Effect of urea on micellar properties of aqueous solutions of nonionic surfactants

Journal Article · Thu Oct 31 00:00:00 EST 1991 · Journal of Physical Chemistry; (United States)

DOI:https://doi.org/10.1021/j100175a103· OSTI ID:7241441

Briganti, G; Puvvada, S; Blankschtein, D ^[1]

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1. Massachusetts Inst. of Tech., Cambridge (United States)

The authors present results of a systematic experimental and theoretical investigation of the effect of urea on micellization, micellar growth, and phase separation of aqueous micellar solutions of the nonionic surfactant n-dodecyl hexaethylene oxide (C{sub 12}E{sub 6}). The experimental studies, which cover a wide range of urea concentrations from 0 to 6 M, involve determinations of the critical micellar concentration (cmc), micellar shape and size as a function of temperature, and liquid-liquid phase separation coexistence curves. They find that the addition of urea significantly affects micellar solution properties. In particular, (1) the cmc increases, (2) micellar size decreases, (3) the sphere-to-rod' shape transition temperature shifts to higher values, and (4) the critical point associated with the coexistence curve, shifts to a higher temperature and concentration. They also find that the measured coexistence curves, at 0, 2, 4, and 6 M urea concentrations, collapse onto a single universal curve when plotted in reduced coordinates. In addition, it is found that plots of the mean micellar hydrodynamic radius, R{sub h}, vs {Tc} {minus} T, where {Tc} is the critical temperature and T is the actual temperature, overlap for 0, 2, 4, and 6 M urea concentrations, with the resulting universal curve exhibiting a pronounced break at a value of {Tc} {minus} T {approx} 37C.

• OSTI ID: 7241441
• Journal Information: Journal of Physical Chemistry; (United States), Vol. 95:22; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
02 PETROLEUM
MICELLAR SYSTEMS
CHEMICAL PROPERTIES
UREA
AQUEOUS SOLUTIONS
EXPERIMENTAL DATA
MATHEMATICAL MODELS
QUANTITY RATIO
SURFACTANTS
THEORETICAL DATA
AMIDES
CARBONIC ACID DERIVATIVES
DATA
DISPERSIONS
INFORMATION
MIXTURES
NUMERICAL DATA
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
SOLUTIONS
400201* - Chemical & Physicochemical Properties
020300 - Petroleum- Drilling & Production