Theoretically speaking, your PEO has a high molecular weight but it must be soluble in water. However, PEO forms viscous, chewy solutions in water at concentrations less than 1 wt %. Solutions of higher concentrations are elastic gels. At 20 wt % solids, the solutions are hard & tough water-plasticized polymers. Near the boiling point of water, the water solubility decreases, phase separation can occur, and the solution can become cloudy.

My advice is to use a mixture of solvents instead of a single solvent. Try to dissolve PEO in the combination water/ethanol or water/methanol at a temperature which is not low & not high. I suggest warm solvent mixture, say at 40- 50 oC . Try first 0.1g polymer in 10 ml. solvent mixture in stoppered test tube overnight. If you see, a clear solution in the next day then it is fine. If not, change the concentration up or down but not far from (0.1 in 10). Best wishes for success.

Thank you so very much Dr. Nizar

While totally agreeing on what Nizar Matar has explained above. I just want to say you can dissolve PEO 1-2%Wt in water by stirring (magnetic stirring) overnight at around 50C. I have done that so if you prefer not to have alcohol in your polymer you can try that way to ensure homogeneous solution (viscous).