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Interfacial tension colloids

Kunieda, H. and Shinoda, K. (1980) Solution behaviour and hydrophile-lipophile balance temperature in the Aerosol OT-isooctane-brine system-correlation between microemulsions and ultralow interfacial tensions. /. Colloid Interface Sci., 75, 601-606. [Pg.396]

Nushtaeva, A.V. and Kruglyakov, P.M. (2004) Investigation of model emulsion films stabilized by solid partides thickness of films, their stability, and interfacial tension. Colloid J., 66, 456. [Pg.390]

The last field of ion specificity is the most complex one ion effects in inhomogeneous systems where interfaces are present macroscopic interfaces, colloidal systems, or polymer solutions. In such systems, the presence of salt affects a whole range of properties interfacial tensions, colloidal coagulation, protein stability, and protein activity, just to name a few. It is remarkable that the ion specificity for all these properties follows the same order, which is expressed in the Hofmeister series, and that sometimes this order is completely reversed. [Pg.2051]

Levine S, Bowen BD. Capillary interactions of spherical particles adsorbed on the surface of an oil-water droplet stabilized by the particles 3. Effective interfacial tension. Colloids Surf A 1993 70(1) 33 5. [Pg.372]

Vinckier, I., Minale, M., Mewis, J., and Moldenaers, P. 1999. Rheology of semi-dilute emulsions Viscoelastic effects caused by the interfacial tension. Colloids Surf. A 150 217-228. [Pg.260]

The entropically driven disorder-order transition in hard-sphere fluids was originally discovered in computer simulations [58, 59]. The development of colloidal suspensions behaving as hard spheres (i.e., having negligible Hamaker constants, see Section VI-3) provided the means to experimentally verify the transition. Experimental data on the nucleation of hard-sphere colloidal crystals [60] allows one to extract the hard-sphere solid-liquid interfacial tension, 7 = 0.55 0.02k T/o, where a is the hard-sphere diameter [61]. This value agrees well with that found from density functional theory, 7 = 0.6 0.02k r/a 2 [21] (Section IX-2A). [Pg.337]

A separate class of materials, known as protective colloids, exerts a stabilizing influence by acting as a bridge between the continuous phase and the particles which they envelop. In many instances the optimum stabilizing effect is achieved when the protective colloids are used in conjunction with a compatible interfacial tension depressant. The protective colloid must have an affinity for the continuous phase. When stabilization occurs through protective colloidal action, the particles lose their surface property identities in respect to charge, agglomeration, etc., and assume the properties of the protective colloid. [Pg.86]

The computer interface system lends itself well to the determination of interfacial tension and contact angles using Equation 3 and the technique described by Pike and Thakkar for Wilhelmy plate type experiments (20). Contact angles for crude oil/brine systems using the dynamic Wilhelmy plate technique have been determined by this technique and all three of the wetting cycles described above have been observed in various crude oil/brine systems (21) (Teeters, D. Wilson, J. F. Andersen, M. A. Thomas, D. C. J. Colloid Interface Sci., 1988, 126, in press). The dynamic Wilhelmy plate device also addresses other aspects of wetting behavior pertinent to petroleum reservoirs. [Pg.564]

Larpent and coworkers were interested in biphasic liquid-liquid hydrogenation catalysis [61], and studied catalytic systems based on aqueous suspensions of metallic rhodium particles stabilized by highly water-soluble trisulfonated molecules as protective agent. These colloidal rhodium suspensions catalyzed octene hydrogenation in liquid-liquid medium with TOF values up to 78 h-1. Moreover, it has been established that high activity and possible recycling of the catalyst could be achieved by control of the interfacial tension. [Pg.227]

This latter case is the same result as Einstein calculated for the situation where slip occurred at the rigid particle-liquid interface. Cox15 has extended the analysis of drop shape and orientation to a wider range of conditions, but for typical colloidal systems the deformation remains small at shear rates normally accessible in the rheometer. The data shown in Figure 3.11 was calculated from Cox s analysis. His results have been confirmed by Torza et al.16 with optical measurements. The ratio of the viscous to interfacial tension forces, Rf, was given as ... [Pg.82]

V. Schroder, O. Behrend, and H. Schubert Effect of Dynamic Interfacial Tension on the Emulsification Process Using Microporous Ceramic Membranes. J. Colloid Interface Sci. 202, 334 (1998). [Pg.43]

S. Sugiura, M. Nakajima, T. Oda, M. Satake, and M. Seki Effect of Interfacial Tension on the Dynamic Behavior of Droplet Formation During MicroChannel Emulsification. J. Colloid Interface Sci. 269, 178 (2004). [Pg.44]

C. A. Miller, R.-N. Hwan, W.J. Benton, and T.J. Fort Ultralow Interfacial Tensions and Their Relation to Phase Separation in Micellar Solutions. J. Colloid Interface Sci. 61,554(1977). [Pg.45]

D. Langevin In S.-H. Chen, J. S. Huang, and P. Tartaglia (eds), Low interfacial tensions in microemulsion systems. Structure and Dynamics of Strongly Interacting Colloids and Supramolecular Aggregates in Solution. 325. p. Kluwer, Dordrecht (1992). [Pg.47]

The effect of slow accumulation of surface-active materials is indicated in Fig. 18, which is a series of photographs of drops suspended in a tapered tube (H9). Tiny amounts of fine solids of colloidal dimensions, as described by Elzinga and Banchero (El), gradually collected at the interface and were swept around to the rear of the drop. Circulation was progressively hindered until it was nearly stopped. Yet no measurable change could be detected in any physical property, including interfacial tension of the separated phases. [Pg.83]

W. Wu, G.H. Nancollas, Determination of interfacial tension from crystallization and dissolution data A comparison with other methods, Adv. Colloid Interface Sci. 79 (1999) 229-279. [Pg.325]

Doe PH, Wade WH, Schechter RS (1977) Alkyl benzene sulfonates for producing low interfacial tensions between hydrocarbons and water. J Colloid Interface Sci 59 525-531... [Pg.109]

Cash L, Cayias JL, Pournier G, MacAllister D, Shares T, Schechter RS, Wade WH (1977) The application of low interfacial tension scaling rules to binary hydrocarbon mixtures. J Colloid Interface Sci 59 39-44... [Pg.111]

Queste S, Salager JL, Strey R, Aubry JM (2007) The EACN scale for oil classification revisited thanks to fish diagrams. J Colloid Interface Sci 312 98-107 Cayias JL, Schechter RS, Wade WH (1976) Modeling Crude Oils for Low Interfacial tension. Soc Petrol Eng J 16 351-357... [Pg.111]

Ding, P., Wolf, B., Frith, W.J., Clark, A.H., Norton, I.T., Pacek, A.W. (2002). Interfacial tension in phase-separated gelatin / dextran aqueous mixtures. Journal of Colloid and Interface Science, 253, 367-376. [Pg.297]

Low-molecular-weight surfactants ( emulsifiers ) are important ingredients in food products. The types of surfactants most commonly studied in food colloids research are phospholipids (lecithin), mono/diglycerides (particularly glycerol monostearate), polysorbates (Tweens), sorbitan monostearate or monooleate (Spans), and sucrose esters. These small lipid-based amphiphiles can typically lower the interfacial tension to a greater extent than the macromolecular amphiphiles such as proteins and certain gums (Bos and van Vliet, 2001). [Pg.323]

Emulsions and foams are two other areas in which dynamic and equilibrium film properties play a considerable role. Emulsions are colloidal dispersions in which two immiscible liquids constitute the dispersed and continuous phases. Water is almost always one of the liquids, and amphipathic molecules are usually present as emulsifying agents, components that impart some degree of durability to the preparation. Although we have focused attention on the air-water surface in this chapter, amphipathic molecules behave similarly at oil-water interfaces as well. By their adsorption, such molecules lower the interfacial tension and increase the interfacial viscosity. Emulsifying agents may also be ionic compounds, in which case they impart a charge to the surface, which in turn establishes an ion atmosphere of counterions in the adjacent aqueous phase. These concepts affect the formation and stability of emulsions in various ways ... [Pg.322]

The phenomena of association colloids in which the limiting structure of a lamellar micelle may be pictured as composed of a bimolecular leaflet are well known. The isolated existence of such a limiting structure as black lipid membranes (BLM) of about two molecules in thickness has been established. The bifacial tension (yh) on several BLM has been measured. Typical values lie slightly above zero to about 6 dynes per cm. The growth of the concept of the bimolecular leaflet membrane model with adsorbed protein monolayers is traceable to the initial experiments at the cell-solution interface. The results of interfacial tension measurements which were essential to the development of the paucimolecular membrane model are discussed in the light of the present bifacial tension data on BLM. [Pg.111]

Girault, H.H.J., Schifrin, D.J., and Smith, B.D.V. 1984. The measurement of interfacial tension of pendant drops using video image profile analyzer. J. Colloid Interface Sci. 101 257-266. [Pg.645]

Zhichu, B. Zhenshu, Z. Fei, X. Yueying, Q. and Jiayong, Y. (1999). Wettability, Oil Recovery, and Interfacial Tension with an SDBS-Dodecane-Kaolin System, Journal of Colloid and Interface Science, 214, 368-372. [Pg.269]

Of course, interfacial tension lowering alone may not be sufficient to stabilize an emulsion, in which case other interfacial properties must be adjusted as well. These simple calculations do, however, show how important the interfacial properties can become when colloidal-sized species are involved, as in the case of emulsions. [Pg.58]

Microemulsions, like micelles, are considered to be lyophilic, stable, colloidal dispersions. In some systems the addition of a fourth component, a co-surfactant, to an oil/water/surfactant system can cause the interfacial tension to drop to near-zero values, easily on the order of 10-3 - 10-4 mN/m, allowing spontaneous or nearly spontaneous emulsification to very small drop sizes, typically about 10-100 nm, or smaller [223]. The droplets can be so small that they scatter little light, so the emulsions appear to be transparent. Unlike coarse emulsions, microemulsions are thought to be thermodynamically stable they do not break on standing or centrifuging. The thermodynamic stability is frequently attributed to a combination of ultra-low interfacial tensions, interfacial turbulence, and possibly transient negative interfacial tensions, but this remains an area of continued research [224,225],... [Pg.97]


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See also in sourсe #XX -- [ Pg.77 ]

See also in sourсe #XX -- [ Pg.77 ]




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