1. Chapter 55 – CLUSTERING IN MACROMOLECULAR MEDIA 55:2. CHAIN END CLUSTERING 55:3. CLUSTERING DUE TO MONOMER STICKING INTERACTIONS

2. 55:2. CHAIN END CLUSTERING

3. SANS data from PEO/d-water: 55:3. CLUSTERING DUE TO MONOMER STICKING INTERACTIONS

4. CLUSTERING AND SOLVATION

5. Ternary RPA: Alternating copolymer with -- oxygen blocks (component 1) -- ethylene blocks (component 2) -- d-water (component 3) PEO monomer: Contrast factors: DATA ANALYSIS RPA factors:

6. RESULTS

7. CLUSTERING DUE TO HYDROPHOBIC STICKING

8. COMMENTS -- Clustering in macromolecular media can be caused by “unhappy” hydrophobic groups sticking to other hydrophobic groups. -- The PEO monomer is modeled as an alternating copolymer of ethylene and oxygen groups. -- The ethylene/d-water and oxygen/d-water interactions characterize LCST phase behavior (phase separation upon heating), while the ethylene/oxygen interactions characterize a UCST phase behavior (phase separation upon cooling).