Some thermodynamic parameters of two indigenous mineral dyes applied on wool material

Some thermodynamic parameters governing the dyeing process of two potential indigenous mineral dyes applied on wool fabric have been investigated. These parameters included percent exhaustion (%E), partition coefficient (K), standard affinity (−Δ μ⁰), enthalpy change (ΔH⁰), entropy change (Δs⁰), diffusion coefficient (D_T) and activation energy of the diffusion(E_D). Relevant physicochemical properties such as solubility, melting point, pH, λ_max and elemental analysis were also discussed. The range of values of %E, K, -Δ μ⁰, ΔH⁰, Δs⁰, D_T, and E_D obtained for the two dyes were: 92.8–98.7%, 20.5 to 73.1lkg⁻¹ -1036.0 to -2626.0cal/mol, -14451 to 6043cal/mol, -15.42 to -48.88cal/molK 1.2–4.1x10⁻³ cm²/min and 3.75 4.03kcal/mol respectively. The implication of the values of each parameter on the dyeing of fabric materials were discussed and used to predict some important properties of the two dyes.