CN-122011497-A - Aramid nanofiber-cellulose composite aerogel and preparation method and application thereof

Abstract

The invention discloses an aramid nanofiber-cellulose composite aerogel and a preparation method and application thereof, wherein the preparation method comprises the steps of respectively putting aramid fibers and cellulose into a solvent containing organic alkali to obtain an aramid nanofiber dispersion liquid and a cellulose dispersion liquid; mixing the aramid nanofiber dispersion liquid and the cellulose dispersion liquid to obtain a composite dispersion liquid, and gelling, solvent replacing and drying the composite dispersion liquid to obtain the aramid nanofiber-cellulose composite aerogel. The preparation process is simple and easy to implement, the obtained composite aerogel has extremely low apparent density, is adjustable at a density of 5-500mg/cm 3 , has high porosity, excellent mechanical property and low heat conductivity coefficient, and has wide application prospects in the fields of mechanical compression, thermal management, sound absorption and noise reduction, environmental management, electronic information and the like.

Inventors

• HU PEIYING
• WANG BINHAO
• CHEN FENGXIANG
• Wei Quanru
• HUANG ZIXI

Assignees

• 武汉纺织大学

Dates

Publication Date

20260512

Application Date

20260410

Claims (6)

1. 1. The preparation method of the aramid nanofiber-cellulose composite aerogel is characterized by comprising the following steps of: respectively placing aramid fiber and cellulose into a solvent containing organic alkali to obtain an aramid nanofiber dispersion liquid and a cellulose dispersion liquid; Mixing the aramid nanofiber dispersion liquid and the cellulose dispersion liquid to obtain a composite dispersion liquid; Gelatinizing the composite dispersion liquid, replacing a solvent and drying to obtain the aramid nanofiber-cellulose composite aerogel; the mass fraction of the aramid nanofiber in the aramid nanofiber dispersion liquid is 0.1-30wt%, and the mass ratio of the aramid nanofiber to the organic base is 1-20:20; the mass fraction of cellulose in the cellulose dispersion liquid is 0.1-30wt%, and the mass ratio of cellulose organic alkali is 0.1-2:2-6; The volume ratio of the aramid nanofiber dispersion liquid to the cellulose dispersion liquid is 1-9:9-1; the organic base comprises at least one of an organic amine and a hydrate of the organic amine; the organic amine comprises at least one of tetrabutylammonium fluoride, tetrabutylammonium chloride, tetrabutylammonium bromide, tetraethylammonium chloride and tetraethylammonium fluoride; the solvent comprises at least one of dimethyl sulfoxide, sulfolane, diethyl sulfone and ethyl methyl sulfone.
2. 2. The method of preparing an aramid nanofiber-cellulose composite aerogel according to claim 1, wherein the aramid fibers comprise at least one of waste aramid, aramid 1414, aramid 1313 and heterocyclic aramid; The waste aramid fibers comprise at least one of waste aramid fibers 1414, waste aramid fibers 1313 and waste hybrid aramid fibers.
3. 3. The method of preparing an aramid nanofiber-cellulose composite aerogel according to claim 1, wherein the cellulose comprises at least one of cotton fiber, microcrystalline cellulose, and carboxymethyl cellulose.
4. 4. A method for preparing an aramid nanofiber-cellulose composite aerogel according to any one of claims 1 to 3, wherein the aramid nanofiber dispersion and the cellulose dispersion are obtained by stirring the respective mixtures at a rotation speed of 800 to 1500r/min for 2 to 5 hours.
5. 5. An aramid nanofiber-cellulose composite aerogel obtained by the preparation method according to any one of claims 1 to 4.
6. 6. Use of the aramid nanofiber-cellulose composite aerogel according to claim 5 in the fields of mechanical compression, thermal management, sound absorption and noise reduction, environmental management, electronic information.

Description

Aramid nanofiber-cellulose composite aerogel and preparation method and application thereof Technical Field The invention relates to the technical field of porous aerogel, in particular to an aramid nanofiber-cellulose composite aerogel and a preparation method and application thereof. Background Aerogel is a three-dimensional nano porous material with ultrahigh specific surface area, low density and a communication pore structure, and has wide application prospect in the fields of heat insulation, adsorption, separation, energy storage, buffering, filtration and the like. However, although the traditional inorganic aerogel (such as silica aerogel) has excellent thermal performance and surface characteristics, the problems of high brittleness, insufficient mechanical performance, limited processability, poor wet heat resistance and the like generally exist, and the long-term stable application of the traditional inorganic aerogel under complex working conditions is severely restricted. Aramid fibers (Aramid Nanofibers, ANFs) have been widely used in recent years for constructing high-performance aerogel structures due to their high strength, high modulus, excellent high temperature resistance and chemical stability. However, ANFs mainly depend on hydrogen bonds and Van der Waals force to form a network structure, so that structural collapse is easy to occur in wet processing and drying processes, and meanwhile, the dispersion stability of the aerogel is highly sensitive to a solvent system, so that the prepared aerogel often has the problems of unstable pore structure, insufficient mechanical property, difficult forming and the like. Cellulose is used as a natural polymer material which has wide sources, is renewable and has good biocompatibility, and because the molecular chain of the cellulose is rich in hydroxyl groups, the cellulose can realize effective crosslinking through hydrogen bonding, so that the structural stability of aerogel is improved to a certain extent, and the cellulose is an excellent mechanical reinforcing material. Based on the characteristics, researchers try to compound aramid fibers with cellulose so as to have excellent mechanical properties of the aramid material and processing advantages of the cellulose material. For example, the process reported by Wang et al in "Thermal insulating, light-weight and conductive cellulose/aramid nanofibers composite aerogel for pressure sensing" requires about one week of stripping treatment of the aramid fibers and compounding with cellulose after colloid ANFs is prepared to obtain an ANF/cellulose composite aerogel. The preparation period of the method is too long, time and effort are consumed. Liu et al report "3D-printed shapeable hybrid Nanocellulose/aramid nanofiber aerogels for thermal insulation of portable electronics" on a method for preparing aramid fiber/cellulose aerogel by 3D printing, but aramid fiber and cellulose dispersion liquid of the method are prepared by different solvents, and suspension liquid is formed after water dispersion for printing to prepare aerogel, so that the whole method is long in time consumption and is not beneficial to large-scale preparation. In addition, patent CN201911358518.1 reports a preparation method of aramid fiber/cellulose aerogel, but adopts a suspension system and introduces an external cross-linking agent, the preparation process is complex, and the requirements of high efficiency and simplified preparation are difficult to meet. However, the prior art has a plurality of defects, and is mainly characterized in that (1) the stripping process of the traditional solvent system (such as DMSO and KOH, naOH or potassium tert-butoxide) on the aramid fiber takes longer time, the preparation period is usually Zhou Ji, (2) the synchronous dissolution of the aramid fiber and the cellulose is difficult to realize by the traditional solvent system, multi-step and step treatment is usually required, the process route is long, and (3) the traditional preparation flow is highly sensitive to the dispersion uniformity and the gel rate, the process condition is harsh, and the large-scale processing property is poor. Therefore, there is a need to develop a solvent system capable of simultaneously dissolving and dispersing cellulose and aramid fibers, and constructing a composite dispersion liquid with stable structure and uniform dispersion so as to prepare the aramid fiber-cellulose composite aerogel with excellent structure stability and excellent mechanical properties. The method has important significance for preparing the aerogel with high mechanical property, recycling and reusing the aramid fiber and the cellulose and applying the aramid fiber and the cellulose to high values. Disclosure of Invention The invention aims to develop a solvent system capable of simultaneously dissolving and dispersing cellulose and aramid fiber, and construct a composite dispersion liquid with stable structure and uniform di