Adsorption of a Highly Charged Polyelectrolyte on Hydrophobic Surfaces.
Abstract
We have found that random copolymers of styrene and sulfonated styrene form an adsorbed layer on hydrophobic surfaces even though the polyelectrolyte chain is highly charged (linear charge fractions between 0.4 and 0.9). This adsorption occurs on both a solid hydrophobic surface (silanised silicon wafer) and the air/water interface. We will present results of surface tension, ellipsometry, neutron and x-ray reflectivity experiments to characterize the layers onto both surfaces. In the absence of added salt, the adsorption is found maximum at an intermediate charge fraction. The ionic strength of the solution enhances the amount of adsorption and in some limiting cases, allows it to take place. This unique behaviour of poly(styrenesulfonate) will be discussed in terms of the strong hydrophobicity of the backbone and will be compared with its unusual solution properties.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1998
- Bibcode:
- 1998APS..MAR.M1313W