Temperature dependences of micellar molecular weight and radius of nonionic surface active agent in the aqueous solution

Fujimatsu, Hitoshi; Takagi, Kenichiro; Matsuda, Hideomi; Kuroiwa, Shigetaka

doi:10.1016/0021-9797(83)90254-0

Cited by 17 publications

(9 citation statements)

References 22 publications

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“…In a solution of a given surfactant, it increases, however, with the temperature for NPEO10, while the change is negligible for other surface active agents, as can be seen in Figure 5. The fact, that Rh observed for surfactant of nEO > 20 is practically independent of temperature can be explained in a similar way to Fujimatsu et al [9] by increased and denser packing of molecules in the micelles. At the same time, the aggregation number is also increasing, but obviously the previous factor isthe ruling one as far as the size of the micelle is concerned.…”

Section: Dependence Of Hydrodynamic Radius On Temperature and Number supporting

confidence: 69%

“…If the hydrodynamic radius of micelles has already been determined, some other information for conformation of the micelle can be obtained, e. g. the frictional ratio (f/fo) and the most probable oblate-ellipsoid (9) For an oblate-ellipsoid micelle (a/b > 1), the minor (b) and major (a) axes could be calculated by the following relationship:…”

Section: Shape Of Micellesmentioning

confidence: 99%

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Mass, size and shape of micelles formed in aqueous solutions of ethoxylated nonyl-phenols

Bedö

Berecz

Lakatos

1987

Colloid & Polymer Sci

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The study was extended to analysis of mass, size and conformation of micelles formed in aqueous solutions of ethoxylated nonyl phenols. The results obtained by ultracentrifugal technique between 293 and 323 K have proved that the slightly ethoxylated nonyl phenols form micelles with high molecular mass and larger size at constant temperature, while the increasing length of the ethylene oxide chain favours formation of micelles of smaller molecular mass and size. The transformation of conformation from oblate to spherical shapes ensues with increasing temperature at constant ethoxy number or with ethoxylation at constant temperature. The second virial coefficient decreases with increasing temperature and decreasing ethoxy number. In accordance with the earlier conclucions, the change of the second virial coefficient relates to enhanced variation of monomer solubility, stabilization of micelle structure and increased deviation from ideal behaviour of a given micellar system.

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Section: Dependence Of Hydrodynamic Radius On Temperature and Number supporting

confidence: 69%

Section: Shape Of Micellesmentioning

confidence: 99%

Mass, size and shape of micelles formed in aqueous solutions of ethoxylated nonyl-phenols

Bedö

Berecz

Lakatos

1987

Colloid & Polymer Sci

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“…The apparatuses used to obtain the mutual diffusion coefficients and diffusion constants were the same as in the previous paper [9]. the miceltar radii were estimated from the mutual diffusion constants by Einstein-Stokes' relation.…”

Section: Methodsmentioning

confidence: 99%

“…In a previous paper [1], this phenomenon was investigated in terms of the thermodynamic free volume theory for polymer solutions proposed by Prigogine [2], Patterson [3][4][5][6] and Flory [7,8]. The notion of the apparent theta temperature (point) TO ap was then introduced for a temperature at which the second virial coefficient becomes zero [9]. Some other authors [10][11][12][13][14] also applied the same theory to interpreting the phase separation phenomenon including LCST, but did not discuss it in connection with TO ap. In the present work, the dependences of LCST and TO ap on the polyoxyethylene chain length are investigated in connection with the theta temperature for homogeneous poly(oxyethylene)dodecyl ether derivatives with various polyoxyethylene chain lengths by applying the theory of polymer solutions.…”

Section: Introductionmentioning

confidence: 99%

Lower critical solution temperature (LCST) and theta temperature of aqueous solutions of nonionic surface active agents of various polyoxyethylene chain lengths

Fujimatsu

Ogasawara

Kuroiwa

1988

Colloid & Polymer Sci

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Cloud points of aqueous solutions of homogeneous poly(oxyethylene)dodecyl ether derivatives (C12(OE)n : 1"/= 2-8) and the apparent theta temperature TO ap were determined from the abrupt changes in optical transmittance and the temperature dependence of the second viriai coefficient obtained by light scattering measurements. It was found that the lower critical solution temperature (LCST) shifts to a lower temperature and lower concentration as the number of oxyethylene units in a molecule decreases. Because of this behavior of LCST, the modified Flory-Schultz plot of phase separation was applied to the present nonionie surfactant-water system, and its theta temperature obtained. The dependence of TO ap on the number of oxyethylene units suggests that the polyoxyethylene chain has different effects on the solubility of C12(OE)n in water for n less than or equal to 3 from those for n greater than or equal to 4.

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“…The effect of temperature on the aggregation behaviour of nonionic surfactants of the alkylpolyoxyethyleneglycol monoether type Cm En (m = number of carbon atoms of the alkyl chain, n = number of oxyethylene groups) has been a matter of controversy in the recent literature [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. Recall that the aqueous solutions of Cm En are characterized by the so-called cloud temperature Tc above which the solution phase separates [19].…”

Section: Introductionmentioning

confidence: 99%

Effect of temperature on the aggregation behaviour of nonionic surfactants in aqueous solutions

1985

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2014 L'effet de la température sur les propriétés micellaires de tensioactifs non ioniques a été étudié par déclin de fluorescence (formation d'excimère intramicellaire) du pyrène solubilisé dans les micelles. Pour les surfactants du type C12H25En (E = groupe oxyde d'éthylène; n = 6, 8, 9) le nombre micellaire moyen en nombre N est pratiquement indépendant de la température T quand T TC-35 (TC = température critique du système). Dans le domaine TC-35 T TC, N augmente avec T, jusqu'à TC. Dans le même domaine on note l'existence d'une migration intermicellaire du pyrène. La vitesse de cette migration augmente très rapidement avec T. Ce processus semble se produire par l'intermédiaire de collisions entre micelles accompagnées d'une fusion temporaire et partielle des micelles. Un autre surfactant non ionique étudié, le Triton X-100, se comporte de façon un peu différente : N augmente avec T et le processus de migration existe dans tout le domaine de température étudié. Abstract. 2014 The effect of temperature on the aggregation behaviour of nonionic surfactants in aqueous solution has been investigated by means of transient fluorescence probing (intramicellar excimer formation by pyrene). For surfactants of the C12H25En type (E = ethyleneoxide group, n = 6, 8, 9) the number average aggregation number N of the micelle is nearly independent of the temperature T when T is below TC-35 (TC = critical temperature). In the range TC-35 T TC, N increases with T, up to TC. In the same range, extensive pyrene migration from micelle to micelle is observed. This process is thought to take place through micelle collisions with temporary and partial merging. Triton X-100 was also investigated and found to behave somewhat differently with an increase of N with T and probe migration in the whole T-range.

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Temperature dependences of micellar molecular weight and radius of nonionic surface active agent in the aqueous solution

Cited by 17 publications

References 22 publications

Mass, size and shape of micelles formed in aqueous solutions of ethoxylated nonyl-phenols

Mass, size and shape of micelles formed in aqueous solutions of ethoxylated nonyl-phenols

Lower critical solution temperature (LCST) and theta temperature of aqueous solutions of nonionic surface active agents of various polyoxyethylene chain lengths

Effect of temperature on the aggregation behaviour of nonionic surfactants in aqueous solutions

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