Nanocrystalline cellulose (NCC), also known as cellulose nanocrystals, is a nanoscale cellulose extracted from natural fibres with nanoparticle characteristics.

Structure and Properties Chemical Structure: The main component is cellulose, which is made of D-glucopyranose ring structural units connected by β-1,4 glycosidic bonds, with adjacent units rotated at an angle of 180°, and with reactive hydroxyl groups at C-2, C-3 and C-6 positions in the molecular chain.

High crystallinity: cellulose macromolecules are closely stacked, and the hydroxyl group on the molecular unit provides an opportunity for intermolecular hydrogen bonding, making it highly crystalline, showing good solvent resistance and permeability. High strength and high modulus: NCC has a modulus of elasticity of 150GPa and a tensile strength of 10,000MPa. This high strength and high modulus feature makes it a great potential for application in the field of composite material reinforcement.

Thermal stability: the thermal degradation temperature is 200℃-300℃, which is higher than some polymer matrix, adding NCC can improve the thermal stability and heat resistance of polymer and reduce the thermal expansion of polymer. Optical Properties: The film obtained by natural evaporation of NCC suspension on a specific surface is able to reflect polarized light when observed under a polarized light microscope, and the colour of the reflected light changes with the angle of incident light.

Preparation method Acid hydrolysis: commonly used inorganic acids include sulphuric acid, hydrochloric acid and phosphoric acid, etc. Sulphuric acid is the most common, which can obtain nano-microcrystalline cellulose with high crystallinity and complete crystalline structure, but a large amount of waste acid and impurities will be generated. Enzymatic method: use cellulase enzyme to selectively digest amorphous cellulose, the remaining part is cellulose crystals, the process conditions are mild, but the efficiency is low and the industrialisation cost is high.

 Mechanical method: using high shear, grinding, micro-jet and other physical methods to destroy the cell wall of higher plants, so that the nanocellulose fibres are released, without chemical reagents, but the particle size distribution is broader, the equipment is special, and the energy consumption is high.

Application Fields

Material science field: it can be used as reinforcing agent added to composite materials, such as polylactic acid composite materials, to improve the mechanical properties of the materials; it can also be used to prepare photonic crystal film with special optical properties.

 Energy field: in lithium batteries, after carbonisation, it can form a porous conductive network, which can be used as the supporting skeleton of high-capacity active materials such as silicon base, and can also optimise ion transport and inhibit the growth of lithium dendrites.

Biomedical field: with biodegradability and biocompatibility, it can be used in tissue engineering, drug delivery, etc., such as the preparation of biomedical scaffold materials.

Environmental protection field: it can be used in the treatment of printing and dyeing wastewater, etc., removing pollutants in wastewater through adsorption and other effects. Food field: it can be used in food as thickener and stabiliser to improve the texture and taste of food