Is there any compound which becomes soluable to an agent (be it water or otherwise) when exposed to light (be it visable or UV), but insoluable to that same agent otherwise?

-- anno k (sk_arts@hotmail.com), February 15, 2002

Answers

Try doing a Google search on Gum Bichromate. A popular process from the last part of the nineteenth century.

-- Joe Lipka (joelipka@earthlink.net), February 15, 2002.

Gum Bichromate is soluble when not exposed to UV and becomes unsoluble (hardens) when exposed. If you are only looking for the inverse reaction, you shall not easily find it. I personally don't recall having read about something that reacts by becoming soluble when exposed to UV or light.

-- George Papantoniou (papanton@hol.gr), February 25, 2002.

When microchip producers make microchips they use a photoresist to transfer a printed pattern to the silicon substrate. This photoresist is a polymeric novolac which is practically insoluble in water. Exposing it to light increases it's solubility drastically. Try a Google search on "novolac" or start out at http://dot.che.gatech.edu/henderson/introduction_to_dnq- novolac__resists.htm

-- Jesper Bøgelund (jesper.bogelund@teknologisk.dk), April 22, 2002.