Cellulose is the most abundant renewable resource in the world. Apart from the use of materials based on unmodified cellulose, such as wood and cotton, the cellulose can be extracted from its primitive resources (e.g. lignocellulosic materials) and then be processed into its derivatives via chemical, enzymatic or microbiological methods.

Cellulose is a polydisperse linear homopolymer consisting of regio- and enantioselective β-1, 4-glycosidic linked D-glucose units (e.g. anhydroglucose units, AGU, Fig.1).

Figure 1: Molecular structure of cellulose

Hydrogen bonding patterns play an important role in cellulose reactivity. A further consequence of the supramolecular structure is the insolubility of the macromolecule in common organic solvents as well as water.

Ionic liquids are the group of new organic salts which exist as liquids at a relative low temperatures (<100 °C). It has been previously shown that cellulose can be fully dissolved in hydrophilic ionic liquid, 1-allyl-3-methylimidazolium chloride (AmimCl) even at high concentrations (>45% w/w).

The series of different concentrations (5-45% w/w) of cellulose solutions in AmimCl were prepared in order to investigate the liquid crystal phase of the cellulose. When high concentrations (>35% w/w) of cellulose are dissolved in AmimCl, the liquid crystalline solutions of cellulose, which are optically anisotropic between crossed polarising filters are obtained. The morphology of the solutions was investigated by SEM analysis.

References:

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2.                                      Cowie J.M.G. et al, Macromol. Symp., 2000, 152, 107-116        

3.                                      Zhang H. et al, Macromolecules, 2005, 38, 8272-8277

4.                                      Swatloski R.P. et al, WO Pat., 03/029329, 2003