Knaapila, Matti Evans, Rachel C. Garamus, Vasil M. Almásy, László Székely, Noémi K. Gutacker, Andrea Scherf, Ullrich Burrows, Hugh D. 2010-09-07 We report on the phase transitions, solution structure, and consequent effect on the photophysical properties of poly[3-(6-trimethylammoniumhexyl)thiophene] bromide (P3TMAHT) in aqueous sodium dodecylsulfate (SDS). Polythiophene was mixed with SDS or deuterated SDS to form P3TMAHT(SDS)_<i>x</i> complex (<i>x</i> = the molar ratio of surfactant over monomer units) in D₂O and studied by small-angle neutron and X-ray scattering (SANS/SAXS) and optical spectroscopy. At room temperature, P3TMAHT forms charged aggregates with interparticle order. The addition of SDS eliminates the interparticle order and leads to rod-like (<i>x</i> = 1/5) or sheet-like polymer−SDS aggregates (<i>x</i> = 1/2 to 1) containing rod-like (<i>x</i> = 1/5 to 1/2) or sheet-like (<i>x</i> = 1/2 to 1) polymer associations. Partial precipitation occurs at the charge compensation point (<i>x</i> = 1). Ellipsoidal particles without interparticle order, reminiscent of SDS micelles modified by separated polymer chains, occur for <i>x</i> = 2 to 5. Free SDS micelles dominate for <i>x</i> = 20. Structural transitions lead to a concomitant variation in the solution color from red (P3TMAHT) to violet (<i>x</i> = 1/5 to 1) to yellow (<i>x</i> > 2). The photoluminescence fingerprint changes progressively from a broad featureless band (<i>x</i> = 0) through the band narrowing and appearance of vibronic structure (<i>x</i> = 1/5 to 1) to the return to a blue-shifted broad emission band (<i>x</i> = 5). The polymer stiffness reaches a maximum for <i>x</i> = 1, which leads to minimization of the Stokes shift (0.08 eV). This work gives fundamental information upon how surfactant complexation can influence both the solution structure and photophysical properties of a water-soluble polythiophene. application/pdf https://folia.unifr.ch/global/documents/301742 https://folia.unifr.ch/documents/301742/files/alm_ssp.pdf https://folia.unifr.ch/documents/301742/files/alm_ssp_sm.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1021/la102591b info:eu-repo/semantics/openAccess License undefined Langmuir. - 2010, vol. 26, no. 19, p. 15634–15643 info:eu-repo/classification/udc/54 Structure and "surfactochromic" properties of conjugated polyelectrolyte (CPE): surfactant complexes between a cationic polythiophene and SDS in water http://purl.org/coar/resource_type/c_6501