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Graphene has amazing applications for sensors due to its excellent performances like high strength and good conductivity, but the transfer issue is in the way of its application perspective. Direct growth of spherical graphene films (SGFs) on cemented carbide may offer a good avenue for various applications in sensor technology, especially for electrochemical sensors. Four common methods for graphene preparation are chemical stripping, chemical vapor deposition (CVD), metal catalysis, and laser fabrication; and subject to transfer issues during usage. In order to overcome this limitation, the fabrication of in-situ growth of SGFs on carbide is proposed as a solution for constructing sensor matrices. This review explores various in-situ SGFs and their potential applications in sensors. The findings presented here shed light on transfer-free graphene with controllable structures that can serve as excellent candidates for sensor matrices.

This review presents an overview of the fabrication and performance of diamond-like carbon (DLC) films doped with various elements on different substrates. By incorporating metal and nonmetal elements, the mechanical and tribological properties of DLC films, as well as the density and thermal stability of the coating, are enhanced. The amorphous carbon film exhibits a metastable state characterized by a combination of sp² and sp³ hybridization, which endows it with excellent properties resembling both diamond and graphite. These properties include high hardness, chemical stability, biocompatibility, infrared transmittance, ultra-low friction, and exceptional wear resistance. The application prospects of DLC films in the fields of machinery, biomedicine, microelectronics and optics were analyzed from the aspects of preparation method, doping element, transition layer, surface additive, and friction environment. Furthermore, this paper provides insights into the structure, factors influencing performance, application domains, existing technical challenges, and future development directions of diamond-like films. To study the tribological behavior of DLC films doped with different elements is a necessary condition to ensure its application in various fields. This is important because it ensures that DLC films can be used correctly and safely to the maximum extent possible. In summary, the properties of DLC films doped with different elements on different substrates are summarized in this paper, and some references are provided for their applications in machinery, aerospace, marine, and biomedicine.

Electrophoretic deposition (EPD) is a good method in the fabrication of the coating materials. Its processing parameters are easy to be operate. It is a nonbeeline process and can be used in the deposition on complex shape and porous surface. It has been widely used in many ways. This paper reviews the principles and fabrication steps of EPD and points out the influencing factors. The developments of EPD in the fabrication of materials, such as solid surface coatings, porous structure materials and gradient materials, are introduced in detail. The future of the application of EPD is also discussed.

The relaxor ferroelectric Pb(Mg_1/3Nb_2/3)O₃–PbTiO₃ compositions are of interest owing to their excellent dielectric, electromechanical, electro-optical, and other properties. In this paper, the 0.80Pb(Mg_1/3Nb_2/3)O₃–0.20PbTiO₃ (PMN–PT 80/20) films with pure perovskite structure were synthesized by a single step at 150°C. The corresponding oxides were used as starting materials, namely PbO, MgO, Nb₂O₅, and TiO₂. By using oxides as precursors, we simplified the hydrothermal process, allowing the process to be more economical. The influences of the Ti metal substrate on the PMN–PT 80/20 films are investigated. By surveying the variations of films, it was suggested that the substrate reacted with the ions in the solution. The films were smooth and homogeneous. There were no cracks and abnormity crystals on the surface of the films. The thickness was about 20 μm. The frequencies dependence of the dielectric properties of PMN–PT 80/20 films was stable even at a high frequency range over 1 MHz.

LaTiO₃ films were prepared at room temperature, 60, 140 and 220°C using a thermal vapor deposition technique with an electronic beam gun to investigate the relationship between deposition temperatures and the optical properties of the samples. In the ellipsometric analysis, the corresponding refractive indexes were 1.8993, 1.9123, 1.9197 and 1.9283 at a wavelength of 1064 nm. At the same time, extremely low absorption characteristics of all the samples presented in the visible and IR regions. With the same high-energy testing laser of 200 mJ (about 40 J/cm²) at a wavelength of 1064 nm and a pulse width of 10 ns, the laser-induced damage threshold (LIDT) of the LaTiO₃ samples prepared at different temperatures were 15.5, 16.7, 18.5 and 18.2 J/cm², respectively. This shows that a higher LIDT may be obtained at higher deposition temperatures.

This paper describes a simple and economic approach for fabrication of surface wettability gradient on poly(butyl acrylate – methyl methacrylate) [P (BA–MMA)] and poly(butyl acrylate – methyl methacrylate – 2-hydroxyethyl methacrylate) [P (BA–MMA–HEMA)] films. The (meth)acrylate copolymer [including P (BA–MMA) and P (BA–MMA–HEMA)] films are hydrolyzed in an aqueous solution of NaOH and the transformation of surface chemical composition is achieved by hydrolysis in NaOH solution. The gradient wetting properties are generated based on different functional groups on the P (BA–MMA) and P (BA–MMA–HEMA) films. The effects of both the surface chemical and surface topography on wetting of the (meth)acrylate copolymer film are discussed. Surface chemical composition along the materials length is determined by XPS, and surface topography properties of the obtained gradient surfaces are analyzed by FESEM and AFM. Water contact angle system (WCAs) results show that the P (BA–MMA–HEMA) films provide a larger slope of the gradient wetting than P (BA–MMA). Moreover, this work demonstrates that the gradient concentration of chemical composition on the poly(meth) acrylate films is owing to the hydrolysis processes of ester group, and the hydrolysis reactions that have negligible influence on the surface morphology of the poly(meth) acrylate films coated on the glass slide. The gradient wettability surfaces may find broad applications in the field of polymer coating due to the compatibility of (meth) acrylate polymer.

An environment-friendly technique for depositing a Mg–Al hydrotalcite (HT) (Mg₆Al₂(OH)${}_{16}$-CO${}_3\cdot 4$H₂O) conversion film was developed to protect the Mg–Gd–Zn alloy from corrosion. The morphology and chemical compositions of the film were analyzed by scanning electronic microscope (SEM) equipped with energy dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Raman spectroscopy (RS), respectively. The electrochemical test and hydrogen evolution test were employed to evaluate the biocorrosion behavior of Mg–Gd–Zn alloy coated with the Mg–Al HT film in the simulated body fluid (SBF). It was found that the formation of Mg–Al HT film was a transition from amorphous precursor to a crystalline HT structure. The HT film can effectively improve the corrosion resistance of magnesium alloy. It indicates that the process provides a promising approach to modify Mg–Gd–Zn alloy.