A volumetric study of water-decyltrimethylammonium bromide-pentanol ternary system from 25 to 130 degrees C at 2 and 19 MPa

Density measurements on decyltrimethylammonium bromide (DeTAB)-water and pe ntanol (PentOH)-DeTAB-water systems as functions of both alcohol and surfac tant m(S) concentrations were carried out at 2 and 19 MPa from 25 to 130 de grees C. From experimental data for the water-DeTAB binary system, the stan dard (infinite dilution) partial molar volumes, expansibilities, and compre ssibilities of DeTAB, and the corresponding properties in the micellar phas e are calculated. The trends of the standard partial molar volumes of PentO H V-R(0) in DeTAB micellar solutions as functions of m(S) reflect the trans fer of PentOH from the aqueous to the micellar phase, except at 130 degrees C and 19 MPa. On the basis of an equation previously used, the distributio n constant of PentOH between the aqueous and the micellar phases and the st andard partial molar volume of alcohol in the aqueous and the micellar phas es are obtained from V-R(0) data. Comparisons with data for PentOH in dodec yltrimethylammonium bromide are made.