Study of micelle formation by the diblock copolymer poly(styrene-b-dimethyl siloxane) in n-dodecane by small angle x-ray scattering

✍ Scribed by David S. Brown; John V. Dawkins; Angela S. Farnell; Graham Taylor

• Publisher: Elsevier Science
• Year: 1987
• Tongue: English
• Weight: 435 KB
• Volume: 23
• Category: Article
• ISSN: 0014-3057
• DOI: 10.1016/0014-3057(87)90137-6

✦ Synopsis

The diblock copolymer poly(styrene-b~limethyl siloxane) (PS-PDMS) in n-dodecane forms multimolecular micelles in which insoluble PS blocks associate in a core surrounded by a shell of solvated PDMS blocks. Small angle X-ray scattering data have been obtained for PS-PDMS concentrations in the range 0.5 10%. Intensity data have been interpreted by the Guinier method in order to determine the radius of the PS core of a micelle. Scattering intensities exhibit negative deviations from Porod's law, which is characteristic of a diffuse interfacial layer, permitting the determination of the thickness of the shell of solvated PDMS blocks. Scattering curves for solutions having high PS PDMS concentrations have a peak maximum indicating ordered arrays of micelles.