Ringing gels

Note A ringing gel is often a hydrogel with a surfactant as a third component and has a composition within an isotropic, one-phase region of its ternary phase diagram... 

Karino T, Okumura Y, Ito K, Shibayama M, (2004) SANS studies on spatial inhomogeneities of slide-ring gels. Mactomolecules 37 6177-6182... 

Karino T, Okumura Y, Zhao C, Kataoka T, Ito K, Shibayama M. (2005) SANS studies on deformation mechanism of slide-ring gel. Macromolecules 38 6161-6167 Haraguchi K, Takehisa T. (2002) Nanocomposite hydrogels a unique organic-inorganic network structure with extraordinary mechanical, optical, and swel I ing/de-swelling properties. Adv Mater 10 1120-1124... 

Figure 3.3. Synthesis scheme of azobenzene-containing slide-ring gels. Sakai et al., 2007.

Figure 3.4. Swelling behavior of slide-ring gels in DMSO upon alternate irradia-tion of UV and visible light. D and Do are diameters of the gel and inner diameter of mold capillary, respectively. Source Sakai et al., 2007.

Sakai T, Murayama H, Nagano S, Takeoka Y, Kidowaki M, Ito K, Seki T. 2007. Photoresponsive slide ring gel. Adv Mater 19 2023 2025. 

Microemulsion gels are usually based on nonionic ethoxylated ether surfactants based on oleyl, lauryl, or isocetyl alcohol either alone or in combination with ethoxylated phosphate esters. Long hexagonal liquid crystalline structures present in the gel can vibrate when the container is tapped, resulting in a ringing gel [18], Table 10 presents a versatile ringing gel microemulsion base formula from ICI [16] for three clear cosmetic products. 

They are very viscous, and nearly solid in some cases (occasionally termed ringing gels in the older literature). All examples firmly established to date... 

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