THE EFFECT OF UREA ON HYDROPHOBIC BONDS: THE CRITICAL MICELLE CONCENTRATION OF n-DODECYLTRIMETHYLAMMONIUM BROMIDE IN AQUEOUS SOLUTIONS OF UREA1

1961 ◽  
Vol 83 (23) ◽  
pp. 4865-4866 ◽  
Author(s):  
Walter Bruning ◽  
Alfred Holtzer
2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Sujit Kumar Shah ◽  
Sujeet Kumar Chatterjee ◽  
Ajaya Bhattarai

Viscosity measurements have been made to the solutions of dodecyltrimethylammonium bromide (DTAB) and cetyltrimethylammonium bromide (CTAB) in 0.10, 0.20, 0.30, and 0.40 volume fractions of methanol in methanol-water mixed solvent media at 298.15, 308.15, 318.15, and 323.25 K. Critical micelle concentration (CMC) values have been determined. From relative viscosity for surfactant solutions, related viscosityBcoefficients are calculated and the values are interpreted in terms of solute-solvent interactions.


2020 ◽  
Vol 17 (4) ◽  
pp. 1207
Author(s):  
Sangita Acharya ◽  
Tulasi Niraula ◽  
Ajaya Bhattarai

The physicochemical behaviour of dodecyltrimethylammonium bromide (DTAB) in water and ethanol-water mixture in the presence and absence of ZnSO4 were studied by measuring the conductivity at 298.15 K. The pre-micellar (S1) and post-micellar slopes (S2) were obtained and calculated the degree of dissociation (α) and the critical micelle concentration (cmc). With an increase in ethanol content, the cmc and α of DTAB increased whereas, in the presence of ZnSO4, the cmc and α decreased. By using cmc and α, thermodynamic properties as the standard free energy of micellization ( ) were evaluated. With an increase in ethanol content, the negative values of  are decreased indicating less spontaneous in the micellization which makes micellization less favourable. The correlation of the pre-micellar and post-micellar slopes with the volume fraction of ethanol were discussed. DTAB micellization was tested in contexts of specific solvent parameters and solvophobic parameter.


2012 ◽  
Vol 550-553 ◽  
pp. 99-102
Author(s):  
Bao Cai Xu ◽  
Gui Ju Zhang ◽  
Yun Xia Li ◽  
Lu Cui

Amide surfactants have modified structures with lipophilic groups connecting hydrophilic groups through amido bond. The preparation of three families of amide surfactants including long chain N-acyl sarcosinates, amidopropyl dimethyl hydroxypropyl sulfobetaines and lauryl amidopropyl trimethyl ammoniums were discussed. The study of the surface activity of these compounds by measuring the equilibrium surface tensions of their dilute aqueous solutions were described. The minimum surface tension and the critical micelle concentration values of these compounds are given.


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