Scattering sponges

G. Gompper, M. Schick. Scattering from internal interfaces in microemulsion and sponge phases. Phys Rev E 49 1478-1482, 1994. 

Thus, these mesostructures are predominantly lamellar, and identified as conventional (parabolic) lamellar phases, although they may in fact be hyperbolic. Indeed, unless v/al is exactly unity, a planar interface (lamellar mesophase) incurs a bending energy cost hyperbolic sponge monolayers or bilayers or mesh monolayer mesophases are favoured if v/al differs from unity. It is likely then that many "lamellar"" phases in fact adopt a hyperbolic geometry. Careful neutron-scattering studies of a lamellar phase have revealed the presence of a large number of hyperbolic "defects" (pores within the bilayers) in one case [16]. (An example of this mis-identification of hyperbolic phases in block copolymers is discussed in section 4.10.)... 

Sponges contain structures that support the cell layers and give the animals shape. In many types of sponges, these structures are small, mineralized needles called spicules that are scattered throughout the mesoglea. Instead of spicules, some species possess fibers made of a tough, rubbery protein called spongin. 

A great deal of experimental work has been carried out to examine these conjectures. An example is shown in Fig. 5.27. The osmotic compressibility of the sponge phase, measured by light scattering, has been plotted as a function of (p in axes chosen to reveal the logarithmic correction. Agreement with theory... 

Keywords lipid-water phases liquid crystals swelling sponge phase small-angle X-ray scattering SANS micelles glycerol monooleate octyl glucoside... 

The SANS and SAXS pattern in Figure 2 and 3a were fitted with a bilayer sponge cell-cell correlation function (solid line). The scattering, I(q), was calculated according to the equation ... 

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