Home

About

Advanced Search

Browse by Discipline

Scientific Societies

E-print Alerts

Add E-prints

E-print Network
FAQHELPSITE MAPCONTACT US


  Advanced Search  

 
Transport Properties for Aqueous Sodium Sulfonate Surfactants 2. Intradiffusion Measurements: Influence of the Obstruction Effect
 

Summary: Transport Properties for Aqueous Sodium Sulfonate Surfactants
2. Intradiffusion Measurements: Influence of the Obstruction Effect
on the Monomer and Micelle Mobilities
Onofrio Annunziata, Lucia Costantino, Gerardino D'Errico, Luigi Paduano, and Vincenzo Vitagliano
Dipartimento di Chimica, Universita` di Napoli, Federico II, via Mezzocannone 4, 80134 Napoli, Italy
E-mail: VITA@chemna.dichi.unina.it
Received July 24, 1998; accepted April 14, 1999
Intradiffusion coefficients of sodium alkylsulfonates [CH3­
(CH2)n 1SO3 Na , CnSNa] (n 5­9, 11) in mixtures with heavy
water were measured by the PGSE-NMR technique at 25°C. A
slope change in the experimental trends permits the determination
of the critical micelle concentration (CMC). In the micellar com-
position range, solubilized TMS molecules were used to determine
the micelle intradiffusion coefficient, from which the micelle radii
were obtained. Both the monomer surfactant and the micelle
intradiffusion coefficients show a sharp decrease above the CMC.
These results can be interpreted in terms of the obstruction effect
due to the micelles. The electrostatic repulsion among charged
particles strongly enhances this effect. A simple approach that
permits the computation of the Gouy­Chapman layer thickness

  

Source: Annunziata, Onofrio - Department of Chemistry, Texas Christian University

 

Collections: Chemistry