Wolff M, Steitz R, Gutfreund P, Voss N, Gerth S, Walz M, Magerl A, Zabel H. Shear induced relaxation of polymer micelles at the solid-liquid interface.
LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2008;
24:11331-11333. [PMID:
18817420 DOI:
10.1021/la801945q]
[Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A 20% aqueous solution of (ethylene oxide) 99-(propylene oxide) 65-(ethylene oxide) 99, F127, was investigated by combining rheology in a cone/plate-geometry and surface-sensitive grazing incident neutron scattering. The crystalline structure formed by the polymer micelles becomes less pronounced for low shear rates, but correlations increase for higher shear rates. After stopping shear a slow relaxation of the micelles is found in the vicinity (50 mum thick layer) of a hydrophilic silicon wall (strong micelle-wall interaction), while a fast relaxation is observed in the boundary layer against the hydrophobic silicon wall (weak micelle-wall interaction). The results show that in the vicinity of the interface wall-particle interactions compete heavily with the shear force acting on the liquid.
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