Comparative structural study of aqueous fluorinated non-ionic micelles

Moujahid, Chaouki El; Ravey, Jean-Claude; Schmitt, Véronique; Stébé, M.J.

doi:10.1016/s0927-7757(97)00354-3

Cited by 9 publications

(10 citation statements)

References 23 publications

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“…For both fluorocarbon ones, P values are rather close to 1/2, which is characteristic of cylindrical or lamellar structures. Since the fluorocarbon chains are bulkier than the hydrocarbon ones, fluorocarbon surfactant need to have a very large headgroup to form a spherical aggregate in order to balance the effect of the bulky perfluoroalkylated tail [31].…”

Section: Resultsmentioning

confidence: 99%

Synthesis and comparative behaviour study of fluorocarbon and hydrocarbon cationic surfactants in aqueous media

Ngo

Damas

Naejus

et al. 2010

Journal of Fluorine Chemistry

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Section: Resultsmentioning

confidence: 99%

Synthesis and comparative behaviour study of fluorocarbon and hydrocarbon cationic surfactants in aqueous media

Ngo

Damas

Naejus

et al. 2010

Journal of Fluorine Chemistry

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“…It was shown before that micelles grow in size as the temperature rises toward the lcb . Moreover, micellar structure is related to the critical concentration, which corresponds to the minima of the consolute curve . Finally, in the close vicinity of the critical point, critical phenomena exist .…”

Section: Introductionmentioning

confidence: 89%

“…18 Moreover, micellar structure is related to the critical concentration, which corresponds to the minima of the consolute curve. 19 Finally, in the close vicinity of the critical point, critical phenomena exist. 20 Thus, the phenomena associated to the cloud curve likely disturb the CTM, which governs the mesoporous material formation.…”

Section: ' Introductionmentioning

confidence: 99%

Structural Investigation of Nonionic Fluorinated Micelles by SANS in Relation to Mesoporous Silica Materials

Michaux¹,

Blin²,

Teixeira

et al. 2011

J. Phys. Chem. B

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In an attempt to answer the question if there is dependence between the pore ordering of the mesoporous silica, obtained through the cooperative template mechanism, and the shape of the micellar aggregates of the surfactant solutions, the micellar structures of two nonionic fluorinated surfactant based-systems are studied by SANS. By fitting the experimental spectra with theoretical models, the structural evolution of the molecular aggregates can be described, and some important parameters can be obtained, such as the water and eventually oil penetration into the surfactant film, the aggregation number, the area per polar head of the surfactant, and the surfactant chain conformations. We have shown that for the C(8)F(17)C(2)H(4)(OC(2)H(4))(9)OH system, the micelles are prolate spheroids. The increase of the surfactant concentration in water does not change the characteristics of the interfacial film, but the aggregation number raises and the particles become more elongated. By contrast, the experimental curves of C(7)F(15)C(2)H(4)(OC(2)H(4))(8)OH cannot be fitted considering a small particle model. However, progressive incorporation of fluorocarbon induces a change of size and shape of the globules, which become smaller and more and more spherical. Regarding the material mesopore ordering, it appears that the micelles that lead to hexagonal mesoporous silica materials are described with a model of quasi-spherical globules. On the contrary, when large micelles are found, only wormhole-like structures are obtained.

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“…The cpp values for spherical, cylindrical, and lamellar particle are ∼1/3, 1/3 < cpp < 1/2, and 1/2 < cpp < 1, respectively. Since the fluorocarbon chains are bulkier than the hydrocarbon chain, with the volume of -CF 2 and -CF 3 being higher than that of the -CH 2 and -CH 3 , respectively [19], fluorinated surfactant having a very large head group is needed to form a spherical aggregate (cpp 1/3), to balance the effect of bulky fluorocarbon chain [20]. Therefore, cylindrical micelles are often observed at solution conditions where spherical micelles are expected in hydrocarbon surfactant systems.…”

Section: Introductionmentioning

confidence: 99%

Small-angle X-ray scattering (SAXS) study on nonionic fluorinated micelles in aqueous system

Shrestha

Sharma

Sato

et al. 2007

Journal of Colloid and Interface Science

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We have investigated the self-organization structures of perfluoroalkyl sulfonamide ethoxylate, C(8)F(17)SO(2)N(C(3)H(7))(CH(2)CH(2)O)(10)H, a nonionic fluorinated surfactant in aqueous system by small-angle X-ray scattering (SAXS) technique. Structural modulation of the nonionic fluorinated micelle induced by temperature change, surfactant concentration, and the added fluorinated oils have been systematically studied. The SAXS data were analyzed by the indirect Fourier transformation (IFT), and the generalized indirect Fourier transformation (GIFT) depending on the volume fraction of the surfactant. Various plausible classical model calculations have been performed to confirm the consistency of the GIFT analysis of the SAXS data. Upon successive increase in temperature, the cylindrical micelles formed at lower temperatures undergo a continuous one-dimensional growth and ultimately near the cloud point an indication of flat planar like structural pattern is observed. The evolution in structure of particle near the demixing temperature may be due to onset of attractive interactions. The shape and size of the micelle is apparently unaffected by changing the surfactant concentration from 1 to 5 wt% at 25 degrees C. Nevertheless, addition of small amount of perfluoropolyether (PFPE) oil, of structure F(CF(2)CF(2)CF(2)O)(n)CF(2)CF(2)COOH (n approximately 21) modulate the micellar shape and size. Long cylindrical micelles eventually transform into globular like particles. The onset cylinder-to-sphere transition in the structure of micelles in the surfactant/water/oil system is probably due to amphiphilic nature of the oil, which tends to increase the spontaneous curvature. The lipophilic part of the oil tends to reside in the micellar core, whereas, the hydrophilic part goes close to the polar head group of the surfactant so that effective cross-sectional area per surfactant molecules increases and as a result spherical micelles tend to form. Perfluorodecalin (PFD) also decreases size of the micelles but its effect is poor compared to the PFPE oil.

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Comparative structural study of aqueous fluorinated non-ionic micelles

Cited by 9 publications

References 23 publications

Synthesis and comparative behaviour study of fluorocarbon and hydrocarbon cationic surfactants in aqueous media

Synthesis and comparative behaviour study of fluorocarbon and hydrocarbon cationic surfactants in aqueous media

Structural Investigation of Nonionic Fluorinated Micelles by SANS in Relation to Mesoporous Silica Materials

Small-angle X-ray scattering (SAXS) study on nonionic fluorinated micelles in aqueous system

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