Solid Polymer Electrolytes Based on Chitosan and Europium Triflate

The solid polymer electrolytes (SPEs) have been extensively studied since the pioneering work of Wright and Armand et al[1, 2]. Previous studies were focused on poly(ethylene oxide) (PEO) and lithium salts [3]. However recent research aimed at developing SPE based on natural polymers, which are interesting due to their natural abundance, low price and environmentally friendly nature [4].

Chitosan is a natural polymer obtained from chitin and it has been largely investigated due to its biodegradability, non-toxicity, absorption properties and biocompatibility.

In this presentation are described the preparation and characterization of novel systems from chitosan and europium (III) trifluoromethanesulfonate salt. The transparent samples were characterized by thermal analysis (DSC and TGA), impedance spectroscopy and electron paramagnetic resonance (EPR). The Chitosan_55.04%Eu(Trif)₃ sample showed the best ionic conductivity of 1.52×10^-6 and 7.66×10^-5 S∙cm^-1 at 25ºC and 80ºC, respectively. The thermal analysis revealed that the degradation started at around 120 - 145ºC and the weight loss ranged from 15 to 40%. The EPR analysis showed a broadening of the EPR resonance lines with increasing europium contents in the chitosan membranes due to the magnetic dipole–dipole coupling and spin-spin exchange between the Eu²⁺ions.

 

ACKNOWLEDGEMENTS

 

We are grateful to the Fundação para a Ciência e Tecnologia (PestC/QUI/UI0686/2013,  POPH/FSE for a grant  SFRH/BD/97232/2013 (R. Alves)) for financial support of this work. The authors are also grateful to, FAPESP, CNPq and CAPES for financial support. M. M. Silva acknowledges CNPq, for the mobility grant provided by this institution.

 

REFERENCES

[1] P. V. Wright, British Polymer Journal 7 (1975) 319.

[2] M. B. Armand. J. M. Chabagno, M. J. Duclot, In Fast Ion Transport in Solids; Vashishta, P., Mundy, J. N., Shenoy, G. K., Eds.; North-Holland: Amsterdam, The Netherlands, 1979, p 131.

[3] P. K. Varshney, S. Gupta, Ionics 17 (2011) 479-483.

[4] I. S. M. Noor, S. R. Majid, A. K. Arof, D. Djurado, S. C. Neto, A. Pawlicka, Solid State Ionics 225 (2012) 649-653.