Wetting of glass surface covered with Teflon by ferrofluid as a function of concentration and size of grains, and pH of the solution

In this paper we investigate the wetting of glass surfaces, covered with a Teflon film, by ionic ferrofluids, as a function of the concentration and size of magnetic grains, and pH of the solution, using an optical technique. The optical phase shift induced by the surface field of the glass covered with Teflon is about eight times larger than that induced by the untreated glass. The induced phase shift was shown to be independent of the grains concentration investigated, but dependent on the grains size and pH of the solution.