Mechanochemically driven formation of protective carbon films from ethanol environment
Mechanochemically driven formation of protective carbon films from ethanol environment
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DOI：
10.1016/j.mtchem.2022.101112
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发表时间：
2022
影响因子：
7.3
通讯作者：
A. Shirani;Yang Li;J. Smith;J. Curry;P. Lu;M. Wilson;M. Chandross;N. Argibay;D. Berman
中科院分区：
文献类型：
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作者：
A. Shirani;Yang Li;J. Smith;J. Curry;P. Lu;M. Wilson;M. Chandross;N. Argibay;D. Berman
界面的磨损和退化仍然是各行业常用机械组件中的一个重要障碍，导致其效率和最终功能的损失。为了推动摩擦学应用的最先进水平，必须开发新材料，不仅要在极端环境(如高温、接触/剪切力等)下抵抗降解、磨损和更高的摩擦损失，而且还必须从这些方面受益。通过采用坚硬的催化界面，可以出现多种接触条件，其中机械力化学作用会导致保护性或自愈性润滑膜的形成。在这里，我们演示了在乙醇环境中滑动时，机械力化学驱动的保护性碳膜在铂-金合金上的形成。我们演示了温度和接触压力对薄膜形成的影响。拉曼光谱和电子显微镜分析表明，在铂-金合金表面形成的薄膜具有高度的石墨化结构。分子动力学模拟进一步证实了乙醇分子的解离和转化随外加压力和温度的变化。这些结果对接触中的转变有了新的理解，并为解决低粘度燃料中运行的机械系统中的摩擦学挑战提供了解决方案。
Wear and degradation of interfaces remain a significant roadblock in commonly used mechanical assemblies across various industries, resulting in loss of their efficiency and ultimately functionality. To advance the state-of-the-art in tribological applications, new materials must be developed not only to resist degradation, wear, and higher frictional losses in extreme environments (i.e. high temperatures, contact/shear forces, etc.), but also to benefit from them. By adopting hard, catalytic interfaces, a wide range of contact conditions can emerge where mechanochemical interactions lead to the formation of protective or self-healing lubricious films. Here, we demonstrate the mechanochemically driven formation of protective carbon films on Pt-Au alloys during sliding in an ethanol environment. We demonstrate the effect of temperature and contact pressure on film formation. The films formed on Pt-Au alloys exhibit a highly graphitic structure as indicated by Raman and Transmission Electron Microscopy (TEM) analyses. The observed results are further supported by molecular dynamics simulations that show the changes in the dissociation and transformation of ethanol molecules with applied pressure and temperature. The results create a new understanding of transformations in the contact and suggest a solution for addressing tribological challenges in the mechanical systems operated in low viscosity fuels.