Nanocellulose properties and applications in colloids and interfaces

• Published in: Current opinion in colloid & interface science Vol. 19; no. 5; pp. 383 - 396
• Main Authors: Salas, Carlos, Nypelö, Tiina, Rodriguez-Abreu, Carlos, Carrillo, Carlos, Rojas, Orlando J.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.10.2014
• Subjects: acid hydrolysis; aerogels; Anisotropic particles; Assemblies; cell walls; Cellulose; cellulose microfibrils; Cellulose nanocrystals; Cellulose nanofibrils; Colloids; Construction; Density; emulsions; fiber cells; Fibers; Foams; Nanocellulose; nanocrystals; Nanoparticles; Nanostructure; optical isomerism; Self-assembly; surface area; Walls; Nanoparticles; Nanocellulose; Self-assembly; Cellulose nanofibrils; Anisotropic particles; Cellulose nanocrystals
• ISSN: 1359-0294; 1879-0399
• DOI: 10.1016/j.cocis.2014.10.003

In this review we introduce recent advances in the development of cellulose nanomaterials and the construction of high order structures by applying some principles of colloid and interface science. These efforts take advantage of natural assemblies in the form of fibers that nature constructs by a biogenetic bottom-up process that results in hierarchical systems encompassing a wide range of characteristic sizes. Following the reverse process, a top-down deconstruction, cellulose materials can be cleaved from fiber cell walls. The resulting nanocelluloses, mainly cellulose nanofibrils (CNF) and cellulose nanocrystals (CNC, i.e., defect-free, rod-like crystalline residues after acid hydrolysis of fibers), have been the subject of recent interest. This originates from the appealing intrinsic properties of nanocelluloses: nanoscale dimensions, high surface area, morphology, low density, chirality and thermo-mechanical performance. Directing their assembly into multiphase structures is a quest that can yield useful outcomes in many revolutionary applications. As such, we discuss the use of non-specific forces to create thin films of nanocellulose at the air–solid interface for applications in nano-coatings, sensors, etc. Assemblies at the liquid–liquid and air–liquid interfaces will be highlighted as means to produce Pickering emulsions, foams and aerogels. Finally, the prospects of a wide range of hybrid materials and other systems that can be manufactured via self and directed assembly will be introduced in light of the unique properties of nanocelluloses. [Display omitted] •Nature constructs natural assemblies by a biogenetic bottom-up process.•Top-down deconstruction is used to engineer cellulose nanomaterials from fiber cell walls.•Nanocelluloses have appealing intrinsic properties: strength, morphology, low density, chirality, etc.•Numerous opportunities exist for assemblies at the liquid–liquid, air–liquid and solid–liquid interfaces•Recent advances in resulting cellulose nanomaterials are reviewed.