Effects of low-temperature plasma treatment on wettability of glass surface: Molecular dynamic simulation and experimental study

The improvement of wettability of glass surface plays a vital role in the bonding between glass and other materials. Low-temperature plasma treatment can improve the wettability of glass surface, but the micro-mechanism needs further study. In this paper, the glass surface was treated by low-temperature plasma, and the wettability of the treated surface was studied by experiment and molecular dynamics (MD) simulation. The results show that the relative content of oxygen of the glass surface increases while that of carbon impurity decreases after low-temperature plasma treatment. After low-temperature plasma treatment, the wettability of glass surface is improved obviously while the surface morphology is almost unchanged. MD simulation results show that the active groups are more easily adsorbed on the glass surface in a free state and interact strongly with water. Among them, the interaction between the hydroxylated glass surface and water droplets is the strongest, so the wettability of glass surface is obviously improved. The number of chemical bonds between the glass surface and water increases after low-temperature plasma treatment and the number of chemical bonds in the hydroxylated glass system increases the most. Therefore, the interfacial bonding is enhanced, and the wettability of the glass surface is improved. The simulation results are in agreement with the experimental ones. The above research provides a theoretical basis for improving the strength of glass bonded joints. © 2019 Elsevier B.V.