ISSN:
1022-1352
Keywords:
Chemistry
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Micellization in water of two homologous series of AB-type diblock copolymers, composed of polystyrene (PS) as the A block and poly(ethylene oxide) (PEO) as the B block, were investigated by small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS). The copolymers have molecular weights Mn in the range 2 000 - 34 800, and have in a given series, the same number of repeating units of the PS block, (NPS = 10 and 38), and a variable number of repeating units of the PEO block (NPEO values in the range 23-704). In order to avoid secondary association of micelles, a dialysis technique was used to prepare the micellar systems, in the case of copolymers having high Mn values of the PS block. The experimental micelle properties such as the core radius Rc and the aggregation number N of non-equilibrium structures, so called “frozen micelles”, obtained by dialysis, were found to be independent of the copolymer characteristics. However, for equilibrium structures, obtained by direct solubilization of the copolymers (NPS = 10) in water, Rc and N were found to decrease with increasing NPEO for the homologous series.
Additional Material:
2 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/macp.1996.021971117
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