ABSTRACT
Polymer gels are known to exist in two distinct phases, swollen and collapsed, and to exhibit unique properties, particularly with respect to the volume phase transition and critical behavior [1-14]. The transition between two phases is de„ned as a reversible, discontinuous volume change in response to in„nitesimal changes in the external conditions, that is, physical and chemical stimuli (Figure 7.1). It has been observed in various gels made of synthetic and natural polymers.
