> Well, I don't know if this is any help or not, but 1,2,3 Propan-triol > (also known as Glycerol) has the same IOR at 20 degrees C as borosilicate > glass. Unfortunately I don't know any numbers off the top of my head.
Whoops, that should really have been Propan-1,2,3-triol...
Never mind.
Bye for now,
Jamie.
