Dear Ali Husnain, different procedures are followed, see documents below. However, from my personal experience, the following points should be considered:
- best homegenization is obtained by simultaneous stirring and sonication
- don't use plastics covered stirring bar, it will be errodated and contaminate your composite.
- be carefull about the unseen loss of solvent(s) during sonication
- be aware by the possible polymer degradation by sonication