 |
Recently, State Key Laboratory of Functional Materials for Materials and Materials, Institute of Microsystem and Information Technology, Chinese Academy of Sciences, State Key Laboratory of Tribology, Tsinghua University, and Key Laboratory of Applied Mechanics, Ministry of Education, School of Aerospace, Tsinghua University, Micro-nano Researchers at the Center for Research in Mechanics and Multidisciplinary Interdisciplinary Innovations have made progress in the regulation of the planar structure of two-dimensional material molecules and the control of two-dimensional material lubrication properties. The researchers found that when single crystal germanium and graphene grown on it are stacked together at an appropriate angle, graphene can maintain a good two-dimensional flat structure and continue its excellent friction lubrication even after undergoing severe chemical reactions from the outside. Characteristics, related results are helpful to promote the application of two-dimensional materials in the field of micro-nano friction and lubrication. The topic “Robust ultra-low friction state of graphene via moiré superlattice confinement†was recently published in Nature Communications, 7: 13204, 2016) on.
In recent years, it has been found that two-dimensional materials have very peculiar and excellent friction properties due to their special planar atomic structure, and are expected to be used as an ultra-thin lubricant material in the micro-nano field. However, due to the exceptionally large specific surface area of ​​two-dimensional thin film materials, it is prone to decrease or even lose lubricating properties due to the working environment, especially surface chemical effects. Therefore, how to effectively maintain the stability of monomolecular two-dimensional materials from atomic scale under complex sliding conditions presents researchers with a whole new challenge. Researchers have observed polycrystalline graphene grown on the iridium (111) crystal surface. Due to the different ways in which the upper and lower crystals are stacked, regions with periodic moiré and non-Moiré fringes are produced at the same time. After fluorination, oxidation and other chemical treatments, the lubrication performance of the non-Moire area is greatly weakened. However, graphene with a periodic moiré area still maintains good lubrication characteristics. Through first-principles calculations, researchers found that the interaction between carbon atoms of graphene and helium atoms in the periodic moiré region is much stronger than the ordinary van der Waals force; this strong anchoring The role of graphene can resist changes in the surface structure of the graphene molecule against external disturbances, thereby enhancing the robustness of its lubrication. Relevant studies are expected to be extended to other two-dimensional material systems to promote the application of monolayer lubricants in micro-nano systems.
This work was supported by the National Natural Science Foundation of China's Innovative Research Group, Outstanding Youth Fund, Face Fund, the National Major Scientific Research Program of the Ministry of Science and Technology ("973" Project), the Youth Talents and Young Talents Project of the Central Organization Department, and Tsinghua University's autonomy. Scientific research projects, Tang Zhongying Fund, Shanghai academic leaders and other related research programs support.
Galvanized Roller Shutter Door
Using advanced hot-dip galvanized material , precision roll forming production process, polyurethane foam that free of hydrofluorocarbon inside door, light weight, high strength, appearance nice. The doors have advantages of tamper anti-theft , noise isolation thermal insulation and corrosion resistance;the doors are widely used in shops, garages, houses, supermarkets, warehouses and industrial plants,etc.
Depending on the characteristics of the buildings,we can choose interior, exterior and intermediate three different installation ways, doors stay in the upper part of door after rolling up , this could save garage space, and also could keep the garage clean and beautiful by prevent the mud, rain and snow ,etc going into the garage.
Galvanized Roller Shutter Door,Standard Galvanized Roller Shutter Door,Automatic Galvanized Roller Shutter Door,Steel Roller Shutter Safe Door
Shenzhen Hongfa Automatic Door Co., Ltd. , https://www.selfrepairinghighspeeddoor.com