Micro-nano lignocellulose, preparation method and applications thereof

Abstract

The invention provides micro-nano lignocellulose, a preparation method and applications thereof. The micro-nano lignocelluloses contain lignin structures; lignin is bonded with cellulose through hydrogen bonds and chemical bonds. The preparation method comprises following steps: a lignin containing cellulose raw material is dispersed in a hot urea aqueous solution so as to obtain a cellulose raw material dispersion liquid; mechanical pre-treatment is adopted for peeling and grinding so as to obtain a pre-treatment product; and the pre-treatment product is subjected to high pressure homogenizing using a high pressure homogenizer so as to obtain a micro-nano lignocelluloses dispersion liquid. According to the preparation method, removing of the lignin in the lignin containing cellulose raw material is not needed, the hot urea aqueous solution is combined with mechanical pre-treatment and high pressure homogenizing so as to prepare the product; the diameter of the obtained micro-nano lignocelluloses ranges from 5 to 180nm; the length/diameter ratio is 200 or larger; the lignin content ranges from 10 to 35wt%; micro-nano cellulose performance is improved; and the application prospect is promising.

Description

technical field [0001] The invention belongs to the field of nanomaterial preparation, and relates to a micronano lignocellulose and its preparation method and application. Background technique [0002] With the continuous development of social economy, non-renewable resources such as petroleum and coal are increasingly scarce, and problems such as environmental pollution have become increasingly prominent. The application of renewable resources in various fields has attracted more and more attention. Plant fiber raw material is the most important biomass resource on the earth, and its efficient and comprehensive utilization will occupy an extremely important position in the entire biomass industry. Plant fibers are mainly composed of cellulose, lignin and hemicellulose. Cellulose is a ubiquitous and renewable resource on earth. Nanocellulose prepared from natural cellulose not only has huge specific surface area, high hydrophilicity, high Young's modulus, high strength, g...

AI Technical Summary

Problems solved by technology

Since the hard lignin is interwoven in the middle of the cellulose, it cannot be directly mechanically peeled off to prepare nanocellulose. There is no method for preparing nanocellulose with high lignin content in the current method of preparing nanocellulose.

In the prior art, it is still necessary to pretreat the plant fiber with acid, alkali or organic solvent to remove lignin and hemicellulose, and then perform mechanical peeling. The steps are cumbersome, and the acid, alkali or organic solvent used in the pretreatment process is still cause some pollution to the environment

[0005] CN 101949103A discloses a method for preparing micro-nano cellulose, which is directly prepared by plant straw, but still uses a delignification agent for delignification treatment; CN 103194027A discloses a nano-cellulose / lignin light-blocking The preparation method of the membrane obtains nano-cellulose materials with high lignin content, but in the preparation process, it is necessary to remove and extract lignin, then perform cellulose nano-processing, and then mix lignin and nano-cellulose, and the preparation process is cumbersome and complicated; CN104693464A Disclosed is a method for preparing lignocellulose-reinforced polylactic acid composite membranes, which adopts sulfuric acid hydrolysis-high-pressure homogenization method to prepare lignocellulose. Sulfuric acid is used in this process, which has a great impact on the environment

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