Masoud Mofarahi

In this work, the density and viscosity of aqueous solution of tetrabutyl ammonium fluoride (TBAF) in the temperature range of 3 to 30 degrees Celsius and the weight fraction range of 0.1 to 0.5344 have been measured. The density data were then modeled using the CPA equation of state, CPA plus MSA term and mixing rules. Viscosity data were also modeled using the CPA equation of state and the friction theory. Finally, a comparison was made between experimental data and modeling results. The results showed that the average absolute error obtained from modeling experimental density data using the CPA equation was 0.306%, for the CPA + equation plus the MSA term (three fitting parameters) was equal to 0.308% and for the CPA + equation plus the MSA term (five fitting parameters) was equal to 0.571%. By changing the mixing rules in the CPA equation of state, the average absolute error obtained was equal to 0.310%. According to these results, it can be seen that the CPA equation of state had better results for calculating the density of aqueous solution of tetrabutyl ammonium fluoride, and the addition of the MSA term and mixing rules did not have much effect on improving the results. The calculated average absolute error for modeling the experimental viscosity data using the CPA equation of state and friction theory was 10.375%. According to the obtained results, it can be said that the CPA equation of state and friction theory are suitable for modeling the density and viscosity of aqueous solution of tetrabutyl ammonium fluoride