Colloid foam stability

I. C. Callaghan, C. M. Gould, R. J. Hamilton, and E. L. Neustadter. The relationship between the dilatational rheology and crude oil foam stability 1. Preliminary studies. Colloids and Surfaces, 8(1) 17-28, November 1983. 

Murray, B.S., Ettelaie, R. (2004). Foam stability proteins and nanoparticles. Current Opinion in Colloid and Interface Science, 9, 314-320. 

Schmitt, C., Kolodziejczyk, E., Leser, M.E. (2005). Interfacial and foam stabilization properties of p-lactoglobulin + acacia gum electrostatic complexes. In Dickinson, E. (Ed.). Food Colloids Interactions, Microstructure and Processing, Cambridge, UK Royal Society of Chemistry, pp. 284-300. 

A foam is a colloidal dispersion in which a gas is dispersed in a continuous liquid phase. The dispersed phase is sometimes referred to as the internal (disperse) phase, and the continuous phase as the external phase. Despite the fact that the bubbles in persistent foams are polyhedral and not spherical, it is nevertheless conventional to refer to the diameters of gas bubbles in foams as if they were spherical. In practical occurrences of foams, the bubble sizes usually exceed the classical size limit given above, as may the thin liquid film thicknesses. In fact, foam bubbles usually have diameters greater than 10 pm and may be larger than 1000 pm. Foam stability is not necessarily a function of drop size, although there may be an optimum size for an individual foam type. It is common but almost always inappropriate to characterize a foam in terms of a given bubble size since there is inevitably a size distribution. This is usually represented by a histogram of sizes, or, if there are sufficient data, a distribution function. 

The stabilizing function of macromolecular surfactants in solid-liquid systems is exercised through protective colloid action. To be effective, they must have a strong solution affinity for hydrophobic and hydrophilic entities. In liquid-liquid systems, surfactants are more accurately called emulsifiers. The same stabilizing function is exercised in gas-liquid disperse systems where the surfactants are called foam stabilizers. 

Another point of view concerning foam stability appeared in relation to the development of the general theory of stability of colloid systems (DLVO-theory). It has already been noted that this theory was verified for the first time with foam films [35]. This gave rise to the concept of foam stabilisation on the account of the electrostatic component of disjoining pressure [e.g. 24, 32, 36],... 

Water is an essential component of the colloidal structures stabilizing the foam. Separation of water followed by boiling reduces the strength of these structures to cause partial defoaming. ... 

As with other viscous polyanions such as carrageenan, pectin may be protective towards milk casein colloids, enhancing the properties (foam stability, solubility, gelation and emulsification) of whey proteins whilst utilizing them as a source of calcium. 

Use Protective colloid, dispersing agent, thickener, binder, adhesive and size in coatings, detergents, emulsions, paper, textiles, leather, latex, rust preventive, foam stabilizer. 

Imitation dairy Emulsifying, colloidal stability Solubility, foaming, foam stability... 

Figueredo, R. C. R., and Sabadini, E., Firefighting foam stability the effect of the drag reducer poly(ethylene) oxide. Colloids Surf. A, 215, 77-86 (2003). 

Aramaki, K., Aratani, K., and Kunieda, H. (2005) Interfadal properties and foam stability effect of novel gemini-type surfactant in aqueous solutions./. Colloid Interface Sci., 291, 236-243. 

Principal component analysis is another statistical technique that has been applied to the results of profile analysis [55]. Ales and lagers were examined and two-dimensional plots of the results using the first two principal components as axes showed resolution of the ales from the lagers and the close proximity of the majority of duplicate samples. Profile analysis has also been used to differentiate various brands of whisky [56]. Throughout the work on profile analysis hedonic expressions have been strictly excluded but other workers [57] have used principal component analysis to classify Continental European beers correctly as good, average or poor on the basis of nine physicochemical parameters colloidal stability (7 days at 40°C/1 day at 0°C), cold sensitivity (24 hours at 0°C), brightness at 12°C, six months test, the content of p-phenylethanol, ethyl caprylate, isoamyl acetate, and isobutanol and foam stability. 

Nishioka, G. and Ross, S., A new method and apparatus for measuring foam stability, J. Colloid Interface Sci., 81, 1, 1981. 

Brown AG, WC Thuman, and JW McBain, Transfer of air through adsorbed surface films as a factor in foam stability. Journal of Colloid Science, 5, 508-519,1953. 

Dickinson E. Izgi E. Foam stabilization by protein-polysaccharide complexes. Colloid and Surfaces. 1996,113, 191-201. 

Boris Vladimirovich Derjaguin (1902-1994). .. was a Russian chemists and physicist whose work is tightly connected with the development of the modem science of colloids and surfaces. Most prominent is his theory on colloidal stability, now known as DLVO theory, which he developed together with Landau and independently from Verwey and Overbeek. Additionally, he examined the adhesion and friction of solid bodies, developed the theory of capillary osmosis, started investigation into foam stability, worked on the direct measurements of molecular attraction, and contributed to the theory of electrokinetic phenomena. 

FIGURE 4.39 Foamability ( ) and foam stability ( , after 60 s) by hand shaking of cylinders as function of temperature for 1 wt.% of Triton X-100 containing 0.3 wt.% of a PDMS-EOPO copolymer (of mol.wt. 29,000, EO-PO ratio 0.66, PDMS-EOPO ratio 0.26). Open symbols give foam behavior of dilute conjugate solution formed by centrifuging the turbid dispersion at 50°C foamability (O), foam stability ( , after 60 s). (After Nemeth, Z. et al., J. Colloid Interface Sci., 207, 386, 1998.)... 

FIG U RE 4.67 Effect of in situ formation of calcium oleate from dissolved sodium oleate on foam stability of 0.1 g dm aqueous solution of commercial alcohol ethoxylate (C,2 i5.EO,) in 3 mM Ca at pH 9. (a) Immediate effect of calcium oleate formation. , absence of oleate , 10 mM oleate A, 3 X 10 mM oleate. (b) Comparison of effect of in situ formation of calcium oleate immediately and after 60 h aging. , absence of oleate , immediate effect of 3 X 10 mM oleate A, effect of 3 X 10 mM oleate after 60 h. (After Zhang, H., Miller, C.A., Garrett, P.R., Raney, K., J. Colloid Interface ScL, 279,539, 2004.)... 

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