A kind of cellulose type II nanocrystalline particle and its preparation method and application

Abstract

The invention relates to the field of cellulose nanocrystals, in particular to a cellulose II type nanocrystal particle and its preparation method and application. The crystallinity of the cellulose II type nano crystal particles is more than or equal to 80%, the number average molecular weight is 1200-2500, and the molecular weight distribution coefficient Mw / Mn is less than or equal to 1.30. The preparation method of the cellulose type II nanocrystalline particles includes: first performing amorphization and reconstruction of the cellulose raw material, recrystallization and acid hydrolysis, and the crystallization and acid hydrolysis can be carried out under low-concentration acidic conditions, and the cellulose nanocrystalline material is realized. efficient, clean production and quality control. The cellulose type II nanocrystalline particles prepared by the method have high crystallinity, small molecular weight, narrow molecular weight distribution, narrow size distribution, clear surface conformation and great surface chemical modification potential, and can be used for catalyst carrier, composite material reinforcement and other purposes.

Description

Technical field: [0001] The invention relates to the field of cellulose nanocrystals, in particular to a cellulose II type nanocrystal particle and its preparation method and application. Background technique: [0002] Cellulose nanocrystals are high-end cellulose materials that have been extensively studied in recent decades. The unique physical, chemical and biological properties such as surface modification have broad application prospects in materials, light industry, chemical industry, food, medicine, health care, environmental protection, information, energy and other fields. [0003] At present, there are two crystal structures of cellulose nanocrystals, one is cellulose type I, and the other is cellulose type II. Existing cellulose type II nanocrystals are mainly prepared by the following three methods: method one, mercerizing the cellulose raw material, and then carrying out acid-catalyzed hydrolysis treatment to obtain spherical cellulose type II nanocrystals with...

AI Technical Summary

Problems solved by technology

The use of high multiples and high concentrations of strong acids not only causes severe corrosion of equipment, but also produces a large amount of industrial wastewater that needs to be treated harmlessly—each quality nanocrystalline product will generate hundreds or even thousands of times, or even tens of thousands of The high cost of the harmless treatment of these industrial wastewater is undoubtedly an important reason for the abnormally high production cost of the existing cellulose nanocrystals.

[0005] Second, the surface properties of cellulose nanocrystals are difficult to control

Faced with this polycrystalline structure, even if the size and aspect ratio of cellulose nanocrystals can be controlled by precisely controlling the material ratio, temperature, acidity, time and other operational conditions, the crystallinity and crystallinity of the product cannot be accurately controlled. chemical defects, which inevitably lead to the uncontrollability of the surface properties of nanocrystals

[0006] It has been nearly 70 years since the advent of cellulose nanocrystals, and it has also shown promising application prospects. However, it still faces the dual challenges of preparation cost and product quality, so that the application of cellulose nanocrystals still remains at the research level today.

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