A fiber composite material and a method for producing and using the same

Abstract

This invention relates to a fiber composite material, its preparation method, and its application. The fiber composite material contains fiber material and carbon quantum dots. The particle size of the carbon quantum dots is less than 10 nm. The oxygen content on the surface of the carbon quantum dots is 10-50% by weight, and the carbon content on the surface is 50-90% by weight. The fiber composite material of this invention has a good free radical scavenging effect.

Description

Technical Field

[0001] This invention relates to a fiber composite material, its preparation method, and its application. Background Technology

[0002] Fibers are substances composed of continuous or discontinuous filaments, widely used in home furnishings, construction, aerospace, automotive, defense, and military industries. Fibers are mainly classified as chemical fibers and natural fibers. Chemical fibers are fibers produced through chemical processing and mainly include man-made fibers, regenerated fibers, synthetic fibers, and inorganic fibers. Man-made fibers include viscose fiber, acetate fiber, and cuprammonium fiber; regenerated fibers include regenerated cellulose fiber, regenerated protein fiber, regenerated starch fiber, and regenerated synthetic fiber; synthetic fibers include polyester fiber, polyamide fiber, polyvinyl alcohol fiber, polyacrylonitrile fiber, and polypropylene fiber; inorganic fibers include glass fiber, metal fiber, and carbon fiber. Natural fibers are fibers that exist in nature and can be obtained directly, mainly divided into plant fibers and animal fibers. Plant fibers are natural composite nanomaterials, also known as wood fibers and cellulose fibers. Animal fibers are obtained from animal hair or insect glandular secretions, including hair fibers and glandular fibers. The main chemical component of animal fibers is protein, hence they are also called protein fibers. In addition, natural fibers also include mineral fibers, which are obtained from fibrous mineral rocks.

[0003] Free radicals are the main culprit in human aging, and how to destroy and eliminate free radicals has become an important research direction for scientists in recent years. Currently, the fibers used in daily life, such as household items, are mainly plant and animal fibers and synthetic fibers, such as fabrics used in clothing and facial masks. However, these fibers themselves are not very effective at eliminating free radicals. Summary of the Invention

[0004] The purpose of this invention is to provide a fiber composite material, its preparation method, and its application. The fiber composite material of this invention has good free radical scavenging properties.

[0005] To achieve the above objectives, the first aspect of the present invention provides a fiber composite material comprising fiber material and carbon quantum dots, wherein the particle size of the carbon quantum dots is less than 10 nm, the oxygen content on the surface of the carbon quantum dots is 10-50% by weight, and the carbon content on the surface is 50-90% by weight.

[0006] Optionally, the carbon quantum dots have a particle size of 2-10 nm, and the oxygen content on the surface of the carbon quantum dots is 20-40% by weight, and the carbon content on the surface is 60-80% by weight.

[0007] Optionally, the molar ratio of the surface carbon-oxygen double bond C=O to carbon-oxygen single bond CO of the carbon quantum dot is 1:(0.5-2).

[0008] Optionally, based on the total weight of the fiber composite material, the content of carbon quantum dots is 0.0001-1% by weight, preferably 0.0005-0.01% by weight;

[0009] The distribution deviation of the number of carbon quantum dots per unit area on the surface of the fiber composite material is 0-50%, preferably 0-30%.

[0010] Optionally, the fiber material includes chemical fibers and natural fibers;

[0011] Preferably, the fiber material is selected from one or more of man-made fibers, regenerated fibers, synthetic fibers, inorganic fibers, plant fibers, and animal fibers;

[0012] More preferably, the fiber material is plant fiber and / or animal fiber.

[0013] The second aspect of the present invention provides a method for preparing the fiber composite material provided in the first aspect of the present invention, the method comprising: contacting and compounding the fiber material with a solution containing carbon quantum dots, and subjecting the fiber material after contacting and compounding with the solution containing carbon quantum dots to heat treatment at 120-280°C.

[0014] Optionally, the solution containing carbon quantum dots is prepared by the following steps: in a heat-resistant sealed container, an aqueous solution containing organic acid is subjected to hydrothermal treatment at 150-300°C for 1-48 hours;

[0015] The content of organic acids in the aqueous solution is 1-60% by weight; the organic acids are selected from citric acid, tartaric acid, oxalic acid, quinic acid, salicylic acid, malic acid or ascorbic acid, or a combination of two or three of them.

[0016] Optionally, the contact conditions include: a temperature of 30-100℃, a pressure of 0-2MPa, and a time of 2-60min;

[0017] The heat treatment conditions include: a temperature of 120-280℃ and a time of 1-240 min.

[0018] Optionally, the amount of the carbon quantum dot-containing solution is 10-1000 parts by weight relative to 100 parts by weight of the fiber material; the concentration of the carbon quantum dot-containing solution is 0.0001-10 g / L.

[0019] The solvent of the solution containing carbon quantum dots is one or more of water, methanol, ethanol, acetone and acetic acid.

[0020] The third aspect of the present invention provides the application of the fiber composite material provided in the first aspect of the present invention in the preparation of knitted fabrics and / or nonwoven fabrics.

[0021] Through the above technical solution, the preparation method of the present invention can make carbon quantum dots highly dispersed on fibers under mild conditions. The prepared fiber composite material containing carbon quantum dots has good free radical scavenging performance and can be used in knitted fabrics and / or non-woven fabrics.

[0022] Other features and advantages of the present invention will be described in detail in the following detailed description section. Detailed Implementation

[0023] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0024] The first aspect of this invention provides a fiber composite material containing fiber material and carbon quantum dots. The carbon quantum dots have a particle size of less than 10 nm, and the oxygen content on the surface of the carbon quantum dots is 10-50% by weight, while the carbon content on the surface is 50-90% by weight. The fiber composite material of this invention has good free radical scavenging performance.

[0025] In this invention, particle size refers to the maximum three-dimensional length of the carbon quantum dot particle, that is, the distance between the two points on the carbon quantum dot particle that are furthest apart. The particle size can be measured using methods well known to those skilled in the art, such as transmission electron microscopy.

[0026] In a preferred embodiment, the particle size of the carbon quantum dots is 2-10 nm. When the particle size of the carbon quantum dots is within the above range, the fiber composite material has better free radical scavenging performance.

[0027] According to the present invention, the carbon quantum dots in the fiber composite material are uniformly distributed, and the surface area of ​​the fiber composite material per unit area (e.g., 1-5000 μm) is... 2 The distribution deviation of carbon quantum dots on the fiber composite material is 0-50%, preferably 0-30%. The distribution deviation can reflect the uniformity of carbon quantum dot distribution on the fiber composite material. The distribution deviation can be calculated by testing the number of carbon quantum dots in any two different areas of the same area on the surface of the fiber composite material with scanning electron microscopy, and then comparing the difference between the two measurements.

[0028] To further optimize the performance of the fiber composite material, in a preferred embodiment of the present invention, the surface oxygen content of the carbon quantum dots is 20-40% by weight, and the surface carbon content is 60-80% by weight. The surface element content of the carbon quantum dots can be measured using XPS. More preferably, when the molar ratio of the carbon-oxygen double bond C=O to the carbon-oxygen single bond CO on the surface of the carbon quantum dots is 1:(0.5-2), the resulting fiber composite material exhibits superior free radical scavenging performance.

[0029] According to the present invention, the content of carbon quantum dots can vary within a wide range based on the total weight of the fiber composite material, for example, it can be 0.0001-1% by weight, preferably 0.0005-0.01% by weight. When the weight of carbon quantum dots is within the above range, the weight ratio of carbon quantum dots to fibers is suitable, the dispersion of carbon quantum dots on the composite fibers is better, and the fiber composite material has better free radical scavenging performance.

[0030] According to the present invention, the fiber material is well known to those skilled in the art, and the fiber material may include chemical fibers and natural fibers; preferably, the fiber material is selected from one or more of man-made fibers, regenerated fibers, synthetic fibers, inorganic fibers, plant fibers and animal fibers; more preferably, the fiber material is plant fiber and / or animal fiber.

[0031] This invention does not impose specific restrictions on the type and source of carbon quantum dots, which can be commercially available or prepared in-house, such as polymer dots, graphene dots, etc. In one specific embodiment, carbon quantum dots are prepared by a method comprising the following steps: In a heat-resistant, sealed container, an aqueous solution of an organic acid is hydrothermally treated at 150-300°C for 1-48 hours. The pressure of the hydrothermal reaction can be the self-generated pressure or an applied pressure; when applied pressure, the pressure is 1-5 MPa. According to this invention, the content of organic acid in the aqueous solution can vary within a wide range, for example, it can be 1-60% by weight, preferably 5-30% by weight. The organic acid can be a natural organic acid found in plants such as fruits, specifically selected from citric acid, tartaric acid, oxalic acid, quinic acid, salicylic acid, malic acid, or ascorbic acid, or a combination of two or three of them.

[0032] The second aspect of the present invention provides a method for preparing the fiber composite material provided in the first aspect of the present invention, the method comprising: contacting and compounding the fiber material with a solution containing carbon quantum dots, and heat-treating the fiber material after contacting and compounding with the solution containing carbon quantum dots at 120-280°C.

[0033] In this invention, the strong adsorption properties of carbon quantum dots and a heat treatment process are utilized during the contact between the fiber material and the solution containing carbon quantum dots to effectively composite the fiber material and carbon quantum dots. The method of this invention is simple, easy to implement, and operates under mild conditions, resulting in a fiber composite material with excellent free radical scavenging properties.

[0034] This invention does not impose specific restrictions on the type and source of carbon quantum dots, which can be commercially purchased or prepared in-house. In one specific embodiment, carbon quantum dots are prepared by a method comprising the following steps: In a heat-resistant, sealed container, an aqueous solution containing organic acid is subjected to hydrothermal treatment at 150-300°C for 1-48 hours. The pressure of the hydrothermal reaction can be the self-generated pressure or an applied pressure; when applied pressure, the pressure is 1-5 MPa. According to this invention, the content of organic acid in the aqueous solution can vary within a wide range, for example, 1-60% by weight, preferably 5-30% by weight. The organic acid can be an organic acid found in natural fruits, such as citric acid, tartaric acid, oxalic acid, quinic acid, salicylic acid, malic acid, or ascorbic acid, or a combination of two or three of them.

[0035] In order to enable better contact and composite between the fiber material and carbon quantum dots, according to the present invention, the contact conditions in step S1 may include: a temperature of 30-100℃, preferably 50-80℃, a pressure of 0-2MPa, preferably 0-1MPa, and a time of 2-60min, preferably 5-30min.

[0036] According to the present invention, heat treatment can be carried out in an open system, i.e., in an environmental system such as a heating treatment device connected to the atmosphere, for example, a commonly used heating treatment device; or it can be carried out in a closed system, i.e., in an environmental system such as a heating treatment device not connected to the atmosphere, for example, various closed reaction heating devices. The atmosphere for heat treatment is not specified, and can be either an air atmosphere or a nitrogen atmosphere. The conditions for heat treatment may include: a temperature of 120-280°C, preferably 130-240°C, and a time of 1-240 min, preferably 10-60 min.

[0037] In one specific embodiment of the present invention, the amount of the carbon quantum dot-containing solution is 10-1000 parts by weight, preferably 50-500 parts by weight, relative to 100 parts by weight of fiber material. The fiber composite material prepared within the above-mentioned dosage range has a suitable content of carbon quantum dots, and the fiber composite material exhibits good free radical scavenging performance.

[0038] According to the present invention, the concentration of the carbon quantum dot-containing solution can vary within a wide range, for example, from 0.0001 to 10 g / L, preferably from 0.001 to 1 g / L. When the concentration of the carbon quantum dot-containing solution is within the above range, it facilitates sufficient contact between the carbon quantum dots and the fiber material, resulting in a fiber composite material with superior free radical scavenging performance. The solvent for the carbon quantum dot-containing solution is not specifically limited; for example, it can be one or more of water, methanol, ethanol, acetone, and acetic acid.

[0039] A third aspect of the present invention provides the application of the fiber composite material provided in the first aspect of the present invention in the preparation of knitted fabrics and / or nonwoven fabrics.

[0040] The present invention will be further illustrated by the following examples, but the present invention is not limited thereto.

[0041] The method for determining the content of carbon quantum dots and fiber material in the fiber composite material in the embodiment is as follows: A five-position electronic balance (Mettler-Toledo, Switzerland, XS105DU type) was used to weigh 2g of fiber material. The content of carbon quantum dots and fiber material was calculated based on the mass difference before and after the addition of carbon quantum dots. The measurement was repeated three times, and the average value was taken as the final data result.

[0042] The particle size of carbon quantum dots was measured using transmission electron microscopy, and the content of surface elements and the molar ratio of surface carbon-oxygen double bonds (C=O) to carbon-oxygen single bonds (CO) were obtained by XPS testing.

[0043] Example 1

[0044] (1) Preparation of carbon quantum dots

[0045] At room temperature and pressure, 25g of a 20% by weight citric acid aqueous solution and 25g of a 10% by weight ascorbic acid aqueous solution were mixed and treated under hydrothermal conditions at 210℃ and autogenous pressure for 40 hours to obtain an aqueous solution containing carbon quantum dots. The concentration of carbon quantum dots in the aqueous solution was measured to be 6.1g / L.

[0046] (2) Preparation of fiber composite materials containing carbon quantum dots

[0047] A suitable amount of the aqueous solution containing carbon quantum dots obtained in step (1) was diluted (the concentration of carbon quantum dots after dilution was about 0.04 g / L) and then composited with 10 g of loose viscose fiber under the conditions of 55 °C and 0.1 MPa. The weight ratio of the diluted carbon quantum dot solution to the fiber was 5:1, the contact time was 30 min, and then the composite viscose fiber was heat-treated in air at 200 °C for 1 h to obtain a fiber composite material containing carbon quantum dots.

[0048] Based on the total weight of the fiber composite containing carbon quantum dots, the carbon quantum dot content was 0.007 wt%, the distribution deviation of carbon quantum dots on the surface of the fiber composite per unit area was 15%, the particle size of the carbon quantum dots was 3 nm, the oxygen content on the surface was 26 wt%, the carbon content on the surface was 74 wt%, and the molar ratio of carbon-oxygen double bonds (C=O) to carbon-oxygen single bonds (CO) on the surface of the carbon quantum dots was 1:1.2.

[0049] Example 2

[0050] The fiber composite material was prepared using the same method as in Example 1, except that in step (2), the adhesive fiber was replaced with Tencel fiber.

[0051] The results showed that, based on the total weight of the fiber composite containing carbon quantum dots, the content of carbon quantum dots was 0.009 wt%, the distribution deviation of the number of carbon quantum dots on the surface of the fiber composite per unit area was 11%, the particle size of the carbon quantum dots was 3 nm, the content of oxygen on the surface was 27 wt%, the content of carbon on the surface was 73 wt%, and the molar ratio of carbon-oxygen double bonds C=O : carbon-oxygen single bonds CO on the surface of the carbon quantum dots was 1 : 1.3.

[0052] Example 3

[0053] The fiber composite material was prepared using the same method as in Example 1, except that in step (1), the concentration of the citric acid aqueous solution was 40% by weight, the concentration of the ascorbic acid aqueous solution was 20% by weight, and the hydrothermal temperature was 280°C. The concentration of carbon quantum dots in the prepared aqueous solution containing carbon quantum dots was 13.5 g / L.

[0054] According to the test, based on the total weight of the fiber composite material containing carbon quantum dots, the content of carbon quantum dots is 0.009% by weight, the distribution deviation of the number of carbon quantum dots on the surface of the fiber composite material per unit area is 20%, the particle size of carbon quantum dots is 8nm, the oxygen content on the surface of carbon quantum dots is 56% by weight, the carbon content on the surface is 44% by weight, and the molar ratio of carbon-oxygen double bond C=O : carbon-oxygen single bond CO on the surface of carbon quantum dots is 1:0.4.

[0055] Example 4

[0056] The fiber composite material was prepared using the same method as in Example 1, except that in step (2), the concentration of carbon quantum dots after dilution was approximately 1.1 g / L.

[0057] According to the test, based on the total weight of the fiber composite material containing carbon quantum dots, the content of carbon quantum dots is 0.2% by weight, the distribution deviation of the number of carbon quantum dots on the surface of the fiber composite material per unit area is 18%, the particle size of carbon quantum dots is 3nm, the oxygen content on the surface of carbon quantum dots is 26% by weight, the carbon content on the surface is 74% by weight, and the molar ratio of carbon oxygen double bond C=O : carbon oxygen single bond CO on the surface of carbon quantum dots is 1:1.3.

[0058] Example 5

[0059] The fiber composite material was prepared using the same method as in Example 1, except that in step (2), the concentration of carbon quantum dots after dilution was approximately 0.0002 g / L.

[0060] According to the test, based on the total weight of the fiber composite material containing carbon quantum dots, the content of carbon quantum dots is 0.0004 wt%, the distribution deviation of the number of carbon quantum dots on the surface of the fiber composite material per unit area is 32%, the particle size of carbon quantum dots is 3 nm, the oxygen content on the surface of carbon quantum dots is 27 wt%, the carbon content on the surface is 73 wt%, and the molar ratio of carbon oxygen double bond C=O : carbon oxygen single bond CO on the surface of carbon quantum dots is 1 : 1.2.

[0061] Example 6

[0062] The fiber composite material was prepared using the same method as in Example 1, except that in step (2), the contact temperature was 150°C, the time was 1440 min, the pressure was 2.5 MPa, and the heat treatment temperature was 280°C for 240 min.

[0063] Based on the total weight of the fiber composite material containing carbon quantum dots, the carbon quantum dot content was 0.01 wt%, the distribution deviation of carbon quantum dots on the surface of the fiber composite material per unit area was 38%, the particle size of the carbon quantum dots was 10 nm, the oxygen content on the surface was 35 wt%, the carbon content on the surface was 65 wt%, and the molar ratio of carbon-oxygen double bonds C=O : carbon-oxygen single bonds CO on the surface of the carbon quantum dots was 1 : 0.3.

[0064] Comparative Example 1

[0065] The method of Example 1 was used, except that the aqueous solution containing carbon quantum dots was replaced with an aqueous solution containing an equal amount of carbon nanoparticles (average particle size 60 nm) to obtain a fiber composite material containing carbon nanoparticles. It was determined that the content of carbon nanoparticles was 0.03% by weight, based on the total weight of the fiber composite material.

[0066] Test case

[0067] (1) The free radical scavenging performance (DPPH method) of the fiber materials of the examples and comparative examples was tested:

[0068] The concentration of DPPH· was detected in the 450-600 nm wavelength range using a UV-Vis spectrophotometer in a Biotec microplate reader. Fiber materials were immersed in a freshly prepared 100 μM anhydrous methanol solution of DPPH· and allowed to stand in the dark for 1 h; parallel experiments were conducted without immersion in fiber materials. Measurements were repeated three times, and the average value was taken as the final result. A higher DPPH free radical scavenging rate indicates better free radical scavenging performance. The results are shown in Table 1.

[0069] The DPPH radical scavenging rate (%) after the reaction was tested and calculated using the following formula:

[0070] DPPH free radical scavenging rate (%) = (A0 - A) i ) / A0×100%, where A i A0 is the absorbance of an anhydrous methanol solution of DPPH·(100μM) after immersion in the fiber sample at 450-600nm, and A0 is the absorbance of the DPPH· solution without immersion in the fiber, i.e., the absorbance of the DPPH free radical solution.

[0071] Table 1

[0072] Free radical scavenging rate, % Example 1 36 Example 2 39 Example 3 32 Example 4 28 Example 5 25 Example 6 21 Comparative Example 1 11 viscose fiber 8 Tencel fiber 12

[0073] As can be seen from the results of the above embodiments and comparative examples, the fiber composite material of the present invention has good free radical scavenging performance.

[0074] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0075] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable way without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0076] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A fiber composite material, said fiber composite material being composed of fiber material and carbon quantum dots, wherein, based on the total weight of said fiber composite material, the content of carbon quantum dots is 0.009-0.01 wt%; the distribution deviation of the number of carbon quantum dots per unit area on the surface of said fiber composite material is 0-11%; the particle size of said carbon quantum dots is 3-10 nm; the oxygen content on the surface of said carbon quantum dots is 20-27 wt%; the carbon content on the surface of said carbon quantum dots is 73-80 wt%; and the molar ratio of carbon-oxygen double bonds C=O to carbon-oxygen single bonds CO on the surface of said carbon quantum dots is 1:(1.3-2). The fiber material is Tencel fiber.

2. A method for preparing the fiber composite material according to claim 1, the method comprising: The fiber material is brought into contact with a solution containing carbon quantum dots for composite bonding, and the composite fiber material is then heat-treated at 120-280°C.

3. The method according to claim 2, wherein, The solution containing carbon quantum dots is prepared by the following steps: the aqueous solution containing organic acid is subjected to hydrothermal treatment at 150-300°C for 1-48 hours in a heat-resistant sealed container. The content of organic acids in the aqueous solution is 1-60% by weight; the organic acids are selected from citric acid, tartaric acid, oxalic acid, quinic acid, salicylic acid, malic acid or ascorbic acid, or a combination of two or three of them.

4. The method according to claim 2, wherein, The contact conditions include: temperature of 30-100℃, pressure of 0-2MPa, and time of 2-60min; The heat treatment conditions include: a temperature of 120-280℃ and a time of 1-240 min.

5. The method according to claim 2, wherein, The amount of the carbon quantum dot-containing solution used is 10-1000 parts by weight relative to 100 parts by weight of the fiber material; the concentration of the carbon quantum dot-containing solution is 0.0001-10 g / L. The solvent of the solution containing carbon quantum dots is one or more of water, methanol, ethanol, acetone and acetic acid.

6. The use of the fiber composite material of claim 1 in the preparation of knitted fabrics and / or nonwoven fabrics.