abstract
- The water contact angle is a surface analytical technique that provides invaluable information regarding a surface¿s chemical and physical characteristics. The surface wetting qualities of the material are achieved by calculating the contact angle of a water drop on a surface. Research regarding these physicochemical interactions is important as minimal changes to the surface, in turn, affect the surface energy notably shown in the observed water contact angle. Changes in the water contact angle also hint at physical and/or chemical alteration of the surface. This chapter introduces the water contact angle method to assess the wettability of surfaces and provides information regarding the hydrophobic or hydrophilic characteristics of different surfaces. The chapter also provides the history, mechanism of operation, advantages, disadvantages of this analysis, and applications of the technique centered on biosensors. The last section of the current chapter describes some of the common errors when using this technique and the possible causes and solutions.