#solvatochromism

[materialsscienceandengineering]

Solvatochromism

When a solution changes color depending on the solvent a given solute is dissolved in, the effect is known as solvatochromism. This effect is also said to be a "response to a change in polarity of the local environment", and thus solvatochromism can be used as an indicator of solvent polarity. Solvatochromic materials are typically dyes, and are used to differentiate organic solvents.

Sources/Further Reading: (Image—Wikipedia) (2015 article) (2008 article) (Ball State University) (2001 article)

[labphoto]

Purification of some crude Nile Red. 

Nile Red is a quite interesting, solvatochromic and highly fluorescent dye. The raw product was contaminated with a few impurities, but a fast purification, by simple filtering the mixture through a short column helped a lot and ended up with a +95% pure product.

At first I concentrated the product from a dilute solution (that orange fluorescent stuff at the to of the column) on the column. It’s interesting to see, that it has a different fluorescence in solution (orange) and while it’s absorbed on the solid phase (pink, highly fluorescent).

After all the product was on the solid phase, I added another solvent and washed down the pure, HIGHLY FLUORESCENT product. Everything else, what was mainly products of side reactions, stuck at the top of the column as seen over here: 

https://youtu.be/W0Lk5jkd_B0

To read a bit more from the fascinating dye, look up the Nile Red tag on the blog: http://labphoto.tumblr.com/search/nile+red

[materialsscienceandengineering]

New color-changing sensor detects alcohol with a smartphone snap

Scientists developed a smartphone-compatible ethanol sensor using a metal-organic framework called Cu-MOF-74. The sensor visually detects et

Determining how strong your drink is doesn't need to be either guesswork or lab work. New research has made it as simple as checking your messages -- and more colorful, too. Osaka Metropolitan University researchers have developed a smartphone-compatible alcohol sensor that can visually detect a full range of ethanol concentrations, without the need for complex electronics or lab tools. Their technology allows for a broad array of potential applications in environmental monitoring, healthcare, industrial processes, and alcohol breath analysis. Ethanol is used widely in food, pharmaceuticals, and fuel. It is also the intoxicating ingredient in many alcoholic beverages. Accurate detection of ethanol concentration, particularly in products containing both ethanol and water, is crucial for product hygiene management and quality maintenance.

Read more.

[thechemistrynerd]

25.10.16 - 11:18 pm // Messed with a solvatochromic dye today in organic lab. What does this mean? Wellllll, it means that the compound absorbs different wavelengths or colors when present in solvents with a variety of polarities. Such a basic explanation but it works for me :). OH and did some organic notes to introduce myself to the new material we’ll learn in lecture tomorrow. 

[labphoto]

My new favorite: Solvatofluorescence of Nile Red

Solvatochromism is the ability of a chemical substance to change color due to a change in solvent polarity, so it has different color in different solvents.

Also in some cases, the emission and excitation wavelength both shift depending on solvent polarity, so it fluoresces with different color depending on the solvent what it’s dissolved in. This effect is solvatofluorescence.

On the video the highly solvatochromic organic dye, Nile Red was added to different organic solvents and was diluted with another, different polarity organic solvent. As the polarity of the solution changed, the emitted color from the fluorescent dye also varied as seen on the gifs above and as seen on the video:

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