Appearing green on a vial lid (left), this structural color material becomes colorless (right) when warmed.
Adapted from ACS Nano 2023, DOI: 10.1021/acsnano.3c00467
Some foods and medicines, such as many COVID-19 vaccines, must be kept cold. As a step toward a robust, stable technique that could indicate when these products exceed safe limits, researchers in ACS Nano report a class of brilliantly colored microcrystals in materials that become colorless over a wide range of temperatures and response times. As a proof of concept, the team packaged the color-changing materials into a vial lid and QR code.
Walk-in freezers and refrigerated trucks generally maintain their set temperatures, but accidents can happen. Wireless sensors can monitor the temperature of individual products, but these devices produce a lot of electronic waste. Recently, researchers have suggested using materials that act as visual indicators to provide this information with less waste. Yet some current options using colorful reactions or dyes produce hues that can fade. Or they only track above-freezing temperatures, which isn’t useful for some COVID-19 vaccines that can actually start breaking down below freezing — above -4 or -94 degrees Fahrenheit. So, Yadong Yin, Xuemin Du and colleagues wanted to develop a better color-changing material with tunable melting to track a wide range of temperatures.
The researchers used structural colors, instead of dyes, for their indicator system. The team made glycerol-coated silicon dioxide nanoparticles, which appeared bright green or red when they clustered together into microcrystals in water. Next, they created liquids with variable melting points by mixing different proportions of polyethylene glycol or ethylene glycol and water. When these two parts were put together, they could produce an irreversible color loss when the temperature-triggered solution melted and the microcrystals broke apart. The materials could be customized to track temperature exposures from -94 to +99 degrees Fahrenheit that lasted from a few minutes to multiple days. In other experiments, the two-part indicator systems were packaged into flexible round vial labels and a QR code. These systems were very sensitive and successfully indicated when the materials got too warm. The researchers say that structural color-changing materials hold promise for the diverse scenarios encountered in medical cold supply chains.
Original Article: Color-changing material shows when medications get too warm
More from: University of California Riverside | American Chemical Society | Chinese Academy of Sciences
The Latest Updates from Bing News
Go deeper with Bing News on:
Color-changing materials
- Connectivity for Material Handling Offers Greater Visibility
Motan’s Gravicolor 110 will supplant the GC 100 blender, which has been redesigned with interchangeable material compartments. The dosing units are removable for quick color changes and the mixing ...
- How to Change EVE’s Hairstyle in Stellar Blade
If you want to try different hairstyles, hair colorings, and hair length in Stellar Blade, find out how to change them right here!
- Stellar Blade - How To Change Eve's Hairstyle
Stellar Blade stars Eve, who, like her comrades from the Colony, is called an Angel. Still, there's one fella who's not that impressed. Help him out, and you can change our heroine's looks. Here's our ...
- Embracing Inevitable Change: The Art of Art Conservation
The dynamic, ever-changing nature of art conservation is exemplified in the field’s rare usage of the term “restoration.” ...
- Bye, gray yolks: This color-changing egg timer takes the guesswork out of boiling, and it's down to $7 at Amazon
The fan-favorite gizmo lets you know when they're cooked just how you like 'em — get it while it's 45% off.
Go deeper with Bing News on:
Structural colors
- How do birds get their colors? A guide to your vibrantly hued, winged friends
Learn how birds chirping near your feeder get their rainbow of colorful feathers, how they serve them, and why we perceive them the way we do ...
- Have Explored the Spectrum of Colors in Diamond Rings?
Detailed price information for Microsoft Corp (MSFT-Q) from The Globe and Mail including charting and trades.
- Tremaine Emory Refuses to Hide the Scars
Streetwear’s Black history raconteur survived Kanye, Supreme and a near-death experience. But can he survive the internet?
- Study details a common bacterial defense against viral infection
One of the many secrets to bacteria's success is their ability to defend themselves from viruses, called phages, that infect bacteria and use their cellular machinery to make copies of themselves.
- These Flowering Trees Are Actually Banned in Some States
Bradford pear trees are an invasive species, plus they stink and have weak branches. Learn which flowering trees to plant instead.