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 than Angels Less than Angels Less Than Angels is a novel by Barbara Pym, first published in 1955. The novel is largely concerned with the activities of a group of anthropologists, and is to some extent based on the author's own experiences working at the International African Institute in London. It is set in a period of social change which is subtly represented within the novel's plot and setting Catherine Oliphant is a young writer, who lives with anthropologist Tom Mallow. Tom begins a romance with a student, Deirdre Swann, and his relationship with Catherine fizzles out. At the same time, she