Zhang Chi, Li Xin, Wang Shuo, Wang Junsheng, Zhu Shijie, Guan Shaokang
School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
Advanced Research Institute of Multidisciplinary Science, Beijing Institute of Technology, Beijing 100081, China.
ACS Omega. 2021 Jan 6;6(2):1099-1107. doi: 10.1021/acsomega.0c03755. eCollection 2021 Jan 19.
In a humid environment, water droplets on the solid surface can act as a medium to accelerate corrosion. If the solid material has hydrophobic properties, the surface of the material will remain "clean" and corrosion may be retarded to a certain extent. In theory, MgO itself is a hydrophilic material, and we can apply additional stress or strain to change its lattice constant and adjust the wetting behavior of water on the MgO surface, resulting in changes of corrosion resistance. In order to study the effects of MgO lattice expansion or contraction on the wetting behavior of nano-water, molecular dynamics simulations have been performed in this work. It is found that the changes of the lattice constants on the MgO surface can significantly change the wetting tendency. It will alter the interaction forces between water molecules and MgO surfaces, which in turn changes the atomic density profiles, the orientation of OH bonds, and hydrogen bond networks. The contraction of MgO can actually result in the increase of wetting angles of nano-water droplets on the MgO surface and gradually exhibits hydrophobic properties.
在潮湿环境中，固体表面的水滴可作为加速腐蚀的介质。如果固体材料具有疏水特性，材料表面将保持“清洁”，并且腐蚀可能会在一定程度上受到抑制。理论上，MgO本身是一种亲水材料，我们可以施加额外的应力或应变来改变其晶格常数，并调整水在MgO表面的润湿性，从而导致耐腐蚀性的变化。为了研究MgO晶格膨胀或收缩对纳米水润湿性的影响，本文进行了分子动力学模拟。研究发现，MgO表面晶格常数的变化会显著改变润湿性趋势。这将改变水分子与MgO表面之间的相互作用力，进而改变原子密度分布、OH键的取向和氢键网络。MgO的收缩实际上会导致纳米水滴在MgO表面的接触角增大，并逐渐呈现出疏水特性。
