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Definition of Critical Micelle Concentration q
Ruckenstein, E.; Nagarajan, R. Critical
Micelle Concentration - A Transition Point for Micellar Size Distribution. Journal
of Physical Chemistry 79, 2622-2626 (1975). q
Ruckenstein, E.;. Nagarajan, R. On
Critical Concentrations in Micellar Solutions. Journal
of Colloid and Interface Science 57, 388-390 (1976). q
Ruckenstein, E.; Nagarajan, R. Critical
Micelle Concentration and the Transition Point for Micellar Size
Distribution. Journal
of Physical Chemistry 85, 3010-3014 (1981). q Nagarajan, R.; Ruckenstein, E. Relation Between the Transition Point in Micellar Size Distribution, the CMC and the Cooperativity of Micellization. Journal of Colloid and Interface Science 91, 500-506 (1983). q
Nagarajan, R. Modeling Solution Entropy
in the Theory of Micellization. Colloids
and Surfaces A: Physicochemical and Engineering Aspects 71, 39-64 (1993).
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Size Distribution of Micelles |
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Size distribution of
micelles (micelle concentration vs micelle size) at
various concentrations of singly dispersed (monomeric) surfactant, for a
model system. The curves from the bottom
to the top correspond to increasing monomer concentrations. At a critical
monomer concentration, the size distribution shows a point of inflection and
this concentration is defined as the theoretical critical concentration, Ccrit.
Below this concentration, the size distribution is a monotonically
decreasing function of the micelle size. Above this critical concentration,
the size distribution exhibits a minimum and a maximum. In proposing such a
theoretical definition for the critical concentration, an analogy is made to
the critical point in fluids, characterized by an inflection in the pressure
– volume behavior of fluids. The experimentally
determined critical micelle concentration (CMC) is generally a little larger
than the theoretically defined Ccrit. |
