Preparation of cellulosic soft and composite materials using ionic liquid media and ion gels

Ionic liquids (ILs) are powerful media for the modification and functionalization of cellulose. This review article discusses the preparation of cellulosic soft and composite materials through the dissolution and gelation of cellulose with ILs. Based on the fact that the IL, 1-butyl-3-methylimidazolium chloride (BMIMCl) forms a cellulosic ion gel, the gel formation process has been employed to prepare a variety of cellulosic materials, of which the following are examples. (1) The gel is converted into a thermoplastic composite film. (2) The cellulose/BMIMCl composite film is reinforced with self-assembled chitin nanofibers. (3) Solutions of cellulose in BMIMCl are converted into hydrogels, organogels, or organic solutions. (4) Binary ion gels of cellulose with other natural polysaccharides, such as starch, chitin, and hydrocolloid polysaccharides, are fabricated using BMIMCl and other ILs. (5) The binary ion gels are converted into composite materials, such as films and fibers.