Soap Foams

You may have noticed that when you drop a bar of soap into your bubble bath all of the bubbles start to burst, and the foam collapses. This happens because surfactant from the soap bar (nonionic sodium stearate, for example) rapidly begins to displace the bubble bath surfactant in the 

We can estimate the thickness of the fluid films in a soapy shampoo foam, or even a single soap bubble, by noting the beautiful reflected colors. This phenomenon is due to thin-film interference wavelengths comparable to the thickness of the film ( 300-700 nm) constructively interfere to produce distinct reflection colors. 

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For a long time it was thought that soap foams, grains in metals and so on were icosahedra. It took Lord Kelvin (of the degree K) to get it right. 

Foam level measurement - European and American detergent and appliance manufacturers follow different philosophies and use changing chemical detergent compositions resulting in varying soap foam quantity. 

Dispersion/suspension of the oil and dirt particles in the soap foam, preventing these particles from being redeposited on the surface. 

The physicochemical properties of foam and foam films have attracted scientific interest as far back as a hundred years ago though some investigations of soap foams were carried out in the seventeen century. Some foam forming recipes must have been known even earlier. The foundations of the research on foam films and foams have been laid by such prominent scientists as Hook, Newton, Kelvin and Gibbs. Hook s and Newton s works contain original observations on black spots in soap films. 

Foam stability is governed by similar factors as emulsion stability. Thus in a soap foam the negative charges located at the air-water interface lead to repulsion as the... 

Note This formula may be further diluted to meet cost requirements. Even the addition of another 100 parts of water produces an exceptional hand soap. One percent sodium chloride may be added to increase viscosity. Unlike a straight soap, the above formulation will not clog dispen er valves if no sodium chloride is added. It is important that a potassium soap be used because triethanolamine soaps foam considerably less in such combinations. 

The silver coating on old mirrors is dissolved with nitric acid and the surface is rinsed with water. The hands are scrubbed with soap, and the soap foam is transferred to the surface, which is then scrubbed for some time with the foam. Scrubbing is continued while the surface is rinsed, first with tap water, then with distilled water. In the end, the units surface must be perfectly wetted by the water. If any greasy, water-repellent area remains, the entire operation must be repeated. After rinsing, the piece to be mirrored is placed in a dish of distilled water. 

Products and Uses An additive in coconut oil, laurel oil, vegetable fats, soaps, detergents, and flavorings in foods. Used as a lubricant, soap, foam, or bubble agent. 

Grain boundaries are internal interfaces and behave much like external surfaces, but now we have to be concerned with two crystal orientations, not one. Just as for surfaces, we have a pressure difference associated with the GB curvature and a driving force that tends to lead to an overall increase in grain size whenever possible. Grain morphology and GB topology are two aspects of the same topic. It is instructive to think of the model of soap foams a soap film is flat when in equilibrium and it has a finite thickness. Three soap films meet along a line—a TJ. If you blow on a soap film (apply a pressure) it bows out until the surface tension balances the applied pressure. 

Uses Antistat, vise, control agent in cosmetics surfactant for soaps foam stabilizer Trade Name Synonyms Alkamide R-280 t[Rhodia HPCII http //www.rhodia-hpcii.com], Emid 6573 t[Cognis/Chems. Group http //www.cognis-us.com], Rewomid R 280 t[Goldschmidt-Rewo GmbH]... 

Explain why the addition of a small amount of octyl alcohol to a soap foam breaks it, but does not prevent its formation if added to the solution before foam formation. 

FIGURE 4.66 Foam volume as function of time of 3 mM aqueous sodium dodecylbenzene sulfonate solution containing 0.018 mM CaCl2 and 0.02 g dm sodium soap. Foam generation by hand shaking cylinders at 25°C. , Sodium laurate , sodium oleate A, sodium palmitate and sodium stearate (identical results). (After Peper, H., J. Colloid ScL, 13, 199, 1958.)... 

Mono- and di-fatty-amides are used as antifoams [6,66,67]. Monoamides are active at levels as low as 1%. Diamides are, in most cases, used in combination with polysiloxanes, hydrocarbons, or soaps. Foam killing depends on chain length [68], as does soap, but not on water hardness. 

In classical wet soap foams, the growth exponent is typically A 0.33, whereas in tire liquid crysti, A 0.2 was observ both in tiie nematic and smectic phases. This may be explained by the presence of defects at the surface of the bubbles, thus slowing down the coarsening. Such statement is corroborated with the observation that, in the isotropic phase, the foam rapidly mptures. 

Chapters 1 and 2 introduce the main phases and basic properties of liquid crystals and other anisotropic fluids, such as soaps, foams, mono-layers, fluid membranes and fibers. These chapters do not include difficult mafliematical formulas and are probably suitable for imdergraduates or for other professionals, such as K-12 teachers. Chapter 3 describes the nature of phase transitions based on the phenomenological Landau-de Gennes theories, and on the self-consistent mean-field theories that use concepts in statistical physics. 

FIGURE 5.14 A soap foam formed from a simple mixture of ionic surfactant and water, imaged using polarized optical microscopy. The soapy films at the air-water interface are birefringent (see Chapter 2) and can be visualized using this technique. 

Quillaya saponaria Quaillaya, Murillo s-bark Soaps, foaming agents Bark >25... 

Yucca schidigera Mohave yucca, Joshua tree Soaps, foaming agents Stalk and roots 10... 

Uses Detergent, emulsifier, wetting agent for shampoos, liq. soaps, foam baths, feminine hygiene prods., low irritation formulas PU foam for orthopedic use Properties Water-wh. cl. liq. sp.gr. 1.0 kg/l vise. 100 mPa-s pH 6.5-7.5 22% act. Toxicology Nonirritant Environmental Biodeg. 

Uses Soap, foaming agent for shampoos, bubble baths, liq. hand soaps, industrial hand soap, surgical scrub soap, carwash... 

Uses Surfactant, conditioner, foam stabilizer, vise, builder for shampoos and hand soaps foam stabilizer in fracturing foams in oil field applies. 

Uses Strongly foaming base surfactant for detergents, shampoos, liq. soaps, foam baths... 

Chem. Descrip. Sodium lauryl sulfate, glycol stearate Uses Special surfactant blends which impart pearl effidently using a cold blend find use in shampoos, liq. hand soaps, foam baths, and other personal care and industrial prods. 

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