Lamellar acid salts

Lamellar compounds based on highly oriented graphite can be deintercalated more completely. By electrochemical deintercalation of first-stage acid salts (cf. 16.4.2.1.4) based on highly oriented pyrolytic or natural graphite 95% of the intercalant can be removed under quasi-equilibrium conditions " for much less crystalline carbon fibers, the corresponding value is 80 %. ... 

There are two types of lipid-water phase diagrams. The first type, discussed above, is obtained from polar lipids, which are insoluble in water (i.e. the solubility is quite small, monolaurin for example has a solubility of about 10 m). Fig. 8.12 illustrates the principles of phase equilibria in this type of lipid-water system. The second type of binary system is obtained when the lipid is soluble as micelles in water. Examples of such lipids are fatty acid salts and lysolecithin. An aqueous soap system is illustrated in Fig. 8.13. When the lipid concentration in the micellar solution is increased, the spherical micelles are transformed into rod-shaped micelles. At still higher lipid concentrations the lipid cylinders are hexagonally arranged and the liquid-crystalline phase Hi is formed. The lamellar liquid-crystalline phase is usually formed in the region between Hi and the anhydrous lipid. Excellent reviews of the association behaviour of amphiphiles of this type have been published (Wennerstrom and Lindman, 1979 Lindman and Wennerstrom, 1980). 

In common with long-chain fatty acid salts (soaps), the amphipathic phospholipids are capable of forming lamellar sheets or spherical micelles in which the polar hydrophilic ends (the phosphate groups) point outwards (Figure 10.31). 

A new class of compounds able to form lamellar structures consisting of bilayers separated by water-layers are dialkylammonium-salts of 2-[((trifluormethyl)-phenyl)-amino]-benzoic acid (Flufenamic acid) as was found by Eckert and Fischer 80). 

Typically the formulation may contain up to 60% active with builder salts and a water level of about 30-40% [52]. The weight ratio of LAS/AE may range from 1.5 1 up to 4 1. The combination of LAS and AE is especially effective for two reasons. First, LAS and AE interact strongly to form the lamellar phase liquid crystals. Second, both ingredients can be introduced into the liquid formulation as a 95 + % active liquid to control the amount of water going into the formulation. LAS can be introduced into the formulation as sulfonic acid and neutralized in situ. 

Certain azacrown-appended cholesterol derivatives can form unique vesicular or lamellar structures in the absence and the presence of metal salts in aqueous solution.187-190 These superstructures created from the azacrown-appended cholesterol derivatives are useful as a template for the transcription into the silica structure. Azacrown-appended cholesterol gelator creates the novel multilayered spherical structure in acetic acid, whereas this gelator results in the fluffy globular aggregates in the presence of Pd(N03)2.191... 

Near the surfactant region the crystalline or lamellar phase is found. This is the region one finds in hand soaps. The ordinary hand soap is mainly the salt of fatty acid (coconut oil fatty acids or mixtures [85%] plus water [15%] and some salts. X-ray analyses have shown that the crystalline structure consists of a layer of soap separated by a water layer (with salts). The hand soap is produced by extruding under high pressure. This process aligns the lamellar crystalline structure lengthwise. If the degree of expansion versus temperature is measured, the expansion will be found... 

Complexes of sodium poly(a,L-glutamate) with salts of various fatty acids form a lamellar structure, consisting of alternating layers of polymer-chain and double-... 

Sayari et al [202,203] extended the LCT technique to the synthesis of mesostructured zirconium oxide. The use of long chain quaternary ammonium salts or primary amines as templates led to the formation of hexagonal and lamellar Zr02 phases, respectively. Zr(S04)2 was used as zirconium source, which provided a highly acidic medium, pH < 1.5. Consistent with the synthesis conditions and EDX analysis data a S X I mechanism where the surfactant-inorganic interaction is mediated by sulfate anions was proposed. Unfortunately, both structures collapsed upon removal of the surfactant either by high temperature calcination or by solvent extraction [203]. However, the hexagonal form was successfully... 

The lamellar phases on the surface of the emulsion particles are mainly composed of monoacylglycerides, lyso-phospholipids and ionized fatty acids. When the phases have reached a certain size, they will desorb from the emulsion surface and form multi-lamellar vesicles, which are transformed into uni-lamellar vesicles upon increased incorporation of bile salts (Rigler et al., 1986). Upon further incorporation of bile salts, the ratio of lipid amphiphiles to bile salts will decrease to 1 or lower, whereby the uni-lamellar vesicles are transformed to mixed micelles (Staggers et al., 1990). These events are presented in Figure 4. 

Lamellar crystals or crystalline powder odorless Or faint benzoic acid odor gradually loses NH, on exposure to air. d 1.26. mp 198". One gram dissolves in 4.7 ml water. 1.2 ml boil, water, 36 ml alcohol, 8 ml boil, alcohol, 8 ml glycerol. The aq soln is slightly acid. Keep well closed. Incompat. Ferric salts, acids, alkali hydroxides or carbonates. 

Moooclinic needles (lamellar twinning on 001) from water mp 357", Sublimes 290-295 . Kb at 18 L3 X IQ"1 Ka 0,9 X JO-10, Absorption spectrum Hartley, J. Chem-Soc- 87, 1803, 1810 (1905), One gram dissolves in about 2000 ml water, 150 ml boiling water, 2220 ml 95% alcohol sol in the fixed alkali hydroxides, coned acids, in about 22 parts of 20% aq tribasic sodium phosphate soln moderately sol in ammonia. Almost insol in benzene, ether, chloroform, carbon tetrachloride. Forms salts which are dec by water, and compds with bases which are more stable. 

The introduction of sulfonic acid groups in the alkyl side chains affords water-soluble self-doped polypyrrole. Using the sodium salt of the 3-alkylsulfonic acid pyrrole, the monomer acts as electrolyte for the electrochemical synthesis as well. A second long alkyl chain on the opposite side of the pyrrole ring affords a highly ordered lamellar polymer also soluble in chloroform [96]. 

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