Integrative chemistry portfolio toward designing and tuning vanadium oxide macroscopic fibers sensing and mechanical properties
Résumé
Under certain synthetic conditions vanadium oxide gels are made of nanoribbons subunits. Due to this textural specificity it is possible to align the ribbons while employing an extrusion process, generating thereby vanadium oxide macroscopic fibers. In this process V2O5 gel is extruded through a syringe within a PVA (1% wt) solution rotating beaker. A composite fiber can be then extracted from the beaker. These as-synthesized fibers are bearing outstanding mechanical properties (20 GPa of Young modulus) addressed with transversal flexibility that alloys macroscopic knot formation. Furthermore, they appear to be excellent alcohol sensors, enable to detect 0.1 ppm of ethanol within 16 s at 40 8C, sensitivity being associated with a good selectivity. Subsequently, we were able to tune the fibers' sensing and mechanical properties by varying the shear rate addressed to the vanadium oxide extruded gel. In order to better appreciate the correlation between fibers' porosity, nanoribbons subunits alignment and the addressed properties (mechanical and sensing) we tuned the porosity making the use of latex nanoparticles inclusion followed by their calcinations while varying still the imposed sheer rate during the extrusion. Finally synthesis of hybrid PANI–V2O5 allowed reaching enhanced tenacity 12 J g1, concomitant with a loss of sensitivity. We show that all the parameters involved within the mechanical and sensing performances are acting within a strong partitioning mode rather than a cooperative one. Overall, these iterative synthetic approaches demonstrate once more the importance of the correlation between structures and properties, approaches where the integrative chemistry is appearing, via its versatility, as an essential tool of chemical science to conceive rationally functional architectures bearing enhanced properties.
