Self-Sustainable, self-healable, Load Bearable and Moldable stimuli responsive ionogel for the Selective Removal of Anionic Dyes from aqueous medium

Abstract

Among the tested strategies to remove the toxic dyes from the aquatic environment, absorption is widely preferred owing to its ease of formation, lower cost and modulating ability of the absorbents used. Designing advance absorbents that offer higher absorptivity, selectivity, reusability, moldability and high pre-concentration factor for the analyst is a challenging task yet to be achieved. Herein, we had designed new age low molecular weight gelator from prototypical molecular gelators, an ionic liquid based gelator; 1-n-hexadecyloxy-carbonylmethylpyridinium bromide (C16EPyrBr) that exhibited unusual, unprecedented stimuli responsive reversible transition from opaque to transparent ionogel due to the change in the gel microstructure from lamellar for the opaque ionogel to cylindrical for the transparent ionogel. Small angle neutron scattering and scanning and scanning electron microscopy measurements characterized the microstructure and morphology of the ionogel respectively. Although having lower molecular weight based, the ionogel show excellent tolerance against the salinity (1500 mM concentration of NaCl), offer good mechanical strength and have self-healing, self-sustaining, and load bearing characteristics. The ionogel could be loaded in apparatus like dialysis membrane and syringe with 99% removal efficiency and can selectively remove the anionic dye, methyl orange from the aqueous medium even after 20 cycles. As a final thought, the low molecular weight ionic liquid based gelator could be a promising alternative to the traditional anionic dye absorbents.