Surfaces with special wettability have broad application in industrial production, daily life and basic research area. In recent years, the preparation of super-hydrophobic/super-oleophobic surfaces has attracted considerable attention. Much work has been dedicated to preparing surfaces with special wettability.
Super-oleophobic surfaces have super-hydrophobic property as well. In this way, super-oleophobic surfaces have broader application. However, less effort has been made in the research on super-oleophobic surfaces compared with that of super-hydrophobic surfaces. Moreover, the known methods to prepare super-oleophobic surfaces all have certain shortcomings, such as limitation in the use of substrates, high production cost, etc. In this sense, it is of great necessity to prepare super-oleophobic surfaces applicable to practical needs.
Researchers at the State Key Laboratory of Solid Lubrication of the Lanzhou Institute of Chemical Physics of the CAS have developed a super-hydrophobic and super-oleophobic surface. They have received a Chinese invention patent for the technique on October 19, 2011. The patent is 200810183392.4.
In the preparation technology, aluminum or aluminum alloy sheets are subjected to two-step electrochemical treatment, and then are modified by using perfluorinated octadecyl trichlorosilane or perfluorinated polymethacrylate to prepare the super-hydrophobic and super-oleophobic surface.
The surface has super-hydrophobic property on aqueous solution of which the pH value is between 1 and 14 and super-oleophobic property on various oil drops, wherein a contact angle of the surface on water is 171 degrees, and a rolling angle is less than 1 degree. The surface expresses the super-oleophobic property on various oil drops except for perfluorinated polymer liquid, and all contact angles between the oil drops and the surface are more than 150 degrees, and rolling angles are generally less than 10 degrees. Moreover, the surface can also be put in air for a long time and can still maintain the super-hydrophobic property and super-oleophobic property. The preparation technique is simple, practical and easy to be applied industrially.
The above-mentioned advantages of the surfaces endow the surfaces with wide application in industry, daily life and areas requiring hydrophobic and oleophobic properties, namely anti-fouling and anti-corrosion of aluminum and its alloy, vehicles for water transportation, water-resistant and anti-corrosive out surfaces of facilities long placed outside, lubrication in space equipment, preparation of pipes used to transport crude oil, lubricating oil and corrosive liquid and containers of these liquids, loss-free transportation and storage of ultra-micro liquid, anti-frosting and anti-freezing materials used in fridges, refrigeration systems and air conditioners.