Nona Semana Integrada do Instituto de Física de São Carlos

Effects of crosslinking agents on PEDOT:PSS films

Não agendado

20m

Mestrado

Palestrante

Sr. Rafael Francisco Santiago de Souza (Instituto de Fìsica de São Carlos- IFSC/USP)

Descrição

The electrical conductivity of poly(3,4-ethylenedioxidethiophene) with polystyrenesulfonate( PEDOT: PSS) depends significantly on its morphology, microstructure and number of counter ions that balance the positive doping charges carried by the conjugated PEDOT chains. However, due to the high solubility of PSS-rich domains in water or other polar solvents, PEDOT:PSS films easily undergo dissolution when exposed to such solvents. (1) In order to prevent such dissolution, crosslinking agents are normally added to the polymer solution, prior to film formation, to stabilize the solid-state film. As consequence of crosslink addition, both the film morphology and electronic/ionic conductivity are negatively impacted, generating films with lower performances when compared to crosslink-free samples. Here we aim to analyze the behavior of PEDOT:PSS films mixed with different crosslinking agents, namely the 3-glycidyloxypropyltrimethoxysilane, 3-chloropropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, and 3-Methacryloxypropyltrimethoxysilane. The electrical conductivity was evaluated by means of four-probe measurement, revealing that PEDOT:PSS film crosslinked with 3-Methacryloxypropyltrimethoxysilane is the one with the closest electrical conductivity to the pristine PEDOT:PSS films. Regarding the ionic conductivity, we have conducted Impedance Spectroscopy and results suggest that the traditionally used 3-glycidyloxypropyltrimethoxysilane is not among the crosslink agents with the best ionic conductivity. Our work suggest that the usage of more optimized crosslink agents can enhance the performance of PEDOT:PSS mixed ionic-electronic conductor devices.

Acknowledgements:

This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001

Referências

1 HAKANSSON, A. et al. Effect of (3-glycidyloxypropyl)trimethoxysilane (GOPS) on the electrical properties of PEDOT:PSS films. Journal of Polymer Science B, v. 55, n. 10, p. 814-820, May 2017.