Cellulose swelling and dissolution as a tool to study the fiber structure

The swelling and dissolution mechanisms of cotton or wood fibers cellulose fibers in aqueous (as N - methylmorpholine N-oxide and water mixtures, or soda solutions) or in ionic liquids are studied. Some cellulose samples treated by enzyme mixtures are investigated too. Six dissolution modes are found and detailed. The swelling (homogeneous or by ballooning) is the precursor of the dissolution step, which occurs by bursting of balloons or by unwinding of cellulose structure. These phenomena are due to morphological structure of the native cellulose fibres. The balloons formation reveals the elasticity and semi - permeability of primary and S1 layers, which play the role of a membrane. The intern stresses frozen during biosynthesis are revealed by unwinding. The study allows the influence of the solvent quality on the dissolution mechanism.