Effects of micelle-to-vesicle transitions on the degree of counterion binding

Ono, Yousuke; Kawasaki, Hideya; Annaka, Masahiko; Maéda, Hiroshi

doi:10.1016/j.jcis.2005.02.021

Cited by 37 publications

(26 citation statements)

References 36 publications

(79 reference statements)

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“…Unlike CVC (see Table S1 and S2 and Refs. [16][17][18][19][20][21]), T m (Table S3) is well-defined for DDAB in water (T m ≈ 16 • C) and highly cooperative (peak width T 1/2 < 0.5 • C) [2,5,13]. To the best of our knowledge the reverse liquid crystalline-to-gel transition temperature (T m ), has not been reported for DDAB so far because of its exceedingly slow kinetics [3,13].…”

Section: Thermal Behavior Of Ddab In Watermentioning

confidence: 90%

Thermal and phase behavior of didodecyldimethylammonium bromide aqueous dispersions

Feitosa

Adati

Alves

2015

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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h i g h l i g h t s• On increasing DDAB concentration, the following phase sequence appears: monomer, vesicle, lamellae.• DDAB unilamellar vesicles are formed in water only in a very narrow concentration range.• DDAB multilamellar vesicles co-exist with unilamellar vesicles in this concentration range.• Phase separation occurs in DDAB/water, with lamellae on top and vesicles on bottom.• The reverse melting temperature of DDAB/water is around 9.5 • C. g r a p h i c a l a b s t r a c t a b s t r a c t This work aims to delineate the single isotropic vesicle phase (Ves) in the binary didodecyldimethylammonium bromide (DDAB)/water system, limited by the critical vesicle concentrations, CVC 1 ≈ 0.05 mM (2.3 × 10 −3 wt%) and CVC 2 ≈ 0.7 mM (3.1 × 10 −2 wt%), as the onset of unilamellar vesicle formation and of two-phase separation into Ves + Lam (lamellar) phases, respectively. Isothermal titration calorimetry (ITC), turbidity, and crossed polaroids observations indicate that below CVC 1 the dispersion is dominated by free monomers or micelles, but rich in uni-and multilamellar vesicles between CVC 1 and CVC 2 , with CVC 2 = 0.21 mM (9.5 × 10 −3 wt%) being the onset of multilamellar vesicle formation. Above CVC 2 , the volume of the Lam phase increases, while the volume for the Ves phase decreases to vanish around CVC 3 ≈ 21 mM (0.95 wt%). Differential scanning calorimetry (DSC) data show that the gel-to-liquid crystalline transition at T m ≈ 16 • C is highly cooperative ( T 1/2 ≈ 0.3 • C), and the melting enthalpy ( H m ) increases with DDAB concentration. Because of the remarkably slow liquid crystalline-to-gel kinetics, a cooling transition around T m ≈ 9.5 • C is reported here for the first time, we ascribe to the liquid crystalline-to-gel transition (thermal hysteresis T m ≈ 6.5 • C). Vesicle and lamellar structure formation E. Feitosa et al. / Colloids and Surfaces A: Physicochem. Eng. Aspects 480 (2015) 253-259 is supported also by hydrodynamic diameter (D H ) data, being 100-140 and 800-1200 nm, respectively, at 25 • C. The zeta potential ( ) increases with DDAB concentration but does not change much with temperature, indicating no pronounced structural change when temperature varies around T m .

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Section: Thermal Behavior Of Ddab In Watermentioning

confidence: 90%

Thermal and phase behavior of didodecyldimethylammonium bromide aqueous dispersions

Feitosa

Adati

Alves

2015

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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“…Adding hydrophobic non-polar additives to cationic surfactant solutions is also found to increase the micellar growth [13,14]. Several research papers on the micellar solution of cationic surfactant and salt systems are available [15][16][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31]. Many cationic micellar solution were prepared from mixing long-chain cationic surfactants such as hexadecyltrimethylammonium (CTA + ) and hexadecylpyridinium (CPy + ) with organic counterions such as, salicylate, Sal -,tosylate T−)), and (HNC−) [32][33][34][35][36][37][38][39][40].…”

Section: Introductionmentioning

confidence: 99%

Biopolymer Surfactant Interactions

Sreejith¹,

Nair²,

George³

2010

Biopolymers

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“…The change of the degree of counter-ion dissociation on ion binding of DDAB vesicles and that of SDS micelles were 0.98 24) and 0.78 25) , respectively, which correspond to a= 0.02 (DDAB vesicle) and a = 0.22 (SDS micelle). These results indicate that the counter-ions can bind more strongly to DDAB vesicular surface than SDS micellar surface, and the counter-ion dissociation induced by solubilization of 1-alkanols is suppressed for DDAB vesicles compared with the case of SDS micelles.…”

Section: Fig 2 Plot Of Differential Conductivity (Dk/dc S ) As a Funmentioning

confidence: 96%

Partition Coefficients of 1-Alkanols between Water and DDAB Vesicle Membrane Determined by Differential Conductivity Method

et al. 2009

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The partition coefficients of 1-alkanols between water and didodecyldimethylammonium bromide (DDAB) vesicle membrane, and the change of the degree of counter-ion dissociation on DDAB vesicle caused by the solubilization of 1-alkanols were determined from electric conductivity measurements. A good linear relationship was obtained between logarithmic value of the partition coefficient and carbon number of alkyl chain in 1-alkanols. The standard transfer free energy change per methylene group was evaluated from the slope of this straight line. On the other hand, the effect of 1-alkanols on the degree of counter-ion dissociation was independent of carbon number of 1-alkanols. Comparing the results of the present system with those of sodium dodecylsulfate (SDS) micelle/1-alkanol system, it was found that the interior of DDAB vesicle membrane is more hydrophobic than that of SDS micelles. Furthermore, the increase in counter-ion dissociation caused by solubilized 1-alkanols was much lesser for DDAB vesicles than SDS micelles.

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Effects of micelle-to-vesicle transitions on the degree of counterion binding

Cited by 37 publications

References 36 publications

Thermal and phase behavior of didodecyldimethylammonium bromide aqueous dispersions

Thermal and phase behavior of didodecyldimethylammonium bromide aqueous dispersions

Biopolymer Surfactant Interactions

Partition Coefficients of 1-Alkanols between Water and DDAB Vesicle Membrane Determined by Differential Conductivity Method

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