Wikipedia:Reference desk/Archives/Science/2018 January 19

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January 19

What's a cryogel?

Hi. The word "cryogel" appears in various WP articles but doesn't have its own article or redirect. There's also no Wiktionary entry, and I ask as someone who works on Wiktionary. Could someone give us a quick but clear definition we can use, that distinguishes a cryogel from other things (gel, aerogel, xerogel, whatever)? Thanks! Equinox ◑ 06:56, 19 January 2018 (UTC)

I can't seem to find an explicit definition of the word, but the various things I find that are referred to as "cryogels" have in common that they are made by first dissolving something in a solvent, and then freezing and thawing until it polymerizes. Someguy1221 (talk) 07:19, 19 January 2018 (UTC)

Cryogel seems to be a registered trademark. What would be the inclusive uncapitalised term? I suppose the word might enter the language as a normal term like hoover and vaseline. Dbfirs 08:12, 19 January 2018 (UTC)

This is the website of the company which manufactures it, with plenty of details [1]. Here is a definition from a technical glossary [2] which might be a basis if you wanted to write something, but that is Russian, and elsewhere there might be trademark issues. Wymspen (talk) 10:11, 19 January 2018 (UTC)

Thanks for the feedback! So I gather it might be a trademark. But if ya look at Google Books [https://www.google.co.uk/search?q="cryogels"+the&btnG=Search+Books&tbm=bks&tbo=1&gws_rd=cr&dcr=0&ei=FcZhWo34AcbbgAbirqeQDQ] you can see a lot of apparently generic talk about "cryogels". The plural and lack of caps suggests maybe the writers often see it as a generic term. Equinox ◑ 10:20, 19 January 2018 (UTC)

Found a review of the biological applications, which describes them as "macroporous gels produced at subzero temperatures (known as cryogels)". Klbrain (talk) 00:55, 20 January 2018 (UTC)

References

Current uses of radium-226

Does anyone actually still use radium-226 for anything? (That's the most stable isotope, which used to be the common one used; I know ²²³Ra is used as a radiopharmaceutical). The sources in our radium article on current uses are from last decade, and even then those uses were being supplanted: we usually use other isotopes (e.g. ¹⁹²Ir, ⁶⁰Co) for industrial radiography instead, and we usually use actinides (Pu, Am, Cf) for neutron sources instead of Ra. Is the main use of ²²⁶Ra really just to get rid of it by transmutation to ²²⁷Ac, like Ullmann's Encyclopaedia said in 1993? Double sharp (talk) 13:01, 19 January 2018 (UTC)

According to this the main use is the production of radon. Mikenorton (talk) 13:25, 19 January 2018 (UTC)

That's interesting, though I'd like to see where they got that information from. At first glance it seems to me a bit overdoing it to produce pure Ra specifically to get Rn: you can get Rn from anything above it in its decay chain quite easily (it's a gas, while its parents aren't, so the separation is trivial), so isn't a chunk of uranium ore already a serviceable radon source? Double sharp (talk) 13:49, 19 January 2018 (UTC)

For uses of Radon see Radon#Applications, although it doesn't look like it gets much use these days, for production see Radon#Industrial_production, which supports it being produced normally from radium, even if the need for it is not great. Mikenorton (talk) 16:35, 19 January 2018 (UTC)