Carrageenan based hybrid materials with ionic-liquids for sustainable and recyclable printable pressure sensors

Abstract

In the scope of reducing the environmental impact of electronic systems (e-waste), increasingly implemented in the scope of the digitalization of society, this work reports on the development of a sustainable pressure sensor based on the combination of the natural polymer carrageenan and the ionic liquid (IL) 1-butyl-3-methylimidazolium tetrachloroferrate ([Bmim][FeCl4]). Different IL contents were incorporated into the carrageenan matrix (10, 20 and 40 wt.%) in order to evaluate the influence of IL content in the final properties of the hybrid materials. No variations are induced in the chemical structure of carrageenan by the inclusion of the IL. On the other hand, the thermal stability of the polymer decreases with increasing IL content, as well as the Young Modulus that decreases from 748 MPa for pristine carrageenan to 437 MPa for the composite with 40 wt.% IL content. The ionic conductivity increases up to 8.74 × 10-9 S/cm for the sample comprising 40 wt.% of IL. The recyclability of the developed materials has been accessed and the potential of the blends for the development of printable pressure sensors demonstrated