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Chemistry In Pictures

Chemistry in Pictures: CO₂ capture surprise

by Craig Bettenhausen
April 7, 2022

A vareity of objects with bright and dark blue coatings.
Credit: Submitted by Kevin A. McIntyre

Chemist and inventor Kevin A. McIntyre set out to develop a cheaper way to replicate iron gall printing, which combines iron and tannic acids to create a permanent, waterproof pigment that starts off bold and darkens with age. Iron gall was the dominant ink chemistry in Europe from the 5th to 19th centuries but fell out of favor as options that were less corrosive to paper emerged. Antiquarians and historical reproduction artists still use iron gall to mimic the aesthetics and colors of that 1,400 period, but it can be expensive and incompatible with modern printing methods. McIntyre’s approach expands iron gall into inkjet and 3D printing, as well as other delivery methods, like the Prussian blue formulation coating clay balls and other objects in the photos above, mimicking the slow deepening of the retro ink. But it turns out the material absorbs CO2 out of the air as it darkens. “While originally developed as a novel printing solution,” McIntyre says, “My technology creates a unique tannin-mineral surface that acts as a passive CO2 collector.”

A pile of bright blue clay balls.
Credit: Submitted by Kevin A. McIntyre

Submitted by Kevin A. McIntyre

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