A promising azeotrope-like mosquito repellent blend

Abstract

Topical repellents play a key role in reducing the outdoor transmission of mosquito-borne diseases by reducing human-vector contact. Excellent repellents are available, but there is always room for improvement. This article reports on a particularly effective binary repellent blend of ethyl butylacetylaminopropionate and nonanoic acid. A composition containing 25 mol% of the acid exhibits negative pseudo-azeotrope behaviour at 50 °C, meaning that the liquid vapour pressure is lower than that of the parent compounds and evaporation occurs without a change in the liquid composition. In tests performed using the South African Medical Research Council’s cup-on-arm procedure, this mixture provided better protection for a longer time than the “gold standard of mosquito repellents”, namely N,N-diethyl-m-toluamide, commonly known as DEET.

Herbicides based on pelargonic acid: Herbicides of the bioeconomy

“…Meanwhile, new large‐scale applications such as the recently discovered highly effective mosquito repellent (a novel repellent having a longer lifespan than commercially available repellents with the added benefit of not only repelling mosquitoes but killing them too if they make contact with it), based on a mixture of nonanoic acid and butylacetylaminopropionate, will be commercialized, further increasing the global demand for pelargonic acid.…”

“…Pointing to a strongly structured liquid in pure form, at 760 Torr pressure, the acid boils at 254 °C . Indeed, recent computational simulations of the radial distribution functions of the carbonyl oxygen atom in the molecule in the liquid ascribe the difference in the boiling point of pelargonic acid compared with structural analogue 2‐decanone (210 °C) to pronounced intermolecular interactions and molecular aggregation (strong hydrogen‐bonded cyclic dimers and higher order aggregates) …”

A Simple and Practical Theoretical Model for Interpreting Binary Azeotropes

“…To obtain smooth curves for derivatives, the experimental data points for the partial and total pressure are first fitted by polynomials of order 6 and then the analytical formulae for the first-order derivatives are obtained. Both the polynomials without constraints in the generic form of 𝑦 = 𝑎𝑥 6 + 𝑏𝑥 5 + 𝑐𝑥 4 + 𝑑𝑥 3 + 𝑒𝑥 2 + 𝑓𝑥 + 𝑔 and with constraints at the two ends of 𝑥 = 0 and 1 in the form of 𝑦 = 𝑦 1 (1 − 𝑥) + 𝑦 2 𝑥 + (𝑎𝑥 5 + 𝑏𝑥 4 + 𝑐𝑥 3 + 𝑑𝑥 2 + 𝑒𝑥)(1 − 𝑥) led to comparable results. However, the fitting quality is limited near the two ends due to small number of available data points.…”

Funcionalização de substrato têxtil com partículas poliméricas carregadas com repelente visando proteção contra o mosquito Aedes aegypti

“…A eficácia dos repelentes de mosquitos aplicados na pele ou liberados de tecidos é determinada pela taxa de evaporação. Isso ocorre porque um repelente deve estar presente nas proximidades da pele exposta que precisa de proteção na forma de vapor (IZADI et al, 2017;CIERA, 2014;MAPOSSA et al, 2019).…”

“…vetor destes vírus. No entanto, o uso frequente de repelentes pode causar alergias dermatológicas, tornando alguns deles não recomendados para uso em crianças e gestantes, sendo necessária orientação médica(IZADI et al, 2017;NGUYEN;VU;HEBERT, 2018;MAPOSSA et al, 2019) STEFANI et al, 2009;IZADI et al, 2017)(STEFANI et al, 2009;CIERA, 2014).Porém alguns fatores podem interferir no tempo de proteção e eficácia dos repelentes, como a predisposição individual de acordo com substâncias exaladas pela pele tal como ácido lático, suor e CO2, presença de eczema, sexo masculino, idade adulta, ingestão de álcool, vestimentas escuras, umidade, odor, clima quente e úmido, fragrâncias florais(STEFANI et al, 2009;CIERA, 2014;PALUCH;BARTHOLOMAY;COATS, 2010;BÜCHEL et al, 2015).Conforme STEFANI et al (2009) a cada 10 ºC a mais na temperatura pode reduzir o tempo de proteção do repelente em até 50 %.2014).…”