Method for preparing surface-functionalized cellulose nanospheres

A technology of surface functionalization and cellulose, which is applied in the field of preparation of cellulose nanocrystals, can solve the problems of non-uniform size of cellulose nanospheres, long reaction time of enzymatic hydrolysis, and reduced thermal stability, so as to shorten the preparation cycle and prepare The effect of mild and easy-to-control conditions and narrow distribution

Inactive Publication Date: 2014-06-25
ZHEJIANG SCI-TECH UNIV
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  • Abstract
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  • Application Information

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Problems solved by technology

[0003] The current preparation method of cellulose nanospheres was first reported by Cheng's research group (Wang N, Ding EY, Cheng RS. Preparation and liquid crystalline properties of spherical cellulose nanoparticles. Langmuir 2008;24:5-8.), they used The cellulose nanospheres are obtained by treating microcrystalline cellulose with a mixed acid of inorganic strong acid, centrifuging for many times, dialysis, and vacuum drying; the disadvantage is that the preparation process is complicated and the post-treatment is cumbersome
Later, researchers used enzymatic hydrolysis, sulfuric acid method and sulfuric acid mixed acid method to prepare cellulose nanospheres, but these methods have some problems, such as long reaction time of enzymatic hydrolysis, low yield, comp

Method used

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  • Method for preparing surface-functionalized cellulose nanospheres

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Embodiment 1

[0024] Add the microcrystalline cellulose fiber into the calcium hydroxide solution with a concentration of 1mol / L, swell at room temperature for 4 h, wherein the mass-volume ratio of the fiber to the lye is 0.02 g / mL, filter the above mixed solution, and wash the product with water several times , until PH=7, at 50 o C and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 2 mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution was 0.008 g / mL, put the above solution into the reaction vessel, at 65 oUnder the temperature of C, react for 6 h under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product is naturally cooled, add 2 mol / L ammonia solution, adjust the pH value of the solution to 7, and obtain a uniformly distributed cellulose nanosphere dispersion. Then the dispersion liquid...

Embodiment 2

[0026] Add the lyocell fibers to a sodium hydroxide solution with a concentration of 2 mol / L, and swell at room temperature for 6 h, wherein the mass-volume ratio of the fibers to the alkali solution is 0.1 g / mL, filter the above mixed solution, and wash the product with water for several times until the pH =7 at 75 o C and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and formic acid with a concentration of 5 mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution was 0.016 g / mL, put the above solution into the reaction vessel, at 75 o C, reacted for 8 h under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was naturally cooled, 3 mol / L hydrazine hydrate was added, and the pH value of the solution was adjusted to 7 to obtain a uniformly distributed cellulose nanosphere dispersion. Then the dispersion liquid was c...

Embodiment 3

[0028] Add the waste cotton fiber to the barium hydroxide solution with a concentration of 1mol / L, and swell at room temperature for 4 h, wherein the mass-volume ratio of the fiber to the lye is 0.04 g / mL, filter the above mixed solution, and wash the product several times until PH=7, at 65 o C and dried to constant weight; then the above product was added to the mixed acid solution obtained by mixing hydrochloric acid and acetic acid with a concentration of 7 mol / L and a ratio of 1:9 to fully infiltrate, wherein the mass volume ratio of fiber to acid solution was 0.012 g / mL, put the above solution into the reaction vessel, at 70 o C, reacted for 7 h under stirring with a tetrafluoroethylene stirring paddle, after the above reaction product was naturally cooled, 1mol / L sodium hydroxide solution was added to adjust the pH value of the solution to 7, and a uniformly distributed cellulose nanosphere dispersion was obtained. Then, the dispersion was centrifuged and washed thr...

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Abstract

The present invention relates to a method for preparing surface-functionalized cellulose nanospheres, which comprises (1) adding cellulosic fibers to the alkali liquor, swelling, filtering the solution, washing the product with water for several times until pH is 7, and drying to constant weight; (2) then adding the above product into mixed acid for fully infiltrating, reacting the above solution under stirring for 2-10 hours at 60-90 DEG C, naturally cooling the reaction products, adding an alkali solution until the pH of the solution is adjusted to 7 to obtain a dispersion liquid of cellulose nanospheres, then centrifuging the dispersion liquid, washing with water for three times, carrying out ultrasonic treatment, and then carrying out freeze drying to constant weight to obtain a cellulose nanospheres. The preparation method has advantages of low raw material cost, simple preparation process and mild preparation conditions; the surfaces of the cellulose nanospheres have functional groups, so that thermal stability and hydrophobicity are improved, self-aggregation is reduced, dispersion is easy, size is small, distribution is narrow, control is easy, specific surface area is large, reactivity is high and etc.

Description

technical field [0001] The invention belongs to the field of preparation of cellulose nanocrystals, in particular to a preparation method of surface functionalized cellulose nanospheres. Background technique [0002] Due to the high aspect ratio, excellent mechanical properties, fully degradable and renewable properties of cellulose nanowhiskers or nanocrystals, their use has been proposed as a main component for the development of new inexpensive biomaterials (Sturcova A, Davies GR , Eichhorn SJ. Elastic modulus and stress-transfer properties of tunicate cellulose whiskers. Biomacromolecules 2005; 6: 1055-1061.). Cellulose nanocrystals have some additional advantages for biopolymers due to their non-abrasive processability, allowing high filler content and significant cost savings, including their extensive resources, if compared to other inorganic reinforcing fillers Availability, low energy consumption, easy recycling including combustion, high sound attenuation and fair...

Claims

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Application Information

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IPC IPC(8): C08J3/16C08L1/20C08L1/16C08B7/00C08B5/00
Inventor 余厚咏严晨峰姚菊明
Owner ZHEJIANG SCI-TECH UNIV
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