The dielectric loss factor was the most influenstic parameter in this microwave spectrum. The loss factor values increased as a function of frequency and slight modification in spectrum on changing the solute concentration. The ε˝ values obtained in our experiments are almost similar to our earlier work[43]. Above 8GHz the frequency dispersion spectrum of ε΄& ε˝ were superimposed with each other. The spacing between the dielectric values in dispersion spectrum could be attributed to the relative percentage of solute-solvent interaction which showed significantly more clustered structure than either stearic or stearic – nhexanol formation.
The thermodynamic parameters are evaluated using Eyring equation is given below …show more content…
The Gibb’s free energy change is the driving force and the fundamental criterion of spontaneity. Physical absorption is to be a spontaneous thermodynamic process, mush have a negative value. The thermodynamics parameters of adsorption relaxation strength (Δε) and dielectric activation (ΔF) of stearic acid complex have been calculated and the results are tabulated (3a-3f) using this formula(47) Δε = ε0 - ε∞ and ΔF = ε0 – ε’. The thermodynamic parameters of adsorption of stearic acid complex are tabulated(3a-3f). The Gibb’s free energy change of adsorption was found to be in range of -2.6 to -0.05KJ/mole. These results indicate that the adsorption of stearic acid complex is feasible and spontaneous. The enthalpy(ΔH) and entropy(ΔS) were found negative and positive values respectively. The negative value of enthalpy confirmed that the adsorption of stearic acid complex is an exothermic process. This can be due to energy released after the adsorption process being higher than that need to the solvent molecules. The negative value of enthalpy indicates that the process is exothermic and the physisorption behavior may be physical in nature and it can be easily reversed by supplying the heat equal to the adsorption system. The positive value of entropy significantly suggests that the random orientation in solute-solvent complex or interface between solid/solution during the adsorption. When ΔS is positive, increased spontaneity is favoured in the molecular movement. The negative value of enthalpy and positive value of entropy signifies that molecular dipoles are spontaneously and allinged oriented at all
The thermodynamic parameters are evaluated using Eyring equation is given below …show more content…
The Gibb’s free energy change is the driving force and the fundamental criterion of spontaneity. Physical absorption is to be a spontaneous thermodynamic process, mush have a negative value. The thermodynamics parameters of adsorption relaxation strength (Δε) and dielectric activation (ΔF) of stearic acid complex have been calculated and the results are tabulated (3a-3f) using this formula(47) Δε = ε0 - ε∞ and ΔF = ε0 – ε’. The thermodynamic parameters of adsorption of stearic acid complex are tabulated(3a-3f). The Gibb’s free energy change of adsorption was found to be in range of -2.6 to -0.05KJ/mole. These results indicate that the adsorption of stearic acid complex is feasible and spontaneous. The enthalpy(ΔH) and entropy(ΔS) were found negative and positive values respectively. The negative value of enthalpy confirmed that the adsorption of stearic acid complex is an exothermic process. This can be due to energy released after the adsorption process being higher than that need to the solvent molecules. The negative value of enthalpy indicates that the process is exothermic and the physisorption behavior may be physical in nature and it can be easily reversed by supplying the heat equal to the adsorption system. The positive value of entropy significantly suggests that the random orientation in solute-solvent complex or interface between solid/solution during the adsorption. When ΔS is positive, increased spontaneity is favoured in the molecular movement. The negative value of enthalpy and positive value of entropy signifies that molecular dipoles are spontaneously and allinged oriented at all