Ross-Miles foam method

Test Methods. Surface tension (y) measurements were taken by Wil-helmy method (25+0.1°C). Critical micelle concentrations (cmc) were obtained from Y logC curves. Contact angle. Type GI, Japan. Wetting test. Canvas disk method, CIS,HG-2-380-66. Foam test, Ross-Miles lather method. Emulslbillty was determined by mixing 20 ml of 2.5%... 

Surfactant testing and reagent screening can be performed in a variety of ways. The simplest and most common technique used in the petroleum industry is the standard blender test [7]. Other test methods [4] include Ross-Miles foam height test, flow loop testing, capillary foam testers, contact angle measurements, tensiometers and actual field evaluations. Due to its low cost, easy duplication and ability to be used in the field, blender testing has become the norm in the industry for foam based fluids. 

Chlebicki and Slipko [127] determined the foam ability of sodium propoxyl-ated alcohol sulfates by the Ross-Miles method. These substances are low-foaming surfactants the greatest foam height was observed for dodecyl and tetradecyl chains. As expected, as the number of polyoxypropylene units on the same alcohol chain increases, foam height decreases. The maximum foam height obtained was 225 mm for a 2 g/L solution of sodium tetradecyl (1 PrO) sulfate. 

Gafa and Lattanzi [6] determined the foaming power of commercial surfactants including AOS, LAS, AS, and SAS in 1 g/L solutions at 40°C according to a modified Ross-Miles method [66]. Their data, shown in Table 24, show that the best foaming products are the AOS and AS compounds followed by LAS and SAS. 

FIG. 8 Foaming behavior of sulfosuccinates—Ross-Miles method. 

A great number of nonionic surfactants have been ethoxylated and subsequently reacted with P4O10. The acid phosphate esters from this reaction possess surface properties and detergency similar to the nonionic surface-active agents employed as reactants. Detergency tests and foam heights from the Ross-Miles method have been reported for a series of compounds. Various formulations for all-purpose cleaners are given as well [37,40,41,44,48]. 

Figure 32. Foam properties of propylene oxide adduct of secondary alcohol ethoxylate compared with those of others. Test conditions method—Ross-Miles (JIS-K-3362) surfactant concentration—1.0 wt % water temperature—25°C. ((- -) Cn.H SAE (7EO) + (4.5PO) (-1-) CI2 + Ii PAE (7EO) + (4.5PO) (-U-) HPE (8EO) + (4.5PO))...

The effect of the foam film type has been discussed in Section 7.5.1. However, a question arises as to whether the Ross-Miles method can be employed in testing foams built up by the three types of foam films. The answer is given by the data presented in Fig. 7.12. 

Tsuge et al. [11] present a comparison of three methods for estimation of the defoaming ability i) by the decrease in height of a foam column, produced by pouring the solution (Ross-Miles method) after antifoam introduction the height is measured immediately after foam formation and after 5 min... 

Foaming Ability and Foam Stability. Foaming ability and foam stability were determined in triplicate on 100-mg/mL solutions of freeze-dried raw foam and humic substances from stream, foam, and foam-extract samples. Measurements were made at 25 at pH 3.0, 7.0, and 10.0, with sample pH adjusted using O.IN sodium hydroxide using the Ross Miles method (D1173-53 ASTM standards, 1991). Briefly, a 200-mL... 

Several methods for generating foam have been reported including the use of kitchen blenders [20,164], shaking or rotation [165,166], by dropping from a height into a flask (Ross-Miles) [167], and by bubbling inert gas into the solution [168],... 

In the Ross-Miles method, 200 mL of a solution of surfactant contained in a pipette of specified dimensions with a 2.9-mm-i.d. orifice is allowed to fall 90 cm onto 50 mL of the same solution contained in a cylindrical vessel maintained at a given temperature (often 60°C) by means of a water jacket. The height of the foam produced in the cylindrical vessel is read immediately after all the solution has mn out of the pipette (initial foam height) and then again after a given amount of time (generally, 5 min). 

Dynamic foam test. Here, foam is generated by flowing gas through a porous orifice into a test solution as shown in Figure 2.17. The steady-state foam volume maintained under constant gas flow into the column is then measured. This is usually done in a column, but there are many variations of this kind of test [62, 99,100]. This technique is frequently used to assess the stabihty of evanescent foams. Another kind of dynamic foam test, the continuous plunging jet method [101], is a modification ofthe Ross-Miles test, described later. 

Ross-Miles Test. A method for assessing foam stability in which one measures the rate of collapse of a (static) column of foam that has been generated by allowing a certain quantity of foaming solution to fall a specified distance into a separate volume of the same solution contained in a vessel. 

Figure 2.11. Schematic of the apparatus used in the Ross-Miles pour test. (ASTM (American Society for Testing and Materials) D1173-63 Standard test method). The foam volume is measured immediately after the generation of the foam, and again after periods of 5 and 10 min...

FIGU RE 4.25 (a) Experimental observations of residual foam height (by Ross-Miles method) as function of critical applied capillary pressure, measured by FTT for a variety of surfactant solutions containing 0.1 wt.% emulsified neat PDMS oil. Residual foam heights for solutions requiring high values of are seen to follow the theoretical estimates of by Equation 4.40. 

Testing of Surfactants. Determination of foaming power Modified Ross-Miles method, DIN 53902, Sheet 2, January 1971. 

FIG U RE 6.8 Effect on initial foam volume of increasing the proportion of hydrophobed silica in hydrophobed silica-polydimethylsiloxane antifoam. Foam generation by Ross-Miles method 6 x 10 g dm" antifoam dispersed in 0.014 M SDS solution. Antifoam prepared from mixture of polydimethylsiloxane of 1000 mPa s viscosity and in situ hydrophobed silica Aerosil 200. (From Ross, S., Nishioka, G. Experimental researches on silicone antifoams, in Emulsions, Lattices, and Dispersions, Becher, R, Yudenfreund, M.N., eds., Marcel Dekker, New York, p 237, 1978.)... 

ISO 696. Surface active agents—Measurement of foaming power—Modified Ross-Miles method, 1975. 

Many other test methods and standards are available. Ross-Miles testing is another important test though it is often criticized for not being representative of real life foaming. In this test, a dilute solution of surfactant is dropped from a fixed height into a pool of the same dilute solution and the foam volume developed is measured. 

FIG. 11 Relationship between the hydrophobicity and the foaming power of the sodium salt of M-lauroyl-L-amino acids 0.25%, 40°C by Ross and Miles method. (From Ref. 49.)... 

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