“Is it just me, or do these gold nanoparticles taste like apple pie?”
Ok, you probably won’t hear that one around the lab (taste-testing the nano-gold is a strict no-no), but researchers have discovered a way to replace the toxic chemicals typically used to make gold nanoparticles with cinnamon.
“The procedure we have developed is non-toxic,” Kannan said. “No chemicals are used in the generation of gold nanoparticles, except gold salts. It is a true ‘green’ process.”
The cinnamon takes the place of the toxic agents that remove the gold particles from gold salts, explains Popular Science:
There are several ways to produce gold particles, but most involve dissolving chloroauric acid, also called gold salts, in liquid and adding chemicals to precipitate gold atoms. Common mixtures include sodium citrates, sodium borohydride (also used to bleach wood pulp) and ammonium compounds.
We’ve asked tiny nanostructures to thwart counterfeiters, heal wounds, and boost computing power. Now, we want to eat them. Researchers have made “all-natural metal-organic frameworks”–and hope their creations’ edible frames may find use storing small molecules in foods and medical devices.
Though researchers have made similar metal-organic frameworks since 1999, most of the structures require chemicals from crude oil. As described in a recently published Angewandte Chemiepaper, this team has devised a cheaper method employing starch molecules leftover from corn production.
The trick was to make a substance crystallize as a highly ordered, symmetrical, porous framework. Getting tiny symmetrical structures from asymmetrical natural ingredients had seemed unlikely, but the team found the perfect molecule cages, using a special type of sugar (gamma-cyclodextrin) from the cornstarch and potassium salt. After dissolving gamma-cyclodextrin and potassium salt in water, they crystallized them to form the nano storage cubes.
Despite the sugar and salt combo, the nanostructures are not that tasty, team member Ronald Smaldone says in a press release:
“They taste kind of bitter, like a Saltine cracker, starchy and bland…. But the beauty is that all the starting materials are nontoxic, biorenewable and widely available…”
Remember those high school liquid nitrogen demonstrations? You know, the one where your teacher dipped a banana into the cloudy stuff, pulled it out, and then shattered it on the floor?
Well, Popular Science blogger Theodore Gray recently decided to stick in his hand. As you can see in a video over on their site, his hand survived the encounter. Though he stressed, and we reiterate, that this really isn’t a good idea unless you know what you’re doing, or unless you want your friends to call you Captain Hook, sticking your hand in the cold stuff isn’t necessarily a recipe for digit removal.
Since Gray’s hand was much warmer than the liquid nitrogen (which checks in at around negative 320 degrees Fahrenheit), the hand instantly created a layer of evaporated nitrogen gas–which shielded his skin, temporarily, from frostbite. Gray says on his blog:
“The phenomenon is called the Leidenfrost effect (after Johann Gottlob Leidenfrost, the doctor who first studied it in 1756). I’d known about it for years, but when it came time to test it in real life, I have to admit that I used my left hand, the one I’d miss less.”
Stolichnaya or Grey Goose, martinis shaken or stirred: Everybody’s got a preference. Vodka may not taste like much—in industry terms, it’s neutral—but any bartender can tell you about the fierce partisanship its different types inspire. This division among drinkers, a new study suggests, could be a result of slight differences in the vodkas’ molecular structure.
Vodka is about 60 percent water by volume, and 40 percent ethanol, an alcohol. The water and ethanol naturally mingle in such close quarters, and some of the molecules stick together in interesting ways.
Researchers at the University of Cincinnati and Moscow State University compared the chemical composition of five common brands—Belvedere, Grey Goose, Oval, Skyy, and Stolichnaya—to see if those water-ethanol groupings always happen the same way. They found that two of the vodkas had a higher concentration a certain cage-like chemical structure, in which five or so molecules of water surround each ethanol molecule. This difference, the researchers say, might explain our preferences for one brand over another. It’s even possible that the act of shaking a vodka martini breaks up those cage structures.
It’s not clear if such a subtle change in molecular make-up could affect taste, or even that those cage-like structures hold together long enough to have much of an impact at all. So for now, it may be wise to take this explanation with a grain of salt—and, while you’re at it, maybe a few olives.
If you’ve held the new iPhone 3GS in your sweaty palm, you might’ve marveled at the way its shiny touchscreen deflects fingerprints and smudges. For that feature, you can thank an organic polymer infused into the glass screen by way of an intermediate molecule. This polymeric coating is oleophobic…meaning the oil from your fingers or face is more apt to stick to itself and to your skin than to the iPhone’s screen.
Television host and science educator Bill Nye the Science Guy explained how it works via Gizmodo:
The Applers were able to do this by bonding this oleophobic polymer to glass. The polymer is an organic (from organisms) compound, carbon-based. The glass is nominally inorganic, silicon-based… solid rock. The trick is getting the one to stick to the other. Although it is nominally proprietary, this is probably done with a third molecule that sticks to silicon on one side and to carbon-based polymers on the other side. Chemical engineers get it to stay stuck by inducing compounds to diffuse or “inter-penetrate” into the polymer. The intermediate chemical is a “silane,” a molecule that has silicon and alkanes (chains of carbon atoms)….
The polymer that the 3GS iPhone screen is coated with doesn’t let the oil of your skin stick to it very much. So, you don’t leave fingerprints. The key is in the intermediate compounds, the silanes that hold the plastic to the glass.
Discoblog is DISCOVER's compendium of quirky, funny, and surprising science news from the edge of the known universe. It's written by Veronique Greenwood and Valerie Ross. Email tips and suggestions to vgreenwood [at] discovermagazine [dot] com.