In Situ Formation of Insect Repellent Delivery System

Abstract

Conventional pesticide applications repeatedly failed to adequately control mosquito and sandflypopulations in desert areas, due to effects of either intense heat, blowing sand, ultraviolet light and/or combinations of them under severe environmental conditions. Application of citral oil to the skin provides temporary relief from pests only until the volatile terpene evaporates or is photodegraded by light. It would be advantageous to encapsulate the citral into a solid or waxy polymer that would slowly release a constant stream of citral from reservoir of the naturally occuring pesticide dissolved in the solid polymer. Polysilsesquioxanes have already proven to block UVB and are known to be oxidatively robust. In this study, a solid polysilsesquioxane pesticide delivery system was prepared free radical polymerization of an oligovinylsilsesquioxane in the presence of citral.The molecular consequences of the free radical polymerization were analyzed by MALDITOF spectrometry and the UV absorption properties of the resulting polymer-citral solution were measured by scanning spectrophotometry (SSP).