A study of bacterial cellulose confined ionic liquid and deep eutectic solvent gel materials

Abstract

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI--COLUMBIA AT REQUEST OF AUTHOR.] Pollutants have become more prevalent in the air, water, and ground, necessitating the development of technologies that would help, limit, reverse, monitor, measure, and recycle prevalent pollutants. Ionic liquids (ILs), or molten salts that are liquid at or below 100[degrees]C, as well as deep eutectic solvents (DESs), a mixture of a hydrogen bond donor with a strong hydrogen bond acceptor that remains liquid upon cooling, have been popularized as greener alternatives in industry. These liquids tend to have large electrochemical and thermal windows, a very small vapor pressure, and can be fine-tuned for many applications. The liquid state of ILs and DESs makes them quite useful in their application but complicates their handling. Ionogels and eutectogels enable the liquid-like dynamics of these solvents while adding a pseudo-solid like character that makes for ease of handling. Herein, a new group of confined ILs and DESs within a cellulosic matrix called bacterial cellulose iono/eutecto gels are produced that are shown to be applicable to analyte detection and are studied for a better understanding of the dynamics within the gel. These intriguing gels are flexible, transparent, size-tuneable, shape-tuneable, amenable to incorporation of dyes or other functional material, and capable of confining 99 wt.% of a solvent with little leakage from the gel. These materials affect the crystallinity of cellulose little, while the liquid presents a diffusional change that stems from restructuring of the fluid. These gels are capable of detection of ammonia, hydrogen sulfide, and temperature. Given their properties, iono/eutecto gels offer use in applications, such as electrochemical devices, wound healing, drug delivery, and carbon capture/separation membranes.