ABSTRACT
According to the concept of the ‘‘equilibration of surface state,’’ which is described in detail in Chapter 24, the surface configuration of such a copolymer is always changing according to the conditions of contacting medium, such as temperature and relative humidity. Therefore, the surface configuration of a copolymer depends on the history of a sample, and consequently it is very difficult to establish a reference state for a copolymer in a generic sense. For example, the values of advancing contact angle vary from sample to sample depending on the history of samples.
