ABSTRACT
Polymer gels have attracted considerable attention in recent years [1-10]. A polymer gel consists of an elastic cross-linked network and a fluid filling the interstitial space of the network. The network of long polymer molecules holds the liquid in place and so gives the gel what solidity it has. Gels are wet and soft and look like a solid material, but they are capable of undergoing large deformation. This property is in contrast with most industrial materials such as metal, ceramics, and plastics, which are dry and hard. Living organisms are largely made of gels. Except for bones, teeth, nails, and the outer layers of skin, mammalian tissues are highly aqueous gel materials largely composed of protein and polysaccharide networks in which water contents range up to 90% (blood plasma). This enables the organism to transport ions and molecules more easily and effectively while keeping its solidity
A polyelectrolyte gel is a charged polymer network with macroions fixed on the polymer chains and the microcounter ions that localized in the network frame. The polyelectrolyte gel has the ability to swell in water and absorbs a significant fraction (~2000 times the polymer weight) of water within its structure, but it will not dissolve in water. This chapter describes some of our results on the fundamental aspects and electroresponsive properties of polyelectrolyte gels. In Section II, of this chapter, the electrostatic potential distribution as well as the counterion distribution of the charged network is theoretically estimated by the Poisson-Boltzmann equation using a twodimensional stacking model. The presence of the potential wells at the cross-linking points is predicted. The electrical conductance and the low-frequency dielectric relaxation of the gel is experimentally measured and compared with the corresponding polymer solution and the effect of the cross-linking points on the counterion conduction is discussed.
