Thermodynamic analysis of 1,4-diaminoanthraquinone adsorption on polyethylene terephthalate in alkane media

Thermodynamic adsorption parameters of 1,4-diaminoanthraquinone on polyethylene terephthalate (PET) were determined using several alkane media ranging from pentane to decane. In the range from pentane to decane, as the number of carbon atoms in the alkane decreased, the standard affinity (−Δμ0) increased. From the results of the enthalpy change (ΔH0) and the entropy change (ΔS0), it is found that when adsorbed in the longer chain of alkane medium than in the shorter one, the dye molecules were more strongly embedded within the PET substrate. The diffusion coefficient (DT) of the dye decreased and the activation energy (ED) increased with increasing number of carbon atoms in the alkane.