Encapsulated citronella oil as mosquitoes repellent agent in water based paint / Mastura Abd Manaf

Mosquito has been recognized as vectors for a number of infectious diseases but current control measures are less efficient and chemical mosquito repellent harmful to human and environment. Other alternative which is natural repellent is very volatile and release rapidly. Thus the study aim to produce a Citronella oil (CiO) paint as mosquito repellent tools that give long time protection and safe to health and environment. To provide control release, CiO was encapsulated via coacervation method by using arabic gum and gelatin as wall materials. Performance of the CiO paint was indicated by its mosquito repellency properties and standard paint characteristics which are paint VOCs content, adhesion and viscosity. Mosquito repellency performance was measured by release kinetic study and repellency test against Aedes aegypti. Both encapsulation methods have provided good encapsulation efficiency around 94%. Capsules from complex coacervation have lower release kinetic compared to simple coacervation. The complex coacervation's capsules also more suitable to be added in water based paint because the capsule's wall able to sustain in wet and the capsule's wall start ruptured in dried conditions. Water based paint was prepared for the study because emission of chemical VOCs from the commercial paint was considered can decrease the concentration of citronella compounds in air and addition of CiO has increase the paint's viscosity gradually. CiO was added in water based paint at 0 to 5 %v/v and 3.5 % CiO paint has function as mosquito repellent. However, release kinetic study found that citronella released from the paint in just 4 days and give too strong odor. While 12% Encapsulated CiO (ECiO) paint has lower release kinetic and able to provide protection for 1 year and 236 days. With the calculated dosage, the ECiO paint able to give 100% repellency to A. aegypti.