Silicon carbide is considered as a bio‐inert semiconductor material; consequently, it has been proposed for potential applications in human body implantation. In this study, we study the effect of implanting different metal ions on the surface properties of silicon carbide single crystal. The valence states of the elements and the surface roughness of implanted SiC were studied using X‐ray photoelectron spectroscopy and atomic force microscope, respectively. Osteoblastic MG‐63 cells were utilized to characterize the cytocompatibility of ion implanted SiC. The results show that after Nb ion implantation on the SiC surface, it mainly exists in the form of Nb–C bond, Nb–O bond, and a small amount of metallic niobium. The titanium implanted on SiC primarily forms Ti‐C bond and Ti‐O bond. The tungsten implanted on SiC mostly presents as metallic tungsten and W–O bond. The roughness of silicon carbide single crystal is improved by ion implantation of all three metal ions. Ion implantation of titanium and niobium can improve the cell compatibility and hydrophilicity of silicon carbide, whereas ion implantation of tungsten reduces the cell compatibility and hydrophilicity of silicon carbide.

Graphene has exhibited outstanding properties of reducing friction and wear when it is utilized as a novel solid lubricant, while its durability, especially at the macroscale, remains a challenge for robust industrial applications. In this study, we demonstrate a remarkable substrate‐dependent enhancement of the durability and load capacity of graphene film prepared with electrophoretic deposition method. The tribological performance of graphene films on four typical engineering material surfaces was examined. Graphene films exhibit highly consistent coefficients of friction ranging from 0.1 to 0.16, decreasing by 76%–87% compared with that obtained for the bare substrates (0.60–0.83). As for durability, graphene films on the stainless steel and titanium alloy substrates show largely enhanced lifetime compared with that on the silicon or cemented carbide substrates. The graphene film on titanium allay can sustain up to 260,000 cycles, 10–20 times longer than that on brittle substrates. Such a remarkably enhanced durability should be attributed to the relatively higher ductility of the substrates and its high adhesion with graphene, which is beneficial for forming a dense layer of graphene‐containing tribo‐film within the sliding interface. The results of this study may provide a useful guideline for utilizing graphene films as solid lubricants in engineering fields.

In this study, we prepared a‐C:H films with different nanostructures at different methane flow rates. The effect of the methane flow rate on the tribological properties of 440 steel/a‐C:H friction pairs and a‐C:H:Ti/a‐C:H friction pairs in an atmospheric environment was studied by a reciprocating friction machine. The results show that there is no relationship between the tribological properties of 440 steel/a‐C:H friction pair and methane flow rate. The tribological performance of the a‐C:H:Ti/a‐C:H friction pair was greatly improved. In particular, in the friction pair of a‐C:H:Ti/a‐C:H with a methane flow rate of 20 sccm, superlubricity is shown, and the wear rate is only 4.04 × 10 −9 mm 3 /Nm. After tribological experiments, Raman spectroscopy, XPS, and other characterization methods were used to study the relationship between the nanostructure and tribological properties of a‐C:H:Ti films and a‐C:H prepared with different methane flow rates. This study is great significance to the application of a‐C:H:Ti/a‐C:H friction pair in mechanical parts under atmospheric environment.

Lithium‐ion batteries are commonly used for electrical energy storage in portable devices and are promising systems for large‐scale energy storage. However, their application is still limited due to electrode degradation and stability issues. To enhance the fundamental understanding of electrode degradation, we report on the Raman spectroscopic characterization of LiCoO 2 cathode materials of working Li‐ion batteries. To facilitate the spectroscopic analysis of the solid electrolyte interface (SEI), we apply in situ surface‐enhanced Raman spectroscopy under battery working conditions by using Au nanoparticles coated with a thin SiO 2 layer (Au@SiO 2 ). We observe a surface‐enhanced Raman signal of Li 2 CO 3 at 1090 cm −1 during electrochemical cycling as an intermediate. Its formation/decomposition highlights the role of Li 2 CO 3 as a component of the SEI on LiCoO 2 composite cathodes. Our results demonstrate the potential of Raman spectroscopy to monitor electrode/electrolyte interfaces of lithium‐ion batteries under working conditions thus allowing relations between electrochemical performance and structural changes to be established.

Octenidine dihydrochloride (OCT) has a wide spectrum of antibacterial, antifungal and virucidal activity. OCT is also newly used in tissue engineering. The aim of this work was to create a new nanocomposite consisting of OCT‐grafted polymer with (i) antibacterial effect and/or (ii) surface for better cell adhesion and proliferation. The polymer foils were chemically activated with Piranha solution and subsequently grafted with OCT. Changes in surface properties before and after modifications were detected by electrokinetic analysis, goniometry, atomic force microscopy, scanning electron microscopy and X‐ray photoelectron spectroscopy. The final nanocomposite polymer/OCT exhibits antibacterial activity against Staphylococcus epidermidis ( S. epidermidis ). The new nanocomposite material has also been shown to support the growth of B14 cell culture on the substrate and to form cell multilayers, which could lead to the formation of spheroids. This behaviour strongly depends on the concentration of OCT grafted onto the polymer surfaces. This new nanocomposite could be used in medicine, for bioapplications, environmental protection.

Reflection electron energy loss spectra (REELS) were measured for five insulating organic compounds: Kapton, polyethylene (PE), poly(methyl methacrylate) (PMMA), polystyrene (PS) and polytetrafluoroethylene (PTFE), as well as for Ni and Si, in the energy range between 200 and 1600 eV. The average number of surface excitations for a single surface crossing were determined from the experimental data and were found to be considerably smaller than for earlier studied materials, which mainly consisted of elemental metals [Surf. Sci. 486(2001)L461]. The surface excitation parameter, a material parameter used to quantify the relative intensity of surface losses in (photo)electron spectroscopy, was extracted from the data and compared with values found in the literature. The results indicate that surface excitations only have a minor influence on quantification of XPS spectra of polymers. On the other hand, a correction for surface excitations turns out to be essential for measurements of the electron inelastic mean free path of polymers when a metal is used as reference material.

The effects of 1 wt.% Ca or 1 wt.% Ca + 1 wt.% Ag addition and heat treatment on the corrosion behavior of Mg‐7Sn (wt.%) alloy in 3.5 wt.% NaCl solution were investigated by electrochemical measurements and immersion tests. The alloys were characterized by optical microscope (OM), X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X‐ray photoelectron spectroscopy (XPS). It was found that all alloys were corroded by pitting corrosion and grain boundary corrosion and further corroded with time going. Loose layers of compounds, including Mg (OH) 2 , MgO, SnO 2 , and other compounds containing Ca and Ag elements, were calibrated on the surface of corroded Mg‐7Sn‐1Ca‐1Ag alloy. The Ca addition improved the corrosion resistance of Mg‐7Sn alloy due to the formation of relatively stable compounds containing calcium element and grains refinement. Furthermore, the solid solutioned alloys obtained a superior corrosion resistance due to the dissolve of eutectic Mg 2 Sn phase and homogenization treatment. However, the aging treatment is slightly detrimental to the corrosion resistance of Mg‐7Sn alloys with the formation of Mg 2 Sn precipitates. In conclusion, the aged Mg‐7Sn‐1Ca‐1Ag alloy exhibited a better corrosion resistance and a noticeable micro‐hardness property compared with those of as‐cast Mg‐7Sn alloy. And this study provides an important idea for the research on the comprehensive properties of Mg‐Sn alloys.