Surfactant-free nano-emulsions from two lemongrass essential oils: Investigation of temperature ramp influence

•Nano-emulsions were prepared with pure water or infusions for two lemmon-grass species.•Nanodroplets were generated without addition of surfactants.•Loss of lipophilic volatiles may destabilize diluted nano-emulsions.•An infusion with higher polar constituents may destabilize diluted nano-emulsions.•Overall the nano-emulsions had potential thermal stability against droplet growth.