CN114703651A - Method for extracting silk micro/nano fibers through oxidation modification and application of silk micro/nano fibers - Google Patents

Method for extracting silk micro/nano fibers through oxidation modification and application of silk micro/nano fibers Download PDF

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CN114703651A
CN114703651A CN202210245176.8A CN202210245176A CN114703651A CN 114703651 A CN114703651 A CN 114703651A CN 202210245176 A CN202210245176 A CN 202210245176A CN 114703651 A CN114703651 A CN 114703651A
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silk
fiber
fibers
paper
micron
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郑可
乔欢欢
汪书杰
范宁
汪钟凯
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Anhui Agricultural University AHAU
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    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M11/00—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising
    • D06M11/07—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof
    • D06M11/30—Treating fibres, threads, yarns, fabrics or fibrous goods made from such materials, with inorganic substances or complexes thereof; Such treatment combined with mechanical treatment, e.g. mercerising with halogens; with halogen acids or salts thereof; with oxides or oxyacids of halogens or salts thereof with oxides of halogens, oxyacids of halogens or their salts, e.g. with perchlorates
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M10/00—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements
    • D06M10/02—Physical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. ultrasonic, corona discharge, irradiation, electric currents, or magnetic fields; Physical treatment combined with treatment with chemical compounds or elements ultrasonic or sonic; Corona discharge
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M16/00—Biochemical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. enzymatic
    • D06M16/003—Biochemical treatment of fibres, threads, yarns, fabrics, or fibrous goods made from such materials, e.g. enzymatic with enzymes or microorganisms
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
    • D21H13/10—Organic non-cellulose fibres
    • D21H13/28—Organic non-cellulose fibres from natural polymers
    • D21H13/34—Protein fibres
    • D—TEXTILES; PAPER
    • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
    • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
    • D21H15/00—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution
    • D21H15/02—Pulp or paper, comprising fibres or web-forming material characterised by features other than their chemical constitution characterised by configuration
    • D—TEXTILES; PAPER
    • D06—TREATMENT OF TEXTILES OR THE LIKE; LAUNDERING; FLEXIBLE MATERIALS NOT OTHERWISE PROVIDED FOR
    • D06M—TREATMENT, NOT PROVIDED FOR ELSEWHERE IN CLASS D06, OF FIBRES, THREADS, YARNS, FABRICS, FEATHERS OR FIBROUS GOODS MADE FROM SUCH MATERIALS
    • D06M2101/00—Chemical constitution of the fibres, threads, yarns, fabrics or fibrous goods made from such materials, to be treated
    • D06M2101/02—Natural fibres, other than mineral fibres
    • D06M2101/10—Animal fibres

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  • Textile Engineering (AREA)
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Abstract

The invention discloses a method for extracting silk micron/nano fiber by oxidation and a preparation method of silent fire-resistant paper thereof, belonging to the technical field of silk fiber. The invention takes waste silk or degummed silk fiber as a raw material, does not need other pretreatment processes, realizes the high-efficiency preparation of the silk micron fiber slurry which has the size distribution in micron scale, electronegativity and better original structure reservation by oxidation modification under specific conditions and the assistance of a slight ultrasonic mechanical dispersion mode. The invention utilizes micron-sized silk fibers in silk fiber slurry to prepare the silk fiber-based paper through a papermaking process, the prepared silk fiber paper has excellent performances of organic solvent resistance, acid resistance, fire resistance, soundness, shape maintenance after carbonization and the like, the high-efficiency recycling of waste silk fabrics can be realized, and the unique properties of the prepared silk fiber paper have great potential utilization value in the field of related functional materials.

Description

Method for extracting silk micro/nano fibers through oxidation modification and application of silk micro/nano fibers
Technical Field
The invention belongs to the technical field of silk fiber extraction, and particularly relates to a method for extracting silk micro/nano fibers through oxidation modification and application thereof.
Background
Silk is one of the earliest and largest yields of natural fiber materials known to be utilized at present. As a natural protein material, the silk and the silk protein thereof have the advantages of soft hand feeling, bright luster, skin friendliness, moisture absorption, air permeability, safety, no toxicity, no immunogenicity and the like, and have the reputation of 'fibre queen'. The processing and use of silk products in China has been over 4000 years old, and the silk products are important basic raw materials in the textile industry and play an important role in the development of agriculture and industrial economy. In recent years, with the development of technologies such as chemistry, biology, material science and the like, the knowledge of unique mesostructure in natural silk fiber has been steadily developed, and the change form of the final service performance of the material brought by the mesostructure characteristics thereof has gradually attracted the interest of related researchers. Therefore, how to extract the mesoscopic unit of the animal silk in a large amount and efficiently and retain the advantages of the structure and the properties to the maximum extent becomes a problem to be solved urgently. However, animal silks have evolved in billions of years to create unique compact, complex structures that have presented difficulties in the extraction of their mesostructure. In the existing research, the obtained micron fiber has the defects of non-uniformity, poor operability, low yield and the like due to the difference of preparation methods. How to obtain the fibroin mesoscopic material with complete structure and performance reservation from natural silk fiber has been the focus and difficulty of the research in the field. It is worth noting that tussah silk, an important component of natural silk fiber, is widely distributed in northeast China. Tussah cocoons are produced in excess of 60000 tons every year in the world, and tussah silk is treated as industrial waste silk, so that the tussah silk is cheaper and more easily available than mulberry silk and spider silk. Therefore, tussah silk is suitable and feasible for extracting the mesostructure of the tussah silk as a large-scale raw material. In addition, when artificial materials are constructed by using waste silk protein, researchers expect to retain the natural structure and properties to the maximum extent so as to facilitate the construction of silk fiber functional materials with excellent mechanical properties.
The paper is one of four ancient inventions in China, and the invention of the paper greatly promotes the propagation and development of human culture and science and technology. Nowadays, paper has become a multipurpose product that people can not keep away from daily work and life. Common paper is mostly made by taking plant fibers such as trees or grasses as raw materials and adding some auxiliary agents and fillers, and the pulping and papermaking process causes serious pollution to the environment; one of the fatal weaknesses of the traditional plant cellulose is flammability, and books and paper documents are completely burnt in a fire, which is also a main reason for the disappearance of a plurality of paper cultural relics for centuries. On the other hand, paper making using silk fibers has been described as early as in the time of western han. A layer of flocculent fibers are remained on the thin bamboo mat after the silk is rinsed, and the earliest silk paper is manufactured through grinding, soaking and the like. At present, mulberry silk fiber paper with high price also exists, and the single selling price of the mulberry silk fiber paper can break through the thousand yuan RMB. However, for papermaking paper by using silk fiber, a series of problems of difficult acquisition of silk fiber, poor pulping performance, difficult grinding, high cost, poor paper performance and the like still exist. The document "Silk dispersion and regeneration at the nanofiber scale.j. mater.chem.b.2014" reports that partially dissolving natural Silk fibers by a formic acid/calcium chloride system, obtaining nanofibers in a solvent with unstable structure and being incapable of being operated in an aqueous phase; the document "Liquid extruded Natural Silk fibers: Applications in Optical and electric devices. adv. Mater.2016" reports that by simply combining the partial dissolution and ultrasonic dispersion methods, the Silk nanofibers yield is low. Chinese patent publication No. CN 104532365A, published as 2015, 4.22.3, entitled "a method for preparing silk nanofiber" can obtain silk aggregates with nanometer morphology by infiltration and long-time mechanical treatment, but the silk fibers obtained in this way are tightly wound with each other to form hydrogel-like shape, do not have single morphology and surface electronegativity, and can be settled even by centrifugation. The Chinese patent publication No. CN201611095798.8 discloses a method for preparing novel inorganic refractory paper by taking hydroxyapatite nano-fiber as a raw material, and the novel inorganic refractory paper is environment-friendly, resistant to high temperature, fire and strong alkali, but has unsatisfactory acid resistance, so that the application of the novel inorganic refractory paper in the field of acid corrosion resistance is limited. Chinese patent publication No. CN 111910467A, the publication date is 11/10/2020, entitled "a barium sulfate fiber inorganic fire-resistant paper and its preparation and application" the inorganic fire-resistant paper which can resist strong acid and strong base can be obtained by blending barium sulfate fiber, inorganic reinforcing fiber and inorganic adhesive dispersion to form fiber slurry, but this method still needs inorganic adhesive to be filled into the pores of the composite porous network structure, and it can still keep the shape performance lower after resisting organic solvent, soundless and carbonizing, and its application is limited. Therefore, it is necessary to develop a method for preparing environment-friendly and biocompatible silk fiber paper by using waste silk.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the defects of low utilization rate and economic benefit of the waste silk, the invention provides a method for macro-extracting the waste silk micron fibers, and the obtained silk micron fibers have relatively uniform size distribution and high yield. According to the preparation method, waste silk is used as a raw material, oxidation modification is carried out under specific conditions, and a slight ultrasonic mechanical dispersion mode is used for obtaining the silk micron fiber with electronegativity and a better original structure. Meanwhile, the method can pertinently obtain the silk micron fibers with specific size distribution, and waste silk-based paper with excellent performances of organic solvent resistance, acid resistance, fire resistance, soundness, shape retention after carbonization and the like is prepared through a papermaking process.
The technical scheme is as follows: in order to achieve the above purpose, the invention adopts the following technical scheme:
a method for extracting silk micron fibers by oxidation modification comprises the following steps:
adding a chemical oxidant into silk fibers for degradation to obtain a silk fiber dissolving system; the chemical oxidant is sodium hypochlorite or sodium chlorite, the concentration of the chemical oxidant is 5-100mmol/g, and the degradation treatment is carried out for 0.5-2 h.
Secondly, reacting the silk fiber dissolving system for 0.5-2 hours in a closed environment at normal temperature and normal pressure, and adding excessive distilled water into the system to terminate the reaction after the reaction is finished to obtain partially dissolved tussah silk fibers;
removing residual chemical oxidant in the partially dissolved tussah silk fiber by centrifugation and filtration, homogenizing and drying to obtain dry tussah silk short fiber;
and fourthly, adding the dry tussah silk short fibers into pure water, and performing ultrasonic treatment to obtain the oxidized modified silk micron fibers.
Wherein the diameter of the modified silk micron fiber is 10-20 μm.
Wherein the homogenization treatment is specifically carried out for 20-40min under the condition of 5000-20000 rpm
In the step (iv), the solid-liquid ratio of the dry tussah silk micro fibers to the pure water is 1:500 g/mL.
Wherein the ultrasonic treatment conditions are as follows: the amplitude of the ultrasonic probe is 30-42 mu m, the frequency is 20-40 kHz, and the ultrasonic wave passes through the ultrasonic probe for 20-60 min.
The invention also provides a method for extracting the silk nanofiber by oxidation modification, which comprises the following steps:
adding silk fibers into 80 +/-5 wt% formic acid solution according to the solid-to-liquid ratio of 1: 10-1: 30, soaking for 1-3 h, and centrifugally separating the silk fibers from the formic acid solution to obtain silk fibers treated by methanol;
washing the silk fiber treated by the methanol with distilled water to be neutral for later use;
dispersing the silk fiber after formic acid treatment in pure water according to the solid-liquid ratio of 1: 20-1: 200g/mL, adding a chemical oxidant or an enzyme oxidant, stirring, and reacting at room temperature under the condition of maintaining the pH value at 10 +/-0.5;
adjusting the pH of the system to be neutral after the reaction is finished, centrifugally cleaning a precipitate part, placing the precipitate part into deionized water for ultrasonic treatment, and obtaining the oxidized modified silk nanofiber after the ultrasonic treatment is finished.
Wherein the ultrasonic treatment conditions comprise that the ultrasonic frequency is 18-22.5 kHz, the ultrasonic power is 265-350W, and the ultrasonic time is 1-3 min.
Wherein the oxidized modified silk micro/nano fiber is used for preparing silent fire-resistant paper, and the silent fire-resistant paper has the characteristics of organic solvent resistance, acid resistance, fire resistance, soundness and shape retention after carbonization.
The silk fiber comprises degummed natural silk fiber and waste silk, wherein the degummed natural silk fiber comprises the following degummed natural silk fiber and waste silk, and the degummed natural silk fiber comprises the following steps: and (3) soaking the natural silk fiber in a sodium carbonate solution for degumming treatment for 1-2 hours, wherein the concentration of the sodium carbonate solution is more than 0.5 wt%.
Wherein the chemical oxidant is an enzyme oxidant, and the enzyme oxidant is laccase; the laccase dosage is 200-1000U/g, and the treatment time is 12-48 h.
Advantageous effects
Compared with the prior art, the silk fiber depolymerization method does not need to carry out pretreatment on the silk fiber or carry out depolymerization treatment on the fine structure of the silk fiber in advance. Only through simple oxidation treatment, charges can be introduced into the silk fiber part in the waste silk product, and the efficient preparation of the silk microfiber pulp with better original structural performance is realized by assisting a slight ultrasonic mechanical dispersion mode.
The invention can use waste silk as raw material, realizes the high-efficiency preparation of silk micron fiber slurry with dimension distribution in micron scale, electronegativity and better original structure reservation by simple oxidation modification and assistance of slight ultrasonic mechanical dispersion. Micron-sized silk fibers in the silk fiber slurry are utilized to prepare the waste silk fiber-based paper through a papermaking process, and the prepared silk fiber paper has excellent performances of organic solvent resistance, acid resistance, fire resistance, soundness, shape retention after carbonization and the like. The method not only can realize the high-efficiency recycling of the waste silk fabrics, but also has great potential utilization value of the unique properties of the prepared silk fiber paper in the field of related functional materials.
The invention adopts a top-down method to extract silk micron/nano fiber from natural silk, uses simple oxidized silk fiber to be treated by high-speed homogenization machinery, and is assisted with a slight ultrasonic mechanical dispersion mode to obtain single silk micron fiber pulp with electronegativity and better retained original structure, and finally prepares the silk fiber paper by papermaking.
In addition, the invention relates to the manufacture of waste silk fiber paper consisting of natural silk micron/nano fiber with electronegativity, and the paper can still maintain the shape in the fields of organic solvent resistance, acid resistance, fire resistance, silence and carbonization.
Drawings
Fig. 1 is a topography of silk micro fibers in silk slurry: the A picture is the silk micron fiber atomic force microscope picture, and the B picture is the silk micron fiber structure performance.
FIG. 2 is a graph comparing the effect of pretreatment on the distribution of silk fiber morphology: the A picture is a transmission electron microscope picture of silk nano-fibers obtained after traditional pretreatment, and the B picture is a scanning electron microscope picture of micro-fibers with long and uniform fiber sizes obtained by the method.
FIG. 3 is a schematic diagram of the preparation of waste silk fiber paper: graph A is waste silk fiber pulp, graph B is silk fiber pulp before papermaking, graph C is undried silk fiber paper after drying papermaking (without using adhesive), and graph D is silk fiber paper after complete drying.
Fig. 4 is a comparison graph of two size distributions of silk fibres prepared paper: the A picture is paper prepared by silk micron fibers and can be easily bound into a book-like shape, and the B picture is a picture which is prepared by silk nano fibers after pretreatment and can not form a complete shape after suction filtration.
Fig. 5 is solvent resistance of silk fiber paper: formic acid, HFIP, acetone, dimethyl sulfoxide, toluene and chloroform solvent are sequentially arranged from left to right,
fig. 6 is acid resistance of silk fiber paper: a is a picture before and after acid soaking of common cellulose paper, and B is a picture before and after acid soaking of silk fiber paper;
fig. 7 is the soundness of silk fiber paper: a is a decibel range (41.4-43.7 dB) of a static state, B is a decibel range (60.60-79.10 dB) of the swinging noise of the common cellulose paper in the air, C is a decibel range (50.7-60.08 dB) of the swinging noise of the silk silent fire-resistant paper in the air, D is a decibel range (0-40 dB) of the noise increased by the common cellulose paper in the air and a decibel range (0-15 dB) of the noise increased by the silk silent fire-resistant paper in the air.
Fig. 8 is the fire resistance of plain cellulose and silk fiber papers: panel a shows the initial state of the two paper samples before they were ignited. And B shows the ignition states of the two paper samples. And the C chart shows the continuous burning state of the two paper samples. And D is the burning stopping state of the two paper samples.
Fig. 9 is a photograph of a silk fiber paper sheet which has been carbonized into a desired arbitrary shape (a paper crane shape) and which retains its original shape (a paper crane shape) after carbonization.
Detailed Description
The invention is further illustrated by the following examples. The examples are intended to illustrate, but not to limit, the invention. It will be understood by those of ordinary skill in the art that these examples are not intended to limit the present invention in any way and that appropriate modifications may be made without departing from the spirit and scope of the present invention.
Example 1
The embodiment provides a method for extracting silk micron fibers through oxidation modification, the silk micron fibers are prepared from degummed natural silk fibers, and the degumming method comprises the following steps: the preparation method of the silk microfiber comprises the following steps of soaking natural silk fibers for 1-2 hours by adopting a 0.5 wt% sodium carbonate solution to obtain degummed silk fibers.
Adding 5mmol NaClO into each 1g of degummed silk fiber, and carrying out oxidative degradation at room temperature to obtain a silk fiber dissolving system. And then, placing the partially dissolved system in a chemical safety cabinet for reaction for 0.5-2 h, and after the reaction is finished, adding excessive distilled water into the system to terminate the reaction to obtain the partially dissolved tussah silk fiber.
Centrifuging and filtering the partially dissolved tussah silk fibers to remove residual NaClO solution, and homogenizing at 10000rpm for 20-40min to obtain tussah silk short fibers with the length of less than 1 cm.
Thirdly, the tussah silk short fibers after partial dissolution are further processed in a low-scale mode by ultrasonic treatment to prepare silk micro fibers, wherein a Qsonica Q500 type ultrasonic treatment device is adopted, 500mL of distilled water is added into each 1g of dry tussah silk micro fibers, and ultrasonic treatment is carried out for 20-60min by adopting an ultrasonic probe with the amplitude of 36 mu m and the frequency of 20 kHz. Obtaining the modified silk micron fiber.
The diameter of the modified silk micrometer fiber is 10-20 μm by determination.
Example 2
The embodiment provides a method for extracting silk micron fibers through oxidation modification, the silk micron fibers are prepared from natural silk fibers subjected to degumming, and the degumming method comprises the following steps: the preparation method of the silk microfiber comprises the following steps of soaking natural silk fiber for 2 hours by adopting a 1 wt% sodium carbonate solution to obtain degummed silk fiber.
Adding 100mmol NaClO into each 1g of degummed silk fiber, and carrying out oxidative degradation at room temperature to obtain a silk fiber dissolving system. And then, placing the partially dissolved system in a chemical safety cabinet for reaction for 0.5-2 h, and after the reaction is finished, adding excessive distilled water into the system to terminate the reaction to obtain the partially dissolved tussah silk fiber.
And secondly, centrifuging and filtering the partially dissolved tussah silk fibers to remove residual NaClO solution, and homogenizing at 5000 rpm for 20-40min to obtain tussah silk short fibers with the length of less than 1 cm.
Thirdly, carrying out further low-scale treatment on the partially dissolved tussah silk short fibers by adopting ultrasonic treatment to prepare silk micron fibers, wherein a Qsonica Q500 type ultrasonic treatment device is adopted, 500mL of distilled water is added into each 1g of dry tussah silk micron fibers, and ultrasonic treatment is carried out for 20-60min by adopting an ultrasonic probe with the amplitude of 42 microns and the frequency of 20-40 kHz. Obtaining the modified silk micron fiber.
The diameter of the silk micrometer fiber after modification is measured to be 3-10 μm, which is shown in figure 1.
Example 3
The embodiment provides a method for extracting silk micron fibers through oxidation modification, the silk micron fibers are prepared from degummed natural silk fibers, and the degumming method comprises the following steps: the preparation method of the silk microfiber comprises the following steps of soaking natural silk fiber for 1 hour by using a 5 wt% sodium carbonate solution to obtain degummed silk fiber.
Adding 100mmol NaClO into each 1g of degummed silk fiber2And carrying out oxidative degradation at room temperature to obtain a silk fiber dissolving system. And then, placing the partially dissolved system in a chemical safety cabinet for reaction for 0.5-2 h, and after the reaction is finished, adding excessive distilled water into the system to terminate the reaction to obtain the partially dissolved tussah silk fiber.
② removing residual NaClO from the tussah silk fiber after partial dissolution by centrifugation and filtration2Homogenizing at 20000rpm for 20-40min to obtain tussah silk short fiber with length of 1cm or less.
Thirdly, carrying out further low-scale treatment on the partially dissolved tussah silk short fibers by adopting ultrasonic treatment to prepare silk micron fibers, wherein a Qsonica Q500 type ultrasonic treatment device is adopted, 500mL of distilled water is added into each 1g of dry tussah silk micron fibers, and ultrasonic probe is adopted to carry out ultrasonic treatment for 60-100 min with the amplitude of 30 microns and the frequency of 20-40 kHz.
Obtaining the modified silk micron fiber.
The diameter of the modified silk micrometer fiber is 10-20 μm by measurement.
Example 4
The embodiment provides a preparation method of silk micro fibers, the silk fibers are waste silk fibers, and the preparation method of the silk micro fibers comprises the following steps.
Adding 500U of laccase into every 1g of waste silk fiber, and performing oxidative degradation at room temperature to obtain a silk fiber dissolving system. And then, placing part of the dissolving system in an air or pure oxygen environment for reaction for 0.5-2 h, and after the reaction is finished, adding excessive distilled water into the system to terminate the reaction to obtain the oxidized tussah silk fiber.
② removing residual NaClO from the oxidized tussah silk fiber by centrifugation and filtration2Homogenizing at 10000rpm for 20-40min to obtain tussah silk short fiber with length below 1 cm.
Thirdly, carrying out further low-scale treatment on the partially dissolved tussah silk short fibers by adopting ultrasonic treatment to prepare silk micron fibers, wherein a Qsonica Q500 type ultrasonic treatment device is adopted, 500mL of distilled water is added into each 1g of dry tussah silk micron fibers, and ultrasonic treatment is carried out for 120min by adopting an ultrasonic probe with the amplitude of 36 microns and the frequency of 20-40 kHz. Obtaining the modified silk micron fiber.
The diameter of the modified silk micrometer fiber is 10-20 μm by measurement.
Example 5
The present embodiment provides a method for preparing oxidized modified silk nanofibers, which includes the following steps.
Taking 10g of degummed silk fiber, mixing the degummed silk fiber with the weight ratio of 1:20 percent of solid-liquid ratio is added into 80 percent of formic acid solution by weight, and the silk fiber and the formic acid solution are centrifugally separated after being soaked for 2 hours. Washing silk fiber with distilled water to neutrality for use; the formic acid solution obtained by centrifugation can be reused. 1g of the formic acid-treated silk fibers were dispersed in 100mL of distilled water, and 15mM HClO was added thereto, followed by stirring at 200r/min, and the reaction was carried out at room temperature for 1 hour while maintaining the pH at 10. After the reaction is finished, adjusting the pH value of the system to be neutral by adopting 0.5mol/L HCl, centrifuging for 10min at 10000r/min, repeatedly centrifuging and cleaning a precipitate for 5 times, placing a water-insoluble part in 100mL deionized water, performing ultrasonic treatment for 2min at 19.5kHz and 300W power, and repeating for 5 times; centrifuging to obtain supernatant, namely the silk nanofiber dispersion. The size distribution of the silk nanofibers in this case is compared with the size distribution of the microfibers in the other examples of this patent, see FIG. 2.
Example 6
The present embodiment provides a method for preparing oxidized modified silk nanofibers, which includes the following steps.
Taking 10g of waste silk fiber, and mixing the raw materials in a proportion of 1:30 percent of solid-liquid ratio, soaking for 1h, and centrifugally separating the silk fiber from the formic acid solution. Washing silk fiber with distilled water to neutral for use; the formic acid solution obtained by centrifugation can be reused. 5g of the formic acid-treated silk fibers were dispersed in 100mL of distilled water, 10mM HClO was added thereto, and the mixture was stirred at 100r/min and reacted at room temperature for 0.5 hour while maintaining pH at 9.5. After the reaction is finished, adjusting the pH value of the system to be neutral by adopting 1mol/L HCl solution, centrifuging for 20min at 5000r/min, repeatedly centrifuging and cleaning a precipitate for 3 times, placing a water-insoluble part in 100mL deionized water, performing ultrasonic treatment for 3min at 18kHz and 265W power, and repeating for 5 times; centrifuging to obtain supernatant, namely silk nanofiber dispersion, and drying to obtain the oxidized modified silk nanofiber.
Example 7
The present embodiment provides a method for preparing oxidized modified silk nanofibers, which includes the following steps.
Taking 10g of degummed natural silk fiber, mixing the degummed natural silk fiber with the weight ratio of 1: adding 10 percent of solid-to-liquid ratio into 85 percent of formic acid solution, soaking for 3 hours, and centrifugally separating silk fibers from the formic acid solution. Washing silk fiber with distilled water to neutral for use; the formic acid solution obtained by centrifugation can be reused. 0.5g of the formic acid-treated silk fiber was dispersed in 100mL of distilled water, and 5mM HClO was added thereto, followed by stirring at 300r/min, and the reaction was carried out at room temperature for 2 hours while maintaining the pH at 10.5. After the reaction is finished, adjusting the pH value of the system to be neutral by adopting 0.1mol/L HCl solution, centrifuging for 5min at 20000r/min, repeatedly centrifuging and cleaning a precipitate for 5 times, placing a water-insoluble part in 100mL deionized water, performing ultrasonic treatment for 1min at 22.5kHz and 350W power, and repeating for 5 times; centrifuging to obtain supernatant, namely the silk nanofiber dispersion.
Example 8
The silk fiber paper is prepared from the silk micron fibers prepared in the embodiments 1-7, and the specific operation steps are as follows.
The silk fiber pulp is processed by a typical pulping and papermaking process to prepare silk fiber paper, and the preparation process of the silk fiber paper is shown in figure 3: a4 paper (297X 210mm) size silk silent fire-resistant paper is prepared by using 100 mesh filter screen, and 80g/m can be prepared by filtering 500mL silk micron fiber slurry without adding adhesive2The silk fiber paper. While the silk nano-fiber obtained by the traditional pretreatment method cannot obtain paper or film with self-supporting property in a suction filtration mode in time, as shown in fig. 4. In fig. 4, examples 1 to 4 (a) are papers made of silk micro fibers, which can be easily bound into a book-like shape, and example 5 (B) is a paper made of silk nano fibers after pretreatment, which cannot form a complete shape after suction filtration.
Solvent resistance of silk fiber paper
The silk nanofibers of example 5 above were selected to make A4 paper (297X 210mm, 80 g/m)2) Silk fiber paper of the same size, cut into sample strips of the same size (20.0mm x 10.0mm), soaked in various common organic solvents and extreme solvent environments for more than 90 days, respectively, and observed for resistance. The common organic solvents in the experiment comprise a plurality of common organic solvents such as formic acid, HFIP, acetone, dimethyl sulfoxide, toluene, chloroform and the like. The solvent resistance of the silk fiber paper is shown in figure 5: formic acid, HFIP, acetone, dimethyl sulfoxide, toluene and chloroform solvents are sequentially arranged from left to right, and the silk fiber paper shows excellent solvent resistance to the solvents.
Acid resistance of silk fiber paper
The silk nanofibers of example 5 above were selected to prepare A4 paper (297X 210mm, 80 g/m)2) Silk micron fiber paper of the same size and plain cellulose A4 paper (297X 210mm, 80 g/m) of the same size2) They were cut into sample strips of the same size, each soaked in 98% formic acid for more than 90 days, and observed for tolerance. The silk fiber paperThe acid resistance of the sheets is shown in FIG. 6: the picture A is the picture before and after the acid soaking of the common cellulose paper, the picture B is the picture before and after the acid soaking of the silk fiber paper, the common cellulose paper is completely decomposed after the acid soaking, the silk fiber paper basically keeps unchanged after the acid soaking, and the silk fiber paper shows excellent acid resistance compared with the common fiber paper.
Soundness of silk fiber paper
The silk nanofibers of example 5 above were selected to prepare silk fiber paper of size A4 (297X 210mm, 80g/m2) and plain cellulose A4 paper of the same size (297X 210mm, 80g/m2), in the same mute environment, the paper is swung in the air in the same manner, and a real-time decibel test is carried out by adopting a handheld high-precision decibel meter (Dada Wei, SW-523), the test process is shown in fig. 7, wherein the graph A is a static state decibel range (41.4-43.7 dB), the graph B is a normal cellulose paper decibel swing noise range (60.60-79.10 dB), the graph C is a silk fiber paper decibel swing noise range (50.7-60.08 dB), and the graph D is a graph which is a noise decibel increase range (0-40 dB) of the normal fiber paper when the normal fiber paper swings in the air and a noise decibel increase range (0-15 dB) of the silk silent paper when the silk silent paper swings in the air. Therefore, the air swing noise decibel of the silk fiber paper is obviously lower than that of the common cellulose paper. The silent nature of silk fiber paper is seen.
Fire resistance of silk fibre paper
The silk fiber paper of size A4 paper (297X 210mm, 80g/m2) prepared in example 5 above was selected and cut into any shape ("house" shape in this experiment). The same general cellulose A4 paper (297X 210mm, 80g/m2) with the same size was also selected, cut into the shape of "house" with the same size, and then the sample was ignited simultaneously by the same flame, and the burning process of the general cellulose paper and the silk fiber paper is shown in FIG. 8: panel a is the initial state of the two paper samples before ignition. And B, the two paper samples are in an ignited state, the common paper begins to burn, and the silkworm silk fiber paper basically burns. And the C picture is the continuous combustion state of the two paper samples, the common paper continuously burns and has obvious flame, and the silk fiber paper burns and has no flame. And D, the graph shows that the two paper samples stop burning, the common paper is basically completely burnt into paper ash, the original shape is damaged, but the silk fiber paper is burnt by a small part and still maintains the original shape. Thus, the silk fiber paper has good fire resistance.
Carbonized silk fiber paper capable of keeping shape
A4 paper (297X 210mm, 80 g/m) prepared in example 5 above was selected2) The silk fiber paper with the size is folded into any specified shape (the shape of the paper crane in the experiment), and then the silk fiber paper is carbonized, the appearance after carbonization is shown in figure 9, and the original shape (the shape of the paper crane) can be still kept after the carbonization of the paper crane folded by the silk fiber paper. Therefore, the appearance of the original article can be well kept after the silk fiber paper is carbonized.
TABLE 1 comparison of the properties of the silk fiber paper of the present invention with those of unoxidized silk fiber paper
Figure RE-GDA0003602449560000101

Claims (10)

1. A method for extracting silk micron fibers by oxidation modification is characterized by comprising the following steps: the method for extracting the silk micron fibers through oxidation modification comprises the following steps:
adding a chemical oxidant into silk fibers for degradation to obtain a silk fiber dissolving system; the chemical oxidant is sodium hypochlorite or sodium chlorite, the concentration of the chemical oxidant is 5-100mmol/g, and the degradation treatment is carried out for 0.5-2 h.
Secondly, reacting the silk fiber dissolving system for 0.5-2 hours in a closed environment at normal temperature and normal pressure, and adding excessive distilled water into the system to terminate the reaction after the reaction is finished to obtain partially dissolved tussah silk fibers;
removing residual chemical oxidant in the partially dissolved tussah silk fiber by centrifugation and filtration, homogenizing and drying to obtain dry tussah silk short fiber;
and fourthly, adding the dry tussah silk short fibers into pure water, and performing ultrasonic treatment to obtain the oxidized modified silk micron fibers.
2. The method for the oxidative modification extraction of silk micro fibers according to claim 1, characterized in that: the diameter of the modified silk micron fiber is 10-20 μm.
3. The method for extracting silk microfiber through oxidative modification as claimed in claim 1, wherein: the homogenization treatment is specifically carried out for 20-40min under the condition of 5000-20000 rpm.
4. The method for the oxidative modification extraction of silk micro fibers according to claim 1, characterized in that: in the step (iv), the solid-liquid ratio of the dry tussah silk micro fibers to the pure water is 1:500 g/mL.
5. A method for extracting silk nano-fiber by oxidation modification is characterized by comprising the following steps: the method for extracting the silk nanofiber through oxidation modification comprises the following steps:
firstly, silk fibers are taken and added into 80 +/-5 wt% formic acid solution according to the solid-to-liquid ratio of 1: 10-1: 30, and after the silk fibers and the formic acid solution are soaked for 1-3 hours, the silk fibers and the formic acid solution are separated centrifugally to obtain the silk fibers treated by methanol;
washing the silk fiber treated by the methanol with distilled water to be neutral for later use;
dispersing the silk fiber after formic acid treatment in pure water according to the solid-liquid ratio of 1: 20-1: 200g/mL, adding a chemical oxidant or an enzyme oxidant, stirring, and reacting at room temperature under the condition of maintaining the pH value at 10 +/-0.5;
fourthly, after the reaction is finished, the pH value of the system is adjusted to be neutral, the deposition part is centrifugally cleaned and is placed in deionized water for ultrasonic treatment, and after the ultrasonic treatment is finished, the oxidized modified silk nanofiber is obtained.
6. A method for extracting silk nano-fiber by oxidation modification is characterized by comprising the following steps: the ultrasonic treatment conditions are that the ultrasonic frequency is 18-22.5 kHz, the ultrasonic power is 265-350W, and the ultrasonic time is 1-3 min.
7. Use of oxidatively modified silk micro/nanofibers according to claim 1 or claim 5 for the preparation of silent fire-resistant paper with resistance to organic solvents, acid resistance, fire resistance, soundness and shape retention after carbonization.
8. The method for oxidative modification extraction of silk micro/nanofibers according to claim 1 or claim 5, wherein the silk fibers comprise degummed natural silk fibers and waste silk, wherein the degummed natural silk fibers are obtained by the following steps: and (3) soaking the natural silk fiber in a sodium carbonate solution for degumming treatment for 1-2 hours, wherein the concentration of the sodium carbonate solution is more than 0.5 wt%.
9. The method for the oxidative modification extraction of silk micro/nanofibers according to claim 1 or claim 5, wherein said chemical oxidizing agent is either an enzymatic oxidizing agent, in particular laccase; the laccase dosage is 200-1000U/g, and the treatment time is 12-48 h.
10. The method for the oxidative modification extraction of silk micro fibers according to claim 1, wherein the ultrasonic treatment conditions are as follows: the amplitude of the ultrasonic probe is 30-42 mu m, the frequency is 20-40 kHz, and the ultrasonic wave passes through the ultrasonic probe for 20-60 min.
CN202210245176.8A 2022-03-14 2022-03-14 Method for extracting silk micro/nano fibers through oxidation modification and application of silk micro/nano fibers Pending CN114703651A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009221401A (en) * 2008-03-18 2009-10-01 Tokyo Univ Of Agriculture & Technology Reclaimed silk material and method of producing the same
JP2010150712A (en) * 2008-12-25 2010-07-08 Shinshu Univ Silk protein nano-fiber, method for producing the same, silk protein composite nano-fiber, and method for producing the same
CN107083674A (en) * 2017-05-25 2017-08-22 南京林业大学 A kind of preparation method of silk nanofiber dispersion liquid
CN108277683A (en) * 2018-01-23 2018-07-13 福州大学 A kind of preparation method of the flexible fluorescent paper based on azelon or cell cellulose

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2009221401A (en) * 2008-03-18 2009-10-01 Tokyo Univ Of Agriculture & Technology Reclaimed silk material and method of producing the same
JP2010150712A (en) * 2008-12-25 2010-07-08 Shinshu Univ Silk protein nano-fiber, method for producing the same, silk protein composite nano-fiber, and method for producing the same
CN107083674A (en) * 2017-05-25 2017-08-22 南京林业大学 A kind of preparation method of silk nanofiber dispersion liquid
CN108277683A (en) * 2018-01-23 2018-07-13 福州大学 A kind of preparation method of the flexible fluorescent paper based on azelon or cell cellulose

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
刘伟: "生物高分子材料及其应用研究", 电子科技大学出版社 *
朱友胜等: "废蚕丝纤维抄造书画纸的生产工艺研究", 丝绸, vol. 58, no. 7, pages 223 - 1 *

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