RESUMEN
Commercial electrowetting-based liquid lenses are optical devices containing two immiscible liquids as an optical medium. The first phase is a droplet of a high refractive index oil phase placed in a ring-shaped chassis. The second phase is electrically conductive and has a similar density over a wide temperature range. Droplet curvature and refractive index difference of two liquids determine the optical strength of the lens. Liquid lenses take advantage of the electrowetting effect, which induces a change of the interface's curvature by applying a voltage, thereby providing a variable focal that is useful in autofocus applications. The first generation of lens modules were highly reliable, but the optical strength and application scope was limited by a low refractive index difference between the oil and conductive phase. Described herein is an effort to increase the refractive index difference between both phases, while maintaining other critical application characteristics of the liquids, including a low freezing point, viscosity, phase miscibility, and turbidity after thermal shock. An important challenge was the requirement that both phases have to have matching densities and hence had to be optimized simultaneously. Using high throughput experimentation in conjunction with statistical design of experiments (DOE), we have developed a series of empirical models to predict multiple physicochemical properties of both phases and derived ideal locations within the formulation space. This approach enabled the development of reliable liquid lenses with a previously unavailable refractive index difference of Δ nD of ≥0.290, which enabled true optical zooming capability.
Asunto(s)
Electrohumectación/métodos , Lentes , Refractometría , Diseño de Equipo/instrumentación , Interacciones Hidrofóbicas e Hidrofílicas , Aceites/química , Transición de Fase , Temperatura de Transición , Viscosidad , Agua/químicaRESUMEN
BACKGROUND: Sulfoxaflor, a new insect control agent developed by Dow AgroSciences, exhibits broad-spectrum control of many sap-feeding insect pests, including aphids, whiteflies, leafhoppers, planthoppers and lygus bugs. During the development of sulfoxaflor, structure-activity relationship (SAR) exploration of the sulfoximine functional group revealed that the nature of the sulfoximine nitrogen substituent significantly affects insecticidal acitivity. As part of the investigation to probe the various electronic, steric and lipophilic parameters at this position, a series of N-heterocyclic sulfoximines were synthesized and tested for bioactivity against green peach aphid. RESULTS: Using a variety of chemistries, the nitrile substituent was replaced with different substituted five- and six-membered heterocycles. The compounds in the series were then tested for insecticidal acitivty against green peach aphid in foliar spray assays. In spite of the larger steric demand of these substituents, the resulting N-heterocyclic sulfoximine analogs displayed good levels of efficacy. In particular, the N-thiazolyl sulfoximines exhibited the greatest activity, with LC50 values as low as 1 ppm. CONCLUSIONS: The novel series of N-heterocyclic sulfoximines helped to advance the current knowledge of the sulfoxaflor SAR, and demonstrated that the structural requirement for the sulfoximine nitrogen position was not limited to small, electron-deficient moeities, but rather was tolerant of larger functionality.