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Correlation length of hydrophobic polyelectrolyte solutions

D. Baigl·R. Ober·D. Qu·A. Fery·C. E. Williams
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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 highly charged hydrophobic polyelectrolyte as a function of the polymer concentration $C_p$, 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 $f$. In particular a continuous transition has been observed from $ξ\sim C_p^{-1/2}$ to $ξ\sim C_p^{-1/3}$ 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 of the chains and the anomalously strong reduction of the effective charge fraction.

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D. Baigl, R. Ober, D. Qu, A. Fery, C. E. Williams. 2003-02-24. Correlation length of hydrophobic polyelectrolyte solutions. https://doi.org/10.1209/epl%2Fi2003-00391-2

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