Direct measurements of the effects of salt and surafactant on interaction forces between colloidal particles at the oil-water interface

The forces between colloidal particles at a decane-water interface were studied using laser tweezers. Averaging over several particle pairs was necessary to obtain reliable averages of the effects of salt and surfactant. Increasing the electrolyte concentration yields, on average, a reduction of the magnitude of the interaction force with electrolyte concentration. Charges on the water side still contribute significantly to the electrostatic interactions. The basis for understanding the aggregation kinetics of two-dimensional suspensions is discussed. This is an abstract of a paper presented at the 2007 AIChE Annual Meeting (Salt Lake City, UT 11/4-9/2007).