Mixed soap crystals

Hexagonal phosphorus pentoxide, 29 49 Hexagonal prism lattice, 8 114t Hexagonal soap phase, 22 726, 727 mixed soap crystals in, 22 729 Hexagonal structure... 

Mixed Soap Crystals in Nonsuper-Fatted Formulation Soap bars consist of mixture of soaps with different chain lengths and chain saturations. They are classified as soluble soaps and insoluble soaps. The soluble soaps usually form a hexagonal liquid crystalline phase with water, as shown in Fig. 2.1, which dissolves in water during washing and provides lather. The insoluble soaps stay in crystalline formats in the bar and provide mechanical strength. The solid crystals present in a soap bar can include kappa, zeta, eta, and delta phases. 

Mixed Soap Crystals in Super-Fatted Formulations A small quantity of fatty acid, usually less than 10%, is added to normal soap to produce a super fatted soap. The fatty acid is added to the soap phase at temperatures above the fatty acid melting point and new solid crystalline and liquid crystalline phases are formed on cooling. 

The vinasse of sugar beet.—Sugar beet contains about 0 5 per cent, of potash, K20, largely in combination with organic acids. The potash accumulates in the molasses of the best sugar factories. The molasses are fermented and distilled for alcohol. The residue which remains in the retort—called vinasse—may be used as a manure, or it may be mixed with lime and ignited to form what was once called vinasse cinder, and used in the manufacture of soft-soap. It is, however, more profitably refined for potash by fractional crystallization.6 The product has approximately the composition ... 

Palmitic acid is present as cetyl ester in spermaceti from which, by hydrolysis, the acid may be obtained it is present in bee s wax as the mehssic ester and in most vegetable and animal oils and fats, in greater or lesser amounts, as glyceryl tripalmitate or as mixed esters, along with stearic and oleic adds, Palmitic acid is separated from stearic and oleic acids by fractional vacuum distillation and by fractional crystallization. With NaOH, palmitic add forms sodium palmitate, a soap, Most soaps are mixtures of sodium stearate, palmitate, and oleate. 

Forming Solids from Solutions Under certain conditions, a solute can come back out of its solution and form a solid. This process is called crystallization. Sometimes this occurs when the solution is cooled or when some of the solvent evaporates. Crystallization is the result of a physical change. When some solutions are mixed, a chemical reaction occurs, forming a solid. This solid is called a precipitate (prih SIH pub tayt). A precipitate is the result of a chemical change. Precipitates probably have formed in your sink or shower because of chemical reactions. Minerals that are dissolved in tap water react chemically with soap. The product of this reaction leaves the water as a precipitate called soap scum, shown in Figure 3. 

The finishing operation of soap manufacture is designed to fulfil several requirements. Minor ingredients such as colourants, perfume and titanium dioxide must be accurately dosed and mixed uniformly into the soap, grit particles which can form during drying must be removed, the soap must be converted from a particulate mass into a compact solid containing no occluded air and the crystal structure of the soap may be modified to produce specific phase structures. 

Oentele s Process-— A process was suggested by M. Qentele for making soft soap with one-fifth part of soda mixed with the potash ley. By preference, crystals of soda are used and it is important that the leys should be free from chloride of sodium or other saline impuiities. The fatty materials recommended for this process are red oil, 100 lbs. tallow, 40 lbs. hempseed-oil, 3,750 lbs. 

C. J. Geoffroy mentioned as a volatile salt the crystals deposited from essential oils. He published on antimony, tartar emetic, and kermes mineral. He showed that soap is readily soluble in hot alcohol, the liquid on coohng setting to a clear jelly, and that the oil set free from the soap (really oleic acid) by the action of acids is more soluble in alcohol than the original oil. In his paper on Prussian blue he argued that the soufre animal of the organic material sets free iron in a fine state of division which, when mixed with the sulphurous principle and absorbent earth, exhibits a blue colour. (Until recently, the blue colour of ultramarine was ascribed to finely-divided sulphur.) He translated the work on assaying of Christian Carl Schindler. ... 

For some spectroscopic applications lyotropic lamellar mesophases of soaps may be of great value. Lamellar liquid crystals are formed in sodium decanoate-decanol-water systems [14]. A convenient system is obtained by mixing 28 wt% sodium... 

Lyotropic liquid crystals acquire their anisotropic properties from the mixing of two or more components. One component is amphiphilic and contains a polar head group, the second component is usually water. Lyotropic liquid crystals occur abundantly in nature, particularly in all living systems. The most familiar example of a lyotropic liquid crystal is soap in water. During the last few years considerable progress has been made toward understanding the experimental and theoretical aspects of the method reviewed in this book. 

In soap bar processing free fatty acid is usually added in formulations to create so-called super-fatted soap. An acid-soap complex with a fixed stoichiometric ratio between alkaline soap and the fatty acid is formed. For example, the ratio of potassium acid soap is 1 1 while sodium soap forms acid soaps with various ratios. The fixed ratio complex exits not only in anhydrous crystalline phase but also in a hydrous liquid crystalline phase (11, 12). Oleic acid and its potassium soap form a 1 1 complex acid soap when equal molar acid and soap are mixed. Above the Krafft boundary, the acid soap in water forms a lamellar liquid crystal phase at low surfactant concentration, from a few percent, and the lamellar liquid crystal phase extends to ca 60% surfactant concentration. A hexagonal liquid crystal phase is formed after the lamellar liquid crystal phase with further increasing the surfactant concentration. This phase behavior is different from the soap and water phase behavior, in which the hexagonal liquid crystalline phase is formed first followed by the lamellar liquid crystalline phase. Below the Krafft boundary the acid soap complex forms a solid crystal and separates from water (4). 

---