Colloid chemical studies on bitumen-in-water emulsions part III. Comparison of particle size analysis techniques and determination of emulsifier adsorption at the bitumen/water interface

• Published in: Colloids and surfaces 1981, Vol.2 (1), p.89-99
• Main Authors: Tausk, R.J.M., Stassen, W.J.M., Wilson, P.N.
• Format: Article
• Language: English
• ISSN: 0166-6622; 1873-4340
• DOI: 10.1016/0166-6622(81)80056-X

Three different techniques, Coulter counter, light transmission and disc centrifugation, have been used to characterize various cationic bitumen emulsions. The agreement between the Coulter counter and the light transmission method was good. Disc centrifugation gave slightly deviating results, probably due to the problems connected with deriving particle concentrations from optical signals. The magnitude of the change in average particle see with absorption of water by the bitumen indicates that water is distributed unevenly over the binder droplets: larger particles contain relatively more water. From the chance in emulsifier (N-alkylpropylenediamine, HCl) concentration in the aqueous phase during emulsification the surfactant adsorption at the bitumen/water interface could be calculated. A saturation adsorption of around 30 × 10 −20 m 2 per molecule was obtained. This value depended slightly on emulsifier solution composition.