Photon correlation spectrometric measurements of the hydrodynamic layer thicknesses of adsorbed polyethylene oxides on precipitated silica

Autor: P. Kaniut, H. Maier, E. Killmann, N. Gütling
Rok vydání: 1985
Předmět:
Zdroj: Colloids and Surfaces. 15:261-276
ISSN: 0166-6622
DOI: 10.1016/0166-6622(85)80077-9
Popis: Photon correlation spectrometry (PCS) is used to determine the hydrodynamic layer thicknesses of polyethylene oxides (PEO) adsorbed on precipitated silica particles in hydrous suspension. The resulting thicknesses in the plateau zone of the adsorption isotherms show a square root dependence on molar mass of the PEOs ranging from 4·10 4 to 3.3·10 6 g mol −1 . The results are compared with layer thicknesses obtained by different methods and in other systems. The large hydrodynamic thicknesses can be attributed to the long tails of the adsorbed macromolecules dangling into the bulk and enlarging the effective hydrodynamic size of the covered particles. The behaviour of the long tails in the adsorbed layer determines the thicknesses and their square root dependence on M W . The findings are in agreement with conformations of adsorbed macromolecules obtained from new theories on polymer adsorption.
Databáze: OpenAIRE