Electrolyte Depedence of Ac Electro-osmosis
نویسندگان
چکیده
This paper reports the first investigation of the dependence of AC electro-osmosis (ACEO) on the solution chemistry. It is argued that classical dilute-solution theory breaks down in ACEO, since the large applied voltage leads to ion crowding near the electrode surfaces. A modified theory is proposed with steric effects (finite ion sizes) and a charge-dependent viscoelectric effect, which predicts that ACEO flow depends on the salt concentration, ion sizes and valences. Experiments demonstrate significant variations in ACEO pumping upon varying salt concentration (μM – mM KCl) or ionic species (μM NaCl, CaCl2, MgCl2, KI, KOH), which merit further experimental and theoretical study.
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