Contact angle a contact angle of 0°. This is often the case for water on bare metallic or ceramic surfaces, although the presence of an oxide layer or contaminants on the solid surface can significantly increase the contact angle. Generally, if the water contact angle is smaller than 90°, the solid surface is considered hydrophilic and if the water contact angle is larger than 90°, the solid surface is considered hydrophobic. Many polymers exhibit hydrophobic surfaces. Highly hydrophobic surfaces made of low surface energy (e.g. fluorinated) materials may have water contact angles as high as ~120°. Some materials with highly rough surfaces
Less-is-better effect Less-is-better effect The less-is-better effect is a type of preference reversal that occurs when the lesser or smaller alternative of a proposition is preferred when evaluated separately, but not evaluated together. The term was first proposed by Christopher Hsee. In a 1998 study, Hsee, a professor at the Graduate School of Business of The University of Chicago, discovered a less-is-better effect in three contexts: "(1) a person giving a $45 scarf (from scarves ranging from $5-$50) as a gift was perceived to be more generous than one giving a $55 coat (from coats ranging from $50-$500); (2) an overfilled ice