Design and Fabrication of Hydrophobic Copper Mesh with Striking Loading Capacity and Pressure Resistance

Abstract

Mimicking the Asparagus setaceus, hydrophobic copper meshes were fabricated with chemical surface modifications. According to the reformed Cassie−Baxter equation, the superhydrophobicity of the copper meshes is explained and predicted. Water contact angles as high as 134.6° were achieved. Good agreement between the predictions and experiments was obtained. Dynamic contact angles are also performed, and the largest contact angle hysteresis is obtained with 1.0 wt % (heptadecafluoro-1,1,2,2,-tetradecyl)trimethoxysilane (HFTES) treated whereas the smallest hysteresis occurs for 8.0 wt % HFTES treated sample. This is explained in terms of sorption of liquid by the solid and penetration of liquid into the polymer film. Furthermore, the loading capacities and the water pressure resistances of the hydrophobic copper meshes were all performed. The highest loading weight, 18.59 g, and the deepest height of pressure resistance, 66.5 mm, were obtained, when the copper mesh was treated with 1.0 wt % HFTES. In addition, the capillary model was borrowed to explain the phenomena of copper mesh with water pressure resistance. From the capillary model, we predicted the height of pressure resistance, and the predicted and measured values were in good agreement.