The Roughness Effect on the Preparation of Durable Superhydrophobic Silver-Coated Copper Foam for Efficient Oil/Water Separation

Abstract

In recent decades, there has been a significant interest in superhydrophobic coatings owing to their exceptional properties. In this research work, a superhydrophobic coating was developed on copper foams with a different roughness via immersion in AgNO3 and stearic acid solutions. The resulting foams exhibited water contact angles of 180°. Notably, surface roughness of the substrate influenced the development of silver dendrites and stearic acid morphologies, leading to different structures on rough and smooth copper foams. Separation efficiency was maintained above 94% for various pollutants, suggesting good stability and durability, irrespective of the substrate’s roughness. Conversely, absorption capacity was influenced by surface roughness of the substrate, with smooth copper foams demonstrating higher absorption values, primarily due to its uniform porosity and microstructure, which allowed for efficient retention of pollutants. Both copper foams exhibited excellent thermal and chemical stability and maintained their hydrophobic properties even after a 40 h exposure to harsh conditions. Mechanical durability of modified copper foams was tested by dragging and in ultrasounds, exhibiting promising results. The samples with the smooth substrate demonstrated improved coating stability.

Hydrophobic and Transparent Tantalum Pentoxide-Based Coatings for Photovoltaic (PV) Solar Panels

“…The resulting coated foams exhibited water contact angles of 180 • [17]. Separation efficiency was maintained at 94% for different pollutants, suggesting good stability and durability with no respect to roughness [17]. Fern [30] showed the CoFeSm film thickness increased, decreasing the crystalline size and surface roughness.…”

“…Hydrophobic lotus leaf presents self-cleaning properties due to a high-water contact angle of 150 degrees [15]. Lotus leaves become a symbol of hydrophobicity and self-cleaning surfaces, known as the 'lotus effect' [17]. The hydrophobicity and self-cleaning of lotus leaves are induced by a roughness given by microand nanoscale structures [16].…”

“…The literature data reported thin films obtained by various methods [17][18][19][20][21][22][23][24][25][26]. The implementation of light management textures in thin film solar cells often simultaneously causes an unwanted deterioration of electronic performance [27][28][29].…”

“…Baxevani [17] studied the effect of roughness on the superhydrophobic silver foil on copper foam for good oil/water separation. The resulting coated foams exhibited water contact angles of 180 • [17].…”

“…Baxevani [17] studied the effect of roughness on the superhydrophobic silver foil on copper foam for good oil/water separation. The resulting coated foams exhibited water contact angles of 180 • [17]. Separation efficiency was maintained at 94% for different pollutants, suggesting good stability and durability with no respect to roughness [17].…”