A facile preparation of gel materials from a solution of cellulose in ionic liquid

This paper reports a facile preparation of a flexible gel material from a solution of cellulose (15% w/w) in an ionic liquid of 1-butyl-3-methylimidazolium chloride by keeping it at room temperature for 7 days. Elemental analysis data indicated that the obtained gel material was composed of cellulose, the ionic liquid, and water. Both XRD and TGA results suggested that crystalline structure of cellulose was largely disrupted in the material. However, the existence of non-crystalline aggregates was assumed by the XRD data of the material. The gel material was probably obtained by the formation of cellulose aggregates in the solution, attributed to the gradual absorption of water. When the material was heated at 120 °C, it became soft, and converted into a fluid at 150 °C. By keeping the soft material at room temperature for 2 days, a gel material was regenerated, which was more transparent compared with the original material.