Cationic Guar Gum Loaded with Essential Oil-Based Nanoemulsion Formulations as Mosquito Repellents for Fabrics Against Aedes aegypti

The global incidence of mosquito-borne diseases has markedly increased in recent years. The control of mosquito vector is crucial in order to prevent epidemics across many countries. Nanoemulsions have been regarded as good carriers for delivering essential oil with the intervention of biopolymers to increase their efficacy. Therefore, the present study aimed to assess the effectiveness of three types of nanoemulsion formulations which consist of betel and clove essential oils encapsulated with cationic guar gum as fabric finishes. The nanoemulsion formulations were characterised using dynamic light scattering (DLS) and high-resolution transmission electron microscopy (HR-TEM), while field emission scanning electron microscopy (FESEM) was used to characterise treated fabrics. All nanoemulsion formulations exhibit up to more than 50% of encapsulation efficiency and are able to control the release of essential oils from their colloidal systems up to 150 h. Nanoemulsion formulations recorded -16.8 to -25.2 mV of zeta potential with 0.25 to 0.49 polydispersity index values. Based on the Excito chamber study, after a single washing and heating cycle, the effectiveness of repellency against Aedes aegypti applied to cotton and polyester fabrics was in the range of 98 to 100%. Following 5 washing and heating cycles, the nanoemulsion formulations were able to retain 30 to 50% of essential oil on cotton and polyester fabrics and repel 36 to 40% of mosquitoes. Overall, results from this study are significant to research and development particularly innovation of anti-mosquito fabric finishes.