Protecting wool carpets from beetle and moth larvae with nanocidal titanium dioxide desiccant

Nanopesticides are an emerging type of engineered nanomaterial that has been shown to enhance several physical, photo-physical and antimicrobial properties of wool textiles. Nanoparticles have an advantage over the more widely used continuous coatings for wool textiles, as they are less likely to adversely affect haptic properties, due to less pinning of cuticle scales and less inter-fibre bonding. Hence, the nanocidal activities of titanium dioxide nanoparticles (TiO₂) towards two insect pests of textiles made from wool and other proteinaceous fibres were investigated, namely Anthrenocerus australis and Tineola bisselliella. The nanoparticles were applied to wool carpet at levels between 0.01 and 1.5% by mass, and the carpets assessed by bioassay. The TiO₂ exhibited statistically significant (p < 0.05) control of larvae of both species. A. australis was the more readily controlled species and a “borderline” effectiveness against it, was achieved according to internationally recognised criteria. The lowest mass losses of the treated wool carpets (as a proportion of the mass losses of the untreated voracity controls) were 38% for A. australis (1.5% TiO₂) and 57% for T. bisselliella (0.5% TiO₂). It was shown to be more difficult to reduce the feeding of T. bisselliella on carpet, than on fabric. This investigation widens understanding of the action of entomotoxic nanocides on textiles to a new species (A. australis) and a new product (carpet) and advances this technology closer to the high level of effectiveness desired by consumers and wool processors.