A common belief proposed by Peierls and Landau that two-dimensional material cannot exist freely in a three-dimensional world has been proved false when graphene was first synthesized in 2004. Graphene, which is the base structure of other carbon materials, has drawn much attention of scholars and researchers due to its extraordinary electrical, mechanical and thermal properties. Moreover, methods for its synthesis have developed greatly in recent years. This review focuses on the mechanism of the thermal growth method and the different synthesis methods, where epitaxial growth, chemical vapor deposition, plasma-enhanced chemical vapor deposition and combustion are discussed in detail based on this mechanism. Meanwhile, to improve the quality and control the number of graphene layers, the latest research progress in optimizing growth parameters and developmental technologies has been summarized. The strategies for synthesizing high-quality and large-scale graphene are proposed and an outlook on the future synthesis direction is also provided.

Graphene, as the earliest discovered two-dimensional (2D) material, possesses excellently physical and chemical properties. Vast synthetic strategies, including chemical vapor deposition, mechanical exfoliation, and chemical reduction, are proposed. In this paper, a method to synthesize multilayer graphene in a semi-opened environment is presented by introducing arc-discharge plasma technology. Compared with previous technologies, the toxic gases and hazardous chemical components are not generated in the whole process. The synthesized carbon materials were characterized by transmission electron microscopy, atomic force microscopy, X-ray diffraction, and Raman spectra technologies. The paper offers an idea to synthesize multilayer graphene in a semi-opened environment, which is a development to produce graphene with arc-discharge plasma.

In this study, the filled nitrile rubber (NBR) was prepared with micro glass flake (GF). The tribological behaviors of filled NBR were tested by a ball-on-disk tribometer. Material properties such as glass transition temperature (T_g), fracture energy, tensile strength and dispersity of GF filler were also investigated. The results showed that the coefficient of friction (COF) of NBR reduced and the wear-resistant enhanced with the GF filler. Compared to unfilled NBR, the COF of filled NBR suffered a maximal drop percent (about 21.1%) at a rotation speed of 100 rpm and normal load of 1.5 N. Mechanical and wear behaviors were dependent on the interfacial performance of filler in the rubber matrix. Filler with smaller size was more conducive to enhance the interfacial strength of the polymer matrix. That can increase the interfacial strength of filler and benefits to improve the anti-wear behavior of rubber.

Fast-growing flexible electronics bring technological innovation to all industries, including personal health management, clinical diagnosis, and smart agriculture. However, conventional synthesis strategy fails to reconcile the divergent mechanical property demands for monitoring disparate targets (such as humans and plants), impeding the development of a universal strain sensor. In this work, a universal ions pre-incorporation strategy is first proposed to develop ultrasoft and durable ionic hydrogels for multipurpose biosensing. Through iron-mediated Fenton-like reactions and Cl⁻-dominated radical scavenging effects, the glycerin-doped PAAM/PVA hydrogel pre-incorporated with Fe ions (GPPFe) exhibits ultrasoft mechanical properties (Young’s modulus = 41.7 kPa, 84.8% softer than post-incorporated samples), effectively avoiding the excessive stiffness of ionic hydrogels prepared by the conventional ions post-incorporation strategy, which can be well applied for the monitoring of plant growth considering its good conformal contact with the plant surface and less pressure on the plant tissues. The reversible and sacrificial bonds formed between Fe³⁺ and polymers ensure excellent mechanical stability of the GPPFe hydrogel (1.12% permanent deformation after successive loading–unloading 50 cycles test at a tensile strain of 150%, 94.7% lower than post-incorporation strategy), thus ensuring its utilization as a comfortable and durable human wearable strain sensor. Additionally, this strategy can be extended to design various types of synthetic hydrogels, providing an innovative approach for designing the multipurpose wearable electronic devices oriented to various target objects.