Liquid Crystals and Cellulose Derivatives Composites
This chapter summarizes recently developed researches concerning cellulose derivatives composites obtained by blending of cellulose derivatives or of cellulose derivatives with different polymers, as well as by processes involving nano-particles in the cellulose derivative matrix. Knowledge and understanding of the interactions manifested in these cellulose systems constitute essential elements for the conception and optimization of novel structures. Different characterization techniques allow a more complete evaluation of the mechanisms of multicomponent systems, of their fundamental interactions, such as hydrogen bonding, and the manner in which these interactions affect the final properties. This research reveals the relation between the molecular interactions and physical properties, which represents an important challenge from both scientific and industrial perspectives. On the other hand, the chapter shows that, like many other cellulose derivatives, hydroxypropylcellulose (HPC), is the most common ether of native cellulose, whose concentrated solutions possess optical properties characteristic to cholesteric liquid crystals. In crystalline state, on one hand, these types of cellulose present specific arrangements, while, on the other, these arrangements depend on the concentration of their solutions. In cellulose derivative composites, the absence or presence of liquid crystals properties is dependent on mixture composition, solution concentration and used solvent, according to the application in biomedical or electronic domain.