Inhomogeneous Gel Research Articles

Enhancement of inhomogeneities in gels upon swelling and stretching

AbstractIn this paper, it is shown how a percolation process can be used to describe the inhomogeneities of polymer concentration, appearing in gels prepared by random crosslinking of a semi‐dilute solution, and how they are modified by swelling or stretching of the network. Neutron scattering experimental data are compared to the predictions of this model in the isotropic and anisotropic cases. A good agreement is found. In particular, “abnormal” butterfly patterns in the iso‐intensity curves have been detected, as expected from the model.

Effects of inhomogeneities in polyacrylamide gels on thermodynamic and transport properties

The difference in swelling of polyacrylamide gels of various polymer concentrations and the nuclear magnetic resonance self-diffusion measurements of water in these gels suggest that inherent inhomogeneities in dilute gels play an important role in the thermodynamic and transport properties of these gels.

Biochemistry of Cervical Mucus

Cervical mucus is an inhomogeneous gel of micellar network structure with tricot-like molecular gel arrangements. Structural elements of the semisolid material are characteristic epithelial glycoproteins. The network of filaments is filled with a fluid which may be thought of as cervical plasma. Estrogens and gestagens influence changes in the structure and composition of the cervical mucus. The estrogenic type of mucus represents an open channel system for sperm and shows low concentrations of soluble proteins. Under the influence of gestagens this changes to a dense network of swollen micelles with high concentrations of soluble proteins. Interactions between the cervical plasma and the structural elements of the network as well as with the penetrating sperms remain to be investigated.(Author modified)