Optical sensor for on-line determination of solvent mixtures based on a fluorescent solvent polarity probe

RSC Adv., 2016

Tetraphenylpyrazine-triphenylamine detects water traces by fluorescence peak wavelength shifting and optical fibres were used for a remote and field-deployable sensing ability.

Applied Spectroscopy, 1996

Analytical Sciences, 2010

Abstract: Monodisperse polystyrene nanoparticles with a diameter of 173 nm were incorporated into a polydimethylsiloxane matrix where they display an iridescent color that can be attributed to the photonic crystal effect. The film is violet in plain water, but turns to red in the presence of the non-polar solvent n-hexane. Several solvents were studied. The films are capable of monitoring the water content of ethanol/water mixtures, where only 1% of water leads to a shift of the peak wavelength of reflected light by 5 nm. The method also can be applied to determine, both visually and instrumentally, the fraction of methanol in ethanol/methanol mixtures. Here, a fraction of 1% of methanol results in a wavelength shift of 2 nm. The reflected wavelength is not influenced by temperature changes nor impeded by photobleaching. The signal changes are fully reversible, and response times are <1 s. ______________

2008

Chemical Reviews, 2008

1998

2024

Back to the enigma of Diring-Yuryakh Keilmessers of Sukhaya Mechetka Mammoth from Lenino and the question of the peopling of the Lower Volga region New dates for the Late Palaeolithic of the Russian Plain Weapons of the Mesolithic hunters of Crimea Вновь к загадке Диринг-Юряха Кайльмессеры сухой Мечётки Мамонт из Ленино и проблема заселения низовьев Волги Новые датировки для позднего палеолита Русской равнины Вооружение охотников крымского мезолита