  We report simultaneous dissolution of agarose (AG) and chitosan (CH) in
varying proportions in an ionic liquid (IL), 1-butyl-3-methylimidazolium
chloride [C4mim][Cl]. Composite materials were constructed from AG-CH-IL
solutions using the antisolvent methanol, and IL was recovered from the
solutions. Composite materials could be uniformly decorated with silver oxide
(Ag2O) nanoparticles (Ag NPs) to form nanocomposites in a single step by in
situ synthesis of Ag NPs in AG-CH-IL sols, wherein the biopolymer moiety acted
as both reducing and stabilizing agent. Cooling of Ag NPs-AG-CH-IL sols to room
temperature resulted in high conductivity and high mechanical strength
nanocomposite ionogels. The structure, stability and physiochemical properties
of composite materials and nanocomposites were characterized by several
analytical techniques, such as Fourier transform infrared (FTIR), CD
spectroscopy, differential scanning colorimetric (DSC), thermogravimetric
analysis (TGA), gel permeation chromatography (GPC), and scanning electron
micrography (SEM). The result shows that composite materials have good thermal
and conformational stability, compatibility and strong hydrogen bonding
interactions between AG-CH complexes. Decoration of Ag NPs in composites and
ionogels was confirmed by UV-Vis spectroscopy, SEM, TEM, EDAX and XRD. The
mechanical and conducting properties of composite ionogels have been
characterized by rheology and current-voltage measurements. Since Ag NPs show
good antimicrobial activity, Ag NPs -AG-CH composite materials have the
potential to be used in biotechnology and biomedical applications whereas
nanocomposite ionogels will be suitable as precursors for applications such as
quasi-solid dye sensitized solar cells, actuators, sensors or electrochromic
displays.
