阅读说明：本技术 一种纯天然纳米木质素基眼膜及其制备方法 (Pure natural nano lignin-based eye mask and preparation method thereof ) 是由 娄瑞 刘钰 戴航 田杰 薛香玉 张斌 赵元元 于 2020-12-29 设计创作，主要内容包括：本发明公开了一种纯天然纳米木质素基眼膜及其制备方法,属于纳米木质素基眼膜技术领域。利用低共熔溶剂对秸秆生物质进行生物质精炼处理,分离得到木质素纳米颗粒,将所得木质素纳米颗粒与珍珠粉和芦荟提取物混合制得纯天然纳米木质素基眼膜。经上述方法制得的纯天然纳米木质素基眼膜是基于木质素纳米颗粒的高抗氧化性和抗菌性,采用生物质DES预处理的精炼技术制备出木质素纳米颗粒,并将其与珍珠粉和芦荟提取物混合后得到纳米木质素基眼膜。本发明提供的的纯天然纳米木质素基眼膜制备方法具有操作简单,低成本,天然纳米木质素基眼膜具有改善黑眼圈及眼周皱纹效果显著的特点。(The invention discloses a pure natural nano lignin-based eye mask and a preparation method thereof, belonging to the technical field of nano lignin-based eye masks. The straw biomass is subjected to biomass refining treatment by using a eutectic solvent, lignin nanoparticles are obtained by separation, and the obtained lignin nanoparticles are mixed with pearl powder and aloe extract to prepare the pure natural nano lignin-based eye mask. The pure natural nano lignin-based eye mask prepared by the method is based on the high oxidation resistance and antibacterial property of the lignin nanoparticles, the lignin nanoparticles are prepared by adopting a refining technology of biomass DES pretreatment, and the lignin nanoparticles are mixed with pearl powder and aloe extract to obtain the nano lignin-based eye mask. The preparation method of the pure natural nano lignin-based eye mask provided by the invention has the characteristics of simple operation and low cost, and the natural nano lignin-based eye mask has the obvious effect of improving black eye circles and wrinkles around eyes.)

1. A preparation method of a pure natural nano lignin-based eye mask is characterized by comprising the following steps: the straw biomass is subjected to biomass refining treatment by using a eutectic solvent, lignin nanoparticles are obtained by separation, and the obtained lignin nanoparticles are mixed with pearl powder and aloe extract to prepare the pure natural nano lignin-based eye mask.

2. The method for preparing the pure natural nano lignin-based eye mask according to claim 1, comprising the following steps:

1) mixing choline chloride and lactic acid to obtain a choline chloride-lactic acid solid-liquid mixture, and carrying out a synthesis reaction on the obtained choline chloride-lactic acid solid-liquid mixture to obtain a eutectic solvent;

2) mixing straw biomass with the obtained eutectic solvent, then carrying out biomass refining treatment, cooling after the reaction is finished to obtain a mixed product, carrying out solid-liquid separation on the obtained mixed product, and reserving filtrate;

3) adding the obtained filtrate into water, standing, precipitating lignin, and performing centrifugation and washing cycle operation on the obtained lignin precipitate to obtain a colloidal lignin product; freezing the obtained colloidal lignin product to obtain a frozen product, and carrying out vacuum freeze drying on the obtained frozen product to obtain lignin nanoparticles;

4) mixing lignin nanoparticles, Margarita powder and Aloe extract uniformly to obtain natural nanometer lignin-based eye mask.

3. The method for preparing the pure natural nano lignin-based eye mask according to claim 1, wherein in the step 1), the ratio of the amounts of choline chloride and lactic acid is 1: 1-10.

4. The method for preparing the pure natural nano lignin-based eye mask according to claim 1, wherein in the step 1), the temperature of the synthesis reaction is 40-80 ℃ and the time is 2-4 h.

5. The preparation method of the pure natural nano lignin-based eye mask as claimed in claim 1, wherein in the step 2), the reaction temperature of the biomass refining treatment is 80-150 ℃ and the reaction time is 8-15 h.

6. The preparation method of the pure natural nano lignin-based eye mask as claimed in claim 1, wherein in the step 2), the mass ratio of the straw biomass to the eutectic solvent is 1: 1-10.

7. The preparation method of the pure natural nano lignin-based eye mask as claimed in claim 1, wherein in the step 2), the particle size of the straw biomass is 60-80 meshes.

8. The method for preparing the pure natural nano lignin-based eye mask according to claim 1, wherein in the step 3), the diameter of the lignin nanoparticles is 20-50 nm.

9. The method for preparing a pure natural nano lignin-based eye mask according to claim 1, wherein the vacuum freeze-drying operation in step 3) specifically comprises: the first stage is as follows: t is-40 ℃, T is 4 h; and a second stage: t is-30 ℃, T is 8 h; and a third stage: t is-15 ℃, T is 10 h; a fourth stage: t is 0 ℃, T is 12 h; the fifth stage: t is 5 ℃, T is 14 h.

10. The pure natural nano lignin-based eye mask prepared by the preparation method of any one of claims 1 to 9 is characterized by comprising the following steps: lignin nanoparticles, pearl powder and aloe extract;

wherein the mass ratio of the lignin nanoparticles to the pearl powder to the aloe extract is 1: 2-4: 8-20.

Technical Field

The invention belongs to the technical field of nano lignin-based eye masks, and relates to a pure natural nano lignin-based eye mask and a preparation method thereof.

Background

The lignin nanoparticles have rich benzene ring structures and rich phenol structural units, so that the lignin nanoparticles have good oxidation resistance, and can inhibit the oxidation-reduction reaction of free radicals when acting on skin, thereby achieving the anti-aging effect. Therefore, the skin care product is increasingly applied to the preparation of daily skin care products.

Although the lignin has excellent oxidation resistance and antibacterial property, the large particles and irregular shapes limit the application of the lignin as a high value-added material, for example, the lignin extracted by the conventional method cannot be scattered and agglomerated due to the structural characteristics of the material, and even the lignin is agglomerated, so that the oxidation resistance and antibacterial functions of the lignin cannot be exerted in a balanced manner, and therefore, the mixed use effect of the lignin and each component in the skin care product is limited.

Disclosure of Invention

In order to overcome the defects of the prior art, the invention aims to provide a pure natural nano lignin-based eye mask and a preparation method thereof. The preparation method successfully solves the problem that lignin is easy to agglomerate and agglomerate, and can obtain the pure natural nano lignin-based eye mask with uniform and stable mixed system.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

the invention discloses a preparation method of a pure natural nano lignin-based eye mask, which comprises the following steps: the straw biomass is subjected to biomass refining treatment by using a eutectic solvent, lignin nanoparticles are obtained by separation, and the obtained lignin nanoparticles are mixed with pearl powder and aloe extract to prepare the pure natural nano lignin-based eye mask.

Preferably, the preparation method of the pure natural nano lignin-based eye mask comprises the following steps:

1) mixing choline chloride and lactic acid to obtain a choline chloride-lactic acid solid-liquid mixture, carrying out a synthesis reaction on the obtained choline chloride-lactic acid solid-liquid mixture, and cooling to obtain a eutectic solvent;

2) mixing straw biomass with the obtained eutectic solvent, then carrying out biomass refining treatment, cooling after the reaction is finished to obtain a mixed product, carrying out solid-liquid separation on the obtained mixed product, and reserving filtrate;

3) adding the obtained filtrate into water, standing, precipitating lignin, and performing centrifugation and washing cycle operation on the obtained lignin precipitate to obtain a colloidal lignin product; freezing the obtained colloidal lignin product to obtain a frozen product, and carrying out vacuum freeze drying on the obtained frozen product to obtain lignin nanoparticles;

4) mixing lignin nanoparticles, Margarita powder and Aloe extract uniformly to obtain natural nanometer lignin-based eye mask.

Preferably, in the step 1), the ratio of the amounts of the choline chloride and the lactic acid is 1: 1-10.

Preferably, in the step 1), the temperature of the synthesis reaction is 40-80 ℃ and the time is 2-4 h.

Preferably, in the step 2), the solid-liquid mass ratio of the straw biomass to the eutectic solvent is 1: 1-10.

Preferably, in the step 2), the reaction temperature of the biomass refining treatment is 80-150 ℃ and the time is 8-15 h.

Preferably, in the step 2), the particle size of the straw biomass is 60-80 meshes.

Preferably, the straw biomass comprises wheat straw or rice straw.

Preferably, in the step 3), the diameter of the lignin nanoparticles is 20-50 nm.

Preferably, in step 3), the temperature of the freezing operation is-26 ℃ and the time is 6 h.

Preferably, in step 3), the vacuum freeze-drying operation specifically comprises: the first stage is as follows: t is-40 ℃, T is 4 h; and a second stage: t is-30 ℃, T is 8 h; and a third stage: t is-15 ℃, T is 10 h; a fourth stage: t is 0 ℃, T is 12 h; the fifth stage: t is 5 ℃, T is 14 h.

Preferably, in the step 5), the mass ratio of the lignin nanoparticles to the pearl powder to the aloe extract is 1: 2-4: 8-20.

The invention also discloses a pure natural nano lignin-based eye mask, which comprises: lignin nanoparticles, pearl powder and aloe extract;

wherein the mass ratio of the lignin nanoparticles to the pearl powder to the aloe extract is 1: 2-4: 8-20.

Compared with the prior art, the invention has the following beneficial effects:

the invention discloses a preparation method of a pure natural nano lignin-based eye mask, wherein a green and environment-friendly eutectic solvent (DES) refining technology is adopted in the preparation method, lignin nanoparticles are preferentially separated and prepared, and compared with the existing preparation method of the lignin nanoparticles, the preparation method ensures the high purity, high yield and structural performance of the nano lignin, so that the yield and the purity of the nano lignin are greatly increased and promoted; by the DES system lignin nanoparticle self-assembly principle, the obtained nano lignin is ensured to have stable spherical structural characteristics; by using the straw biomass, high value-added utilization of agricultural waste straw resources is realized, so that the cost investment is reduced, and the environmental pollution is reduced. Therefore, the invention discloses a preparation method of a pure natural nano lignin-based eye mask with simple operation process and low cost, which can ensure that the nano lignin has the advantages of high purity, small particle size and strong oxidation resistance, so that after being uniformly mixed with pearl powder and aloe extract, the obtained green and pure natural nano lignin-based eye mask can be easily pushed open, thereby being beneficial to absorption of a user and exerting the functions and absorption of various components of the eye mask.

Furthermore, a eutectic solvent DES prepared from choline chloride and lactic acid has unique and obvious selectivity on lignin, and through temperature control treatment of vacuum freeze drying, the lignin nanoparticles can be quickly frozen and dried and fluffed, and are easily and uniformly mixed with aloe and pearl powder.

Furthermore, by selecting the staged freeze drying operation in the vacuum freeze drying process, the drying speed of the nano lignin can be increased, the cost can be reduced, and the nano lignin particles can be uniformly dispersed.

Furthermore, the nano lignin particles prepared by the preparation method can ensure that the diameters of the nano lignin particles are uniformly distributed in a range of 20-50 nm, so that the defects that the lignin particles used in the existing products are too large and are not uniformly distributed and cannot be directly applied to eye masks are overcome, and meanwhile, the nano lignin particles can maximize the oxidation resistance effect due to the nano particle size.

Furthermore, the pearl powder and the aloe extract are used in the preparation method, wherein the aloe extract contains polyphenol substances, organic acids, various vitamins and mineral substances, and can play a role in moistening skin and relaxing bowel when being used alone; the pearl powder contains calcium carbonate, taurine and trace elements required by human body, and can play a role in regulating oil secretion and controlling water and oil balance of skin by adding. Therefore, the pure natural nano lignin-based eye mask prepared by the preparation method can simultaneously select nano lignin, pearl powder and aloe extract for use together, and can achieve the effects of regulating endocrine and lightening dark circles by mutual cooperation.

The invention also discloses the pure natural nano lignin-based eye mask prepared by the preparation method. Because the nano lignin particles with uniform and stable particle size are adopted, the defects that the lignin used in the existing product cannot be directly applied to eye masks due to overlarge particles and uneven distribution are overcome, and meanwhile, the nano lignin particles with the nano particle size can maximize the oxidation resistance effect. In addition, in the components of the pearl powder and the aloe extract, the aloe extract contains polyphenol substances, organic acids, various vitamins and mineral substances, and can play a role in moistening skin and relaxing bowel when being used independently; the pearl powder contains calcium carbonate, taurine and trace elements required by human body, and can play a role in regulating oil secretion and controlling water and oil balance of skin by adding. Therefore, the pure natural nano lignin-based eye mask disclosed by the invention selects nano lignin, pearl powder and aloe extract for use together, and can achieve the effects of regulating endocrine and lightening dark circles simultaneously by mutual cooperation.

Drawings

FIG. 1 is a 12 w-fold scanning electron micrograph of a lignin nanoparticle of the present invention;

FIG. 2 is a 16 w-fold scanning electron micrograph of a lignin nanoparticle of the present invention;

FIG. 3 is a 20 w-fold scanning electron micrograph of a lignin nanoparticle of the present invention;

FIG. 4 is a flow chart of the preparation of the pure natural nano lignin eye mask of the present invention;

FIG. 5 is a graph of the results of the antioxidant activity test of the pure natural nano lignin eye mask of the present invention;

FIG. 6 is a graph showing the distribution of the particle size of lignin nanoparticles prepared in example 4 of the present invention;

FIG. 7 is a graph showing the distribution of the particle size of lignin nanoparticles prepared in example 5 of the present invention;

FIG. 8 is a particle size distribution diagram of lignin nanoparticles prepared in example 2 of the present invention.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The invention discloses a pure natural nano lignin-based eye mask and a preparation method thereof, which are shown in a combined figure 1 and comprise the following steps:

(1) preparing a choline chloride-lactic acid (DES) mixture by using choline chloride and lactic acid (the molar ratio is 1: 1-10);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at the temperature of 40-80 ℃ for 2-4 hours to perform a synthetic reaction, and stirring once every 0.5 hour in the process until a uniform transparent liquid separated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (15-25 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air, and obtaining a eutectic solvent (DES);

(4) drying, grinding and crushing a straw biomass sample such as wheat or rice straw in the air, and then screening to 60-80 meshes to obtain straw powder of straw biomass;

(5) weighing the straw powder obtained in the step (4) (absolute dry) and the transparent liquid precipitated product DES obtained in the step (3), wherein the mass ratio of the straw powder to the transparent liquid precipitated product DES is 1: 1-10;

(6) slowly pouring DES into the weighed straw powder, sealing the straw powder with tin foil paper, putting the straw powder into an oven, carrying out biomass refining treatment, and reacting for 8-15 hours at the temperature of 80-150 ℃;

(7) after the reaction is finished, standing and cooling to room temperature (15-25 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) by adopting vacuum filtration, washing filter residue for 3-5 times by using absolute ethyl alcohol, and cleaning filtrate;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring the concentrated filtrate, pouring the concentrated filtrate into deionized water, and precipitating after lignin is separated out. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 3-5 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1: 2-4: 8-20, and stirring for 24 hours at room temperature (15-25 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

The invention is further illustrated by the following specific examples:

example 1

(1) Preparing a choline chloride-lactic acid (DES) mixture from choline chloride and lactic acid (molar ratio 1: 5);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at 60 ℃ for 2 hours to perform a synthesis reaction, and stirring the mixture once every 0.5 hour during the synthesis reaction until a uniform transparent liquid precipitated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (15 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air to obtain a eutectic solvent (DES);

(4) drying, grinding and crushing the wheat straw sample, and then screening to 60 meshes to obtain wheat straw powder;

(5) weighing the straw powder (3 g) obtained in the step (4) and the transparent liquid precipitated product DES (30g) obtained in the step (3), wherein the mass ratio of the straw powder to the transparent liquid precipitated product DES is 1: 10;

(6) slowly pouring DES into the weighed wheat straw powder, sealing the wheat straw powder with tin foil paper, putting the wheat straw powder into an oven, carrying out biomass refining treatment, and reacting at the temperature of 150 ℃ for 12 hours;

(7) after the reaction is finished, standing and cooling to room temperature (15 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) of solid/liquid phase by adopting vacuum filtration, and washing filter residue with absolute ethyl alcohol for 5 times until the filtrate is clear;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring and pouring the concentrated filtrate into 2L of deionized water to precipitate lignin after precipitation. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 5 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1:3:10, and stirring for 24 hours at room temperature (15 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

Through detection, in the pure natural nano lignin-based eye mask prepared in the embodiment, the average particle size of the lignin nanoparticles is 20 nm.

Example 2

(1) Preparing a choline chloride-lactic acid (DES) mixture from choline chloride and lactic acid (molar ratio 1: 1);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at 40 ℃ for 4 hours to perform synthetic reaction, and stirring every 0.5 hour during the synthetic reaction until a uniform transparent liquid precipitated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (25 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air to obtain a eutectic solvent (DES);

(4) drying, grinding and crushing the wheat straw sample, and then screening to 80 meshes to obtain wheat straw powder;

(5) weighing the straw powder (10g) obtained in the step (4) and the transparent liquid precipitated product DES (10g) obtained in the step (3), wherein the mass ratio of the straw powder to the transparent liquid precipitated product DES is 1: 1;

(6) slowly pouring DES into the weighed wheat straw powder, sealing the wheat straw powder with tin foil paper, putting the wheat straw powder into an oven, carrying out biomass refining treatment, and reacting for 15 hours at the temperature of 80 ℃;

(7) after the reaction is finished, standing and cooling to room temperature (25 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) of solid/liquid phase by adopting vacuum filtration, and washing filter residue for 3 times by using absolute ethyl alcohol until filtrate is clear;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring and pouring the concentrated filtrate into 2L of deionized water to precipitate lignin after precipitation. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 3 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1:2:8, and stirring for 24 hours at room temperature (25 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

Through detection, in the pure natural nano lignin-based eye mask prepared in the embodiment, the average particle size of the lignin nanoparticles is 50 nm. The particle size distribution is shown in FIG. 8.

Example 3

(1) Preparing a choline chloride-lactic acid (DES) mixture from choline chloride and lactic acid (molar ratio 1: 10);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at 80 ℃ for 3 hours to perform synthetic reaction, and stirring every 0.5 hour during the synthetic reaction until a uniform transparent liquid precipitated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (20 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air to obtain a eutectic solvent (DES);

(4) drying, grinding and crushing the rice straw sample, and then screening to 70 meshes to obtain rice straw powder;

(5) weighing the rice straw powder (6g, oven-dried) obtained in the step (4) and the transparent liquid precipitated product DES (30g) obtained in the step (3), wherein the mass ratio of the rice straw powder to the transparent liquid precipitated product DES is 1: 5;

(6) slowly pouring DES into the weighed rice straw powder, sealing the rice straw powder with tin foil paper, putting the rice straw powder into an oven, carrying out biomass refining treatment, and reacting for 8 hours at the temperature of 130 ℃;

(7) after the reaction is finished, standing and cooling to room temperature (20 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) of solid/liquid phase by adopting vacuum filtration, and washing filter residue for 4 times by using absolute ethyl alcohol until filtrate is clear;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring and pouring the concentrated filtrate into 2L of deionized water to precipitate lignin after precipitation. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 4 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1:4:20, and stirring for 24 hours at room temperature (20 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

Through detection, in the pure natural nano lignin-based eye mask prepared in the embodiment, the average particle size of the lignin nanoparticles is 40 nm.

Example 4

(1) Preparing a choline chloride-lactic acid (DES) mixture from choline chloride and lactic acid (molar ratio 1: 2);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at 50 ℃ for 3 hours to perform synthetic reaction, and stirring every 0.5 hour during the synthetic reaction until a uniform transparent liquid precipitated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (18 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air to obtain a eutectic solvent (DES);

(4) drying, grinding and crushing the rice straw sample, and then screening to 75 meshes to obtain rice straw powder;

(5) weighing the straw powder (5g, oven-dried) obtained in the step (4) and the transparent liquid precipitated product DES (35g) obtained in the step (3), wherein the mass ratio of the straw powder to the transparent liquid precipitated product DES is 1: 7;

(6) slowly pouring DES into the weighed rice straw powder, sealing the rice straw powder with tin foil paper, putting the rice straw powder into an oven, carrying out biomass refining treatment, and reacting for 13 hours at the temperature of 100 ℃;

(7) after the reaction is finished, standing and cooling to room temperature (18 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) of solid/liquid phase by adopting vacuum filtration, and washing filter residue for 4 times by using absolute ethyl alcohol until filtrate is clear;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring and pouring the concentrated filtrate into 2L of deionized water to precipitate lignin after precipitation. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 4 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1:4:15, and stirring for 24 hours at room temperature (18 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

Through detection, in the pure natural nano lignin-based eye mask prepared in the embodiment, the average particle size of the lignin nanoparticles is 30 nm. The particle size distribution is shown in FIG. 6.

Example 5

(1) Preparing a choline chloride-lactic acid (DES) mixture from choline chloride and lactic acid (molar ratio 1: 3);

(2) drying the choline chloride-lactic acid (DES) mixture obtained in the step (1) in an oven at 73 ℃ for 4 hours to perform synthetic reaction, and stirring every 0.5 hour during the synthetic reaction until a uniform transparent liquid precipitated product is obtained;

(3) then, cooling the transparent liquid precipitation product obtained in the step (2) to room temperature (23 ℃) in a dry environment to avoid moisture absorption and moisture absorption in the air to obtain a eutectic solvent (DES);

(4) drying, grinding and crushing the rice straw sample, and then screening to 65 meshes to obtain rice straw powder;

(5) weighing the straw powder (8 g) obtained in the step (4) and the transparent liquid precipitated product DES (24g) obtained in the step (3), wherein the mass ratio of the straw powder to the transparent liquid precipitated product DES is 1: 3;

(6) slowly pouring DES into the weighed rice straw powder, sealing the rice straw powder with tin foil paper, putting the rice straw powder into an oven, carrying out biomass refining treatment, and reacting at the temperature of 115 ℃ for 10 hours;

(7) after the reaction is finished, standing and cooling to room temperature (23 ℃) to obtain a mixed product, carrying out solid/liquid phase separation on the mixed product obtained in the step (6) of solid/liquid phase by adopting vacuum filtration, and washing filter residue for 4 times by using absolute ethyl alcohol until filtrate is clear;

(8) collecting clear filtrate, volatilizing absolute ethyl alcohol by adopting a rotary evaporator, stirring and pouring the concentrated filtrate into 2L of deionized water to precipitate lignin after precipitation. Performing solid-liquid separation on the precipitated lignin on a high-speed centrifuge (5000r/min, 4 ℃), pouring out supernatant, washing solid substances by using a mixed solution of absolute ethyl alcohol/water (1:9, v/v), and performing circulating centrifugal washing for 3 times to obtain a colloidal lignin product; freezing the obtained colloidal lignin product at-26 ℃ for 6h, and then carrying out vacuum freeze drying (the first stage is divided into 5 stages, namely T is-40 ℃, T is 4h, the second stage is divided into-30 ℃, T is 8h, the third stage is divided into-15 ℃, T is 10h, the fourth stage is divided into 0 ℃, T is 12h, the fifth stage is divided into 5 ℃, T is 14h) to obtain DES-lignin powder, namely the lignin nano-particles;

(9) cutting aloe leaf, removing thorns on two sides, repeatedly cleaning emodin in aloe, scraping pulp, placing in a high shear colloid mill, and crushing to obtain aloe extract;

(10) mixing the lignin nanoparticles, the pearl powder and the aloe extract according to the mass ratio of 1:3:18, and stirring for 24 hours at room temperature (23 ℃) by a magnetic stirrer at the speed of 1000r/min to obtain the pure natural nano lignin-based eye mask.

Through detection, in the pure natural nano lignin-based eye mask prepared in the embodiment, the average particle size of the lignin nanoparticles is 24 nm. The particle size distribution is shown in FIG. 7.

Specifically, in particular embodiments of the present invention, straw biomass comprises wheat straw, rice straw, or the like.

The apparatus used in the above preparation process is shown in table 1 below.

TABLE 1 statistics of the instruments used in the preparation

The pure natural nano lignin-based eye mask prepared by the invention contains lignin nanoparticles, and the lignin nanoparticles have rich benzene ring structures and rich phenol structural units, so that the lignin nanoparticles have good oxidation resistance and antibacterial effects, and can inhibit the redox reaction of free radicals when acting on skin, thereby achieving the anti-aging effect.

Application method

Thoroughly cleaning the skin area needing to use the eye mask; taking out a proper amount of pure natural nano lignin-based eye mask by a spoon and applying the eye mask to the cleaned skin; timing after finishing smearing, and washing the pure natural nano lignin-based eye mask with clear water after 15-20 min.

The invention is described in further detail below with reference to the accompanying drawings:

referring to fig. 1, it can be seen that, in the scanning electron microscope image of the pure natural nano-lignin prepared in example 1, the lignin nanoparticles prepared by using the eutectic solvent in example 1 have a regular shape and are widely distributed. The diameter of the skin care product can reach 20nm at minimum, and with further increase of magnification (figures 2-3), good sphericity and proper diameter distribution are more obviously observed, and good appearance state of the skin care product is beneficial to halation and rubbing on the skin.

Application testing

The test method comprises the following steps: the antioxidant properties of the samples were tested by DPPH free radical scavenging. The specific test method is as follows: dissolving 7.83mg DPPH in absolute ethanol, fixing the volume in a 100mL volumetric flask, and preparing to have a concentration of 2X 10^-4Storing the mol/L DPPH test solution in a refrigerator in a dark place for later use; then dissolving a sample to be detected in a solvent to prepare a series of sample liquids with concentration gradients; during testing, 3.3mL of sample solution is mixed with 6.1mL of DPPH test solution, and the absorbance of the mixed solution at 519nm is measured by an ultraviolet spectrophotometer after mixing for 30 min. Wherein, the free radical clearance rate IP of the sample to be measured is calculated according to the following formula:

wherein A is₀Represents the absorbance of the blank solution; a. the₁Representing the initial absorbance of the mixture; a. the₂Represents the absorbance of the mixture after 30 min. Respectively aiming at 4 different lignin nanoparticles disclosed by the patentThe DPPH free radical scavenging ability of the pure natural nano lignin-based eye mask sample with particle content is shown in table 1 and fig. 5, and the influence of adding nano lignin on the DPPH free radical scavenging rate of the eye mask can be seen in fig. 5.

TABLE 1 Effect of Nano Lignin addition on Ocular Membrane DPPH, scavenging free radicals

As can be seen from table 1 and fig. 5, DPPH radical scavenging ability is enhanced with the increase of the content of nano lignin because nano lignin has a large number of active hydroxyl structures, can be used for forming hydrogen bonds with organic macromolecules, and can capture radicals in an oxidation process, so that nano lignin has a better anti-oxidation effect, DPPH scavenging rates of 0g, 0.5g, 1.0g and 1.5g of added lignin nanoparticles are 3.2%, 24.8%, 26.3% and 28.1%, respectively, and DPPH scavenging rate of a sample added with 3g of lignin nanoparticles is 8.7 times that of a sample without nano lignin. Wherein the mass ratio of the lignin nanoparticles to the pearl powder to the aloe extract is 1:3: 10.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.