Adsorption of sodium dodecyl sulfate and sodium dodecyl phosphate at the surface of aluminium oxide studied with AFM

Artikel i vetenskaplig tidskrift, 2010

Within the framework of water-based aluminium pigments the difference in inhibition offered by the adsorption of sodium dodecyl sulfate (SOS) and sodium dodecyl phosphate (SDP) was studied by atomic force microscopy (AFM). While SOS did not show strong adsorption on aluminium oxide, SDP adsorbed strongly forming bilayers which patches did not change noteworthy over several hours of SDP exposure, indicating irreversible binding to the surface. Quantization of the surface coverage of the adsorbed SDP revealed that only 63% coverage was achieved, which shows surprisingly that a complete coverage is not necessary to inhibit oxidation of aluminium pigment particles.