The Chain-Length Compatibility and Molecular Area in Mixed Alcohol Monolayers

Shah, D. O.; Shiao, S. Y.

doi:10.1021/ba-1975-0144.ch011

Cited by 11 publications

(8 citation statements)

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“…For example, the surface viscosity and foam stability are influenced by the alkyl chain length of the mixed surfactants. Moreover, it has also been shown previously (Schick and Fowkes, 1957;Shah and Shiao, 1975; Lawrence, 1960; Ries and Gabor, 1967;Meakins, 1968; Cameron and Crouch, 1963;Fort, 1962) that the critical micelle concentration (cmc), the average area per molecule in mixed monolayers, emulsion stability, rust prevention, dielectric absorption, and lubrication properties are strongly influenced by the alkyl chain length compatibility of the mixed surfactants.…”

Section: Introductionmentioning

confidence: 61%

“…The cones with the dashed lines (Figure 10) show the time-average space occupied by the segment of hydrocarbon chain of surfactants. A similar concept was also used by previous investigators (Shah and Shiao, 1975;Phillips et al, 1970) to explain results on mixed monolayers of various ionic and nonionic surfaceactive agents. Shah and Shiao (1975) reported that in the mixed monolayers of various alcohols, the average area per molecule is at a minimum when both components possess the same chain length.…”

Section: Introductionmentioning

confidence: 83%

“…These results show that the chain length compatibility of the surfactant molecules strikingly affects the surface tension and surface viscosity of the surfactant solutions. The surfactant molecules having the same chain length are tightly packed at the air-liquid interface, as compared to the molecules of the dissimilar chain length (Shah et al, 1978;Shah and Shiao, 1975). The high surface viscosity is known (Brown et al, 1953) to reduce the rate of thinning of the liquid films which in turn increase the foam stability.…”

Section: Introductionmentioning

confidence: 99%

“…The average bubble size was a minimum for the mixed foaming agents of similar chain length and increased with increasing difference in the chain length. Upon using mixed monolayers (Shah and Shiao, 1975), it has been shown that the molecules pack tightly at the air-liquid interface when the chain length of both of the components is equal. It was proposed that as the difference in the chain length increases, the thermal disturbances (e.g., rotational, vibrational, and oscillational indicate that molecular packing at the interface is strikingly influenced by chain length compatibility which, in turn, affects the bubble size as well as surface properties of the mixed surfactant solutions.…”

Section: Introductionmentioning

confidence: 99%

“…If thermal motions were limited to the portion above the height of the adjacent hydrocarbon chain, it would not change the packing of the molecules or the average area/molecule. However, the thermal disturbances probably extend along the alkyl chain toward the polar part of the surfactant molecule which, in turn, exhibit a greater area/molecule in mixed monolayers at the air-liquid interface (Shah and Shiao, 1975). Moreover, as the difference in hydrocarbon chains of foaming agents increases, the expansion of a mixed monolayer also increases because the length of the segment undergoing rotation, vibration, and oscillation increases.…”

Section: Introductionmentioning

confidence: 99%

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Correlation of chain length compatibility and surface properties of mixed foaming agents with fluid displacement efficiency and effective air mobility in porous media

Sharma¹,

Shah²,

Brigham³

1984

Ind. Eng. Chem. Fund.

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The effects of chain length compatibility and surface properties of mixed foaming agents on fluid displacement efficiency and effective air mobility in porous media were investigated. Sodium dodecyl sulfate (C12H25S04Na) and various alkyl alcohols (e.g., C8OH,C10OH,C12OH,C14OH, and C16OH) were used as mixed foaming agents. It was observed that the surface properties of surfactant solutions and flow behavior of foams through porous media were influenced by the chain length compatibility of the surfactant molecules. The increase in the length of porous media improved fluid displacement efficiency while breakthrough time per unit length decreased slightly with increase in the length of porous media. For mixed surfactant systems, a minimum in surface tension, a maximum in surface viscosity, a minimum in bubble size, a maximum in breakthrough time, a maximum in fluid displacement efficiency, and a minimum in effective air mobility were observed when the two components of the surfactant system had the same chain length. These results indicate that the surface properties of foaming solutions and molecular packing at interfaces exhibit a striking correlation with breakthrough time, fluid displacement efficiency, and effective air mobility in porous media.

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Section: Introductionmentioning

confidence: 61%

Section: Introductionmentioning

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Correlation of chain length compatibility and surface properties of mixed foaming agents with fluid displacement efficiency and effective air mobility in porous media

Sharma¹,

Shah²,

Brigham³

1984

Ind. Eng. Chem. Fund.

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Effect of oil viscosity on recovery processes in relation to foam flooding

Sharma

Shah

1984

J Americ Oil Chem Soc

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Laboratory experiments were conducted to determine the effect of oil viscosity on the oil‐recovery efficiency in porous media. The pure surfactants (i.e., sodium dodecyl sulfate and various alkyl alcohols) were selected to correlate the molecular and surface properties of foaming solutions with viscosity, and the recovery of oil. Oil‐displacement efficiency was measured by water, surfactant‐solution and foam‐flooding processes, which included 2 types of foams (i.e., air foam and steam foam). A significant increase in heavy‐oil recovery was observed by steam foam flooding compared with that by air foam flooding, whereas for light oils, the steam foam and air foam produced about the same oil recovery. An attempt was made to correlate the chain‐length compatibility with the surface properties of the foaming agents and oil‐recovery efficiency in porous media. For mixed foaming systems (C12 SO4 Na + Cn H2n+1 OH), a minimum in surface tension, a maximum in surface viscosity, a minimum in bubble size and a maximum in oil recovery were observed when both components of the foaming system had the same chain length. These results were explained on the basis of thermal motions (i.e., vibrational, rotational and oscillational) and the molecular packing of surfactants at the gas‐liquid interface. The effects of chain‐length compatibility and the surface properties of mixed surfactants are relevant to the design of surfactant formulations for oil recovery under given reservoir conditions.

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