Mathematical modeling in the ZnO nanoparticle dispersing in the oil-in-water emulsions for potential Pickering formulation

Abstract

A Pickering emulsion is a system of two immiscible liquids like oil and water containing some solid particles like metal nanoparticles (NPs) that usually stay at the oil/water (O/W) interface, hence affecting their colloidal behavior. Due to their high surface energy, amphiphilic nature, and nanoscale dimensions, ZnO nanoparticles (ZNPs) can effectively function as Pickering stabilizers. The present study undertakes the stability of surfactant-reinforced O/W emulsions with ZNP-mediation under homogenization. The experiments were performed through Taguchi design, and the results were analyzed using the VIKOR approach. The responses included residual oil and ZNP contents, oil retention rate, droplet size/charge, emulsification index, and viscosity. UV–vis spectroscopy and DLS analyses demonstrated that introducing ZNPs facilitated the stability of O/W emulsions over time. The factor effect on the VIKOR index (Q_j) values revealed that temperature exerted the greatest influence (31%) on the response variable, closely followed by ZNP content (26%). CTAB content had a moderate impact (22%), while oil content had the least effect (13%). The optimal formulation was determined by selecting the levels that resulted in the lowest Q_j values, which were CTAB concentration at 450 mg/100 ml, oil content at 10,000 mg/100 ml, ZNP concentration at 50 mg/100 ml, and a processing temperature of 60 °C. The predicted recipe was assessed through a validation run and demonstrated well-fitting of experimental results. Such findings may be employed in optimizing the food, pharmaceuticals, cosmetic, and fine chemical formulations.

Graphical Abstract