Recent content by Decimus

Results: I got three fractions. The fraction first to elute binds to iodine but does not absorb UV light -- this is probably the high molecular weight fraction that is also chemically inert (no functional groups). The second fraction elutes straight after, binds to iodine and absorbs UV light...

Alright, I apologize beforehand if this counts as double-posting, but technically this is a new update. So I ran some tests with the TLC plates. The acetone has trace amounts of impurities in it -- no spots, bands, or splotches can be seen on the acetone blank (acetone is spotted onto the TLC...

I don't know. It's in a bottle labelled "polyurethane resin" and is a thick, viscous liquid with roughly the same consistency as treacle. There's also some sort of dye in it so it appears red. In theory the dye should be of low molecular weight and therefore be the last to elute out of the...

Thanks for the protocol. So it's basically just the usual steps for packing a column except that I'll need to presoak the stationary phase in solvent until they swell completely. Got it. Unfortunately I don't have access to DMF (or fortunately, as I don't want to work with that stuff either.)...

The Tyndall effect is probably what your teacher is looking for. It's simple to administer (just shine a light) and works for all classes of colloids (sol, foam, aerosol, etc.) Still, it could be hard to distinguish solid sols from solid solutions if both are opaque. Coagulation usually only...

So I have been asked to separate a polymer (polyurethane) into high molecular weight and low molecular weight components. I have access to Sephadex LH-20, a simple glass column, acetone (a List II chemical), ethyl acetate, and hexane. I may be able to get access to other solvents, as long as it...