Surface polymerization of (3,4-ethylenedioxythiophene) probed by in situ scanning tunneling microscopy on Au(111) in ionic liquids.
The electropolymerization of 3,4-ethylenedioxythiophene (EDOT) to poly(3,4-ethylenedioxythiophene) (PEDOT) was investigated in the air and water-stable ionic liquids 1-hexyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate [HMIm]FAP and 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) amide [EMIm]TFSA. In situ scanning tunnelling microscopy (STM) results show that the electropolymerization of EDOT in the ionic liquid can be probed on the nanoscale. In contrast to present understanding, it was observed that the EDOT can be oxidised in ionic liquids well below its oxidation potential and the under potential growth of polymer was visualized by in situ STM. These results serve as the first study to confirm the under potential growth of conducting polymers in ionic liquids. Furthermore, ex situ microscopy measurements were performed. Quite a high current of 670 nA was observed on the nanoscale by conductive scanning force microscopy (CSFM).
Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128, Mainz, Germany. ahmad@mpip-mainz.mpg.de
Shahzada
S
Ahmad
Timo
T
Carstens
Rüdiger
R
Berger
Hans-Jürgen
HJ
Butt
Frank
F
Endres
D001881:Borates / Q000737:chemistry; D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000737:chemistry*; D055664:Electrochemical Techniques; D006046:Gold / Q000737:chemistry*; D007093:Imidazoles / Q000737:chemistry; D052578:Ionic Liquids / Q000737:chemistry*; D016252:Microscopy, Scanning Tunneling; D010084:Oxidation-Reduction; D058105:Polymerization; D011108:Polymers / Q000737:chemistry*; D013499:Surface Properties
C528767:1-hexyl-3-methylimidazolium; D001881:Borates; D019086:Bridged Bicyclo Compounds, Heterocyclic; D007093:Imidazoles; D052578:Ionic Liquids; D011108:Polymers; C121383:poly(3,4-ethylene dioxythiophene); D006046:Gold; C518739:1-ethyl-3-methylimidazolium