Gels additional rubber elasticity

In this section, we describe the dynamic features of EOM effects. In particular, we focus on the response times to field-on and field-off these are the rise and decay times, respectively. In the case of the EO effects of nematic liquids, the rise and decay times exhibit the characteristic dependencies on voltage, and these characteristic times reflect the elastic, viscous, and dielectric properties of the materials. They have fully characterized the dynamics of the electric-field responses of LMM-LCs in experiments and established the theoretical background [6]. The dynamic features of the EOM effects in nematic gels are expected to differ from those of the EO effects in LMM-LCs, because the gels possess rubber elasticity and also have a different origin of the memory of the initial director. In addition, the dynamic properties give important information about the applicability of EOM effects in practical applications. 

Gels are similar to rubbers in that they both have long-chain polymers and the properties of elasticity. But rubbers are a one-component system, whereas gels are a two-component system (solute and solvent). In addition, rubbers are solids and gels are solutions. 

Hyaluronic acid has additional functions within the body due to its high solubility in water. In addition to the properties described above, molecules are able to interact with one another at low concentrations to form entanglement networks and produce solutions with viscoelastic properties. In addition, if some permanent cross-bridges can form then gel-like structures with rubber-elastic prop-... 

The seminal work of Flory and Rehner [1-3] set the framework for analysis of swollen polymer gels. In their approach it is assumed that in a crosslinked rubber at equilibrium the free energy of mixing and the change in elastic component are separable and additive. The chemical potential change on dissolution at equilibrium is written as ... 

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