8/1/2023 0 Comments Chromium oxideThe appearance of the Sharpe peak at 460 nm in the UV/Vis spectrum and the colour change caused by surface plasma resonance confirmed the formation of Cr 2O 3 NPs. The synthesis of Cr 2O 3 NPs was validated by UV/VIS spectroscopy, Energy Dispersive X-Ray (EDX), Scanning Electron Microscopy (SEM), and X-ray diffraction (XRD) studies. The current study describes the environmental friendly synthesis of chromium oxide nanoparticles (Cr 2O 3 NPs) using Erythrophleum guineense plant extract. The conventional chemical methods of nanoparticles synthesis have been effectively replaced by nanoparticle synthesis mediated by plants. 5Department of Clinical Laboratory Sciences, College of Applied Medical Sciences, Taif University, Taif, Saudi Arabia.4Department of Chemistry, Bacha Khan University, Charsadda, Khyber Pakhtunkhwa, Pakistan.3Department of Pharmacy, Shaheed Benazir Bhutto University Sheringal, Dir (Upper), Khyber Pakhtunkhwa, Pakistan.2College of Chemistry and Materials Science, Hebei Normal University, Shijiazhuang, China.1Department of Chemistry, University of Malakand, Charsadda, Khyber Pakhtunkhwa, Paksitan.I was certainly inclined to believe they were right.Zainab 1,2, Shujaat Ahmad 3, Idrees Khan 4*, Khalid Saeed 4, Hanif Ahmad 1, Aftab Alam 1, Mazen Almehmadi 5, Ahad Amer Alsaiari 5, Yu Haitao 2* and Manzoor Ahmad 1 Lead study author Marcos Martinon-Torres, now at Cambridge University, admits he was surprised by the findings, calling the 1970s research “remarkably convincing. “It would have been an attractive explanation to both scholars and the public,” Murowchick observes, “as it suggested a nice parallel to the stories passed down by early Chinese historians about the First Emperor of Qin's fascination-perhaps obsession-with discovering an elixir of immortality for himself.” “It was not a wild idea to suggest that Qin workshops intentionally treated their bronzes with chromium to prevent corrosion.” Robert Murowchick, associate director of Boston University’s Center for the Study of Asia, says that the original chromium idea was a reasonable theory for people to have embraced for so long. Thomas Chase, a conservation expert in Chinese bronze technology, says that “ team has done a wonderful job in disproving the chromium-plating theory and an offering a viable alternate explanation.” The study’s analyses of multiple materials-metal, lacquer, and soil-he adds, “are exactly what is necessary to help us understand long-term corrosion and preservation of metal artifacts." The upshot? The chromium came from the lacquer, and the preservation came from the dirt. Further analysis revealed that the lacquer was actually the source of the chromium detected by earlier researchers.Ī study of the site soil yielded more clues: It’s alkaline and finely grained, which limit aeration and organic growth-all factors that can contribute to the stability of metal objects over time. It was generally absent on the best-preserved parts of the bronzes. It’s common where the metal would’ve connected to wood and bamboo handles, shafts, fittings, and fasteners, which would’ve been lacquered and then painted. The large sample size allowed them to see where chromium appears-and where it doesn't. The researchers suggested the weapons could’ve been dipped in a chromium oxide solution, a method known as chromate conversion coating-a technique technically different from modern chrome plating, which involves chromium metal. After early excavation reports suggested a surface treatment could explain the exquisite preservation of the 2,200-year-old bronze weapons, Chinese scientists used a then-pioneering analysis called compositional mapping to reveal a layer of chromium on a small sample of the weapons. This theory dates to the 1970s, the decade when the World Heritage site was first discovered. The claim is even on a plaque at the site’s museum in Xi’an. Yet for 40 years, an alternate theory has circulated in scholarly circles and the popular media: Chrome plating was invented in the third century B.C in China and used to prevent the bronze weapons buried with the Terracotta Army in Emperor Qin’s tomb from corroding. Experiments with this anti-rust technology began in Europe in the 19th century. If your bathroom faucets look like shiny silver, they’re likely chrome plated.
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