A Study Of Interfacial Dilational Properties And Foam Properties Of Foam Combination Flooding Model Systems

In this paper, the dilatational viscoelastic properties of monolayer film at air-water interfaces were investigated by means of two methods: the interfacial tension response to sinusoidal area variations and interfacial tension relaxation method respectively. The foam properties were measured by Ross-Miles method. Furthermore, a correlation between the stability of the films and the surface dilatational elasticity of the respective monolayers was studied. The experiments and results are as following:Firstly, the surface dilatational viscoelasticity properties of three kinds of nonionics solutions with different polyoxyethylene numbers: Octylphenol polyoxyethylene ethers TX-100, TX-102, TX-165; Nonylphenol polyoxyethylene ethers NP-8, NP-10, NP-12; Alkyl secondary alcohol ethoxylates 15-S-7, 15-S-9 and 15-S-12, were investigated by Langmuir trough method. The influence of concentration and the number of ethylene oxide units on surface dilatational properties were expounded. The foamability and foam stability were measured by Ross-Miles method. It showed that the increase of polyoxyethylene numbers resulted in the increase of surface dilatational modulus and elasticity, which may be attributed to the slower relaxation processes caused by the"flat-configuration"of the longer polyoxyethylene chain at the surface. A comparison of the results obtained for 15-S with those obtained for NP reveals a correlation between the stability of thefilms and the surface dilatational elasticity of the respective monolayers. Secondly, the dilatational surface elasticity and foam properties of the two nonionic surfactants (Triton X-100, Triton X-305) and the anionic surfactant sodium dodecylbenzene sulfonic acid (SDBS) were studied. As was discussed, neither of these observations can be explained in terms of surface forces: systems with equal surface forces can have completely different stabilities. It shows that foam film stability and surface elasticity are directly correlated in this study.Thirdly, the surface dilatational properties and foam properties of sodium dodecylbenzene sulfonic acid (SDBS) with different additives, such as ethanol, n-butyl alcohol, 1-dodecanol, hexadecanol, methyl laurate, and methyl oleate were investigated. It was found that hexadecanol increase the foam stability of SDBS solutions with appropriate ratio due to strong ion-dipole interaction. Correspondingly, the surface dilatational elasticity of the SDBS/C16OH mixtures is significantly higher than that of pure SDBS solutions.Lastly, the influences of HAPAM polymers on the dilatational modulus of SDBS solutions were studied. The foam properties of SDBS/polymer and TX-100/polymer mixtures were measured by air flowing method (Bikerman method). It was shown that polymer additive increased the foam stability and surface dilatational modulus remarkably.