A natural polymer conductive fiber, its preparation method and application

Abstract

The present invention discloses a natural polymer conductive fiber, a preparation method, and applications thereof. The method comprises extruding a natural polymer solution through a spinning drum nozzle and sequentially passing it through a first coagulation bath, a conductive component coagulation bath, and a protective layer coagulation bath to produce the natural polymer conductive fiber. The method utilizes natural polymer fibers, a conductive component, and a protective layer component to produce the natural polymer conductive fiber. The method primarily utilizes a high-quality biomass solvent system, such as ionic liquids and sodium hydroxide-urea, with water, alcohol, and functional components (i.e., the conductive component and protective layer components) as the coagulation bath. The resulting conductive fiber exhibits good uniformity, stability, and controllable conductivity.

Description

Technical Field

[0001] The present invention belongs to the field of natural polymer materials, and in particular relates to a natural polymer conductive fiber and a preparation method and application thereof. Background Art

[0002] As a kind of functional material, conductive fiber has become increasingly important in the development of science, from the development and application of basic anti-static and anti-radiation products to the emergence of various wearable flexible sensor devices and smart textiles.

[0003] As people's environmental awareness continues to increase, traditional "microplastics" are destined to be eliminated in the field of conductive fibers. Therefore, the development of degradable and environmentally friendly conductive fibers has become an area of widespread concern in academia and industry.

[0004] Existing methods for preparing conductive fibers mainly include doping spinning and surface treatment. Doping spinning mainly involves doping with metals and their compounds, metal oxides, and conductive polymers; surface treatment mainly includes physical coating and plating methods (electroplating, chemical polymerization). However, there are the following shortcomings: 1) The preparation of composite conductive fibers through dry / wet spinning technology requires the raw material size to be as small as possible and the process precision to be high, so the overall cost varies greatly depending on the conductive filler; 2) Surface treatment is easily distorted by friction due to external forces during use, causing the conductive layer on the surface to fall off and the conductive performance to decrease, resulting in poor stability and durability. Summary of the Invention

[0005] Based on the deficiencies of the prior art, the present invention provides a natural polymer conductive fiber, a preparation method and application thereof. The present invention adopts the dissolution and regeneration of natural polymer materials to prepare gel-state natural polymer fibers. When the fibers are in gel state, conductive components and protective components are introduced through coagulation and diffusion to prepare natural polymer conductive fibers.

[0006] The present invention provides the following technical solutions:

[0007] A method for preparing natural polymer conductive fibers, comprising the following steps:

[0008] The natural polymer solution is extruded through a spinning pot nozzle and sequentially passed through a first coagulation bath, a conductive component coagulation bath and a protective layer coagulation bath to prepare the natural polymer conductive fiber.

[0009] According to an embodiment of the present invention, the natural polymer solution is obtained by dissolving a natural polymer material in a solvent.

[0010] According to an embodiment of the present invention, in the natural polymer solution, the concentration (solid content) of the natural polymer material is 3wt%-15wt%; specifically 6wt%-9wt%; illustratively, it can be 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%.

[0011] According to an embodiment of the present invention, the natural polymer material is, for example, at least one of cellulose, chitosan, chitin, silk protein, etc.; or, low-quality cellulose or natural plant tissue containing one or more of the above components.

[0012] According to an embodiment of the present invention, the first coagulation bath is water or an alcohol solution.

[0013] According to an embodiment of the present invention, the conductive component coagulation bath is a conductive component or a conductive component dispersion. When the conductive component is a liquid, the conductive component coagulation bath can directly use the conductive component. When the conductive component is non-liquid, the conductive component coagulation bath uses a conductive component dispersion. For example, the conductive component dispersion is an aqueous dispersion or an alcohol dispersion of the conductive component, which is obtained by dispersing the conductive component in water or an alcohol solvent. The concentration of the conductive component dispersion is 0.01 mg / mL to 1 mg / mL. For example, the concentration of the silver nanowire dispersion is 0.01 mg / mL to 1 mg / mL, and its conductivity is 0.17 S / cm to 586 S / cm.

[0014] According to an embodiment of the present invention, the conductive component is selected from at least one of conductive substances such as silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, carbon nanotubes, graphene, polyaniline, and polypyrrole.

[0015] According to an embodiment of the present invention, the protective layer coagulation bath refers to a bulk solution or a dispersion of the protective component. For example, the dispersion is an aqueous solution or an alcohol solution of the protective component, wherein the protective component is dispersed in water or an alcohol solvent.

[0016] According to an embodiment of the present invention, the protective component is selected from at least one of water-soluble polyurethane, PDMS prepolymer, water-soluble rubber, and ethyl cellulose.

[0017] According to an embodiment of the present invention, the alcohol in the alcohol solution or alcohol solvent is selected from methanol, ethanol, propanol, n-butanol, glycerol, ethylene glycol, isopropanol or isobutanol.

[0018] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two conductive components; illustratively, the conductive component coagulation bath contains at least two conductive components, that is, the conductive component coagulation bath is a mixed coagulation bath composed of at least two conductive components; or the material extracted from the first coagulation bath is sequentially passed through at least two conductive component coagulation baths, and each conductive component coagulation bath contains one or more conductive components.

[0019] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two protective layer components; illustratively, the protective layer coagulation bath contains at least two protective layer components, that is, the protective layer coagulation bath is a mixed coagulation bath composed of at least two protective layer components; or the material extracted from the conductive component coagulation bath is sequentially passed through at least two protective layer coagulation baths, and each protective layer coagulation bath contains one or more protective layer components.

[0020] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two conductive components and at least two protective layer components; illustratively, the conductive component coagulation bath contains at least two conductive components, and the protective layer coagulation bath contains at least two protective layer components; that is, the conductive component coagulation bath is a mixed coagulation bath composed of at least two conductive components; or the material derived from the first coagulation bath is sequentially passed through at least two conductive component coagulation baths, each conductive component coagulation bath contains one or more conductive components; that is, the protective layer coagulation bath is a mixed coagulation bath composed of at least two protective layer components; or the material derived from the conductive component coagulation bath is sequentially passed through at least two protective layer coagulation baths, each protective layer coagulation bath contains one or more protective layer components.

[0021] The present invention also provides a natural polymer conductive fiber. The conductive fiber has a skin-core structure, which comprises, from the inside to the outside, a natural polymer fiber core structure and a skin structure formed by a conductive layer and a protective layer.

[0022] According to the present invention, the conductive component in the conductive layer and the protective component in the protective layer have the above meanings.

[0023] The present invention also provides applications of the natural polymer conductive fiber in the fields of conduction, electromagnetic shielding, flexible electrodes, sensor devices, etc.

[0024] Beneficial effects of the present invention:

[0025] The core of the present invention is to prepare gel-state natural polymer fibers by dissolving and regenerating natural polymer materials, and to introduce conductive components and protective components into the fibers in the gel state through diffusion through a coagulation bath to prepare natural polymer conductive fibers.

[0026] (1) The present invention can realize the continuous preparation of natural polymer conductive fibers: through the continuous spinning process of natural polymer fibers, the conductive components are introduced by diffusion through the coagulation bath during continuous spinning, thereby realizing the continuous production of conductive fibers with a skin-core structure or a gradient structure. The core layer polymer provides strength, and the skin layer components give the fiber conductive and protective properties.

[0027] (2) The present invention can achieve high conductivity when the proportion of conductive components is extremely low: by preparing the conductive components into a conductive component coagulation bath and interacting with the natural polymer fiber, the conductive components can be firmly covered on the surface of the natural polymer fiber. When the natural polymer fiber body is dry, it will shrink significantly, so that the conductive components are more closely overlapped with each other to obtain higher conductivity. At the same time, the conductivity of the natural polymer conductive fiber can be controlled by regulating the concentration / content of the conductive components in the coagulation bath, thereby realizing its performance regulation in conductors, semiconductors, and insulators, which has considerable economic benefits.

[0028] (3) The present application improves the stability of the surface functional components through the gel shrinkage process, and keeps them basically from falling off under the stirring water washing condition of 1000r / min, and the conductivity remains unchanged before and after water washing.

[0029] (4) The natural polymer conductive fiber provided by the present invention is a fiber with a circular cross-section and a skin-core structure when viewed macroscopically.

[0030] (5) The present invention adopts natural polymer fibers, conductive components and protective layer components to prepare natural polymer conductive fibers. The method mainly uses an excellent biomass solvent system such as ionic liquids and sodium hydroxide-urea, and uses water, alcohol and functional components (i.e., conductive components and protective layer components) as a coagulation bath. The conductive fibers obtained have good uniformity, good stability and controllable conductivity. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a digital photo of the cellulose / silver nanowire conductive fiber obtained in Example 7.

[0032] Figure 2 This is a digital photo of the cellulose / silver nanowire conductive fiber fabric obtained in Example 7.

[0033] Figure 3 This is a diagram showing the electrostatic shielding effect of the cellulose / silver nanowire conductive fiber obtained in Example 7.

[0034] Figure 4 These are digital photos of the cellulose / silver nanowire conductive fibers obtained in Example 7 after passing through a silver nanowire coagulation bath with different concentrations.

[0035] Figure 5The resistance changes of the natural polymer conductive fibers obtained in Example 4 and Comparative Example 1 before and after washing.

[0036] Figure 6 These are the SEM images of silver nanowires before and after washing of wet fibers and dry fibers in Test Example 2. DETAILED DESCRIPTION

[0037] [Preparation method of natural polymer conductive fiber]

[0038] As mentioned above, the present invention provides a method for preparing natural polymer conductive fibers, the method comprising the following steps:

[0039] The natural polymer solution is extruded through a spinning pot nozzle and sequentially passed through a first coagulation bath, a conductive component coagulation bath and a protective layer coagulation bath to prepare the natural polymer conductive fiber.

[0040] According to an embodiment of the present invention, the natural polymer solution is obtained by dissolving a natural polymer material in a solvent.

[0041] According to an embodiment of the present invention, in the natural polymer solution, the concentration (solid content) of the natural polymer material is 3wt%-15wt%; specifically 6wt%-9wt%; illustratively, it can be 3wt%, 4wt%, 5wt%, 6wt%, 7wt%, 8wt%, 9wt%, 10wt%, 11wt%, 12wt%, 13wt%, 14wt% or 15wt%.

[0042] According to an embodiment of the present invention, the natural polymer material is, for example, at least one of cellulose, chitosan, chitin, silk protein, etc.; or, low-quality cellulose or natural plant tissue containing one or more of the above components.

[0043] The cellulose is selected from one or more of the following substances: microcrystalline cellulose, bacterial cellulose, cotton pulp, wood pulp, bamboo pulp, straw pulp, refined cotton, defatted cotton, cotton linters, bagasse, wood and crop straw, etc.; preferably one or more of microcrystalline cellulose, refined cotton, defatted cotton and wood pulp.

[0044] According to the embodiment of the present invention, there is no particular limitation on the selection of chitosan, chitin, silk protein, etc., and those skilled in the art can know and apply them to the system described in the present invention.

[0045] Preferably, the deacetylation degree of the chitosan is 50-100%; more preferably 70-95%.

[0046] The low-quality cellulose is a plant tissue containing at least two components, cellulose and lignin, such as herbaceous plants and / or agricultural and forestry wastes.

[0047] For example, the herbaceous plant is selected from one or more of trees, shrubs, vines, bamboos and the like.

[0048] For example, the agricultural and forestry waste is selected from one or more of bark, leaves, sawdust, crop straw, fruit shells or cores, corn cobs, sugarcane bagasse, etc.

[0049] Preferably, the crop straw can be selected from one or more of wheat straw, rice straw, corn straw, soybean straw, cotton straw, ginger stalk, and sesame straw.

[0050] According to an embodiment of the present invention, the solvent can be selected from one or more of the following solvents: organic solvents, ionic liquids, inorganic salts, organic salts; illustratively, selected from choline-type low eutectic solvent systems, organic solvent / salt systems, amine oxide systems (NMMO), carbamate systems, alkali / water systems, alkali / urea systems, alkali / thiourea systems, liquid ammonia / NH4SCN, organic acids, aqueous metal salt solutions, alcohol solutions of metal salt hydrates, or water-alcohol mixed solutions of metal salt hydrates.

[0051] The organic solvent may be selected from one or more of N,N-dimethyl sulfoxide (DMSO), N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP), N-methylimidazole, imidazole, pyridine, ethylenediamine, hexafluoroacetone, hexafluoroisopropanol, glycerol, methyl isobutyl ketone, tetrahydrofuran, dioxane, and γ-valerolactone (GVL).

[0052] The organic solvent / salt system is selected from organic solvent / metal salt, or organic solvent / organic salt, and can be selected from one or more of N,N-dimethylacetamide / lithium chloride (DMAc / LiCl) system and N,N-dimethyl sulfoxide / tetrabutylammonium fluoride system (DMSO / TBAF).

[0053] The alkali / water system can be selected from one or both of NaOH / H2O and KOH / H2O.

[0054] Wherein, the alkali / urea system is NaOH / Urea.

[0055] Wherein, the alkali / thiourea system is NaOH / thio-urea.

[0056] The organic acid can be selected from one or more of formic acid, acetic acid, propionic acid, butyric acid, succinic acid, lactic acid, glutamic acid, glycine, dichloroacetic acid, trichloroacetic acid, toluenesulfonic acid, phosphoric acid and the like.

[0057] Wherein, the aqueous solution of metal salt is selected from aqueous solutions of metal salts such as CaCl2, ZnCl2, LiClO4, Ca(SCN)2, LiSCN, and Ca(NO)2.

[0058] The alcohol solution of the metal salt hydrate can be selected from a methanol solution of CaBr2·H2O or a methanol solution of CaCl2·2H2O.

[0059] The water-alcohol mixed solution of the metal salt hydrate can be selected from a methanol aqueous solution of CaBr2·H2O or a methanol aqueous solution of CaCl2·2H2O.

[0060] The amine oxide system may be a NMMO / H2O / DMSO system, a NMMO / H2O / diethyltriamine system, or a NMMO / H2O system.

[0061] The ionic liquid is selected from organic molten salts formed by cations such as imidazole, pyridine, and pyrrole and anions with a melting point below 100° C., and is preferably an organic molten salt that can dissolve natural polymer materials.

[0062] For example, the cation of the ionic liquid is one or more cations selected from imidazole, pyridine, pyrrole, amine, phosphine, choline, diazabicyclic, and amino acid type cations that are unsubstituted or substituted with one, two or more substituents; for example, the substituent can be C 1-6 Alkyl, C 1-6 Alkoxy, hydroxy, -C 1-6 -OH, C1-6 alkenyl, phenyl, C 1-6 Alkoxy-substituted phenyl or C 1-6 One or more of alkyl-substituted phenyl groups; preferably, the substituents are one or more of methyl, ethyl, propyl, butyl, allyl, benzyl, methoxymethyl, methoxyethyl, hydroxyethyl, pentyl, m-methoxybenzyl, and m-methylbenzyl;

[0063] Preferably, the cation is selected from one or more of the following cations: 1-ethyl-3-methylimidazolium cation ([EMIM] + ), 3-methylimidazolium cation ([MIM] + ), 1-propyl-3-methylimidazolium cation ([PMIM] + ), 1-allyl-3-methylimidazolium cation ([AMIM] + ), 1-butyl-3-methylimidazolium cation ([BMIM] + ), 1-butyl-2,3-dimethylimidazolium cation ([BMMIM] + ), 1,3-dimethylimidazolium cation ([MMIM] +), 1-methoxyethyl-3-methylimidazolium cation ([MeOEMIM] + ), 1-methoxymethyl-3-methylimidazolium cation ([MeOMMIM] + ), 1-hydroxy-3-methyl-imidazolium cation ([HMIM] + ), 1-(2-hydroxyethyl)-3-methylimidazolium cation ([HOEMIM] + ), 1-methyl-3-benzylimidazolium cation ([MBzIM] + ), 1-pentyl-3-methylimidazolium cation ([PeMIM] + ), 1-benzyl-3-methylimidazolium cation ([BzMIM] + ), 1-m-methoxybenzyl-3-methylimidazolium cation ([MeOBzMIM] + ), 1-m-methylbenzyl-3-methylimidazolium cation ([MeBzMIM] + ), N-methylpyridinium cation ([MPyr] + ), N-ethylpyridinium cation ([EPyr] + ), N-butylpyridinium cation ([BPyr] + ), N-hexylpyridinium cation ([HPyr] + ), 1-butyl-3-methylpyrrolidinium ion ([BMPyrr] + ), tris(2-hydroxyethyl)methylamine ([THEMA] + ), tetrabutylamine ([TBA] + ), tetrabutylphosphine ([PBu4] + ), glycine cation ([Gly] + ), choline cation ([Ch] + ), 1,5-diazabicyclo[4.3.0]keto-5-ene([DBNH] + )wait.

[0064] More preferably, the cation is selected from one or more of the following cations: 1-ethyl-3-methylimidazolium cation ([EMIM] + ), 1-allyl-3-methylimidazolium cation ([AMIM] + ), 1-butyl-3-methylimidazolium cation ([BMIM] + ), choline cation ([Ch] + )wait.

[0065] For example, the anion is selected from one or more of halogen anions, organic acid radical ions, organic acid ester anions, amino acid type anions, and the like.

[0066] Preferably, the anion is selected from one or more of the following anions: chloride ion ([Cl] - ), bromide ion ([Br] - ), fluoride ion ([F] - ), formate ion ([HCOO] - ), acetate ion ([CH3COO] - or [Ac] - ), glycolate ion ([HOCH2COO] - ), propionate ion ([CH3CH2COO] - or [OPr] - ), butyrate ion ([CH3CH2CH2COO] - or [OBu] - ), octanoate ([Oct] - ), benzoate ion ([C6H5COO] - or [PhCOO] - ), lactate ion ([CH3CH(OH)COO] - or [Lac] - ), thioglycolate ion ([HSCH2COO] - ), hexafluorophosphate ion ([PF6] - ), trifluoroborate ([BF3] - ), methyl phosphate ion ([(MeO)HPO2] - or [MP] - ), dimethyl phosphate ion ([(MeO)2PO2] - or [DMP] - ), diethyl phosphate ion ([(EtO)2PO2] - or [DEP] - ), methanesulfonate anion ([MeOSO3] - ), trifluoromethanesulfonate anion ([CF3SO3] - ), glycine anion ([Gly] - ), lysine anion ([Lys] - ), valine anion ([Val] - ), dicyanamide anion ([N(CN)2] - or [DCA] - ), bis(trifluoromethanesulfonimide) ([Tf2N] - )wait.

[0067] More preferably, the anion is selected from one or more of the following anions: chloride ion ([Cl] - ), formate ion ([HCOO]- ), acetate ion ([Ac] - ), methyl phosphate ion ([(MeO)HPO2] - or [MP] - ), dimethyl phosphate ion ([(MeO)2PO2] - or [DMP] - ), and dicyanamide anion ([N(CN)2] - or [DCA] - )wait.

[0068] According to the present invention, the ionic liquid can be selected from 1-ethyl-3-methylimidazolium chloride ionic liquid ([EMIM][Cl]), 1-ethyl-3-methylimidazolium bromide ionic liquid ([EMIM][Br]), 1-ethyl-3-methylimidazolium formate ionic liquid ([EMIM][HCOO]), 1-ethyl-3-methylimidazolium acetate ionic liquid ([EMIM][Ac]), 1-ethyl-3-methylimidazolium octanoate ionic liquid ([EMIM][Oct]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][MP]), 1-ethyl-3-methylimidazolium dimethyl phosphate ionic liquid ([EMIM][DMP]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][MP]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][D ...HCOO]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][Ac]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][MP]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid ([EMIM][DMP]), 1-ethyl-3-methylimidazolium methyl phosphate ionic liquid 1-ethyl-3-methylimidazolium diethyl phosphate ionic liquid ([EMIM][DEP]), 1-ethyl-3-methylimidazolium propionate ionic liquid ([EMIM][OPr]), 1-ethyl-3-methylimidazolium top ionic liquid ([EMIM][OBu]), 1-ethyl-3-methylimidazolium glycinate ionic liquid ([EMIM][Gly]), 1-ethyl-3-methylimidazolium lysine ionic liquid ([EMIM][Lys]), 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]), 1-allyl-3-methylimidazolium bromide ionic liquid ([AMIM][Br]), 1-allyl-3-methylimidazolium formate ionic liquid ([AMIM][ HCOO]), 1-allyl-3-methylimidazolium acetate ionic liquid ([AMIM][Ac]), 1-butyl-3-methylimidazolium chloride ionic liquid ([BMIM][Cl]), 1-butyl-3-methylimidazolium bromide ionic liquid ([BMIM][Br]), 1-butyl-3-methylimidazolium formate ionic liquid ([BMIM][HCOO]), 1-butyl-3-methylimidazolium acetate ionic liquid ([BMIM][Ac]), 1-butyl-3-methylimidazolium hydroxyacetate ionic liquid ([BMIM][HOCH2COO]), 1-butyl-3-methylimidazolium propionate ionic liquid ([BMIM][CH3CH2COO]), 1-butyl-3-methyl imidazolium lactate ionic liquid [BMIM][Lac], 1-butyl-3-methylimidazolium butyrate ionic liquid ([BMIM][CH3CH2CH2COO]), 1-butyl-3-methylimidazolium benzoate ionic liquid ([BMIM][C6H5COO]), 1-butyl-3-methylimidazolium glycine ionic liquid ([BMIM][H2NCH2COO]), 1-butyl-3-methylimidazolium dicyanamide ionic liquid ([BMIM][N(CN)2]), 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide ionic liquid ([BMIM][Tf2N]), 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid ([BMIM][PF6]),1-Butyl-3-methylimidazolium tetrafluoroborate ionic liquid ([BMIM][BF4]), 1-Butyl-3-methylimidazolium methylsulfonate ionic liquid ([BMIM][MeOSO3]), 1-Butyl-3-methylimidazolium trifluoromethylsulfonate ionic liquid ([BMIM][CF3SO3]), 1-Butyl-2,3-dimethylimidazolium tetrafluoroborate ionic liquid ([BMMIM][BF4]), 3-methylimidazolium formate ionic liquid ([MIM][HCOO]), 1,3-dimethylimidazolium chloride ionic liquid ([MMIM][Cl]), 1,3-dimethylimidazolium methyl phosphate ionic liquid ([MMIM][MP]), 1,3-dimethyl imidazolium dimethyl phosphate ionic liquid ([MMIM][DMP]), 1,3-dimethylimidazolium methylsulfonate ionic liquid ([MMIM][MeOSO3]), 1-hydroxy-3-methyl-imidazolium chloride ionic liquid ([HMIM][Cl]), 1-hydroxy-3-methyl-imidazolium trifluoromethylsulfonate ionic liquid ([HMIM][CF3SO3]), 1-(2-hydroxyethyl)-3-methylimidazolium chloride ionic liquid ([HOEMIM][Cl]), 1-methoxymethyl-3-methylimidazolium bromide ionic liquid ([MeOMMIM][Br]), 1-methoxyethyl-3-methylimidazolium bromide ionic liquid ([MeOEMIM][Br]), N -Ethylpyridinium chloride ionic liquid ([EPyr][Cl]), N-ethylpyridinium bromide ionic liquid ([EPyr][Br]), N-methylpicolinate ionic liquid ([MPyr][HCOO]), tris(2-hydroxyethyl)methylamine acetate ionic liquid ([THEMA][Ac]), tris(2-hydroxyethyl)methylamine methylsulfonate ionic liquid ([THEMA][MeOSO3]), tris(2-hydroxyethyl)methylamine trifluoromethylsulfonate ionic liquid [THEMA][CF3SO3], tetrabutylphosphine valine ionic liquid [PBu4][Val], tetrabutylphosphine lysine ionic liquid [PBu4][Lys], tetrabutylphosphine glycinate ...Lys], tetrabutylphosphine methylamine acetate ionic liquid ([THEMA][Ac]), tris(2-hydroxyethyl)methylamine methylsulfonate ionic liquid ([THEMA][MeOSO3]), tris(2-hydroxyethyl)methylamine trifluoromethylsulfonate ionic liquid [THEMA][CF3SO3], tetrabutylphosphine valine ionic liquid [PBu4][Val], tetrabutylphosphine lysine ionic liquid [PBu4][Lys], tetrabutylphosphine glycinate ionic liquid [PBu4][Lys], tetrabutylphosphine methylamine acetate ionic liquid ([THEMA][Ac]), tris(2-hydroxyethyl)methylamine methylsulfonate ionic liquid ([THEMA][MeOSO3]), tris(2-hydroxyethyl)methylamine trifluoromethylsulfonate ionic liquid [ Subliquid [PBu4][Gly], 1-benzyl-3-methylimidazolium chloride ionic liquid ([BzMIM][Cl]), 1-benzyl-3-methylimidazolium dicyanamide ionic liquid ([BzMIM][DCA]), 1-m-methylbenzyl-3-methylimidazolium chloride ionic liquid ([MeBzMIM][Cl]), 1-m-methoxybenzyl-3-methylimidazolium chloride ionic liquid ([MeOBzMIM][Cl]), choline chloride ionic liquid ([Ch][Cl]), choline bromide ionic liquid ([Ch][Br]), choline acetate ionic liquid ([Ch][CH3COO]), choline propionate ionic liquid ([Ch][CH3CH2COO]),One or more of ionic liquids such as choline butyrate ionic liquid ([Ch][CH3CH2CH2COO]), glycine hydrochloride ionic liquid ([Gly][Cl]), and 1,5-diazabicyclo[4.3.0]keto-5-ene acetate ionic liquid ([DBNH][Ac]).

[0069] Preferably, the choline-type deep eutectic solvent system is selected from one or more of [Ch][Cl] / urea, [Ch][Br] / urea, [Ch][Cl] / thio-urea, [Ch][Cl] / glycerol, and [Ch][Cl] / lactic acid.

[0070] Illustratively, the cellulose-dissolving solvent has the above meaning; more preferably, the cellulose-dissolving solvent is selected from one or more of [AMIM][Cl], [BMIM][Cl], [EMIM][Ac], and [BMIM][Ac].

[0071] Exemplarily, the solvent for dissolving chitosan is selected from any one or more of the following solvents: formic acid, acetic acid, hexafluoroisopropanol, hexafluoroacetone, DMAc / LiCl and [AMIM][Cl], [BMIM][Cl], [BMIM][Ac], [BMIM][HCOO], [BMIM][CH3CH2COO], [BMIM][CH3CH2CH2COO], [BMIM][HOCH2COO], [BMIM][C6H5COO], [BMIM][CH3CH(OH)COO], [BMIM][N(CN)2], [BMIM][BF4], [EMIM][Cl], [EMIM][Ac], [HMIM][Cl ], [MMIM][Cl], [Ch][Cl], [Ch][CH3COO], [Ch][CH3CH2COO], [Ch][CH3CH2CH2COO], [Gly][Cl], [BMIM][Cl], etc.; more preferably, selected from [AMIM][Cl], [BMIM][Cl], [BMIM][Ac], [EMIM][Ac], [BMIM][CH3CH2COO], [BMIM][CH3CH2CH2COO], [BMIM][BF4], [Gly][Cl], [HMIM][Cl], [MMIM][Cl], [Ch][Cl], [Ch][CH3CH2CH2COO], etc.

[0072] Preferably, the solvent for dissolving chitin is selected from any one or more of the following solvents: formic acid, acetic acid, glutamic acid, lactic acid, succinic acid, dichloroacetic acid (DCA), trichloroacetic acid (TCA), N-methyl-2-pyrrolidone (NMP), hexafluoroisopropanol, hexafluoroacetone, NMP / LiCl, DMAc / LiCl, CaBr2·H2O or CaCl2·2H2O saturated methanol solution, LiCl, LiSCN, NaOH-urea aqueous solution, [AMIM][Cl], [AMIM][Br], [AMIM][Ac], [BMIM][Ac], [BMIM][Cl], [MMIM][D MP], [EMIM][Ac], [EMIM][DMP], [EMIM][Ac], [EMIM][OPr], [EMIM][OBu], [EMIM][Gly], [EMIM][Lys], [HOEMIM][Cl], [THEMA][Ac], [T HEMA][MeOSO3], [THEMA][CF3SO3], [PBu4][Val], [PBu4][Lys], [PBu4][Gly], [Ch][Cl] / urea, [Ch][Br] / urea, [Ch][Cl] / thio-urea, etc. More preferred are [AMIM][Ac], [BMIM][Ac], [EMIM][Ac], [BMIM][Cl], [AMIM][Cl], [AMIM][Br], [EMIM][OPr], [EMIM][OBu], [Ch][Cl] / urea, [Ch][Br] / urea, [Ch][Cl] / thio-urea, etc.

[0073] Preferably, the solvent for dissolving silk protein is selected from any one or more of the following solvents: phosphoric acid, Ca(NO)2-CH3OH, formic acid / lithium chloride, lithium bromide, calcium chloride ethanol water system and ionic liquids such as [AMIM][Cl], [AMIM][Br], [AMIM][Ac], [BMIM][Ac], [BMIM][Cl], [MMIM][DMP], [EMIM][Ac]; more preferably [AMIM][Cl], [BMIM][Cl], [BMIM][Ac], [EMIM][Ac], etc.

[0074] According to the present invention, the ionic liquid can be a single ionic liquid or a mixture of multiple ionic liquids; for example, the single ionic liquid is an ionic liquid that can completely dissolve or partially dissolve the natural polymer material; for example, the ionic liquid mixture can be all ionic liquids that can dissolve the natural polymer material, or it can be a mixture of ionic liquids that can dissolve the natural polymer material and ionic liquids that cannot dissolve the natural polymer material.

[0075] According to an embodiment of the present invention, the first coagulation bath is water or an alcohol solution.

[0076] According to an embodiment of the present invention, the conductive component coagulation bath is a conductive component or a conductive component dispersion. When the conductive component is a liquid, the conductive component coagulation bath can directly use the conductive component. When the conductive component is non-liquid, the conductive component coagulation bath uses a conductive component dispersion. For example, the conductive component dispersion is an aqueous dispersion or an alcohol dispersion of the conductive component, which is obtained by dispersing the conductive component in water or an alcohol solvent. The concentration of the conductive component dispersion is 0.01 mg / mL to 1 mg / mL. For example, the concentration of the silver nanowire dispersion is 0.01 mg / mL to 1 mg / mL, and its conductivity is 0.17 S / cm to 586 S / cm.

[0077] According to an embodiment of the present invention, the conductive component is selected from at least one of conductive substances such as silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, carbon nanotubes, graphene, polyaniline, and polypyrrole.

[0078] According to an embodiment of the present invention, the protective layer coagulation bath refers to a bulk solution or a dispersion of the protective component. For example, the dispersion is an aqueous solution or an alcohol solution of the protective component, wherein the protective component is dispersed in water or an alcohol solvent.

[0079] According to an embodiment of the present invention, the protective component is selected from at least one of water-soluble polyurethane, PDMS prepolymer, water-soluble rubber, and ethyl cellulose.

[0080] According to an embodiment of the present invention, the alcohol in the alcohol solution or alcohol solvent is selected from methanol, ethanol, propanol, n-butanol, glycerol, ethylene glycol, isopropanol or isobutanol.

[0081] Exemplarily, the method for preparing the natural polymer conductive fiber includes:

[0082] After degassing, the natural polymer solution is poured into the spinning pot, and the natural polymer solution is squeezed out from the spinning pot nozzle by pressure;

[0083] It then passes through a drafting roller and enters the first coagulation bath (i.e., water or alcohol solution) to prepare the core layer;

[0084] Then enter the conductive component coagulation bath and the protective layer coagulation bath in sequence;

[0085] Then the natural polymer conductive fiber is obtained by a hot roller drying process.

[0086] In the present invention, there is no particular limitation on the magnitude of the pressure, as long as the natural polymer solution can be squeezed out from the nozzle.

[0087] According to an embodiment of the present invention, the temperature of the hot roller drying is 60°C-100°C; preferably 80°C.

[0088] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two conductive components; illustratively, the conductive component coagulation bath contains at least two conductive components, that is, the conductive component coagulation bath is a mixed coagulation bath composed of at least two conductive components; or the material extracted from the first coagulation bath is sequentially passed through at least two conductive component coagulation baths, and each conductive component coagulation bath contains one or more conductive components.

[0089] As an exemplary embodiment of the present invention, the method for preparing the natural polymer conductive fiber includes:

[0090] After degassing, the natural polymer solution is poured into the spinning pot, and the natural polymer solution is squeezed out from the spinning pot nozzle by pressure;

[0091] Then it passes through the drafting roller and enters the first coagulation bath (i.e., water or alcohol coagulation bath) to prepare the core layer;

[0092] Then sequentially enter a conductive component coagulation bath, wherein the conductive component coagulation bath is composed of a mixed coagulation bath composed of two or more conductive components, and a protective layer coagulation bath; or sequentially pass through at least two conductive component coagulation baths, each conductive component coagulation bath containing one or more conductive components, and a protective layer coagulation bath;

[0093] Then the natural polymer conductive fiber is obtained by a hot roller drying process.

[0094] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two protective layer components; illustratively, the protective layer coagulation bath contains at least two protective layer components, that is, the protective layer coagulation bath is a mixed coagulation bath composed of at least two protective layer components; or the material extracted from the conductive component coagulation bath is sequentially passed through at least two protective layer coagulation baths, and each protective layer coagulation bath contains one or more protective layer components.

[0095] As an exemplary embodiment of the present invention, the preparation method of the natural polymer conductive fiber is:

[0096] After degassing, the natural polymer solution is poured into the spinning pot, and the natural polymer solution is squeezed out from the spinning pot nozzle by pressure;

[0097] Then it passes through the drafting roller and enters the first coagulation bath (i.e., water or alcohol coagulation bath) to prepare the core layer;

[0098] Then sequentially enter the conductive component coagulation bath and the protective layer coagulation bath, wherein the protective layer coagulation bath is composed of a mixed coagulation bath of two or more protective layer components; or sequentially pass through at least two protective layer coagulation baths, each protective layer coagulation bath containing one or more protective layer components;

[0099] Then the natural polymer conductive fiber is obtained by a hot roller drying process.

[0100] According to an embodiment of the present invention, the natural polymer conductive fiber contains at least two conductive components and at least two protective layer components; illustratively, the conductive component coagulation bath contains at least two conductive components, and the protective layer coagulation bath contains at least two protective layer components; that is, the conductive component coagulation bath is a mixed coagulation bath composed of at least two conductive components; or the material derived from the first coagulation bath is sequentially passed through at least two conductive component coagulation baths, each conductive component coagulation bath contains one or more conductive components; that is, the protective layer coagulation bath is a mixed coagulation bath composed of at least two protective layer components; or the material derived from the conductive component coagulation bath is sequentially passed through at least two protective layer coagulation baths, each protective layer coagulation bath contains one or more protective layer components.

[0101] As an exemplary embodiment of the present invention, the method for preparing the natural polymer conductive fiber includes:

[0102] After degassing, the natural polymer solution is poured into the spinning pot, and the natural polymer solution is squeezed out from the spinning pot nozzle by pressure;

[0103] Then it passes through the drafting roller and enters the first coagulation bath (i.e., water or alcohol coagulation bath) to prepare the core layer;

[0104] Then sequentially enter a conductive component coagulation bath, wherein the conductive component coagulation bath is composed of a mixed coagulation bath composed of the above two or more conductive components; or sequentially pass through at least two conductive component coagulation baths, each conductive component coagulation bath containing one or more conductive components, and a protective layer coagulation bath, wherein the protective layer coagulation bath is composed of a mixed coagulation bath of the above two or more protective layer components; or sequentially pass through at least two protective layer coagulation baths, each protective layer coagulation bath containing one or more protective layer components;

[0105] Then the natural polymer conductive fiber is obtained by a hot roller drying process.

[0106] Preferably, the natural polymer solution, the conductive component coagulation bath, the protective layer coagulation bath, the conductive component, and the protective layer component are all selected as shown above.

[0107] [Natural polymer conductive fiber]

[0108] As mentioned above, the present invention provides a natural polymer conductive fiber, which has a skin-core structure, comprising a natural polymer fiber core structure and a skin structure formed by a conductive layer and a protective layer from the inside out.

[0109] According to the present invention, the conductive component in the conductive layer is selected from at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, carbon nanotubes, graphene, polyaniline, polypyrrole, and the like.

[0110] According to the present invention, the protective component in the protective layer is selected from at least one of water-soluble polyurethane, PDMS prepolymer, water-soluble rubber, ethyl cellulose and the like.

[0111] According to the present invention, the cross section of the natural polymer conductive fiber is circular and has a skin-core structure.

[0112] In the present invention, the core layer of the conductive fiber is a dissolved regenerated fiber of a natural polymer material, which is used to provide strength, the conductive layer is used to provide conductive performance, and the protective layer is used to improve the stability of the conductive fiber, so that the conductive component can better act on the surface of the natural polymer fiber and can provide an elastomer layer.

[0113] According to an embodiment of the present invention, the natural polymer material dissolved regenerated fiber can be a bundle of fibers or a single fiber; specifically, the size (diameter) range of the natural polymer material dissolved regenerated fiber is 5μm-500um, which can be detected by optical microscopy and cryo-scanning electron microscopy data, and the preferred size (diameter) is 10μm-50μm.

[0114] According to an embodiment of the present invention, the natural polymer conductive fiber is prepared by the above-mentioned method for preparing the natural polymer conductive fiber.

[0115] [application]

[0116] The present invention also provides applications of the natural polymer conductive fiber in the fields of conduction, electromagnetic shielding, flexible electrodes, sensor devices, etc.

[0117] The technical solutions of the present invention will be described in further detail below with reference to specific embodiments. It should be understood that the following embodiments are merely illustrative and explanations of the present invention and should not be construed as limiting the scope of protection of the present invention. All technologies implemented based on the above content of the present invention are encompassed within the scope of protection that the present invention is intended to protect.

[0118] Unless otherwise specified, the raw materials and reagents used in the following examples are commercially available or can be prepared by known methods.

[0119] Different conductive materials

[0120] Example 1

[0121] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, along with 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, then into a 1 wt% ethanol-dispersed carbon nanotube dispersion, and then into a 20 wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to obtain the natural polymer conductive fiber. The fiber conductivity was 0.5 S / cm.

[0122] Example 2

[0123] 6g of dried wood pulp with a degree of polymerization of 549 was placed in a three-necked flask, along with 94g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, then into a 1wt% ethanol-dispersed copper nanowire dispersion, and then into a 20wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to produce the natural polymer conductive fiber. The fiber conductivity was 20.7S / cm.

[0124] Example 3

[0125] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, along with 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath. The solution then entered a 1 wt% water-soluble polyaniline coagulation bath and then into a 20 wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to obtain the natural polymer conductive fiber. The fiber conductivity was 0.002 S / cm.

[0126] Different coagulation bath concentrations

[0127] Example 4

[0128] 6g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, along with 94g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, then into a 1wt% ethanol-dispersed silver nanowire dispersion, and then into a 20wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to obtain the natural polymer conductive fiber. The fiber conductivity was 577 S / cm.

[0129] Example 5

[0130] 6g of dried wood pulp with a degree of polymerization of 549 was placed in a three-necked flask, along with 94g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, then into a 0.5wt% ethanol-dispersed silver nanowire dispersion, and then into a 20wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to obtain the natural polymer conductive fiber. The fiber conductivity was 57.2S / cm.

[0131] Example 6

[0132] 6g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, along with 94g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath. The solution then entered a 0.5wt% ethanol-dispersed silver nanowire dispersion and then a 20wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at 80°C to obtain the natural polymer conductive fiber. The fiber conductivity was 2.1S / cm.

[0133]

Different ionic liquids

[0134] Example 7

[0135] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The cellulose solution was squeezed out of the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, and then into a 0.5 wt% ethanol-dispersed silver nanowire dispersion, and then into a 20 wt% water-soluble polyurethane solution. The natural polymer conductive fiber was then obtained by hot roller drying at a temperature of 80°C.

[0136] Figure 1 This is a digital photo of the cellulose / silver nanowire conductive fiber obtained in Example 7.

[0137] The natural polymer conductive fiber is prepared into a woven fabric (or cloth fabric) by a conventional method in the art, and its digital photo is as follows Figure 2 shown.

[0138] Example 8

[0139] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-butyl-3-methylimidazolium chloride ionic liquid ([[BMIM][Cl]) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath. Then, it entered a 0.5 wt% ethanol-dispersed silver nanowire dispersion and then into a 20 wt% water-soluble polyurethane solution. The solution was then dried by hot rollers at a temperature of 80°C to obtain the natural polymer conductive fiber.

[0140] Example 9

[0141] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-ethyl-3-methylimidazolium acetate ionic liquid ([EMIM]]Ac) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath. Then, it entered a 0.5 wt% ethanol-dispersed silver nanowire dispersion and then into a 20 wt% water-soluble polyurethane solution. Subsequently, it was dried by a hot roller at a temperature of 80°C to obtain the natural polymer conductive fiber.

[0142]

Different protection layers

[0143] Example 10

[0144] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, and then into a 20 wt% water-soluble polyaniline coagulation bath, and then into a 5 wt% PDMS prepolymer. Subsequently, it was dried by a hot roller at a temperature of 80°C to obtain the natural polymer conductive fiber.

[0145] Example 11

[0146] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure, then passed through a drafting roller into a water coagulation bath, and then into a 20 wt% water-soluble polyaniline coagulation bath, and then into a 5 wt% water-soluble rubber coagulation bath. Subsequently, it was dried by a hot roller at a temperature of 80°C to obtain the natural polymer conductive fiber.

[0147] Example 12

[0148] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80°C for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure, and then passed through a drafting roller into a water coagulation bath, and then into a water-soluble polyaniline coagulation bath, and then into a 3wt% ethyl cellulose solution coagulation bath. Subsequently, it was dried by a hot roller at a temperature of 80°C to obtain the natural polymer conductive fiber.

[0149]

Different natural polymer fibers

[0150] Example 13

[0151] 6 g of dried chitosan with a deacetylation degree of 75% was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a chitosan solution was formed. The chitosan solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath, and then into a 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. The solution was then dried by hot rollers at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0152] Example 14

[0153] 6 g of dried chitosan was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a chitosan solution was formed. The chitosan solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure and then passed through a drafting roller into a water coagulation bath, and then into a 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. The solution was then dried by a hot roller at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0154] Example 15

[0155] 6 g of dried silk protein was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a silk protein solution was formed. The silk protein solution was degassed and poured into a spinning tank. The solution was squeezed out from the spinning tank nozzle by pressure, then passed through a drafting roller into a water coagulation bath, and then into a 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. It was then dried by a hot roller at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0156]

Different coagulation baths

[0157] Example 16

[0158] 6 g of dried wood pulp with a degree of polymerization of 549 was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure, then passed through a drafting roller into an ethanol coagulation bath, and then into a 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. Subsequently, it was dried by a hot roller at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0159] Example 17

[0160] 6 g of dried wood pulp was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure, then passed through a drafting roller into a methanol coagulation bath, and then into a second 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. Subsequently, it was dried by a hot roller at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0161] Example 18

[0162] 6 g of dried wood pulp was added to a three-necked flask, and 94 g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]) was added. After stirring at 80° C. for 2 hours, a cellulose solution was formed. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out from the spinning pot nozzle by pressure and then passed through a drafting roller into a propanol coagulation bath, and then into a 0.5 wt% water-soluble polyaniline coagulation bath, and then into a 20 wt% water-soluble polyurethane. The solution was then dried by a hot roller at a temperature of 80° C. to obtain the natural polymer conductive fiber.

[0163] Comparative Example 1

[0164] 6g of dried wood pulp with a degree of polymerization of 549 was placed in a three-necked flask, along with 94g of 1-allyl-3-methylimidazolium chloride ionic liquid ([AMIM][Cl]). The mixture was stirred at 80°C for 2 hours to form a cellulose solution. The cellulose solution was degassed and poured into a spinning pot. The solution was squeezed out of the spinning pot nozzle using pressure, then passed through a drafting roller into a water coagulation bath. The resulting fibers were then dried using hot rollers to obtain dried natural polymer fibers. The fibers were then passed through a drafting roller into a 1wt% ethanol-dispersed silver nanowire dispersion and then dried using hot rollers to obtain the natural polymer conductive fibers. The fiber conductivity was 128 S / cm.

[0165] Test Case

[0166] Test Example 1-Conductivity Test

[0167] The conductivity of the fiber was tested using a Keithley 2500 digital multimeter.

[0168] Test Example 2-Water Washing Stability Test

[0169] The natural polymer conductive fiber prepared in Example 4 has an electrical conductivity of 577 S / cm. The protective layer of polyurethane is removed, and the obtained product is recorded as sample ①.

[0170] The natural polymer conductive fiber prepared in Comparative Example 1 is recorded as sample ②. The water washing stability test process of sample ① and sample ② is as follows: take appropriate amounts of sample ① and sample ② and place them in 250mL beakers respectively, add 150mL deionized water to the beakers, add a magnet, stir at 1000r / min, and then put them in a vacuum oven at 60℃ to dry for 6 hours, test their resistance, and then put them in the beaker and continue stirring. The water washing stability of the conductive fiber is tested in this cycle, and the stirring time is 2h, 4h, 6h, 12h, and 24h respectively. The test results are as follows Figure 5 As shown in the figure, Gel fiber (i.e. wet fiber or gel fiber) and triangle represent sample ①, Dry fiber (i.e. dry fiber) and circle represent sample ②. Figure 5 It can be seen that the resistance of the natural polymer conductive fiber obtained by the method of the present invention is almost unchanged after 24 hours of water washing, but the conductive fiber obtained in Comparative Example 1 is insulated after 6 hours, which proves that the conductive fiber prepared by the method of the present invention has water washing stability.

[0171] Figure 6 The SEM images of the silver nanowires before and after washing of the wet and dry fibers in Test Example 2 are shown; Figure 6 (1) is the SEM image of wet fiber (or gel fiber) before washing; Figure 6 (2) is the SEM image of wet fiber (or gel fiber) after washing for 24 hours; Figure 6 (3) is the SEM image of the dry fiber before washing; Figure 6 (4) is the SEM image of the dry fiber after washing for 24 hours; Figure 6 It can be observed that the silver nanowire content in the gel fiber remains almost unchanged before and after washing. Due to process shortcomings, the dry fiber itself contains only a small amount of silver nanowires before washing. After washing, the silver nanowires are almost completely detached. This indicates that the gel fiber of the present invention has better washing stability than the dry fiber.

[0172] Test Example 3

[0173] The electrostatic shielding effect of the fabric in Example 7 was tested. The test results Figure 3 As shown, from Figure 3 It can be seen that the shielding effectiveness of commercial fabrics sold on the market (the commercial fabrics are prepared only through a water coagulation bath, that is, they do not contain the steps of a conductive component coagulation bath and a protective layer coagulation bath) is only 1-3dB, while the shielding effectiveness of the fabric woven from fibers prepared by this process reaches 44dB, indicating that the fabric prepared using the polymer conductive fiber of this application has good electromagnetic shielding performance and can be applied to fields such as maternity clothes.

[0174] Figure 4 The digital photos of the cellulose / silver nanowire conductive fibers obtained in Example 7 after passing through silver nanowire coagulation baths of different concentrations. From left to right, the concentrations of the silver nanowire coagulation baths are 1% wt, 0.5% wt, 0.1% wt, 0.05% wt, 0.01% wt, and 0.001% wt, respectively. Figure 4 It can be seen that after coagulation baths of different concentrations, the conductive fibers have different colors and different contents of conductive components.

[0175] The above is an exemplary description of the embodiments of the present invention. However, the scope of protection of the present invention is not limited to the above embodiments. Any modifications, equivalent substitutions, improvements, etc. made by those skilled in the art within the spirit and principles of the present invention shall be included in the scope of protection of the present invention.

Claims

1. A method for preparing natural polymer conductive fibers, characterized in that: The method comprises the following steps: The natural polymer solution is extruded through a spinning pot nozzle and sequentially passed through a first coagulation bath, a conductive component coagulation bath and a protective layer coagulation bath to prepare the natural polymer conductive fiber; In the natural polymer solution, the solid content of the natural polymer material is 3wt%-15wt%; The natural polymer material is at least one of cellulose, chitosan, chitin, and silk protein; The first coagulation bath is water or alcohol solution; The conductive component coagulation bath is a conductive component dispersion; the conductive component dispersion is an aqueous dispersion or an alcohol dispersion of the conductive component, wherein the conductive component is dispersed in water or an alcohol solvent; the concentration of the conductive component dispersion is 0.01 mg / mL-1 mg / mL; The conductive component is selected from at least one of silver nanowires, silver nanoparticles, copper nanowires, copper nanoparticles, carbon nanotubes, graphene, polyaniline, and polypyrrole; The protective layer coagulation bath refers to a bulk solution or a dispersion of the protective component, and the dispersion of the protective component is an aqueous solution or an alcohol solution of the protective component; The protective component is selected from at least one of water-soluble polyurethane, PDMS prepolymer, water-soluble rubber, and ethyl cellulose.

2. The method according to claim 1, characterized in that The alcohol in the alcohol solution or alcohol solvent is selected from methanol, ethanol, propanol, n-butanol, glycerol, ethylene glycol, isopropanol or isobutanol.

3. The method according to claim 1, characterized in that The natural polymer conductive fiber contains at least two conductive components.

4. The method according to claim 3, characterized in that The natural polymer conductive fiber contains at least two protective layer components.

5. The method according to claim 4, characterized in that The natural polymer conductive fiber contains at least two conductive components and at least two protective layer components.

6. The natural polymer conductive fiber prepared by the method according to any one of claims 1 to 5, characterized in that: The conductive fiber is a skin-core structure, which comprises a natural polymer fiber core structure and a skin structure formed by a conductive layer and a protective layer from the inside out.

7. Use of the natural polymer conductive fiber according to claim 6 in the fields of electromagnetic shielding, flexible electrodes or sensor devices.

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