Design of Renewable Microemulsion Systems using Jatropha Oil–Derived Surfactants and Vegetable oil Methyl Esters

The need for environmentally friendly substitutes to petroleum-based chemicals has driven researchers to explore bio-based surfactants and green solvents at an accelerated pace. The research examines the creation of renewable microemulsion systems which use Jatropha oil-based ethoxylated surfactants (15EO and 20EO), together with Jatropha oil methyl ester (JOME), and Karanja oil methyl ester (KOME) as sustainable oil components. The aqueous titration method helped scientists build pseudo-ternary phase diagrams which enabled them to find stable microemulsion regions. The formulated microemulsions underwent physicochemical property analysis through pH measurement and density assessment, and electrical conductivity testing, and particle size evaluation with dynamic light scattering. The study produced thermodynamically stable oil-in-water (O/W) and water-in-oil (W/O) microemulsions with particle sizes between 101.2 and 178.3 nanometers. Surfactants with HLB values of 9.7 and 11.7 successfully stabilized both methyl ester systems, with higher HLB (11.7) showing superior performance for O/W microemulsions evidenced by enhanced conductivity (350.25–370.31 μS/cm) and smaller droplet sizes. The samples remained stable during centrifugation stability tests which showed no phase separation after 30 days of storage at ambient conditions. These renewable microemulsion systems present promising applications in agrochemical formulations and home care products, offering biodegradable, low-toxicity alternatives to conventional petrochemical-based systems. They support circular economy principles and green chemistry objectives.