Cellulose and other polysaccharides surface properties and their characterisation

This chapter presents comprehensive information about surface phenomena of cellulose and polysaccharide surfaces. It comprises the necessary description of cellulose moieties, of measuring methods and recent results of polysaccharides surface modification and characterisation. The first part describes different cellulose moieties starting with model cellulose surfaces, allowing basic studies of interface phenomena at well-defined surfaces and provides general information and deepens the understanding of interaction processes. It is extended to nanocrystalline cellulose and further to technological cellulose products. The importance of structural information as the degree of crystallinity and amorphous regions and the voids size is briefly mentioned in the second part. The state-of-the-art measurement methods providing information about the chemical surface composition, the surface structure and roughness are discussed. The possibilities to measure thickness of cellulose layers using optical and other methods are presented. Particular attention is given to those methods providing information about polysaccharide surface at the solid/liquid interface, the surface energy, the quantification of surface charge, the interaction ability and the quantitative determination of adsorbed mass. A presentation of molecular modelling methods shows the ability of computational chemistry to describe such complex systems. Molecular mechanics force field, semiempirical and ab initio methods are described. In the third part, recent results of surface modification, their characterisation and interaction abilities are presented. This comprises cellulose nanocrystals and nanocompounds, the stabilising effect of polysaccharides and the creation of functional groups on technical and biocompatible cellulose materials. Finally, results of molecular dynamics simulations of the polysaccharide–water interface are presented estimated by semiempirical and ab initio methods.