Photophysical and structural modulation of poly(3-hexylthiophene) nanoparticles via surfactant-polymer interaction

9 pags., 8 figs.
The optical properties of poly(3-hexylthiophene-2,5-diyl) (P3HT) can be controlled by processing the polymer in the form of nanoparticles dispersed in aqueous mediums. Colloids of P3HT were prepared by two different methods: flash –or reprecipitation- and miniemulsion precipitation technique, which result in the latter case in a polymer-water system whose stability is mediated by an ionic surfactant. Both systems yield different color dispersions, thus different absorption spectra, that is explained to be caused by the influence of the surfactant on the structure of P3HT. Differential scanning calorimetry and synchrotron radiation X-ray diffraction experiments reveal the origin of these optical differences, showing evidences of the formation of a blended structure formed due to the interaction between P3HT and the ionic surfactant. This work evidences the potential use of techniques for preparing nanoparticles in water dispersions as a tool to manipulate the structure and thus, the optical properties of these materials.
This work has been supported by the Spanish Ministry of Science and Innovation under the projects PID2019-107514 GB-I00/AEI/10.13039/ 501100011033 and PID2019-106125 GB- I00/AEI/10.13039/ 501100011033, and Garantía Juvenil/Fondo Europeo. We thank E. Solano for assistance and support during beamtime in ALBA. J.M. thanks MCIU for the Ramon y Cajal contract and the grant Ref. PGC2018- 094620-A-I00 and Ikerbasque Foundation for the Fellow program