Contact angle and rivulet width hysteresis on metallic surfaces. Part I: With heated surface

The paper presents the experimental set up and the results of investigations into the contact angle and width of rivulets on aluminium, brass and copper. The measurements were taken for the increase, decrease and subsequent increase of the flow rate. As a result the hysteresis of the contact angle and rivulet width was observed. It was noticed that aluminium and brass lose their hydrophobic properties under flow conditions. They became hydrophilic materials. Copper has the worst wetting properties. It was observed that the wetting properties of sessile drops and rivulets can differ significantly. It is supposed that the more electrons there are on the last shell, the more hydrophilic a metal is under water rivulet flow. (c) 2008 Elsevier Ltd. All rights reserved.