Electrostatic interactions of colloidal particles in nonpolar solvents: role of surface chemistry and charge control agents.
We study the electrostatic and hydrodynamic interactions of colloidal particles in nonpolar solvents. Using blinking optical tweezers, we can extract the screening length, kappa-1, the effective surface potential, |ezeta*|, and the hydrodynamic radius, ah, in a single measurement. We apply this technique to suspensions of polystyrene and poly(methyl methacrylate) particles in hexadecane with soluble charge control agents, aerosol sodium di-2-ethylhexylsulfosuccinate (AOT) and polyisobutylene succinimide (OLOA-1200). We find that the electrostatic interactions of these particles depend sensitively on surface composition as well as on the concentration and chemistry of the charge control agent.
Departments of Mechanical Engineering, Chemical Engineering, and Physics, Yale University, New Haven, CT 06511, USA.
Sunil K
SK
Sainis
Vincent
V
Germain
Cecile O
CO
Mejean
Eric R
ER
Dufresne
D000336:Aerosols / Q000737:chemistry; D000473:Alkanes / Q000737:chemistry*; D003102:Colloids / Q000737:chemistry*; D052898:Optical Tweezers; D010316:Particle Size; D011108:Polymers / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011137:Polystyrenes / Q000737:chemistry*; D012997:Solvents / Q000737:chemistry; D055672:Static Electricity; D013386:Succinates / Q000737:chemistry*; D013388:Succinimides / Q000737:chemistry*; D013499:Surface Properties; D013816:Thermodynamics
C512554:1,4-bis(2-ethylhexyl) sodium sulfosuccinate; D000336:Aerosols; D000473:Alkanes; D003102:Colloids; D011108:Polymers; D011137:Polystyrenes; D012997:Solvents; D013386:Succinates; D013388:Succinimides; C528462:polyisobutylene succinimide; D019904:Polymethyl Methacrylate; C007932:n-hexadecane