Effect of water traces upon adsorption of PMMA on flat substrates of glassand silica

Using IR spectroscopy and AFM, we investigated the effect of traces of wate r on the adsorbed amount and the morphology of the adsorbed layer in the ad sorption of PMMA on flat silica and flat glass. To obtain very anhydrous so lutions, we used a technique that involves the addition of molecular sieves to the solution. We showed that this method allows direct comparison of PM MA adsorption between dispersed and flat substrates of silica; in the absen ce of water in the solution, as is obtained with this technique, the amount of polymer adsorbed on flat silica is similar to amounts reported in the l iterature for dispersed silicas. We also showed that the adsorption of PMMA occurs in a similar way, with the same adsorbed amount and same layer morp hology, onto glass and silica only when the adsorption takes place in an ex tremely anhydrous solution. On the contrary, when water molecules are prese nt, the adsorbed amount of polymer increases on both substrates, with a hig her amplitude on the glass substrates, and the structures of the polymer ad sorbed layers are different on the two substrates.