Mentha longifolia nanoencapsulated essential oil: Its synthesis and physico-chemical properties

Essential oils app;ication in integrated pest management as alternative or complementary to chemical insecticides appears quite safe and promosing. However the chemical instability, volatility and poor water solubility remain the main disadvantages of essential oils and must be resolved before being incorporated into pest management systems. Incorporation of essential oils into a controlled-release nanoformulation is an efficient approach to overcome these limitations. So the present study aimed to analyze chemical constituents of Mentha longifolia free and nanoencapsulated essential oils by gas chromatography–mass spectrometry (GC–MS) and describe a practical approach to synthesize nano hollow silica spheres by sol-gel method as a Mentha longifolia essential oil carrier. GC–MS analysis resulted in the detection of the 43 components, piperitenone (%32), piperitenone oxide (%24.01) and pulegone (%17.44) were the three most representative constituents. The success of M. longifolia essential oil encapsulated was characterized based on some parameters including particle size, zeta potential, polydispersity index (PDI) and encapsulation efficiency. The Optimised Reaction mixture consisting of TEOS (0.5 ml), CTAB (0.08 g), essential oil (1 ml), ethanol (13 ml), 25% ammonia (0.5 ml), 2 hours of ultrasonication at room temperature and emulsification at 15000 rpm for 5 min, resulted in particle size between 66 to 80 nm, a polydispersity index of 0.2, zeta pontencial of −37 mV and an EE of 79.64%.