Correlation length of hydrophobic polyelectrolyte solutions

Titelangaben

Baigl, Damien ; Ober, R. ; Qu, Dan ; Fery, Andreas ; Williams, Claudine E.:
Correlation length of hydrophobic polyelectrolyte solutions.
In: Europhysics Letters. Bd. 62 (2003) Heft 4 . - S. 588-594.
ISSN 0295-5075
DOI: https://doi.org/10.1209/epl/i2003-00391-2

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Abstract

The combination of two techniques (Small Angle X-ray Scattering and Atomic Force Microscopy) has allowed us to measure in reciprocal and real space the correlation length ξ of salt-free aqueous solutions of a highly charged hydrophobic polyelectrolyte as a function of the polymer concentration Cp, charge fraction f and chain length N. Contrary to the classical behaviour of hydrophilic polyelectrolytes in the strong-coupling limit, ξ is strongly dependent on −1/2 −1/3 f. In particular, a continuous transition has been observed from ξ ∼ Cp to ξ ∼ Cp when f decreased from 100 to 35. We interpret this unusual behaviour as the consequence of the two features characterising the hydrophobic polyelectrolytes: the pearl necklace conformation ofthechainsandtheanomalouslystrongreductionoftheeffectivechargefraction.