Compositional changes between free coatings and surface coating layers during mechanochemical process - An IR-based chemometric analysis

By mid-IR analysis, mixtures of stearic acid, a paraffinic compound and a fluorinated compound were analyzed using attenuated total reflection (ATR) spectroscopy and reflection-ab sorption infrared spectroscopy (RAIRS). The precision of the partial least square (PLS) models created for each of these two techniques were compared in order to work out a quality control process of the mixtures which are involved in mechanochemical coating technology. We obtained a good relationship between spectral data and concentration with ATR spectroscopy. However, RAIRS spectroscopy allows to observe the affinity of long-chain organic acids for steel surfaces, and to determine the actual composition of coatings. (C) 2004 Elsevier B.V. All rights reserved.