ADVANCED MATERIALS & PROCESSES | SEPTEMBER 2023 9 materials for aircraft. This discovery offers important insights into the molecular properties of nanocomposites and how they could be engineered to optimize their unique properties. www.umontpellier.fr/en/. A LOOK AT HOW BENJAMIN FRANKLIN MADE BANKNOTES For the past seven years, a team of researchers at the University of Notre Dame, Indiana, has been studying the printing process used by Benjamin Franklin to print money notes for the American Colonies. During his career, Franklin printed nearly 2,500,000 banknotes using what the researchers have identified as highly original techniques. Led by Khachatur Manukyan, the research team used cutting-edge spectroscopic and imaging instruments. The tools enabled them to get a closer look than ever before at the inks, paper, and fibers that made Franklin’s bills distinctive and hard to replicate. Manukyan and his team determined the chemical elements used for each item in Notre Dame’s collection of Colonial notes. The counterfeits, they found, have distinctively high quantities of calcium and phosphorus, but these elements are found only in traces in the genuine bills. Another of Franklin’s innovations was in the paper itself—Franklin included tiny fibers in the form of colored silks in the paper pulp, visible as pigmented squiggles within the banknotes. The team also discovered that notes printed by Franklin’s network have a unique look due to the addition of a translucent material they identified as muscovite. The team speculates that Franklin initially began adding muscovite to make the printed notes more durable but continued to add it when it proved to be a helpful deterrent to counterfeiters. Manukyan said that it is unusual for a physics lab to work with rare and archival materials, and that it poses special challenges. “Few scientists are interested in working with materials like these. In some cases, these bills are one-of-a-kind. They must be handled with extreme care, and they cannot be damaged,” he says. For him, the project is a testament to the value of interdisciplinary work. nd.edu. Khachatur Manukyan and his team use cutting-edge spectroscopic and imaging instruments to conduct an in-depth study of the materials that made the Benjamin Franklin bills so unique. Courtesy of Barbara Johnston/University of Notre Dame. LE-237i-3 2023.ps T:\MISC\ADS\LE-237\LE-237i-3 2023.cdr Thursday, August 10, 2023 3:36:47 PM Color profile: Disabled
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