Cellulose high-order molecular structure

Cellulose is the most abundant compound produced photochemically by plants on Earth it s estimated that about 20 billion tonnes of cellulose is photosynthesised in nature every year. There are two types of high-ordered molecular structure in cellulose cellulose I is the native form of cellulose, with parallel glucan chains and a thermodynamically metastable form, produced by living organisms, while cellulose II, has an antiparallel glucan chain and is the more stable form. 

Solid cellulose forms a microcrystalline structure with regions of high order, i.e., crystalline regions, and regions of low order that are amorphous. Naturally occurring cellulose (cellulose I) crystallizes monoclinic sphenodic. The molecular chains lay in the fiber direction ... 

By exploiting the use of recombinant DNA technology it is possible to redesign the molecular structure of rPBPs in order to combine bioactive domains and in this way achieve the creation of highly customable functionalized materials. Materials with antimicrobial properties can be obtained by fusion with antimicrobial peptides for biodefensive purposes [36]. By combining the rPBPs with UV protective peptides it is possible to create a photo-protective material for the prevention of photoaging in human skin [36]. The incorporation of cellulose binding peptides... 

Rather recently, we have studied the solid-state structure of various polymers, such as polyethylene crystallized under different conditions [17-21], poly (tetramethylene oxide) [22], polyvinyl alcohol [23], isotactic and syndiotactic polypropylene [24,25],cellulose [26-30],and amylose [31] with solid-state high-resolution X3C NMR with supplementary use of other methods, such as X-ray diffraction and IR spectroscopy. Through these studies, the high resolution solid-state X3C NMR has proved very powerful for elucidating the solid-state structure of polymers in order of molecules, that is, in terms of molecular chain conformation and dynamics, not only on the crystalline component but also on the noncrystalline components via the chemical shift and magnetic relaxation. In this chapter we will review briefly these studies, focusing particular attention on the molecular chain conformation and dynamics in the crystalline-amorphous interfacial region. 

Cellulose is one of the most important aixl most abundant natural polymers. This circumstance and certain specific features of its molecular and supermolecular structures (the linear, strictly regular structure of the macromolecules, the great rigidity dF tte polymeric chains, the possibility of formation elements of the supermolecular structure havii a high d ree of ordering, i.e. crystallites, etc.) are the factors that have stimulated extensive work on the chemistry, physicochemistry and technology of cellulose and its derivatives. 

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