I'm sure this is a silly question but we are trying to make some droplets of a polyacrylamide hydrogel. Ingredients are acrylamide monomer, bis-acrylamide, aps (initiator) and TEMED (accelerator). Mixing solution in glass vial we get a strong gel but take same solution and disperse a small drop in oil (tried silicone and octadecene) and it just doesn't gel! What is happening and what do I need to do to get the drop to gel. Any comments and light on this would be most helpful.
My apologies for what I now realize is an answer to the wrong question. I clearly misread what was written. Sorry to anyone who was misled by my answer.
Below is the original answer, to be disregarded.
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Sounds a lot like the "pearls" they make in "molecular gastronomy" - there, they usually use sodium alginate (a polymeric polyanion) added into an aqueous solution containing a divalent cation like Ca2+. I believe the Na+ is displaced by Ca2+ which can create crosslink points (alginate carboxylate - to - Ca2+ - to - another alginate carboxylate). As the sodium alginate hits the Ca2+ bath, the crosslinking will make the sodium alginate "syrup" fluid into gelly pearls.
Now, to do the same with polyacrylamide might be harder - I think it's too tricky to do in oil. I'm not sure why oil -- are you trying to take something dissolved in the oil and encapsulate with polyacrylamide? Even in a water bath, I think it's tricky because if you have a basic pH, you'll eventually cause release of ammonium so that the acrylamide monomer units become (one by one) acrylic acid or acrylate units.
(my apologies if the above does not address your question)
There are some literature on making hydrogels of polyacrylamide (some of which involves mixing with a polymeric polycarboxylic acid like alginate) - from seas.harvard.edu and ijpcbs.com
I'd obviously be interested to learn from someone in this forum if it can still be done.
I also found a PDF at wsu.edu cautioning the use of polyacrylamide in certain applications, so you might want to read that too.
http://www.molecularrecipes.com/spherification-class/basic-spherification/
http://www.seas.harvard.edu/suo/papers/312.pdf
https://puyallup.wsu.edu/wp-content/uploads/sites/403/2015/03/hydrogels.pdf
http://www.ijpcbs.com/files/18-4193.pdf
The acrylamide is in water so when you put it in oil it forms a sphere that is the only reason
I think point 2 of Michael Päch is the crucial point. TEMED is very good suoluble in hydrocarbons or silicon oil. You need a hydrophilic reduction reagent for your redox polymerization like ascorbic acid or Rongalit. Irgacure 2959 is the only commercially available water soluble photoinitiator it you want to try point 3 of Michael Päch. Another advice would be to thicken the unpolar phase by adding a polymer like polyisobutylene to the octadecane. Alternatively you can also take a silicon oil of high viscosity and molecular weight as dispersion media. In perl polymerization the dispersion media must have a relatively high viscosity. In normal O/W systems polyvinylalcohol is used to thicken the water phase. You need a thickener for the hydrocarbon phase (or a high viscosity silicon oil).
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