nanocellulosic

Nanocellulosic refers to nanoscale cellulose structures derived from natural cellulose. It encompasses several forms, including cellulose nanocrystals (CNC), cellulose nanofibers or nanofibrillated cellulose (CNF), and bacterial nanocellulose (BNC). CNCs are rod-like particles produced by acid hydrolysis that removes amorphous regions, CNFs are entangled networks created by mechanical fibrillation often aided by chemical pretreatment, and BNC is synthesized extracellularly by certain bacteria.

Production methods vary by form. CNCs are typically produced through acid hydrolysis, followed by purification and redispersion. CNFs are generated by mechanical methods such as high-shear refining or homogenization, sometimes combined with chemical oxidation (for example TEMPO-mediated) to facilitate fibrillation. BNC is produced via fermentation under controlled conditions, then purified to remove residual cells and culture medium. Surface modification, including esterification, oxidation, or grafting, enables tuning of hydrophilicity, charge, and compatibility with polymers.

Key properties include high mechanical strength and stiffness, low density, and a high aspect ratio, which contribute to effective reinforcement in composites. Nanocellulosic materials exhibit large surface areas, good barrier properties, and biocompatibility, with surfaces that are initially hydrophilic but can be chemically modified to suit hydrophobic matrices. Films and gels made from nanocellulosic materials can be highly transparent and flexible, depending on processing.

Applications span bio-based composites, packaging films with improved barrier properties, rheology modifiers for paints and cosmetics, inks and coatings, and biomedical uses such as wound dressings and tissue engineering scaffolds. Challenges include production cost, dispersion in nonpolar matrices, moisture sensitivity, and variability due to source material and processing conditions, which can affect reproducibility and regulatory considerations.