With the rapid development of green materials and sustainable technologies, nanocellulose has gradually become an important research and application target in the field of functional materials due to its advantages such as wide sources, renewable nature, and good biocompatibility. Among them, carboxylated nanocellulose (Carboxylated Nanocellulose) has significantly expanded the dispersion, reactivity and application boundaries of nanocellulose by introducing carboxyl functional groups on the surface of cellulose molecules, and has become one of the key directions of current industrialization and scientific research. 1. Structural characteristics of carboxylated nanocellulose Carboxylated nanocellulose usually introduces a -COOH group on the C6 hydroxyl group of the cellulose molecular chain through chemical modification. This structural change makes the surface of nanocellulose carry a stable negative charge, which can form a strong electrostatic repulsion in a water system, thereby building a more uniform and stable nanofiber network structure. with unmodified nanocellulose

——Homologous materials, different scales, different application values ​​Against the background of the continuous development of green materials and bio-based functional materials, cellulose-derived materials are widely used in fields such as daily chemicals, pesticides, coatings, medicines and composite materials. Among them, nanocellulose and microcrystalline cellulose (MCC) are two types of materials with a high degree of industrialization at present. Although the two are derived from natural cellulose, they are essentially different in structural scale, performance and application direction. This article will systematically compare nanocellulose and microcrystalline cellulose from the perspective of structure, performance and application, providing a reference for material selection. 1. The sources of raw materials are the same, but the structural processing methods are different. Both nanocellulose and microcrystalline cellulose use natural plant cellulose as raw materials, such as wood pulp, cotton pulp, etc., but their preparation ideas are completely different: microcrystalline cellulose mainly removes amorphous elements from cellulose through acid hydrolysis.

1. What is nanocellulose? Nanocellulose is a nanoscale material prepared from natural cellulose through physical, chemical or biological methods. The typical size ranges from a few nanometers to tens of nanometers, and the length can reach micron level. Depending on the structure and preparation method, common types include cellulose nanofibers (CNF), cellulose nanocrystals (CNC) and bacterial cellulose (BC). As a natural polymer material that is widely sourced, renewable and biodegradable, nanocellulose not only has environmentally friendly properties, but also exhibits excellent mechanical properties and functional designability. It is considered an important representative of the new generation of green functional materials. 2. Core performance advantages of nanocellulose 1. Ultra-high mechanical strength and toughness Nanocellulose has extremely high specific strength and specific modulus, and the theoretical strength of a single fiber can be close to the level of steel. In composite systems, the resistance of materials can be significantly improved