#vapochromism

[materialsscienceandengineering]

Vapochromism

When materials change color after exposure to molecules of certain gases or vapors, that change is known as vapochromism. The term vapochromism was first used relatively recently, in the late 1980s, to describe the behavior of platinum complexes. Though the mechanisms of vapochromism are not yet well understood, it has been exhibited in several different types of materials such as "organic dyes, metal complexes, metal organic frameworks, and covalent organic frameworks". The primary application of interest for vapochromic materials is in sensors and the detection of dangerous gases.

Sources/Further Reading: (Image 1—2020 article) (Image 2—2022 article) (Image 3—2023 article) (2024 article) (2021 article) (2025 article)

[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.

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[materialsscienceandengineering]

New type of sensor material developed

Hokkaido University scientists have succeeded in developing a nickel complex that changes color and magnetism when exposed to methanol vapor. The new material can potentially be used not only as a chemical sensor, but also with future rewritable memory devices.

The phenomenon of color changes in a substance, triggered by volatile organic compound vapors or inorganic gas, is called vapochromism. Since its discovery at the end of the last century, scientists have focused their research on developing sensory materials that can visibly show the presence of harmful organic solvents. Furthermore, research on materials that synchronize color and other property changes, such as magnetism, could lead to broader applications.

The research team led by Masako Kato at Hokkaido University focused on developing materials that simultaneously change color and magnetism when exposed to vapors. To date, some iron complexes were known to switch magnetism between "paramagnetism" and "diamagnetism" at room temperature, but usually fall into stable states when temperatures are lower.

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