阅读说明：本技术 一种复合浸覆纤维素基气凝胶固形物及其制备方法 (Composite impregnated cellulose-based aerogel solid matter and preparation method thereof ) 是由 陆克文 张微微 于 2020-07-22 设计创作，主要内容包括：本发明涉及一种复合浸覆纤维素基气凝胶固形物及其制备方法,其按重量份的比由100重量份碎米莎草根部纤维素气凝胶微孔粉体和80-350重量份木梨幼叶提取物制得,其中,碎米莎草根部纤维素气凝胶微孔粉体的平均粒径不大于0.72μm,微孔的体积占比不小于75％。根据本发明实施例的复合浸覆纤维素基气凝胶固形物,可以延缓饲料霉变发生的时间,降低饲料霉变的程度；与现有技术相比,显著降低成本,且防霉效果相当,从而实现对化学防霉剂和复合防霉剂的有效替代,绿色无毒害。(The invention relates to a composite impregnated cellulose-based aerogel solid and a preparation method thereof, wherein the composite impregnated cellulose-based aerogel solid is prepared from 100 parts by weight of shredded cyperus esculentus root cellulose aerogel microporous powder and 80-350 parts by weight of a pyrus ussuriensis young leaf extract, wherein the average particle size of the shredded cyperus esculentus root cellulose aerogel microporous powder is not more than 0.72 mu m, and the volume of micropores accounts for not less than 75%. According to the composite impregnated cellulose-based aerogel solid matter disclosed by the embodiment of the invention, the time for generating mildew of the feed can be delayed, and the mildew degree of the feed can be reduced; compared with the prior art, the cost is obviously reduced, and the mildew-proof effect is equivalent, so that the chemical mildew-proof agent and the composite mildew-proof agent are effectively replaced, and the mildew-proof agent is green and non-toxic.)

1. The composite impregnated cellulose-based aerogel solid is characterized by being prepared from 100 parts by weight of shredded cyperus rotundus root cellulose aerogel microporous powder and 80-350 parts by weight of a pyrus betulaefolia young leaf extract, wherein the average particle size of the shredded cyperus rotundus root cellulose aerogel microporous powder is not more than 0.72 mu m, and the volume of micropores accounts for not less than 75%.

2. A method of preparing a composite impregnated cellulose-based aerogel solids, the method comprising:

extraction of cellulose from root of cyperus alternifolius

1) Pretreatment: cutting, drying, crushing and sieving the cleaned root of the cyperus rotundus to obtain 50-micron powder of the root of the cyperus rotundus;

2) acidifying pretreatment: soaking the ground cyperus esculentus root powder for 60min at 35 ℃ by adopting 0.1mol/L oxalic acid solution according to the solid-to-liquid ratio of 1:30, and drying after suction filtration to obtain a first intermediate product;

3) alkalizing and leaching: according to the solid-liquid ratio of 1:15, 0.2mol/L sodium hydroxide solution is adopted to leach the first intermediate product for 80min at 90 ℃, and the second intermediate product is obtained after leaching and drying;

4) and (3) purification treatment: according to the solid-liquid ratio of 1:10, carrying out thermostatic water bath on the second intermediate product for 60min at 80 ℃ by adopting 0.2mol/L sodium hypochlorite solution; washing with anhydrous ethanol to neutrality, and vacuum drying at 60 deg.C to obtain cellulose of root of herba Cyperi;

preparation of crushed cyperus esculentus root cellulose aerogel microporous powder

1) Preparation of shredded cyperus esculentus root cellulose aerogel precursor

And (3) activating treatment of the cellulose at the root of the cyperus rotundus: adding 100 parts by weight of the cyperus rotundus root cellulose into 280 and 400 parts by weight of N, N-dimethylacetamide solvent according to the weight part ratio, and stirring for 20min in a constant-temperature water bath at 100 ℃ to obtain an activated cyperus rotundus root cellulose solution;

dissolving the cellulose in the root of the cyperus rotundus: cooling the cellulose solution at the root of the activated shredded cyperus rotundus to 70 ℃, adding 15 parts by weight of sodium chloride, and stirring at constant temperature for 2 hours to obtain an intermediate cellulose solution;

microfibrillation treatment: carrying out microfibrillation treatment on the intermediate cellulose solution by adopting a high-frequency ultrasonic cell disruptor under the ice-water bath condition to obtain microfibrillated sol;

preparing a gel precursor: standing the microfibrillated sol at 10 +/-1 ℃ for 8 hours, and fully washing the microfibrillated sol by using absolute ethyl alcohol to obtain a precursor of the cellulose aerogel at the root of the chopped cyperus esculentus;

2) crosslinking treatment

Preparing acetic acid and sodium acetate solution into a crosslinking initiation solution according to the mass ratio of 4: 1; fully soaking the precursor of the cellulose aerogel at the root of the cyperus rotundus by using a crosslinking initiation solution at the temperature of 45 +/-2 ℃ for 5 hours to obtain crosslinked and reinforced cyperus rotundus root cellulose gel;

3) purification treatment

Soaking the crosslinked and strengthened shredded cyperus esculentus root cellulose gel into a supercritical purifier which stores absolute ethyl alcohol for purification treatment;

4) shaping process

Molding the purified gel to obtain shredded cyperus esculentus root cellulose aerogel microporous powder;

preparation of extract of young leaf of pyrus ussuriensis maxim

Adding the young leaves of the pyrus ussuriensis maxim into absolute ethyl alcohol according to the solid-liquid ratio of 1:15, carrying out ultrasonic extraction for 80min, filtering, drying at 121 ℃ and sterilizing for 20s to obtain an extract of the young leaves of the pyrus ussuriensis maxim;

preparation of composite impregnated cellulose-based aerogel solid

The weight ratio of: 100 parts of shredded cyperus rotundus root cellulose aerogel microporous powder and 80-350 parts of pyrus ussuriensis young leaf extract by weight are mixed;

adding the extract of the young leaves of the pyrus ussuriensis into absolute ethyl alcohol, fully stirring and dissolving in a sealed reaction kettle, adding the cellulose aerogel microporous powder at the root of the cyperus rotundus, electromagnetically stirring for 100min at the temperature of 60 ℃ under the pressure of 5MPa in the sealed reaction kettle, and evaporating and drying to obtain the composite impregnated cellulose base aerogel solid.

3. The preparation method according to claim 2, wherein the microfibrillation treatment is carried out at an ultrasonic frequency of 15.5 to 17.5kHz, an ultrasonic time of 10min and a pulse interval of 5 s.

4. The method according to claim 2, wherein the concentration of acetic acid is 0.1mol/L and the concentration of the sodium acetate solution is 0.15mol/L in the crosslinking treatment.

5. The method according to claim 2, wherein the supercritical purifier has a temperature of-5 deg.C and a pressure of 5.2MPa, and the purification medium is liquid CO₂。

6. The preparation method according to claim 2, wherein the molding temperature is 105 ℃ and the molding time is 2h to 6.5 h.

Technical Field

The invention belongs to the technical field of feeds, and particularly relates to a composite impregnated cellulose-based aerogel solid matter and a preparation method thereof.

Background

The feed mildew preventive is a common feed additive and is used for inhibiting the generation of mildew and toxin, preventing the loss of nutrient components of the feed during the storage period, slowing down the mildew of the feed and prolonging the storage time of the feed. The existing feed mildew-proof additive mainly comprises a chemical mildew-proof agent, a composite mildew-proof agent and a Chinese herbal medicine mildew-proof agent. The chemical mildew inhibitor mainly comprises propionic acid and its salts, sodium diacetate, sorbic acid, etc. The chemical mildew inhibitor has the defects that the mildew-proof effect is inversely proportional to the corrosivity, and toxic and side effects are easy to generate. The compound mildew preventive is prepared by mixing a plurality of organic acids or organic acid salt mildew preventives according to a certain proportion, the mildew preventive effect of the compound mildew preventive is superior to that of a single chemical mildew preventive, but the compound mildew preventive is easy to damage the whole nutrition level of the feed. The anti-mildew effect of the Chinese herbal medicine mildew preventive is realized by bacteriostatic growth and reproduction, has no residue, no drug resistance and no toxic or side effect, and is an important development direction of the feed mildew preventive. In practical application, the Chinese herbal medicine feed mildew-proof additive also has the following defects: 1) the stability of the device is not high, and the device is easily influenced by light, heat, moisture and the like in the application process and is inconvenient to store; 2) the slow release effect is not obvious, and the mould-proof aging is not durable; 3) the variety of Chinese herbal medicines is various, and how to adopt proper raw materials and preparation process, the raw materials and the manufacturing cost are reduced and the cost performance is improved while the excellent mildew-proof effect is obtained, and continuous and deep research is needed.

The shredded cyperus rotundus is almost spread all over the country, especially grows in farmlands, is harmful to the growth of rice, soybeans, cotton, vegetables and fruit trees, and is a harmful plant. However, the root of the cyperus rotundus L is rich in the special total alkaloids, has the bacteriostatic action, and the difficulty in preparation is how to change the cyperus rotundus L which is low in cost and rich in source into valuable and is worthy of attention and research, and how to ensure the stability of the cyperus rotundus L, and simultaneously ensure the slow-release effect and finally obtain the reasonable mildew-proof bacteriostatic effect.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention provides a composite impregnated cellulose-based aerogel solid and a preparation method thereof, and the gist of the invention is as follows:

according to one aspect of the invention, the composite impregnated cellulose-based aerogel solid is prepared from 100 parts by weight of shredded cyperus esculentus root cellulose aerogel microporous powder and 80-350 parts by weight of an extract of young leaves of pyrus ussuriensis, wherein the average particle size of the shredded cyperus esculentus root cellulose aerogel microporous powder is not more than 0.72 mu m, and the volume of micropores accounts for not less than 75%.

According to another aspect of the invention, a method of preparing composite impregnated cellulose-based aerogel solids, the method comprising:

extraction of cellulose from root of cyperus alternifolius

1) Pretreatment: cutting, drying, crushing and sieving the cleaned root of the cyperus rotundus to obtain 50-micron powder of the root of the cyperus rotundus;

2) acidifying pretreatment: soaking the ground cyperus esculentus root powder for 60min at 35 ℃ by adopting 0.1mol/L oxalic acid solution according to the solid-to-liquid ratio of 1:30, and drying after suction filtration to obtain a first intermediate product;

3) alkalizing and leaching: according to the solid-liquid ratio of 1:15, 0.2mol/L sodium hydroxide solution is adopted to leach the first intermediate product for 80min at 90 ℃, and the second intermediate product is obtained after leaching and drying;

4) and (3) purification treatment: according to the solid-liquid ratio of 1:10, carrying out thermostatic water bath on the second intermediate product for 60min at 80 ℃ by adopting 0.2mol/L sodium hypochlorite solution; washing with anhydrous alcohol to neutrality, and vacuum drying at 60 deg.C to obtain cellulose of root of shredded cyperus esculentus.

Preparation of crushed cyperus esculentus root cellulose aerogel microporous powder

1) Preparation of shredded cyperus esculentus root cellulose aerogel precursor

And (3) activating treatment of the cellulose at the root of the cyperus rotundus: adding 100 parts by weight of the cyperus rotundus root cellulose into 280 and 400 parts by weight of N, N-dimethylacetamide solvent according to the weight part ratio, and stirring for 20min in a constant-temperature water bath at 100 ℃ to obtain an activated cyperus rotundus root cellulose solution;

dissolving the cellulose in the root of the cyperus rotundus: cooling the cellulose solution at the root of the activated shredded cyperus rotundus to 70 ℃, adding 15 parts by weight of sodium chloride, and stirring at constant temperature for 2 hours to obtain an intermediate cellulose solution;

microfibrillation treatment: carrying out microfibrillation treatment on the intermediate cellulose solution by adopting a high-frequency ultrasonic cell disruptor under the ice-water bath condition to obtain microfibrillated sol;

preparing a gel precursor: standing the microfibrillated sol at 10 +/-1 ℃ for 8h, and fully washing the microfibrillated sol by using absolute ethyl alcohol to obtain a precursor of the cellulose aerogel at the root of the cyperus rotundus.

2) Crosslinking treatment

Preparing acetic acid and sodium acetate solution into a crosslinking initiation solution according to the mass ratio of 4: 1; and fully soaking the precursor of the cellulose aerogel at the root of the cyperus rotundus by using a crosslinking initiation solution at the temperature of 45 +/-2 ℃ for 5 hours to obtain the crosslinking-reinforced cyperus rotundus root cellulose gel.

3) Purification treatment

And (3) immersing the crosslinked and strengthened cellulose gel at the root of the cyperus rotundus into a supercritical purifier which stores absolute ethyl alcohol for purification treatment.

4) Shaping process

And (3) carrying out molding treatment on the purified gel to obtain the shredded cyperus esculentus root cellulose aerogel microporous powder.

Preparation of extract of young leaf of pyrus ussuriensis maxim

Adding the young leaves of the pyrus ussuriensis maxim into absolute ethyl alcohol according to the solid-liquid ratio of 1:15, carrying out ultrasonic extraction for 80min, filtering, drying at 121 ℃ and sterilizing for 20s to obtain the extract of the young leaves of the pyrus ussuriensis maxim.

Preparation of composite impregnated cellulose-based aerogel solid

The weight ratio of: 100 parts of shredded cyperus rotundus root cellulose aerogel microporous powder and 80-350 parts of pyrus ussuriensis young leaf extract by weight are mixed;

adding the extract of the young leaves of the pyrus ussuriensis into absolute ethyl alcohol, fully stirring and dissolving in a sealed reaction kettle, adding the cellulose aerogel microporous powder at the root of the cyperus rotundus, electromagnetically stirring for 100min at the temperature of 60 ℃ under the pressure of 5MPa in the sealed reaction kettle, and evaporating and drying to obtain the composite impregnated cellulose base aerogel solid.

According to the exemplary embodiment of the present invention, the microfibrillation treatment is performed at an ultrasonic frequency of 15.5 to 17.5kHz, an ultrasonic time of 10min, and a pulse interval of 5 s.

According to an exemplary embodiment of the present invention, the concentration of acetic acid is 0.1mol/L and the concentration of sodium acetate solution is 0.15mol/L in the crosslinking treatment.

Exemplary according to the inventionIn the example, the temperature in the supercritical purifier is-5 deg.C, the pressure is 5.2MPa, and the purification medium is liquid CO₂。

According to the exemplary embodiment of the present invention, the molding temperature is 105 ℃ and the molding time is 2h to 6.5 h.

The preparation of the composite impregnated cellulose-based aerogel solid matter is realized by extracting the cellulose at the root of the cyperus rotundus, preparing microporous powder of the cellulose aerogel at the root of the cyperus rotundus and preparing extract of the young leaves of the pyrus ussuriensis. According to the composite impregnated cellulose-based aerogel solid matter disclosed by the embodiment of the invention, the time for generating mildew of the feed can be delayed, and the mildew degree of the feed can be reduced; compared with the prior art, the cost is obviously reduced, and the mildew-proof effect is equivalent, so that the chemical mildew-proof agent and the composite mildew-proof agent are effectively replaced, and the mildew-proof agent is green and non-toxic.

Drawings

Fig. 1 is a graph comparing MIC values of composite impregnated cellulose based aerogel solids samples according to embodiments of the present invention and prior art samples.

Detailed Description

In order to make the technical solution and advantages of the present invention more apparent, the present invention is further described in detail by the following specific examples. It is to be understood that the embodiments described are only a few embodiments of the present invention, and not all embodiments. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention.