An Empirical Kinetic Approach for the Determination of the Ion Exchange Constants for Counterions of Cationic Micelles: The Rate of pH-Independent Hydrolysis of Phthalimide as the Kinetic Probe: Effects of (CH3)(4)(N+) on K-X(Y) (X=Br- and Y=Cl-)

作者：Khan M Niyaz^*; Ramakrishnan Hemalatah

来源：Journal of Dispersion Science and Technology, 2011, 32(3): 365-371.

DOI：10.1080/01932691003662373

• An empirical kinetic approach
• cationic surfactant
• determination of ion exchange constant at cationic micellar surface
• hydrolysis at 0
• 02M KOH
• kinetics
• phthalimide
• pseudophase micellar model
• tetramethylammonium chloride and bromide

Pseudo-first-order rate constants (kobs) for pH-independent hydrolysis of phthalimide (1), obtained at constant total concentration of cetyltrimethylammonium bromide (CTABr]T), 2.0x10-4M 1, 0.02M KOH and varying concentration of inert salt MX (=(CH3)4NCl and (CH3)4NBr), follow a kinetic equation derived in terms of pseudophase micellar (PM) model coupled with an empirical equation. This derived equation gives empirical constants. FX/S and KX/S where S represents anionic 1. The magnitude of FX/S is the measure of the fraction of micellized anionic 1 [image omitted] transferred to the aqueous phase by the limiting concentration of X- and the magnitude of KX/S is the measure of the ability of the ion X-, to expel another counterion ion S- from the cationic micellar surface to the aqueous phase through ion exchange process X-/S-. The values of the empirical constants, FX/S and KX/S, are used to determine the usual ion exchange constant [image omitted]. The values of FX/S are 1 for MBr and in the range 0.97-0.78 for MCl within [CTABr]T range 0.006 -0.016M. The mean value of [image omitted] is 2.4 +/- 0.1 and it is comparable with those obtained by other kinetic probes (with M+=Na+) as well as physicochemical techniques.

• 出版日期2011