Optimization of Fe₃O₄/Chitosan nanocomposite concentration on the formation and stability of W/O emulsion

Asphaltene plays a major role in the emulsion stability as an emulsifier. The Fe₃O₄/Chitosan nanocomposite is one of the nanocomposites that are newly studied for asphaltene adsorption. Thus, the presence of the referred nanocomposite in the aqueous phase and adsorption of asphaltene can affect the formation and stability of the water in oil emulsion. In this study, we examined the synthesis of Fe₃O₄/Chitosan and compared two iron oxide and chitosan nanoparticles in terms of the formation and stability of the emulsion. We studied the role of asphaltene in the formation and stability of the emulsion in the presence of nanocomposite by measuring the interfacial viscosity and the elasticity modulus. Also, we quantified the emulsion stability by measuring the average area of water droplets in oil, the bulk viscosity, and the interfacial tension. According to the results of this study, the synthesized nanocomposite was able to further stabilize the emulsion than its constituent compounds. Based on the results from measuring the interfacial viscosity, elasticity modulus, and electrical conductivity, the nanocomposite forms a stable emulsion through the adsorption of asphaltene and placement at the interface of water and oil. By increasing the concentration of nanocomposites up to 0.05% by weight, the size of water droplets in oil decreased, the interfacial tension decreased, and consequently the stability of the emulsion increased. (paper)