Improving emulsification for pesticide control: The role of Phytolacca dodecandra leaf extract and tween 80

Abstract

This study focuses on optimizing the emulsification process utilizing Phytolacca dodecandra leaf extract in combination with emulsifier (Tween 80) for household cockroach control. The main aim is to evaluate and enhance emulsion stability and efficiency through systematic experimentation. Employing the Box-Behnken Design (BBD) within response surface methodology (RSM), key EC variables including mixing time (20, 40, and 60 min), mixing temperature (25, 42.5, and 60 °C), and crude extract with emulsifier ratio (10:10, 15:15, and 20:20 wt/wt) were investigated to determine optimization for the response variables of pH and viscosity of EC. The EC optimization, characterization, and efficiency were investigated. The results were demonstrated significant interactions among variables, with optimal emulsification achieved at mixing time (40 min), mixing temperature (42.5 °C), crude extract to Tween 80 ratio (15:15 wt/wt) with a pH (7.678) and viscosity (5.768 cp). At this optimal point, the UV–Vis spectroscopy (230–400 nm) confirmed the presence of bioactive compounds responsible for emulsification. FTIR analysis identified functional groups involved in stabilization the emulsion. By using natural plant extracts like Phytolacca dodecandra and surfactants like Tween 80, the research advances the development of sustainable and eco-friendly emulsification systems. Bioassay testing on cockroaches showed that the prepared emulsion at optimal result was effective; within ten minutes of exposure, a mortality rate of 100 % was observed using 5 ml of the EC for 15 cockroaches for three replicants. Whereas, a positive control (mortien) and negative control (Tween 80), were laid with three replications. Mortality 100 % and 0 % of cockroaches was recorded after 24 h of exposure for both positive and negative control respectively. This method provides an efficient and safe way to control household cockroaches, lowering the need for dangerous chemical pesticides and fostering safer living conditions.