Introduction and application of carboxylated nanocellulose

Carboxylated Nanocellulose is one of the hot topics in the research and industrial application of nanomaterials in recent years It uses natural cellulose as raw materials and introduces carboxyl ( . –COOH ) functional groups on the surface of nanocellulose through chemical modification (such as TEMPO oxidation, carboxymethylation treatment, etc.) , thereby significantly improving the dispersion, reactive activity and complex properties of the material with other polymer materials.

1. Principles of preparation of carboxylated nanocellulose

Due to the limited number of surface hydroxyl groups in traditional nanocellulose, there is certainly insufficient interfacial compatibility. Carboxylation modification makes it more hydrophilic and chemically active by introducing carboxylic groups on the surface of the cellulose molecular chain:

TEMPO selective oxidation method : Using the TEMPO/NaBr/NaClO system as the catalytic system, the C6- position hydroxyl group of cellulose is oxidized to the carboxy group.

Carboxymethylation method : Carboxymethyl groups are introduced on the surface of cellulose molecules through etherification reaction to improve swelling and dispersibility.

2. Material characteristics

Carboxylated nanocellulose has the following advantages in terms of structure and performance:

Particle size : generally 5-50 nm in diameter and can reach several microns in length;

Surface characteristics : with a large number of carboxyl groups, high Zeta potential, and strong dispersion stability;

Mechanical properties : The enhancement effect is obvious, which can significantly improve the tensile strength and toughness of composite materials;

Chemical reactivity : The carboxyl group can undergo cross-linking or complexing reaction with amine groups, hydroxy groups, metal ions, etc.

III. Application areas

With the promotion of green materials and sustainable development concepts, the application of carboxylated nanocellulose is constantly expanding:

Food packaging : As a base material for biodegradable barrier film, it improves oxygen barrier properties and replaces traditional plastic packaging.

Pharmaceutical and biomaterials : used in drug sustained-release carriers, tissue engineering stents, wound dressings, and has good biocompatibility.

Functional composite materials : Compounded with polymers and inorganic particles to prepare conductive films, sensors and functional coatings.

Water treatment : The surface carboxyl group can be combined with heavy metal ions and is suitable for adsorbents and purification materials.

4. Industry prospects

According to market research data, the global nanocellulose market size is developing at an annual compound growth rate of more than 20% . In particular, carboxylated nanocellulose , due to its better dispersion and modification potential, is considered an important direction for the next generation of high-performance green materials. In the future in the fields of , larger-scale industrial applications are expected to be achieved medical and health, biodegradable packaging, new energy energy storage , etc.