Guar gum as biosourced building block to generate highly conductive and elastic ionogels with poly(ionic liquid) and ionic liquid

Abstract

In this study, we report on the simple and straightforward preparation of ionogels arising from the addition of guar gum (a plant-based polysaccharide) in a solution of precisely-defined poly(ionic liquid) chains (PIL) in imidazolium-based ionic liquid (IL). The development of intermolecular polar interactions (mainly hydrogen bonds) and topologic chain entanglements induces the formation of physical biohybrid ionogels, whose elastic properties can be easily tuned by varying the composition (up to 30000Pa). The combined presence of guar gum and PIL confers excellent dimensional stability to the ionogels with no IL exudation combined with high thermal properties (up to 310°C). The resulting materials are shown to exhibit gel scattering profiles and high conductivities (> 10^-4S/cm at 30°C). The benefit linked to the formation of guar/PIL associations in IL medium enables to find a good compromise between the mechanical cohesion and the mobility ensuring the ionic transport.

Keywords: Guar gum; Ionic liquid; Ionogels; Poly(ionic liquid); Polymer electrolyte; Polysaccharide.