Mixture Effects in Contaminant Reemission

The deposit of a pure contaminant or of contaminant mixtures may exhibit complex behavior. This impacts the possible in-flight reemission of these deposits as well as the interpretation of thermogravimetric analyses. These effects were studied, first on theoretical grounds, and then experimentally on controlled mixtures of pure contaminants or uncontrolled mixtures stemming from a real material outgassing. Several effects were clearly identified, such as phase segregation and various mixture behaviors, corresponding to quick or slow diffusion of the contaminants within the mixture.