Solid surface characterization by contact angle measurements

An instrument to obtain the critical surface tension, and the polar and dispersive contribution to the solid surface tension is described. The measured surface area should be flat and 0.5 x 3 cm. The wettability of a solid surface was determined by contact angle measurements. Such parameters as smoothness, surface heterogeneousness, impurities, and (in part) chemical composition, are estimated by the method. Silicon dioxide surfaces modified with various silanes were characterized. The measurements agree with literature data.