TY - JOUR
T1 - Adsorption of ionic surfactants in particulate systems
T2 - Flotation, stability, and interaction forces
AU - Bremmell, K. E.
AU - Jameson, G. J.
AU - Biggs, S.
PY - 1999/1/15
Y1 - 1999/1/15
N2 - The flotation efficiency of silica particles using the ionic surfactants, sodium dodecylbenzenesulfonate (SDbS) and cetyltrimethylammonium bromide (CPB), have been investigated. Results from adsorption, electrophoretic mobility, dispersion stability and direct interaction force measurements are used to develop an understanding of the role of ionic surfactants in particulate flotation. Adsorption and mobility data indicate that SDbS adsorbs at the silica/solution interface, though without improving the flotation efficiency. CPB was found to adsorb on the silica particles as a result of electrostatic interaction; initially to neutralize the surface charge and destabilize the suspension, and at higher surfactant concentrations, to reverse the particle charge and re-stabilize the suspension: Direct force measurements in the presence of CPB confirm that the electrostatic interactions between approaching surfaces are neutralized at low CPB concentrations. Additionally, evidence for a strong adhesive interaction after contact is seen. At higher concentrations, the surfaces begin to recharge, and the adhesive interaction decreases in magnitude. The flotation efficiency was found to correlate well with the measured particle interactions, and to be a function of the particulate electrophoretic mobility.
AB - The flotation efficiency of silica particles using the ionic surfactants, sodium dodecylbenzenesulfonate (SDbS) and cetyltrimethylammonium bromide (CPB), have been investigated. Results from adsorption, electrophoretic mobility, dispersion stability and direct interaction force measurements are used to develop an understanding of the role of ionic surfactants in particulate flotation. Adsorption and mobility data indicate that SDbS adsorbs at the silica/solution interface, though without improving the flotation efficiency. CPB was found to adsorb on the silica particles as a result of electrostatic interaction; initially to neutralize the surface charge and destabilize the suspension, and at higher surfactant concentrations, to reverse the particle charge and re-stabilize the suspension: Direct force measurements in the presence of CPB confirm that the electrostatic interactions between approaching surfaces are neutralized at low CPB concentrations. Additionally, evidence for a strong adhesive interaction after contact is seen. At higher concentrations, the surfaces begin to recharge, and the adhesive interaction decreases in magnitude. The flotation efficiency was found to correlate well with the measured particle interactions, and to be a function of the particulate electrophoretic mobility.
KW - Adsorption
KW - Direct interaction forces
KW - Electrophoretic mobility
KW - Flotation
KW - Ionic surfactants
KW - Stability
UR - http://www.scopus.com/inward/record.url?scp=0032909502&partnerID=8YFLogxK
U2 - 10.1016/S0927-7757(98)00802-4
DO - 10.1016/S0927-7757(98)00802-4
M3 - Article
AN - SCOPUS:0032909502
VL - 146
SP - 75
EP - 87
JO - COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
JF - COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
SN - 0927-7757
IS - 1-3
ER -