Transport in and Through Gel

Gel is a state of matter that classified into the solid because it consists of the three-dimensional cross-linked polymer network. It, however, shows some liquid-like properties since it also contains a considerable amount of fluid. According to such a characteristic structure, many substances can pass the gel. In many separation technologies, therefore, gel is used as a molecular sieve. Although the gel plays many important roles in the separation technologies, the detailed roles played by the gel in the transport phenomena is not well understood yet. The transport phenomena in the gel are necessary to be clarified. In this chapter, we discuss tow transport phenomena that is related to the gel. The one is the friction of the gel against the liquid that flows through the gel, and the other is the resistance of the gel for the diffusional translation of the substances in the gel.