Studying the effect of gold nanoparticles on mixture of surfactant of sodium dodecyl benzene sulfonate (SDBS) surfactant and folic acid

Abstract

Gold nanoparticles were prepared from yeast dough via gold salt reduction and their effect on rheology of a mixture of folic acid and the surfactant of sodium dodecyl benzene sulfonate (SDBS) was studied. The results revealed that the highest viscosity (pa. s7.1232×102) was at a ratio of 2/8, a temperature of 10oC and a concentration of 0.00004M of nano-gold. So, micelles growth is occurred by increasing nano-gold concentration. In the same manner, measuring the conductivity of the prepared solution revealed that there is a reverse proportion between conductivity and viscosity. Also, thermodynamic functions were calculated such as standard free energy (ΔGo), standard enthalpy (ΔH) and standard entropy (ΔSo) for the formed micelles together with calculating the micellization activation energy. Gold nanoparticles were prepared from yeast dough (Saccharomyces cerevisiae), via gold salt reduction, and the prepared nanoparticles were diagnosed by several techniques (UV-Vis.,x-ray, TEM, SEM), through which the results showed that the prepared gold particles have a purple colour at length (552nm) it has a spherical shape and is within the nano size that was specified by the Shearer equation. The effect of these prepared nanoparticles on the rheology of the mixture of folic acid and the surfactant of Sodium Dodecyl Benzene sulfonate was studied using different temperatures, as this study showed that the highest viscosity Its value was (pa. s7.1232×10 2) at the ratio (2/8) and at a temperature of 10Co and when the concentration of nano-gold was 0.00004M. If these results indicate that the growth of micelles increases with the increase in the concentration of the prepared nano-gold. The conductivity measurement of the solutions prepared for the mixture was also studied, as it was found that the conductivity increases as the viscosity decreases in the presence of nano-gold particles, which leads to an increase in the growth of micelles. From calculating the thermodynamic functions, it was found that the standard free energy (ΔGo) is negative, the standard enthalpy (ΔH) is negative and the standard entropy (ΔSo) is negative for the formed micelles.