Surfactants foaming

The foam volume and stability of alcohol sulfates is relatively increased in hard water compared to soft water. The amount and quality of foam is dependent on the alkyl length. Sulfates with C12-C,4 alkyl chains produce the richest creamy foam with small bubbles. C8-C10 alcohol sulfates are foam depressants and C16-C18 alcohol sulfates are poor foaming surfactants. Foams produced by alcohol sulfates are also relatively stable in the presence of sebum. Sodium and ammonium alcohol sulfates foam better than triethanolamine alcohol sulfates. Alcohol ether sulfates produce lighter foams than those of alcohol... 

W. T. Osterloh. Long chain alcohol additives for surfactant foaming agents. Patent US 5333687, 1994. 

Structured products, such as cosmetics, detergents, surfactant foams, inks, paints, drugs, foods and agrochemicals, combine several functions and properties in a single product. Design of these structured products involve the creation and the control of the particle size distribution in operations such as crystallization, precipitation, generation of aerosols, and nanoparticles as well as... 

Figure 3.28 Sketch of the plateau border in a surfactant foam. Due to the curvature (radius r) a suction effect in the direction of the arrows results.

The extrapolation of the linear parts of vexp(r2) dependence to zero values of border radii allows to estimate the contribution of the flow rate determined by the mobility of border surfaces at large radii of curvature where vs = const. The highest flow rate is obtained for a non-ionic surfactant foam. The real rate exceeds 5 to 9 times the calculated (at r > 60 mm). The lowest flow rate (vs 2-10 2 cm s 1) is measured in a NaDoS foam with NBF and the calculated flow rate is 2 to 3 times lower than the experimentally determined. Beginning with r of approximately 60 pm, a steeper decrease in the flow rate with the reduction of radius size is observed. Obviously, the course of these curves can be explained by the considerable reduction of the surface border mobility within this range of radii. 

For nonionic surfactants foams the xp ( /T) dependence is exponential and is typical for processes that run with overcoming the energy barriers, i.e. 

In Section 6.5 it was emphasised that critical pressure in a foam produced in a porous plate cell corresponds to the equilibrium capillary pressure at which an avalanchelike foam destruction occurs at given dispersity and temperature (the latter is of particular importance for nonionic surfactants foams). 

In order to develop efficient techniques for the preparation and application of foams in industry, agriculture, firefighting, etc., it is necessary to know the physicochemical parameters of surfactants and their relationship with the foam stabilising ability of the surfactant solutions. Usually the criterion of the surfactant foaming ability is the adsorption of these compounds at the solution/air interface and the related to it properties, such as decrease in surface tension, adsorption work, maximum adsorption T. [13,39,43]. CMC is often used as a characteristic of a foaming agent (if micellisation is possible in the surfactant solution). Parameters related to foam stability, such as foam lifetime and foam column height, are also employed [12,13,39],... 

Surfactant Foam in Porous Media Topical report SUPRI TR-48 U.S. Department of Energy, Washington DC, October, 1985. 

The value of the 1.0X 1.5X brine foam volume ratio at 75 C may be taken as a measure of the sensitivity of surfactant foaming properties to aqueous phase salinity. Values of this ratio determined at 75 C in the presence of decane are summarized below ... 

Unlike previous one atmosphere foam test designs, the present test permits the effect of the oil phase on surfactant foaming properties to be determined. Refined hydrocarbons were used as model oil phases. Results summarized in Tables I and Figure 3 indicated that the presence of hydrocarbons decreased the foam stability. Examination of Table I indicated that the presence of a hydrocarbon substantially reduced the 75 C foam volumes produced by AES and AESo surfactants. 

Table II. Effect of an Oil Phase and Aqueous Phase Salinity on Surfactant Foaming Properties...

Table III. Surfactant Foaming in the Presence of West Texas Field Stock Tank Oil at 40°C...

AE surfactants appeared to exhibit two modes of behavior. Generally foam volume did not decrease for AE surfactants containing less than ca 20 moles EO/mole surfactant when COj-extracted stock tank oil was used instead of stock tank oil (Figure 2). However, at EO levels above 30 moles/mole surfactant, foam volume in the presence of COj-extracted stock tank oil was less than in the presence of stock tank oil. 

Surfactant foaming properties are related to surfactant chemical structure parameters such as hydrophobe size, ethylene oxide chain length, and hydrophile functional group. 

Surfactant foaming properties are related to oil phase composition. The composition of the residual oil will change in the course of a COj EOR project. The optimum COj mobility control agent may thus change during the course of the project. 

Reservoir Sandstone (RS) Micromodel. The RS micromodel was used in a variety of experiments examining the effects of surfactant, foam quality, injection scheme and pressure level on foam displacement efficiency and flow patterns. Various gases and brines or surfactant solutions were used, primarily field injection gas and brine, and the surfactant AES (trade name Alipal CD-128) at a concentration of 0.5 wt.%. 

Many surfactants have been suggested as candidates for CO2 foam. However, at high salinity and temperature in the presence of oil, most surfactants foam poorly due to partitioning and emulsion formation and fail to control mobility during CO2 injection. This behavior is analogous to that observed in chemical (microemulsion) oil recovery (5-1). As the salinity, hardness and temperature increase, surfactants form water/oil emulsions, precipitate surfactant-rich coacervate phases, and partition into the oleic phase. CO2 decreases further the solubility of surfactant in the aqueous phase. 

While there have been efforts to polymerize other surfactant mesophases and metastable phases, bicontinuous cubic phases have only very recently been the subject of polymerization work. Through the use of polymerizable surfactants, and aqueous monomers, in particular acrylamide, polymerization reactions have been performed in vesicles (4-8). surfactant foams ), inverted micellar solutions (10). hexagonal phase liquid crystals (111, and bicontinuous microemulsions (121. In the latter two cases rearrangement of the microstructure occured during polymerization, which in the case of bicontinuous microemulsions seems inevitable b ause microemulsions are of low viscosity and continually rearranging on the timescale of microseconds due to thermal disruption (131. In contrast, bicontinuous cubic phases are extremely viscous in genei, and although the components display self-diffusion rates comparable to those... 

On location Heavy solid Vigorous superficial brushing Hard Surfaces Very low foam bath Organic surfactant foam... 

J = 1 1 1 1 1 1 1 - 4> 0.97 0.95 L A r no rigure viscosity as a lunc-tion of shear stress for an aqueous polymer-surfactant foam at the bubble volume fractions 0 shown. (From Khan et al. 1988, with permission... 

Fig. 4.20 Dependence of coalescence behavior of several surfactants (foam breakers) upon their mass fraction from [630],... 

Secondary surfactants/foam boosters — nonionic and amphoteric 0-10... 

The other ingredients of these compositions are surfactants, foam boosters, benefit agents, and water. The water is added in amounts of 10 to 30 % so that the salts are not dissolved. 

The presence of excess surface energy in such gas-liquid disperse system predetermines its nonequilibrium. However, by virtue of the stabilizing effect of surfactants, foam possesses a metastable structure and has a certain lifetime [118], Its properties slowly relax under the action of external factors provided that the latter do not exceed some threshold values beyond which the foam structure is destroyed. 

Ampholak. [Beiol Nobel] Amphoteric surfactants foam booster, vise, modifier, thickener, wetting s ent for industrial and hous ld cleaners, toiletries. 

Atplus. [ICI Am.] Surfactant foaming agent coupling agent stabilizer, wetting agent for agric. formulations. 

Chembetaine. [Chemton] Betaines mild surfactants, foam boosters, vise, builders for baby personal care prods., other cosmetics, industrial drilling fluids. 

IncrosuL [Croda Inc.] Sulfosuccinaies conditioning surfactant, foaming agent for personal cate prods., carpet shampoos. 

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