Micellization Study on Block and Gradient Copolymer Aqueous Solutions by DLS and SANS

• Published in: Macromolecules 2006-02, Vol.39 (4), p.1592-1597
• Main Authors: Okabe, Satoshi, Seno, Ken-ichi, Kanaoka, Shokyoku, Aoshima, Sadahito, Shibayama, Mitsuhiro
• Format: Article
• Language: English
• Subjects: Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Properties and characterization; Solution and gel properties
• ISSN: 0024-9297; 1520-5835
• DOI: 10.1021/ma052334k

The dynamic light scattering and small-angle neutron scattering investigations were carried out on aqueous solutions of block (Block) and gradient copolymers (Grad) comprising EOVE and MOVE, where EOVE and MOVE denote 2-ethoxyethyl vinyl ether and 2-methoxyethyl vinyl ether, respectively. Although aqueous solutions of EOVE homopolymer precipitated at 20 °C, the two copolymer systems showed different temperature dependence. A 0.3 wt % Grad system had a micellization temperature range between 20 and 30 °C, while the Block system underwent a sharp transition at around 20 °C. The micellization was continuous in the Grad system, whereas a stepwise transition was observed in the Block system. The resulting micelle size in Grad system was smaller than that in the Block system. The continuous change and the smaller micelle size of Grad were explained by a “reel-in” effect in the micellization process.