In this work, eco-friendly superhydrophobic coatings were prepared by dispersing hydrophobic silica nanoparticles and a waterborne silicone-modified polyurethane dispersion into an ethanol solution, which was free of fluorine and volatile toxic solvents. The effects of the silica content on the hydrophobicity and scratch resistance of the hydrophobic surfaces were investigated by WCA measurements and a sandpaper abrasion test, respectively. The experimental results indicated that when the silica content exceeded 30% by mass, the silica/silicone-modified polyurethane coatings had superhydrophobicity. Meanwhile, the superhydrophobic coatings with a silica content of 30% by mass simultaneously had the optimal mechanical stability. We studied the morphology and roughness of the hydrophobic surfaces with different silica content and attempted to briefly explain the influence mechanism of silica content. Furthermore, anti-icing and oil–water separation experiments were carried out on the superhydrophobic coatings, which exhibited good anti-icing performance and high separation efficiency. The eco-friendly superhydrophobic coating is expected to be applied in the fields of oil–water separation, anti-icing, and self-cleaning, etc.

To improve the hydrophobic property of polyurethane foam for oil spill cleanup, the polyurethane foam with nitrile groups is modified by grafting with oleophilic octadecylamine. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and optical contact angle measuring device are used to characterize the modified polyurethane foam. The results show that the octadecylamine has been successfully grafted onto the polyurethane foam and improved the foam hydrophobicity. The modified foam exhibits higher contact angle (146.3 ± 2.8°) compared to the unmodified foam (121.4 ± 3.2°). Moreover, the water sorption of the modified foam is 0.11g/g, which is much lower than that of the unmodified foam (0.84g/g). On the other hand, the sorption capacity of the modified foam for toluene, gasoline and diesel sorption is increased by 20˜40%. Therefore, the polyurethane foam prepared by us can be effectively used in oil/solvent spill cleanup.

Carbon nanotubes form a complex network in nanocomposites. In the network, the configuration of the nanotubes is various. A carbon nanotube may be curled or straight, and it may be parallel or crossed to another. As a result, carbon nanotube-based composites exhibit integrated characteristics of inductor, capacitor and resistor. In this work, it is hypothesized that carbon nanotube-based composites all adhere to a RLC interior circuit. To verify the hypothesis, three different composites, viz. multi-walled carbon nanotube/ polyvinylidene fluoride (MWCNT/PVDF), multi-walled carbon nanotube/epoxy (MWCNT/EP), multi-walled carbon nanotube/ polydimethylsiloxane (MWCNT/PDMS) were fabricated and tested. The resistances and the dielectric loss tangent (tanδ) of the materials were measured in direct and alternating currents. The measurement shows that the value of tanδ is highly affected by the volume fraction of MWCNT in the composites. The experimental results prove that the proposed RLC equivalent circuit model can fully describe the electrical properties of the MWCNT network in nanocomposites. The RLC model provides a new route to detect the inductance and capacitance of carbon nanotubes. Moreover, the model also indicates that the carbon nanotube-based composite films can be used as RFID chips, which may lead to the development of wireless strain sensors.

With the development of mobile communication technology, we have now entered the 5G era. At the same time, vertical industries have also made new developments in 5G. Compared with ordinary users, users in vertical industries have more security requirements for their services. While vertical industries are developing in a more digital and networked direction, traditional authentication methods such as VPDN cannot satisfy the new security requirements, which brings greater challenges to the security of vertical industries. In order to satisfy the more security requirements of vertical industries, endogenous secondary authentication is introduced in the 5G network architecture, and the Extensible Authentication Protocol (EAP) is used to satisfy the different security requirements of vertical industries. This paper analyzes three kinds of secondary authentication methods based on the status quo and technological development trends of vertical industries, and proposes a 5G secondary authentication scheme based on 3GPP protocol standards. We use OpenAirInterface (OAI) to build a mobile communication network experimental platform, and realize the secondary authentication between users and authentication servers based on the EAP-TLS protocol by modifying the function of the network element. Experiment results demonstrate that our scheme has high security and reliability. It can provide a reference for the vertical industry to deploy secondary authentication in 5G.

The physical nature of the scratch behavior of CoCrFeMnNi HEA and its deformation mechanism at different morphology densities are investigated by molecular dynamics simulations. The results show that the groove morphology contributes to the reduction of surface plastic deformation and exhibits a friction-reducing effect. As the morphology density decreases, the surface deformation and atom pile-up decrease, and the plastic deformation in the scratch region decreases, resulting in a further enhancement of the friction reduction effect. The increase of scratch depth intensifies the plastic deformation of the specimens, and the average scratch coefficient of friction increases with the increase in scratch depth. The dominant plastic deformation mechanism in the scratch deformation of CoCrFeMnNi HEA with different morphology densities is the slip deformation of Shockley partial dislocations. The MD simulations are verified further by qualitatively comparing them with corresponding experimental observations of CoCrFeMnNi HEA.