Development of mosquito repellent textiles using zanthoxylum limonella essential oil

Mosquitos can transmit hazardous disease to human through blood by attacking the skin. The mechanism is that a mosquito is fed on blood of a sick host, carries the disease from the host, and then attacks a healthy host and transmits the disease. Some of the diseases that could be transmitted by mosquitoes (mosquito-borne diseases) are malaria, dengue fever, chikungunya, yellow fever and zika fever. Therefore, mosquitos are most likely to be a big threat to human life. Moreover, some of these diseases do not have the vaccine to cure them yet so the best way to avoid diseases is by not getting bitten by mosquitos. Textiles are widely used by human being as clothing, tents and other protective gears. They are also potential candidates for mosquito repellent products for human. Performance textiles provide functions such as repellence, resistance, or protection against environmental elements. They have been developed through research and resulted in many new innovations, including mosquito repellence, which keeps mosquitos away from human. Many studies developed anti mosquito clothes by using chemical solution, which could have created side effects to users or environment, so several studies have put their interest in natural products and developed natural mosquito repellence textiles.

However, how to develop effective durable mosquito repellent textiles from natural products with efficacy and environment friendliness benefits is still a big challenge. Thus, the aim of this research is to develop the mosquito repellence textiles, to help prevent wearer from disease vectors and reduce the death rate of human from vector borne diseases.

This thesis reports on the development of a new mosquito repellence treatment method applying natural product to fabricate performance textiles for mosquito repellence. Zanthoxylum Limonella (Makean in Thai) essential oil was chosen as it has been confirmed to have mosquito repellence attributes. Essential oil was extracted using both simple steam distillation method, Soxhlet extraction method and advance supercritical carbon dioxide fluid extraction method, and steam distillation has been found to be most suitable method for oil extraction. The extracted essential oil was then knife-coated on varies fabrics including cotton, nylon, polyester, viscose, and wool at 15, 20, 25 and 30% (W/W) concentrations. The coating method was optimised, and the coated fabrics were characterised and measured to understand the physical and chemical properties of the coated fabrics. The mosquito repellence of the coated samples was then evaluated using multi-chamber mosquito repellence tests. The most effective coating in terms of mosquito repellence was obtained with 30% (W/W) concentration with repellent activity longer than 30 minutes, with 10% mosquito knock-down phenomenon observed. The results suggest that low-cost knife-coating technique of essential oil is a potential method for developing functional fabrics with mosquito repellent performance.

In order to further the commercialisation of the developed mosquito repellent textiles, different prototypes of mosquito repellent products were developed. Information of trend from several reliable trends forecast companies was collected before using selected similar trend and used as ideas for the marketing products. The accessories for women wears were targeted for the potential product development, as they could be put in the desire areas of the wearer, and they do not require frequent washing with easy care. Prototypes of different mosquito repellent products were then designed and realised from the developed mosquito repellent fabrics, with the focus on both the aesthetics and functions.

The research work significantly contributes to the growing field of performance textiles. Especially, mosquito repellent textiles have been contributed with not only prolonged mosquito repellent effects but also using natural products with environmentally friendly nature and less toxicity to human body. This research could greatly reduce the use of conventional mosquito repellent chemicals for the purpose of mosquito repellence and enhance human wellbeing by provide effective but durable mosquito repellent textiles.