Hydrophobic Polyelectrolytes in Better Polar Solvent. Structure and Chain Conformation As Seen by SAXS and SANS

作者：Essafi Wafa^*; Spiteri Marie Noelle; Williams Claudine; Boue Francois

来源：Macromolecules, 2009, 42(24): 9568-9580.

DOI：10.1021/ma9003874

We demonstrate the influence of solvent quality Oil the structure of the semidilute solution of it hydrophobic polyelectrolyte, partially sulfonated polystyrenesulfonate. Two solvents Lire used: (i) one Mixture of water and an organic solvent, THF, which is also slightly polar; (ii) DMSO, a polar organic solvent. In case i, it is shown by SAXS Study that the structure, namely the scattering from all chains, characterized by a maximum ("polyelectrolyte peak"), of the aqueous hydrophobic polyelectrolyte solutions (PSS) depends oil the solvent quality through the added amount of organic solvent THF. This dependence is more Pronounced when the sulfonation rate is low (more hydrophobic polyelectrolyte). It is proposed that when THF is added, the chain conformation evolves from the pearl-necklace shape already reported ill pure water toward the conformation in pure water for fully sulfortated PSS, which is stringlike as also reported previously, Oil the contrary, for a hydrophilic polyelectrolyte, AMAMPS, no evolution Occurs with added THF in the aqueous Solution. In Case ii, it is Shown directly by SANS Study that PSS can behave as a classical solvophilic polyelectrolyte when dissolved in all organic polar solvent such,is DMSO: the structure (total scattering) as well as the form factor (single chain scattering measured by SANS using the zero average contrast method) of the PSS chains is independent of the charge content, in agreement with Manning condensation, and identical to the one of a fully charged PSS chain in pure water, which has a classical polyelectrolyte behavior in the semidilute regime.

• 出版日期2009-12-22
• 单位中国地震局