Introduction to cellulose nanofiber filaments

Cellulose nanofiber filaments (CNF) , also known as cellulose microfiber filaments (MFC), are nanoscale fibers decomposed from natural cellulose through mechanical or chemical treatment. They have unique physical and chemical properties and are widely used in various fields. The following is a detailed introduction to cellulose nanofibers:

• Preparation method

1. High-pressure homogenization: The cellulose suspension is repeatedly processed through a high-pressure homogenizer to depolymerize the cellulose fibers into nano-scale fibers.

2. Grinding: Use a mill to repeatedly grind the cellulose suspension, and depolymerize the cellulose fibers by mechanical force.

3. Ultrasonic treatment: Use the cavitation of ultrasonic waves to disperse and disposize cellulose fibers.

4. TEMPO oxidation: Use TEMPO (2,2,6,6-tetramethylpiperidine oxide) and an oxidant (such as sodium hypochlorite) to oxidize cellulose, so that carboxyl groups are introduced on the surface of the cellulose to enhance its dispersion.

5. Enzyme treatment: Use cellulase to partially hydrolyze cellulose, reduce its molecular weight and crystallinity, and promote mechanical depolymerization.

• Physical characteristics

1. Size: The diameter of cellulose nanofibers is usually between 10-100 nanometers, and the length can reach a few microns to tens of microns.

2. Morphology: Long fibrous shape with high aspect ratio.

3. Surface chemistry: The fiber surface contains a large amount of hydroxyl groups, and different functional groups can be introduced through chemical modification.

• Performance and Advantages

1. High mechanical properties: It has high strength and high modulus, which can significantly enhance the mechanical properties of composite materials.

2. Biocompatibility and biodegradability: It is derived from natural cellulose, has good biocompatibility and biodegradability , and is suitable for biomedical materials.

3. High specific surface area: The nanoscale size makes it have a higher specific surface area, which is conducive to the composite and interface interaction with other materials.

4. Excellent rheological properties: It exhibits unique rheological properties in suspension, suitable for thickeners and stabilizers.

• Application areas

1. Composite material: Added as a reinforcement to polymer-based composite material to improve the mechanical properties, thermal stability and barrier properties of the material.

2. Paper and packaging materials: used to modify paper and packaging materials to improve their strength, water resistance and gas barrier properties.

3. Films and coatings: Prepare high-strength, transparent films and coatings for flexible electronic devices and food packaging.

4. Medical materials: Used to prepare biocompatible and biodegradable medical materials, such as tissue engineering stents, drug delivery systems and wound dressings.

5. Cosmetics and personal care products: Used as thickeners and stabilizers to improve the texture and stability of the product.

• Prospects and Challenges

1. As a new nanomaterial, cellulose nanofibers have wide application prospects, but they also face some challenges in the commercialization process:

2. Production cost: The cost of mass production of CNF is relatively high, and it is necessary to develop efficient and low-cost preparation processes.

3. Dispersion and uniformity: The dispersion and uniformity in different substrates have a significant impact on their performance, and it is necessary to optimize dispersion technology and surface modification methods.

4. Standardization and quality control: formulate standardized production and testing methods to ensure the consistency and reliability of products.

Overall, cellulose nanofibers have unique properties and wide application potential. With the advancement of technology and optimization of process, their application areas will continue to expand.