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Characterization of P. oleracea, R. sativus, and R. officinalis Oil Nano-Emulsions The prepared nano-emulsion formulations which contain 10% (ml/ml) of P. oleracea, R. sativus, and R. officinalis were characterized in terms of droplet size, polydispersity index (PDI), zeta potential, morphological structure, and thermodynamic characterization (Table 4). The droplet size distribution and morphological structure of purslane, rosemary, and radish oil nano-emulsions are shown in Figs. 1 and 2. In our study, the average size of the nano-emulsions was found to be less than 200 nm; the particle sizes for purslane radish and rosemary are 26.67 nm, 134.9 nm, and 97.36 nm. The obtained values in this study of PDI are less than 0.3; the PDI of purslane oil is 0.186, 0.190 for radish oil, and 0.202 for rosemary. Zeta potential which characterizes the surface charge of the nano-emulsion particles is an important factor for nano-emulsion stability. Zeta potentials of purslane, radish, and rosemary nano-emulsions are − 0.69 mV, − 29.9, mV, and − 18.00 mV, respectively (Table 4). The TEM images (Fig. 2) investigated the spherical appearance of synthesized o/w nano-emulsion and showed droplet mean size in the range of 200 nm. The stability of nano-emulsion formulations is an important character that indicates the shelf-life of the formulations. The prepared nano-emulsions passed the thermodynamic tests (freeze–thaw cycle, centrifugation, and heating–cooling cycle). The nano-emulsions showed stable formulation without any sign of instability such as phase separation sedimentation or creaming. The nano-formulations were physically stable up to 3 months from the preparation. The viscosity of prepared nano-emulsions is 24.7 mPas for purslane, 26 mPas for radish, and 6.5 mPas for rosemary (Table 4). Toxicity Effects of Oils and Their Nano-Emulsions The pesticidal efficacy of purslane, radish, and rosemary oil–based nano-emulsions was compared to that of the pure oil against A. gossypii, S. littoralis, and T. urticae in this study. It ... |