Preparation method of biological inorganic composite photo-thermal fiber and fiber

Abstract

The invention belongs to the technical field of functional fiber materials, and particularly relates to a high-photothermal-conversion biological inorganic composite photothermal fiber preparation method and a high-photothermal-conversion biological inorganic composite photothermal fiber. The high-photothermal-conversion biological inorganic composite photothermal fiber preparation method comprises the steps that inorganic nanowires which are formed by assembling bismuth oxide and phosphomolybdic acid and have the photothermal conversion characteristic are prepared; preparing a DNA-quaternary ammonium salt complex, and compounding the DNA-quaternary ammonium salt complex with inorganic nanowires to obtain a compound; the DNA-quaternary ammonium salt complex / inorganic nanowire compound is subjected to wet spinning, and the biological inorganic composite photo-thermal fiber is obtained.The biological inorganic composite photo-thermal fiber is simple in preparation process, free of special equipment, low in cost, environmentally friendly and beneficial to development and popularization of the next generation of biological inorganic composite photo-thermal fiber, and the obtained photo-thermal fiber has the full-spectrum absorption characteristic and has a wide application prospect. According to the present invention, the solar energy can be efficiently utilized, the photo-thermal conversion ability is strong, the rapid heating can be achieved under the sunlight irradiation, the reproducibility and the degradability are provided, and the sustainable and environmental-friendly development of the economic and social resources is easily achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of functional fiber materials. Specifically, the present invention relates to a method for preparing a photothermal fiber with high photothermal conversion characteristics by compounding inorganic nanowires with biological macromolecules, and the composite photothermal fiber obtained thereby. Background Art

[0002] As an important basic material for the development of the national economy and people's livelihood, fiber materials play an irreplaceable strategic role in multiple key fields. Among them, photothermal fiber is a functional fiber material that can convert light energy into heat energy, and has shown broad application prospects in the fields of energy, medicine, smart wearables, environmental governance, etc. In response to the energy crisis, photothermal fiber can be integrated into fabrics or devices in a flexible and lightweight form to collect solar energy and promote the development and utilization of renewable energy. In seawater desalination, photothermal fiber can use solar-driven interfacial evaporation technology to achieve efficient seawater desalination and solve the problem of water resource shortage. In extreme environments, such as extremely cold working environments, photothermal fiber can use solar energy to quickly generate heat and provide a lightweight thermal insulation solution for workers. Therefore, in the face of the wide application requirements of photothermal fiber in multiple fields, it is particularly important to develop photothermal fiber with high-efficiency photothermal conversion.

[0003] The core of the material component design of photothermal fiber lies in the combination of high-efficiency photothermal conversion materials and flexible matrix materials. At present, most of the matrix materials used for the preparation of photothermal fibers are synthetic polymer materials, such as polyurethane, polyamide, polyacrylonitrile, polyvinyl alcohol, etc. Although such chemical fiber materials usually have excellent mechanical properties and relatively mature production processes, chemical fiber materials are basically produced from non-renewable energy sources and face major challenges in terms of resource sustainability and environmental friendliness. On the other hand, biological macromolecules (proteins, DNA, etc.) widely present in nature have received a lot of attention due to their advantages such as renewable and degradable properties, and have currently been used to prepare high-performance fiber materials. On the other hand, some progress has also been made in the research of photothermal conversion materials. Currently, the materials that can be used for the preparation of photothermal fibers mainly include metal nanoparticles (noble metal nanoparticles such as gold, silver, platinum, etc.), organic semiconductor polymers (polypyrrole, polyaniline, etc.), and carbon nanomaterials (carbon nanotubes, graphene, etc.). However, when using these photothermal conversion materials to prepare photothermal fibers, there are also great challenges. First, the spectral absorption range of some materials is relatively narrow, making it difficult to achieve efficient utilization of solar energy. Second, the photothermal conversion efficiency of some materials is relatively low, making it difficult to convert enough heat. In addition, the incompatibility between the photothermal conversion materials and the flexible matrix materials will result in poor mechanical properties of the photothermal fibers. Summary of the Invention

[0004] The object of the present invention is to overcome the disadvantages of the above-mentioned existing technologies, and thus provide a method for preparing a bio-inorganic composite photothermal fiber and the obtained photothermal fiber. The photothermal fiber prepared by this method has the characteristics of full-spectrum absorption of sunlight, high-efficiency photothermal conversion ability, excellent mechanical properties, and the fiber matrix material used has the characteristics of renewability and easy degradability.

[0005] The object of the present invention is achieved by the following technical solutions:

[0006] The present invention provides a bio-inorganic composite photothermal fiber, comprising: a DNA-quaternary ammonium salt complex and inorganic nanowires; the inorganic nanowires include: inorganic nanowires formed by the assembly of bismuth oxide-phosphomolybdic acid, and the ratio of the two components of bismuth oxide and phosphomolybdic acid in the nanowires is 1:1, and the synthesis raw materials of the nanowires are phosphomolybdic acid and bismuth nitrate pentahydrate.

[0007] In some embodiments of the present invention, in the above bio-inorganic composite photothermal fiber, the DNA-quaternary ammonium salt complex includes: DNA extracted from salmon sperm and a quaternary ammonium salt cationic surfactant. The DNA extracted from salmon sperm is a commercially available test material. For DNA molecules, other DNAs with similar molecular weights are also feasible, such as calf thymus DNA and herring sperm DNA. For quaternary ammonium salt molecules, they are generally long-chain fatty quaternary ammonium salts with a carbon chain length of 12 to 18, preferably didodecyldimethylammonium bromide and cetyltrimethylammonium bromide.

[0008] In some embodiments of the present invention, in the above bio-inorganic composite photothermal fiber, the mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires is 1:4 to 4:1, and the preferred ratio is 1:4.

[0009] In some embodiments of the present invention, in the above bio-inorganic composite photothermal fiber, the fiber diameter is at the micron level, and the length is adjustable within a large range and can reach several meters.

[0010] The present invention also provides a method for preparing the above bio-inorganic composite photothermal fiber. The method for preparing an inorganic nanowire with high photothermal conversion characteristics and a bio-macromolecule composite fiber of the present invention includes the following steps:

[0011] (1) Synthesis of inorganic nanowires with photothermal conversion characteristics;

[0012] (2) Preparation of a DNA-quaternary ammonium salt complex and its composite with inorganic nanowires;

[0013] (3) Wet spinning of the DNA-quaternary ammonium salt complex / inorganic nanowire composite.

[0014] In the above method step (1), the inorganic nanowires with photothermal conversion properties are synthesized by a one-step solvothermal method. First, phosphomolybdic acid is dissolved in water and poured into a reaction kettle, then bismuth nitrate pentahydrate is added and stirred vigorously until homogeneous. 1-octadecene and oleylamine are added in sequence and stirred. Finally, after the reaction kettle is reacted at a high temperature for several hours, inorganic nanowires are obtained. The inorganic nanowires are washed with cyclohexane, centrifuged, and then dispersed in chloroform.

[0015] In some embodiments of the present invention, the mass ratio of phosphomolybdic acid to bismuth nitrate pentahydrate in the above method step (1) is 3:1 to 5:1, and the preferred feeding ratio is 4:1.

[0016] In some embodiments of the present invention, the reaction temperature in the above method step (1) is 160 - 200 °C, and the preferred reaction temperature is 170 - 180 °C.

[0017] In some embodiments of the present invention, the reaction time in the above method step (1) is 6 - 12 h, and the preferred reaction time is 8 - 9 h.

[0018] In the preferred embodiment of the present invention, the rotation speed of the centrifugation in the above method step (1) is 5000 - 12000 rpm, and the centrifugation time can be 3 - 5 min.

[0019] In the above method step (2), the DNA molecule and the quaternary ammonium salt molecule are respectively dissolved in water, then mixed evenly to obtain a white precipitate, and finally, after centrifugation and freeze-drying, it is the DNA-quaternary ammonium salt complex. The DNA-quaternary ammonium salt complex is dissolved with a chloroform / ethanol mixed solvent and mixed with the chloroform solution of the inorganic nanowires to obtain a DNA / inorganic nanowire composite.

[0020] In the preferred embodiment of the present invention, the concentration of the DNA solution in the above method step (2) is 3 - 5 mg / mL; the concentration of the surfactant solution is 5 - 15 mg / mL.

[0021] In some embodiments of the present invention, the molar ratio of the charges carried by the DNA molecule and the quaternary ammonium salt molecule in the above method step (2) can be 1:9 to 1:1, and the preferred ratio is 1:3. It should be noted that the DNA molecule and the quaternary ammonium salt molecule form a complex through electrostatic interaction.

[0022] In some embodiments of the present invention, the rotation speed of the centrifugation in the above method step (2) is 5000 - 8000 rpm, and the centrifugation time can be 3 - 5 min.

[0023] In some embodiments of the present invention, the freeze-drying in the above method step (2) is a conventional freeze-drying process, and the time can be 2 - 6 h.

[0024] In some embodiments of the present invention, in the above-mentioned method step (2), the ratio of chloroform to ethanol in the chloroform / ethanol mixed solvent is 1:1 to 9:1, and the preferred ratio can be 6:1 to 7:1.

[0025] In particular, a chloroform / ethanol mixed solvent is used, considering the compatibility problem between inorganic nanowires and DNA-quaternary ammonium salt complexes. The inorganic nanowires carry low-polarity long alkyl chain ligand molecules (oleylamine), so they are difficult to disperse in the high-polarity solvent ethanol. Although quaternary ammonium salt molecules with long alkyl chains are introduced on the surface of DNA molecules through electrostatic interaction, the overall polarity of the complex is still relatively high, so the high-polarity solvent ethanol is needed to dissolve it. After exploring the ratio of the high-polarity solvent ethanol to the low-polarity solvent chloroform, the above-mentioned preferred chloroform / ethanol mixed solvent is obtained for the preparation of the DNA / inorganic nanowire composite solution.

[0026] In the above-mentioned method step (3), the bioinorganic composite photothermal fiber is prepared by wet spinning technology, that is, the DNA / inorganic nanowire composite obtained in step (2) is extruded into a coagulation bath through a syringe at an appropriate extrusion rate to form.

[0027] In some embodiments of the present invention, in the above-mentioned method step (3), the extrusion rate of the wet spinning is 10-70 μL / min, and the preferred extrusion rate is 30-40 μL / min.

[0028] In some embodiments of the present invention, in the above-mentioned method step (3), the concentration of the DNA / inorganic nanowire composite is 10-50 mg / mL, and the preferred concentration is 20-30 mg / mL.

[0029] In some embodiments of the present invention, in the above-mentioned method step (3), the coagulation bath can be ethanol or methanol, and ethanol is preferred.

[0030] The beneficial effects of the present invention are as follows:

[0031] 1. The present invention provides a method for preparing a bioinorganic composite photothermal fiber, in which the contained bismuth oxide-phosphomolybdic acid inorganic nanowires have the characteristics of full-spectrum absorption, and have strong absorption in the entire wavelength range of sunlight, and can realize the efficient utilization of solar energy.

[0032] 2. After the bioinorganic composite photothermal fiber efficiently absorbs sunlight, it can also efficiently convert light energy into heat energy, and the photothermal conversion ability of the composite photothermal fiber is strong, and it can achieve rapid heating under sunlight irradiation.

[0033] 3. The matrix material of the bioinorganic composite photothermal fiber is natural DNA macromolecules, which have the characteristics of renewable and degradable, wide sources and do not rely on fossil energy, which is conducive to the sustainable development of resources and environmental friendliness in economy and society.

[0034] 4. In addition, the preparation process of the present invention is simple, does not require special equipment, has low cost, is green and environmentally friendly, and is conducive to the development and popularization of the next generation of bioinorganic composite photothermal fibers. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required to be used in the embodiments. By referring to the drawings, the features and advantages of the present invention will be more clearly understood. The drawings are schematic and should not be construed as limiting the present invention in any way. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.

[0036] Figure 1 It is the macroscopic image and transmission electron microscope image of the synthesized bismuth oxide-phosphomolybdic acid nanowires in the present invention.

[0037] Figure 2 It is the macroscopic image and scanning electron microscope image of the bioinorganic composite photothermal fiber in the present invention.

[0038] Figure 3 It is the ultraviolet-visible-near-infrared absorption spectra of the bioinorganic composite in the present invention when the mass ratio of DNA to inorganic nanowires is 1:1 and 1:4.

[0039] Figure 4 It is the temperature change curve of the bioinorganic composite photothermal fiber in the present invention under the irradiation of one sun intensity.

[0040] Figure 5 It is the mechanical property curve of the bioinorganic composite photothermal fiber in the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0041] In order to more clearly understand the above-mentioned objects, features and advantages of the present invention, the present invention will be further described in detail below with reference to the drawings and specific embodiments. It should be noted that, without conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

[0042] Embodiment 1

[0043] The inorganic nanowires were prepared by a one-step solvothermal method. First, 0.8 g of phosphomolybdic acid was weighed and dissolved in 16 ml of deionized water in a 40-ml reaction kettle. Then, 0.2 g of bismuth nitrate pentahydrate was added and stirred vigorously until evenly dispersed. Subsequently, 10 ml of 1-octadecene was added and stirred for 10 min. Finally, 6 ml of oleylamine was added, and the mixture was placed in an oven and heated at 180 °C for 8 h. After the reaction was completed and the reaction kettle had completely cooled down, the solid in the reaction kettle was transferred to a 50-ml centrifuge tube, dispersed with a small amount of absolute ethanol, and centrifuged at a high speed of 10000 rpm. After obtaining the solid, it was dispersed with cyclohexane and centrifuged at 10000 rpm for 3 min. The centrifugation was repeated three times to obtain a clean inorganic nanowire sample, which was then dispersed in chloroform for storage.

[0044] Salmon sperm-extracted DNA and quaternary ammonium salt (dodecyl dimethyl ammonium bromide) were respectively dissolved in water to prepare a DNA solution with a concentration of 3 mg / mL and a quaternary ammonium salt solution with a concentration of 10 mg / mL. 13 mL of the aqueous solution of dodecyl dimethyl ammonium bromide was added to 10 mL of the aqueous solution of salmon sperm-extracted DNA, and a white precipitate was formed after stirring. The complex containing the white precipitate was poured into a centrifuge and centrifuged at 8000 rpm for 3 min. After discarding the supernatant, it was washed once with water and then centrifuged, and freeze-dried for 5 h to obtain the DNA-quaternary ammonium salt complex. The freeze-dried DNA-quaternary ammonium salt complex sample was dissolved in ethanol, and then the chloroform solution of inorganic nanowires was added. The mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires was 1:4, and the concentration of the complex solution was 20 mg / mL. The final chloroform / ethanol solvent ratio was 7:1.

[0045] The photothermal fiber forming device mainly includes a commercial 45° elbow 1.5-inch screw-threaded plastic steel dispensing needle tip (model: 20G), a common medical 5-mL syringe barrel, a Longer high-precision injection pump (model: LSP01-2A), and a coagulation bath. Specifically, the prepared DNA-quaternary ammonium salt complex solution was sucked into the syringe barrel, and the dispensing needle tip was installed. The DNA-quaternary ammonium salt complex solution was accurately pumped by the high-precision injection pump to achieve the spinning solution, and the extrusion speed was 30 μL / min. Then, it reached the ethanol in the coagulation bath through the dispensing needle tip and quickly formed under the action of the poor solvent. Further, continuous collection of the composite photothermal fiber was carried out through the collection strand.

[0046] As Figure 1 shown, in the present invention, the macroscopic image of the nanowires in the left figure shows that the inorganic nanowire solution at the macroscopic scale appears dark blue and close to black, indicating that it has strong absorption in the entire wavelength range of sunlight. It can be seen from the transmission electron microscope image in the right figure that the purity of the inorganic nanowires is very high, with a length greater than 1 μm and a diameter of about 1 nm, having a very high aspect ratio.

[0047] Figure 2 This is the macroscopic image and scanning electron microscope image of the bioinorganic composite photothermal fiber in the present invention. Among them, the mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires in the photothermal fiber is 1:4. The macroscopic image on the left shows that the bioinorganic composite photothermal fiber appears dark macroscopically and has good fiber uniformity, enabling continuous preparation. Further, the microscopic morphology of the composite photothermal fiber was characterized by scanning electron microscopy. The SEM image on the right shows that the composite photothermal fiber also has high uniformity at the microscopic scale, with a smooth surface and a diameter of about 20 μm.

[0048] Figure 3 Among them, the absorption rate curve is at the top, the reflectance curve is in the middle, and the transmittance curve is at the bottom. It can be seen from the figure that when the mass ratio of DNA to inorganic nanowires is 1:1 (left figure) and 1:4 (right figure), the composite has a high absorption capacity for the entire solar spectrum, that is, the absorption rate of each band in the entire spectrum is higher than 80%. The light reflectance and light transmittance of the composite in the entire solar spectrum range are relatively low.

[0049] Figure 4 This is the temperature change curve of the bioinorganic composite photothermal fiber in the present invention under the irradiation of one solar intensity. Among them, the mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires in the photothermal fiber is 1:4. From Figure 4 it can be seen that the temperature of the photothermal fiber can rise from 27 °C to 37 °C in about 10 s under the irradiation of a one-solar-intensity light source, indicating that the photothermal fiber has fast and efficient photothermal conversion characteristics.

[0050] Figure 5 This is the mechanical property curve of the bioinorganic composite photothermal fiber in the present invention. Among them, the mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires in the photothermal fiber is 1:4. The mechanical properties of the photothermal fiber were tested by uniaxial tension. Its elongation at break is 5-10%, and the average breaking strength is 20 MPa.

[0051] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation method of a high-light-to-heat conversion bio-inorganic composite photothermal fiber, characterized in that, It includes the following steps: (1) Prepare inorganic nanowires with photothermal conversion properties formed by the assembly of bismuth oxide and phosphomolybdic acid; (2) Prepare a DNA-quaternary ammonium salt complex and compound it with the inorganic nanowires to obtain a composite; (3) Perform wet spinning on the DNA-quaternary ammonium salt complex / inorganic nanowire composite to obtain a bio-inorganic composite photothermal fiber.

2. The preparation method of a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 1, characterized in that, In step (1), phosphomolybdic acid and bismuth nitrate pentahydrate are used as raw materials to prepare the inorganic nanowires, and the molar ratio of the two components of bismuth oxide and phosphomolybdic acid in the nanowires is 1:

1.

3. The preparation method of a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 1 or 2, characterized in that, In step (1), the inorganic nanowires with photothermal conversion properties are synthesized by a one-step solvothermal method. First, dissolve phosphomolybdic acid in water and pour it into a reaction kettle, then add bismuth nitrate pentahydrate and stir vigorously until uniform, successively add 1-octadecene and oleylamine and stir, and finally perform a high-temperature reaction in the reaction kettle to obtain the inorganic nanowires; the inorganic nanowires are washed and centrifuged with cyclohexane and then dispersed in chloroform.

4. The preparation method of a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 3, wherein In step (2), the DNA-quaternary ammonium salt complex includes DNA and a quaternary ammonium salt cationic surfactant; preferably, the DNA is one or more of DNA extracted from salmon sperm, calf thymus DNA, and herring sperm DNA; preferably, the quaternary ammonium salt molecule is a long-chain fatty quaternary ammonium salt with a carbon chain length of 12 to 18, and more preferably, the quaternary ammonium salt molecule is dodecyl dimethyl ammonium bromide or cetyl trimethyl ammonium bromide.

5. The preparation method of a high-light and heat conversion bio-inorganic composite photothermal fiber according to claim 3, characterized in that, In step (2), dissolve the DNA molecule and the quaternary ammonium salt molecule in water respectively to obtain a DNA solution and a surfactant solution, then mix them evenly to obtain a white precipitate, and finally obtain the DNA-quaternary ammonium salt complex after centrifugation and freeze-drying; subsequently, dissolve the DNA-quaternary ammonium salt complex with a chloroform / ethanol mixed solvent and mix it with the chloroform solution of the inorganic nanowires to obtain a DNA / inorganic nanowire composite. Preferably, the concentration of the DNA solution is 3-5 mg / mL; the concentration of the surfactant solution is 5-15 mg / mL.

6. The preparation method of a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 5, characterized in that, The DNA molecule and the quaternary ammonium salt molecule form a complex through electrostatic interaction, and the molar ratio of the charges carried by the DNA molecule and the quaternary ammonium salt molecule can be 1:9 to 1:1, and the preferred ratio is 1:3; In step (2), the rotation speed of the centrifugation is 5000-8000 rpm, and the centrifugation time is 3-5 min; In step (2), the ratio of chloroform to ethanol in the chloroform / ethanol mixed solvent is 1:1 to 9:1, and the preferred ratio can be 6:1 to 7:1; The mass ratio of the DNA-quaternary ammonium salt complex to the inorganic nanowires is 1:4 to 4:1, and the preferred ratio is 1:

4.

7. A method for preparing a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 6, characterized in that, In step (3), the bio-inorganic composite photothermal fiber is prepared by a wet spinning technique, that is, the DNA / inorganic nanowire composite prepared in step (2) is extruded into a coagulation bath through a syringe at an appropriate extrusion rate to form.

8. The preparation method of a high-light and heat conversion bio-inorganic composite photothermal fiber according to claim 7, characterized in that, In step (3), the extrusion rate of the wet spinning is 10-70 μL / min, and the preferred extrusion rate is 30-40 μL / min; In step (3), the concentration of the DNA / inorganic nanowire composite is 10-50 mg / mL, and the preferred concentration is 20-30 mg / mL; The coagulation bath described in step (3) may be ethanol or methanol, preferably ethanol.

9. The high-light-to-heat conversion bio-inorganic composite photothermal fiber prepared by the method according to any one of claims 1-8, characterized in that, The fiber diameter is 10-50 μm, preferably 20 μm, and the length is controllable; the bio-inorganic composite photothermal fiber has an absorption rate higher than 80% in each band within the full solar spectrum range, and the sum of the light reflectance and light transmittance is less than 20%. Within the range of room temperature to 40 °C, under the irradiation of a solar light intensity light source, the heating rate is not less than 1 °C / s.

10. A method for preparing a high-light-to-heat conversion bio-inorganic composite photothermal fiber according to claim 8, characterized in that, The elongation at break is 5-10%, and the average breaking strength is not less than 20 MPa.

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