Pump Effect of a Capillary Discharge in Electrically Conductive Liquids

Abstract

Among the configurations to generate plasma in electrically conductive liquids only the diaphragm and the capillary discharge schemes allow to generate plasma which is not in contact with one of the electrodes. Based on this concept, this work reports for the first time the development of an underwater plasma pump, in which the periodic electrical breakdown inside an asymmetrical (sub-)millimetre hole results in a net flow of aqueous solution through the hole without the use of any moving parts such as valves or diaphragms typically used in micropumps. Certain capillary geometries feature very stable flow rates and even allow altering flow direction by changing the power. By varying the hole's dimensions, the range of time-independent flow rates covers more than one order of magnitude and as the discharge produces some of the strongest oxidants available, we believe that this concept might find application in fields as water decontamination and sterilization.

Non-thermal plasmas in and in contact with liquids

“…Many results are reported on capillary and diaphragm discharges, e.g. [3,[187][188][189][190][191][192] and [193][194][195], respectively.…”

Influence of electrode material on hydrogen peroxide generation by DC pinhole discharge

“…The diaphragm orifice is too small to allow significant mixing of the solutions from different electrode parts. Still, partial pumping effect may appear due to the discharge [18]. Copper ions can react with hydrogen peroxide in a way similar to Fenton's reaction.…”

Selective Surface Modification of Poly(propylene) with OH and COOH Groups Using Liquid‐Plasma Systems

“…This may allow these species to reach the substrate effectively. Thus flow rates48 generated by the geometry of capillary has an effect over the delivery of active species to the desired sites. Based on the knowledge of oxygen low‐pressure glow discharge plasma treatment of polymer surfaces, the presented XPS‐data can be summarized schematically (Figure 18).…”