Cellulose nanocrystal (CNC)-inorganic hybrid systems: synthesis, properties and applications

Cellulose nanocrystal (CNC), a class of sustainable nanomaterial derived from forest and agro-biomass can serve as nature's storage for carbon dioxide. It has many attractive features, such as large specific surface area, high tensile strength and stiffness, abundance of surface hydroxyl groups, and they are also biocompatible, biodegradable and renewable. When dispersed in a polar solvent, they assemble to form multiphase or higher order structures yielding desirable optical and structural properties. They are being explored as templates for the design of a wide range of new functional nanomaterials. CNCs are excellent support for the loading of inorganic nanoparticles (e.g. Ag, Au, Pt, Pd etc.) yielding stable nano-hybrids in aqueous media. Additional surface functionalization of CNCs impart new and attractive physicochemical properties that are being exploited for application in sensors, catalysts, drug delivery vehicles, anti-microbial agents, scaffold for tissue engineering, biomarkers etc. This review provides an overview and future perspective on recent advances in the development on functional CNC-inorganic hybrids with potential applications in biomedical and chemical systems.