Method and an apparatus to measure the .ZETA.-potential of bubbles.

Abstract

A method and an apparatus to measure the^-potential of bubbles has been developed. The apparatus is of microelectrophoresis type. Small bubbles of 20-40/im in diameter are generated by pressure reduction of a solution containing dissolved air and are introduced into an electrophoresis cell of 0.972 mmthickness. As the movementof the bubbles is followed over 4 seconds in this arrangement, the measurement error due to the rapid rising of the bubbles can be considerably decreased. The bubbles were positively charged in a cationic surfactant solution of cetyltrimethylammonium bromide (CTAB)and the charge decreased with increasing electrolyte concentration in the solution. In an anionic surfactant solution of sodium dodecyl sulfate (SDS), both the bubbles and oil particles were negatively charged. But, by the addition of A12(SO4)3, the oil particles maintained their negative charge while the charge of the bubbles was changed to positive. The situation of the attaching of oil particles to bubbles was observed photographically.

Measurement of the Zeta Potential of Gas Bubbles in Aqueous Solutions by Microelectrophoresis Method

“…2b. In this study, the location of the stationary plane was examined experimentally following an approach described by Hunter (2) and Okada and Akagi (27). In electrophoresis measurements, the observed bubble velocity along the horizontal direction, v OB (y), is the algebraic sum of the true bubble electrophoretic velocity, v E , and the liquid velocity, v OM (y), resulting from electroosmosis:…”

Foams: Basic Principles

“…For the most part, these techniques are applied to suspensions and emulsions, rather than foams. In bubble microelectrophoresis, the dispersed bubbles are viewed under a microscope, and their electrophoretic velocity is mea sured taking the horizontal component of motion, because bubbles rapidly float upwards in the electrophoresis cells (33,34). A variation on this technique is the spinning cylinder method, in which a bubble is held in a cylindrical cell that is spinning about its long axis.…”

A novel method of measuring electrophoretic mobility of gas bubbles

“…The most common approach for determining the bubble surface charge is through electrophoretic mobility measurements, from which zeta potential values are calculated [1][2][3][4][5][6]. The main source of error in electrophoretic mobility studies stems from the high rise velocities of the bubbles in a gravitational field.…”

“…Kubota et al [6], and Okada and Akagi [1] used an interesting approach to generate small bubbles in surfactant solutions and measured their electrophoretic mobility. Air was dissolved in three aqueous solutions, each containing a different type of surfactant (sodium dodecylbenzene sulfonate, sodium dodecyl sulfate, and cetylpyridium chloride) under high pressure (∼5 atm).…”