Properties and application prospects of carboxylated modified nanocellulose

Carboxylated modified Nanocellulose (CNCF) is a functional nanomaterial that introduces carboxylated (–COOH) groups on the cellulose surface by chemical modification. This material has the high strength, high specific surface area and good dispersion of nanocellulose, and imparts better hydrophilicity, reactive activity and interface binding ability under the action of surface carboxyl groups. This article will introduce the preparation methods, key properties, typical application fields and future development trends of carboxylated modified nanocellulose, and provide reference for scientific researchers and related companies.

Introduction to carboxylated modified nanocellulose

Nanocellulose is a renewable green material derived from natural cellulose, with advantages such as high crystallinity, lightweight, high strength, and degradability. However, the original nanocellulose has problems such as single surface functional groups, insufficient dispersion, and limited compatibility with other materials. Through carboxylation modification, a large number of –COOH functional groups can be introduced into the cellulose molecular chain, greatly improving its chemical reactivity and surface energy, so that it can show better performance in composite materials, coatings, adhesives and other applications.

Preparation principle

Common carboxylation modification methods include:

1. TEMPO oxidation method : The C6-position hydroxyl group of cellulose is used to selectively oxidize the C6-position hydroxyl group of cellulose, which has the characteristics of mild conditions and efficient selectivity.

2. Chloroacetic acid esterification method : Carboxymethyl groups are introduced by reacting chloroacetic acid with cellulose hydroxyl groups under basic conditions.

3. Ammonium persulfate oxidation method : Use the strong oxidation properties of ammonium persulfate to form carboxyl groups on the surface of cellulose.

Performance Advantages

• Improved dispersion : The negatively charged carboxyl group on the surface significantly enhances the stable dispersion in the aqueous phase and polar systems.

• Enhanced interface compatibility : In polymer composite materials, it can form stronger hydrogen bonds or covalent bonds with matrixes such as resins and rubbers.

• Improved reactivity : The carboxyl group acts as an active site to facilitate further grafting, cross-linking or functional modification.

• Environmental protection and renewable : with a wide range of sources, in line with the development trend of green and low-carbon.

Application areas

1. High-performance composite materials : reinforce plastics, rubbers, coatings, and enhance mechanical strength and durability.

2. Water treatment and environmental governance : Carboxylic groups can adsorb heavy metal ions and organic pollutants and are used in sewage treatment.

3. Pharmaceutical and biomaterials : As drug sustained-release carriers and tissue engineering scaffolds, it has good biocompatibility.

4. Functional coatings and films : Improve barrier properties and antibacterial properties in food packaging.

5. Energy storage materials : used in supercapacitors and battery separators to improve conductivity and cycling stability.

Industry prospects

With the rapid growth of demand for green degradable materials, carboxylated modified nanocellulose, as a new material that combines environmental protection and high performance, has a broad market space in new energy, packaging, biomedicine, environmental governance and other industries. In the future, the in-depth development of its large-scale preparation technology and functional applications will promote its industrial application in the field of high-end materials.