Chemistry

Mercury “beating heart” demo video

This classic chemistry demo involves the use of toxic metallic mercury, so it’s one of those that is best to just watch on YouTube instead of trying yourself. The pulsing action is caused by surface tension effects–metallic mercury is oxidized at the surface of the drop to form a film of mercury (I) sulfate, which lowers the drop’s surface tension and causes it to flatten under its own weight. The flattening brings the drop into contact with the tip of a carefully-positioned iron nail, which reduces the mercury (I) sulfate back to metallic mercury, which in turn increases the drop’s surface tension and causes it to contract away from the nail. Thanks to YouTuber sciencevidds for sharing it with us. [via Boing and then some more Boing]

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Hydrogel is mostly water, but strong as silicone rubber

Hydrogel is mostly water, but strong as silicone rubber

You’re looking at a piece of hydrogel. It is 98% water by weight. It’s moldable, transparent, environmentally friendly, easily synthesized and (get this) if it’s cut it will heal itself. Its creator, Takuzo Aida at the University of Tokyo, has compared it to silicone rubber in terms of strength. And to make it, all you have to do is stir three ingredients into a bunch of water at room temperature. These are sodium polyacrylate, clay, and a special dendritic macromolecule Aida and co-workers call “G3 binder.”

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Journal of Serendipitous and Unexpected Results

Journal of Serendipitous and Unexpected Results

This dude is Hans Christian Ørsted, whose 1820 discovery that electric current produced magnetic fields was, supposedly, entirely accidental: He was preparing a voltaic pile for a lecture demonstration and there happened to be a compass lying nearby. He has become a sort of mascot for the Journal of Serendipitous and Unexpected Results (JSUR), a new open-access journal initiative that hopes to provide a forum for life and computer scientists to publish results they lucked into and maybe can’t fully explain. From their website:

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New catalyst turns atmospheric CO2 into useful chemical

New catalyst turns atmospheric CO2 into useful chemical

Still, every little bit helps, and this copper-based catalyst recently developed by Elisabeth Bouwman and co-workers at Leiden University in the Netherlands represents a vast improvement over previous atmospheric CO2-fixing processes. Most of these are poisoned by oxygen, which means that you can’t just pump air into the reactor without removing the oxygen first. Bouwman’s catalyst, however, reacts with CO2 but not oxygen, producing oxalate, which is a useful feedstock for the manufacture of methyl glycolate and other organic compounds. And while Bouwman’s material is not a “true” catalyst in that it actually forms a compound with CO2 and has to be regenerated in a second reaction, the regeneration step can be done electrochemically with remarkably little energy.

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Beautiful ‘silk frost’ fibrous ice formations

Beautiful ‘silk frost’ fibrous ice formations

Dr. James Carter is a professor in the Department of Geography-Geology at the University of Illinois. One of his many interesting pages collects photos and other reports (dating back to 1884) of so-called “hair ice,” “haareis,” or (my fav) “silk frost.” The fibrous ice crystals seem to be caused by the pore structure of certain woods, and only forms where the bark has been removed. Reportedly, the phenomenon is reproducible: if you find a piece of wood growing hair ice, you can warm it up, then re-freeze it, and it will grow hair ice again. [via Neatorama]

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