Two substances are miscible when their intermolecular forces (IMFs) are similar enough such that the forces of attraction between molecules of different substances are similar in strength to the forces of attraction between molecules of the same substance. If we look at the miscibility of A and B as an example, if A attracts B about as strongly as A attracts A and B attracts B the substances should be miscible. If A and A have much stronger attraction than A and B the substances are less likely to be miscible.
I think he is interested in practical answer not a theory of how miscibility works. In my opinion, you better try some other solvent as acetone is readily miscible with most organic solvents. I had similar situation in my project.
Thank you for your comment. It was a theory which shows what suggestion you gave. Let him to think why it is not possible acetone to use and try with other solvent. Good luck!
Heavily fluorinated solvents tend to only be miscible with other fluorinated solvents/compounds. Ive never used these before so I am not sure if they will mix with acetone or not. In general though acetone is miscible with most things I can think of. Its miscible with water and its miscible with hexanes --- the most polar and nonpolar ends of the spectrum so all I can think is to try a fluorinated solvent.