I need to prepare a 2% PEO (Mw=100000) aqueous solution. I've tried to heat it to 45℃, but there were still some white cotton-like precipitate. I used to make PEG Mw-8000 aqueous solution, which is easy to dissolve.
I want to know if there's hydrogen bond or sth else that prevent it dissolve?
Lukas, in your google groups post you make a differentiation between "PEG" and "PEO", as far as I know both are the same, just difefrent abbreviations for the same stuffexcept for that there is a tendency of using these for different molecular weight classes (Wikipedia): "PEG, PEO, or POE refers to an oligomer or polymer of ethylene oxide. The three names are chemically synonymous, but historically PEG has tended to refer to oligomers and polymers with a molecular mass below 20,000 g/mol, PEO to polymers with a molecular mass above 20,000 g/mol, and POE to a polymer of any molecular mass." (2)
(2) what you observed is what I would understand as follows: the higher molecular weight is not well soluble (the higher the Mw, solubility rapidly decreases, that has to do with solubility parameter and entropy contribution to the solvatation process).
To Wang Chao's question: I would assume that 2% solution for a 100,000 Mw PEO may be above saturation. Explanation as above.
Dear Chao Wang,
I am also facing the same problem. 1 am tried to dissolve PEO (Mw=100000) in water at room temperature by stirring. It getting viscus but still white cotton-like precipitate are there. Have you any suggestion for this? i am going to prepare nanocomposites using PEO as the matrix phase.
- Badges
- Science topic
- Similar topics
- Physical Sciences
- Materials Science
- Materials
- Polymers