Abstract
The adsorption of viologen-containing polyelectrolytes on the surface of carboxylate-terminated, self-assembled monolayers was investigated by voltammetric methods. The two polyelectrolytes used had either butyl (VC4) or undecyl (VC11) linkages between the repeating viologen (4,4′-bipyridinium) subunits. Both polyelectrolytes were found to adsorb at nuetral pH on monolayers prepared by the self-assembly of either 3-mercaptopropionic (HSC2COOH) or 8-mercaptooctanoic (HSC7COOH) acids on golds. However, the adsorption was optimized by using the more hydrophobic polyelectrolyte (VC11) and the longer thiol (HSC7COOH). The gradual deprotonation of the HSC7COOH monolayer in the pH range 6-11 enhances the adsorption of the VC11 polyelectrolyte. From these data, an apparent pKa of ∼8 for the monolayer -COOH groups was obtained. The overall degree of packing of the viologen subunits at the monolayer - solution interface was found to be rather poor. The combined monolayer - polyelectrolytes interfacial structures did not block effectively the reduction or dissolved Ru(NH3)63+ ions on the underlying gold electrode.
| Original language | English |
|---|---|
| Pages (from-to) | 5087-5092 |
| Number of pages | 6 |
| Journal | Langmuir |
| Volume | 12 |
| Issue number | 21 |
| State | Published - Oct 16 1996 |
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ASJC Scopus subject areas
- Colloid and Surface Chemistry
- Physical and Theoretical Chemistry
Cite this
Adsorption of viologen-based polyelectrolytes on carboxylate-terminated self-assembled monolayers. / Godínez, Luis A.; Castro, René; Kaifer, Angel.
In: Langmuir, Vol. 12, No. 21, 16.10.1996, p. 5087-5092.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Adsorption of viologen-based polyelectrolytes on carboxylate-terminated self-assembled monolayers
AU - Godínez, Luis A.
AU - Castro, René
AU - Kaifer, Angel
PY - 1996/10/16
Y1 - 1996/10/16
N2 - The adsorption of viologen-containing polyelectrolytes on the surface of carboxylate-terminated, self-assembled monolayers was investigated by voltammetric methods. The two polyelectrolytes used had either butyl (VC4) or undecyl (VC11) linkages between the repeating viologen (4,4′-bipyridinium) subunits. Both polyelectrolytes were found to adsorb at nuetral pH on monolayers prepared by the self-assembly of either 3-mercaptopropionic (HSC2COOH) or 8-mercaptooctanoic (HSC7COOH) acids on golds. However, the adsorption was optimized by using the more hydrophobic polyelectrolyte (VC11) and the longer thiol (HSC7COOH). The gradual deprotonation of the HSC7COOH monolayer in the pH range 6-11 enhances the adsorption of the VC11 polyelectrolyte. From these data, an apparent pKa of ∼8 for the monolayer -COOH groups was obtained. The overall degree of packing of the viologen subunits at the monolayer - solution interface was found to be rather poor. The combined monolayer - polyelectrolytes interfacial structures did not block effectively the reduction or dissolved Ru(NH3)63+ ions on the underlying gold electrode.
AB - The adsorption of viologen-containing polyelectrolytes on the surface of carboxylate-terminated, self-assembled monolayers was investigated by voltammetric methods. The two polyelectrolytes used had either butyl (VC4) or undecyl (VC11) linkages between the repeating viologen (4,4′-bipyridinium) subunits. Both polyelectrolytes were found to adsorb at nuetral pH on monolayers prepared by the self-assembly of either 3-mercaptopropionic (HSC2COOH) or 8-mercaptooctanoic (HSC7COOH) acids on golds. However, the adsorption was optimized by using the more hydrophobic polyelectrolyte (VC11) and the longer thiol (HSC7COOH). The gradual deprotonation of the HSC7COOH monolayer in the pH range 6-11 enhances the adsorption of the VC11 polyelectrolyte. From these data, an apparent pKa of ∼8 for the monolayer -COOH groups was obtained. The overall degree of packing of the viologen subunits at the monolayer - solution interface was found to be rather poor. The combined monolayer - polyelectrolytes interfacial structures did not block effectively the reduction or dissolved Ru(NH3)63+ ions on the underlying gold electrode.
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M3 - Article
AN - SCOPUS:0001305935
VL - 12
SP - 5087
EP - 5092
JO - Langmuir
JF - Langmuir
SN - 0743-7463
IS - 21
ER -