microstructure of the CaP coatings. When the Zn content is 3.0 wt. %, the corrosion resistance and biocompatibility of the CaP coatings are obviously improved with good biological properties.

Preparation and properties of plasma electrolytic oxidation coating on sandblasted pure titanium by a combination treatment.

Plasma electrolytic oxidation (PEO) is one of the most applicable methods to produce bioceramic coating on a dental implant and sandblasting is a primary technique to modify metal surface properties. This study aims to deposit bioceramic Ca- and P-containing coatings on sandblasted commercially pure titanium by PEO technique to improve its bioactive performance. The time-dependent modified surfaces are characterized in terms of their microstructure, phase, chemical composition, mechanical properties and bioactivities. The results show that the combination-treated coating exhibits better properties than the PEO-treated one, especially in bioactivities, as evidenced by the HA formation after immersion in simulated body fluid (SBF) for 5 days and the cell viability after seeding for 1 or 3 days. The enhancement of the modified surface is attributed to a combination of the mechanical sandblasting and the microplasma oxidation.