Sulfate ion adsorption onto and desorption from silicon dioxide surface has been investigated using a quartz crystal microbalance with dissipation monitoring capability (QCM-D). A viscoelastic model was used to calculate adsorption/desorption amount. Experimental results indicate that the adsorption from Na2SO4 and K2SO4 solutions at a pH of 6.8 results in the formation of a multilayer sulfate film with co-adsorption of Na+ or K+ ions. Sulfate ion uptake varied linearly with sulfate concentration in the range 0.01 M to 0.6 M. The first order rate constant for sulfate desorption with DI water is approximately 0.04 s(-1) and 0.12 s(-1) for flow rates of 0.2 ml/min and 1.0 ml/min, respectively. (C) 2016 The Electrochemical Society. All rights reserved.
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