Effect of the Surface Pretreatment on the Electrokinetic Properties of Silicon and Silicon Oxide

Abstract

The electrokinetic characteristics (the isoelectric point, electrokinetic potential, and surface conductivity) are studied as functions of pH against the background of NaCl solutions for the initial surfaces of silicon (covered with an oxide layer) and silicon oxide (a plane-parallel capillary of quartz glass and aerosil OX-50) and for the same surfaces after a preliminary thermal and chemical (CCl4 vapors at 400°C) treatment. The position of the isoelectric point for the systems in question is shown to be primarily affected by the preliminary annealing, which shifts this point toward higher pH. The electrokinetic behavior of silicon plates covered with an oxide film is compared to the electrode behavior of a similar board of an ion-selective field-effect transistor.