Ion-interactions as driving force in polysaccharide assembly.

The structure of cellulose is characterised by extensive non-covalent interactions. Recent discussions suggest that hydrophobic interactions between polymer chains also play a significant role in governing cellulose solubility. Surprisingly in almost all cellulose shaping processes, chemical systems or solvents are applied, which base on melts or solutions of charged molecules. Ionic interactions play a significant role in the shaping and modification of cellulose based materials. Dependent on the systems used different principles govern the processes and define the results, e.g. formation of associates with alkali hydroxides, ion-exchange reactions to selectively bind multivalent ions at carboxylic groups, adsorption of dissolved polymers through surface charge neutralisation or metal complex formation, where cellulose takes the role of a polymer ligand system. Presence of charged compounds takes a significant role in cellulose swelling and dissolution, but also directs reassembly of polysaccharide material to solid three-dimensional structures.