DailyDirt: Metallic Royalty
from the urls-we-dig-up dept
Noble metals, such as gold and platinum, get their name from their rarity in occurrence and because they don't easily oxidize or corrode when exposed to the atmosphere. It takes a highly corrosive mixture of hydrochloric acid and nitric acid (aka, "aqua regia") to dissolve gold or platinum. In fact, Aqua regia (which is Latin for "regal water") is named for its ability to dissolve "noble" metals. Due to their desirable properties, noble metals have found use particularly in jewelry making as well as chemical catalysts. Here are a few examples of some recent findings related to noble metals.- Researchers at Northwestern University have figured out how to use cornstarch instead of toxic cyanide to selectively extract gold from raw materials and electronic waste. Apparently, alpha-cyclodextrin (a cyclic starch fragment made of six glucose units) works best for isolating gold. [url]
- University of Helsinki researchers have concluded that silver nanoparticles aren't any more toxic than silver ions for aquatic ecosystems. Since silver nanoparticles have anti-bacterial and anti-fungal properties, they are used in many consumer goods like clothing, cosmetics, food storage containers, and medical devices. However, there have been concerns about the increased amount of silver being washed into the environment. [url]
- Scientists at Hokkaido University have developed a platinum nanoparticle catalyst that can keep fruit from ripening prematurely while in storage. Ripening fruit releases ethylene gas, which then accelerates the ripening of other fruit. The platinum nanoparticles were able to effectively oxidize ethylene even at zero degrees Celsius, which is the temperature required in cold storage warehouses. [url]
Filed Under: catalyst, chemistry, cornstarch, cyclodextrins, fruit, gold, nanoparticles, noble metals, platinum, silver
