The study of polythiophene/water interfaces by sum-frequency generation spectroscopy and molecular dynamics simulations

• DOI: 10.1039/c5tb00388a
• Publication Date: 2015-06-24T16:30:39Z
• Authors: S. Bellani; M. Porro; C. Caddeo; M. I. Saba; P. B. Miranda; A. Mattoni; G. Lanzani; M. R. Antognazza
• Keywords: Polythiophene

Semiconducting polymer/water interfaces are gaining increasing attention due to a variety of promising applications in the fields biology and electrochemistry, such as electrochemically-gated transistors photodetectors, which have been used for biosensing neuroscience applications. However, detailed characterization polymer surface presence an aqueous environment is still lacking. In this work, we employed sum-frequency generation vibrational spectroscopy, surface-specific technique compatible with electrochemical/biological conditions, demonstrate that thin films regio-regular poly-3-hexylthiophene (rr-P3HT) undergoes molecular reorientation when exposed electrolytes, respect their structure air. Experimental results corroborated by dynamics simulations. Since orientation believed play fundamental role electrochemical environmental stability conjugated polymers, reported findings not only contribute understanding interfaces, but they may also implications design polymers enhancing performance electrolytic environments.