Preparation method of cellulose nanocrystal/graphene/polyvinyl alcohol aerogel

A technology of nanocrystals and polyvinyl alcohol, applied in airgel preparation, chemical instruments and methods, colloid chemistry, etc., can solve the problem of low mechanical properties of cellulose nanocrystal airgel, difficult control of airgel structure, and preparation process Complicated problems, to achieve good application prospects, improve biocompatibility, good adsorption effect

CN108579626AInactive Publication Date: 2018-09-28NANJING FORESTRY UNIV +1
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Patent Information

Authority / Receiving Office
CN · China
Current Assignee / Owner
Publication Date
2018-09-28
Estimated Expiration
Not applicable · inactive patent

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Abstract

The invention relates to a preparation method of cellulose nanocrystal / graphene / polyvinyl alcohol ternary composite enhanced aerogel. The preparation method comprises 1) preparation of cellulose nanocrystals, 2) preparation of a cellulose nanocrystal / graphene mixed solution, 3) preparation of a cellulose nanocrystal / graphene / polyvinyl alcohol ternary composite solution, 4) inorganic salt induction, 5) alcohol solution replacement, and 6) freeze drying. Through reasonable adjustment of the ratio of cellulose nanocrystals, graphene to polyvinyl alcohol, the aerogel with better performances is prepared. The aerogel has a large specific surface area, a small pore size, low density and good adsorptivity. The graphene oxide sheet improves the mechanical properties of the aerogel. The polyvinyl alcohol improves the biocompatibility and degradability of the product. The spherical aerogel has a large effective adsorption area and high adsorption efficiency. The resource utilization of gas and solid wastes and the water environment control and treatment are effectively combined so that the circular economy is promoted.
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Description

technical field

[0001] The invention relates to a preparation method of cellulose nanocrystal / graphene / polyvinyl alcohol airgel, which belongs to the technical field of nanomaterial manufacture and modification. Background technique

[0002] Cellulose nanocrystalline airgel is an organic airgel. In addition to the characteristics of low density and high porosity, it is widely used in biomedicine, catalyst and adsorbent loading due to its abundant and cheap raw materials and excellent characteristics such as biodegradability. and ecological protection and many other fields. Cellulose aerogels prepared by dissolving and regenerating cellulose have new effects and properties due to their nanometer size, but their mechanical properties are low, and the preparation of aerogels with strong mechanical properties has broad application prospects. At present, the preparation process of cellulose-based aerogels is complicated, and the structure of aerogels is difficult to control the ...

Examples

preparation example Construction

[0022] A preparation method of cellulose nanocrystal / graphene / polyvinyl alcohol ternary composite reinforced airgel, comprising the steps of:

[0023] (1) Preparation of cellulose nanocrystals;

[0024] (2) Preparation of cellulose nanocrystal / graphene mixed solution;

[0025] (3) Preparation of cellulose nanocrystal / graphene / polyvinyl alcohol ternary composite solution;

[0026] (4) Induction by inorganic salts;

[0027] (5) Alcohol solution replacement;

[0028] (6) Freeze drying.

[0029] The step (1) preparation of cellulose nanocrystals: treat microcrystalline cellulose with sulfuric acid with a concentration of 64%, and the ratio is microcrystalline cellulose: H 2 SO 4 =1g: 9.8ml, stirred at 45°C for 1 hour; centrifuged for more than 4 times in a centrifuge until the pH value of the supernatant was 6; dialyzed in distilled water for 3 days, poured out the supernatant and ultrasonicated for 4 hours (16KHz, interval 1.5s), to obtain 0.4wt% -1.7wt% cellulose nanocryst...

Embodiment 1

[0042] The ternary composite reinforced airgel of cellulose nanocrystal / graphene / polyvinyl alcohol is carried out according to the following steps:

[0043] (1) Preparation of cellulose nanocrystals: treat microcrystalline cellulose with sulfuric acid with a concentration of 64%, and the ratio is microcrystalline cellulose: H 2 SO 4= 1g: 9.8ml, stirred at 45°C for 1 hour; centrifuged for more than 4 times until the pH of the supernatant was 6, then dialyzed in distilled water for 3 days, then discarded the supernatant and ultrasonicated for 4 hours ( 16KHz, gap 1.5s), to get 0.4wt% -1.7wt% (wt, ie: mass fraction ratio) cellulose nanocrystal suspension;

[0044] (2) Graphene mixing: 5.970g, 1.7wt% cellulose nanocrystal hydrogel and 0.030g graphene ground through a grinder at 20Hz for 10min, according to m(graphene) / m(cellulose nanocrystal) = 0.5% ratio configuration, evenly mixed;

[0045] (3) Polyvinyl alcohol mixing: Weigh a certain amount of polyvinyl alcohol, add deioniz...

Embodiment 2

[0050] The ternary composite reinforced airgel of cellulose nanocrystal / graphene / polyvinyl alcohol is carried out according to the following steps:

[0051] (1) Preparation of cellulose nanocrystals: treat microcrystalline cellulose with sulfuric acid with a concentration of 64%, and the ratio is microcrystalline cellulose: H 2 SO 4 = 1g: 9.8ml, stirred at 45°C for 1 hour; centrifuged for more than 4 times until the pH of the supernatant was 6, then dialyzed in distilled water for 3 days, then discarded the supernatant and ultrasonicated for 4 hours ( 16KHz, gap 1.5s), to get 0.4wt% -1.7wt% (wt, ie: mass fraction ratio) cellulose nanocrystal suspension;

[0052] (2) Graphene mixing: 6.965g, 1.7wt% cellulose nanocrystal hydrogel and 0.035g graphene ground through a grinder at 20Hz for 10min, according to m(graphene) / m(cellulose nanocrystal) = 0.5% ratio configuration, evenly mixed;

[0053] (3) Polyvinyl alcohol mixing: Weigh a certain amount of polyvinyl alcohol, add deioni...