Previous XPS investigations of insulating poly(o-aminophenol), (PoAP), electrosynthesized by cyclic voltammetry on Pt substrates, revealed the formation of a thin film of about 7nm of thickness, firmly adherent onto the electrode surface and stable even under UHV conditions. A constant repeat formula made of alternating quinoneimine and monomer units was derived with polymer chains terminating as carbonyl-type groups. Based on these findings, we have continued our investigation on insulating PoAP by employing ToF-SIMS whose superior surface sensitivity is well known. The aim was to corroborate the polymer structure with particular reference to the top surface layers in view of possible bio-applications and to understand the possible way of interaction with the underlying platinum electrode surface. In order to do this, we analyzed PoAP films grown at different levels of the electrochemical synthesis (1, 5 and 20 scan cycles) and the platinum substrate itself. The individuation of the main characteristic fragments and the behavior of their intensity by varying the stage of the electropolymerization allowed to confirm the polymer structure as well as the presence of terminating carbonyl groups. Remarkably, from the analysis of the PoAP/Pt interface at the early stage of the polymer formation it was possible to discern that polymer chains tend to interact with the electrode surface preferentially by the nitrogen atom of the oxidized monomers
A comparative ToF-SIMS study of insulating Poly (o-aminophenol) films at different level of electrochemical growth
CARBONE, MARIA ELVIRA EGIDIA;CIRIELLO, Rosanna;SALVI, Anna Maria;
2015-01-01
Abstract
Previous XPS investigations of insulating poly(o-aminophenol), (PoAP), electrosynthesized by cyclic voltammetry on Pt substrates, revealed the formation of a thin film of about 7nm of thickness, firmly adherent onto the electrode surface and stable even under UHV conditions. A constant repeat formula made of alternating quinoneimine and monomer units was derived with polymer chains terminating as carbonyl-type groups. Based on these findings, we have continued our investigation on insulating PoAP by employing ToF-SIMS whose superior surface sensitivity is well known. The aim was to corroborate the polymer structure with particular reference to the top surface layers in view of possible bio-applications and to understand the possible way of interaction with the underlying platinum electrode surface. In order to do this, we analyzed PoAP films grown at different levels of the electrochemical synthesis (1, 5 and 20 scan cycles) and the platinum substrate itself. The individuation of the main characteristic fragments and the behavior of their intensity by varying the stage of the electropolymerization allowed to confirm the polymer structure as well as the presence of terminating carbonyl groups. Remarkably, from the analysis of the PoAP/Pt interface at the early stage of the polymer formation it was possible to discern that polymer chains tend to interact with the electrode surface preferentially by the nitrogen atom of the oxidized monomersI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
