119 results about "Copper nanoparticle" patented technology

The invention discloses copper paste, an electrode and a preparation method and application of the electrode, the electrode comprises copper powder, the copper powder comprises nano-copper particles and flaky copper powder, the nano-copper particles comprise at least two connected copper nanoparticles, and the adjacent copper nanoparticles are connected in a surface contact mode. According to the electrode disclosed by the invention, the nano-copper particles formed by connecting more than two copper nano-particles are filled in the gap areas among the large-size flaky copper powder, so that the nano-copper particles are in direct contact with the flaky copper powder, conductive channels among the conductive particles are smoother, and the structure of the electrode is more compact due to the filling of the nano-copper particles; the bulk resistance of the electrode is greatly reduced and is equal to the conductivity of a silver electrode; the nano-copper particles can also be used as an auxiliary adhesive after being sintered and cured, so that the adhesive force between the copper grid line and the solar cell is improved, and the connection between the grid line and the solar cell is firmer.

The invention relates to the technical field of photocatalytic processes, in particular to a catalyst for preparing methanol through photocatalytic reduction of CO2 as well as a preparation method and application of the catalyst. The catalyst comprises a composite carrier and active sites dispersed on the surface or in pores of the composite carrier, the composite carrier is of a heterojunction composite structure formed by a hollow TiO2 sphere and MCN, the hollow TiO2 sphere comprises a shell layer and a spherical cavity structure located in the shell layer, the shell layer is formed by TiO2 nanoparticles, and the MCN has a mesoporous pore structure; a II-type or Z-type heterojunction interface is formed between the hollow TiO2 spheres and the MCN through physical contact and chemical action; the active sites comprise copper nano species, sulfur vacancy defects and amino groups; the copper nano species are copper nano particles or clusters, and the valence state of copper is 0 and / or + 1 valence amino is grafted on the surface of the composite carrier through an organic long chain. The catalyst provided by the invention can greatly improve the yield and selectivity of methanol prepared by photocatalytic reduction of carbon dioxide.

The application relates to the development and technical field of electrocatalysts, and discloses a benzothiadiazole modified single-atom zirconium-doped metal copper electrode material and a preparation method and application thereof. The preparation method comprises the following steps: dissolving inorganic copper salt and inorganic zirconium salt, adding the inorganic copper salt and the inorganic zirconium salt into an alkaline solution, and performing hydrothermal reaction to obtain a single-atom zirconium-doped copper oxide precursor; dissolving benzothiadiazole, adding the benzothiadiazole into a dispersion solution of the single-atom zirconium-doped copper oxide precursor to obtain a mixed solution; spraying the mixed solution on a polytetrafluoroethylene film substrate loaded with copper nanoparticles to obtain a benzothiadiazole modified single-atom zirconium-doped copper oxide precursor electrode material; and performing electrochemical reduction treatment on the benzothiadiazole modified single-atom zirconium-doped copper oxide precursor electrode material to obtain a benzothiadiazole modified single-atom zirconium-doped metal copper electrode material. The electrode material is applied to an electro-reduction carbon dioxide reaction as a working electrode, exhibits excellent electro-reduction CO2 performance in an acidic environment, and realizes high-value-added C 2+ product with high selectivity.

One object of the present application is to provide composite copper nanoparticles that have high dispersibility in organic solvents and can be used to form a smooth electrode film. The present invention provides composite copper nanoparticles in which the surfaces of copper nanoparticles are modified with a silane coupling agent, wherein the copper nanoparticles have a coating film containing copper oxide on at least a part of the surface, and wherein the mass carbon concentration derived from the silane coupling agent in the composite copper nanoparticles is 0.1 to 1.2% by mass with respect to the total mass of the composite copper nanoparticles or wherein the number of surface groups derived from the silane coupling agent on the surface of the composite copper nanoparticles is 1.0 to 13.0 per 1 nm2 of the surface area of the composite copper nanoparticles

The application relates to the development and technical field of electrocatalysts, and discloses a preparation method and application of a proton sponge modified fluorine atom doped metal copper electrode material, which comprises the following steps: adding a dispersion solution of a proton sponge into a dispersion solution of a hydroxyl copper fluoride precursor to obtain a mixed solution; uniformly spraying the mixed solution on a polytetrafluoroethylene film substrate loaded with copper nanoparticles to obtain a proton sponge modified hydroxyl copper fluoride precursor electrode material; and then electrochemically reducing the proton sponge modified hydroxyl copper fluoride precursor electrode material to obtain the proton sponge modified fluorine atom doped metal copper electrode material. The application further discloses the proton sponge modified fluorine atom doped metal copper electrode material obtained by the above preparation method and application of the proton sponge modified fluorine atom doped metal copper electrode material to an electro-reduction carbon dioxide reaction as a working electrode. The electrode material provided by the application exhibits excellent electro-reduction CO2 performance in an acidic environment, and realizes the preparation of high-value C 2+ products with high selectivity under an industrial-grade current density.

This application provides a method for preparing gallium oxide (GaO) with enhanced ultraviolet absorbance and a GaO material prepared according to this method. First, a GaO thin film capable of generating ultraviolet absorption is grown on a substrate by magnetron sputtering. The GaO thin film is then annealed. Next, a copper thin film is grown on the GaO thin film by magnetron sputtering, followed by rapid annealing, causing the copper film to crack into copper nanoparticles under heat. This preparation method utilizes copper nanoparticles to enhance the ultraviolet absorption performance of GaO. The process steps are simple and easy to operate, thus effectively reducing the preparation cost. Furthermore, the GaO material prepared by this method shows a significant improvement in ultraviolet absorbance.

The invention discloses a photoresist composition based on metal nanoparticles and application of the photoresist composition. The photoresist composition comprises metal nanoparticles, a photosensitizer, an anti-diffusion agent and a photoresist solvent, wherein the metal nanoparticles are silver nanoparticles, copper nanoparticles and gold nanoparticles. The photoresist composition has good film-forming property and excellent patterning imaging capability, photoetching patterns with different resolutions can be obtained through ultraviolet, electron beam or extreme ultraviolet exposure, and the formed patterns have good conductivity after being subjected to heat treatment and can be directly used for processing micro-nano devices.

The invention provides a preparation method of a composite fiber and a fabric with sunlight barrier performance. The preparation method of the composite fiber comprises the following steps: S10, respectively preparing a skin layer melt and a core layer melt; the skin layer melt comprises a thermoplastic polymer matrix and titanium dioxide particles; the core layer melt comprises a thermoplastic polymer matrix, titanium dioxide particles and cesium tungsten bronze nanoparticles; s20, the skin layer melt and the core layer melt are introduced into a composite spinning assembly, the skin layer melt is controlled to wrap the core layer melt to form skin-core type composite fluid, and the skin-core type composite fluid is extruded through a spinneret plate with triangular holes; and S30, carrying out cross air blowing cooling, drafting and winding on the extruded fluid to obtain the sheath-core type composite fiber with a triangular cross section outer contour. The composite fiber can keep good spinnability and hand feeling, can block sunlight and heat at the same time, and provides better wearing comfort.

The application belongs to the technical field of catalysts, and particularly relates to a copper-based catalyst, a preparation method thereof and a method for synthesizing polycarbon alcohol from CO2 / CO. The preparation method of the copper-based catalyst provided by the application comprises the following steps: loading a copper nanoparticle solution into a high-pressure reaction kettle with a stirring rotor, first performing gas washing treatment by using high-purity CO gas, then filling CO, sealing the high-pressure kettle and transferring the high-pressure kettle to a heating container, performing reaction under stirring and heat preservation, performing pressure relief to normal pressure after the reaction, and performing centrifugal separation and drying treatment to obtain copper nanobands. The method adopts CO to assist in growing the copper-based catalyst, and widens the catalyst system for synthesizing polycarbon alcohol products.

Metallic nanoparticle agglomerates can deliver biocidal activity to surfaces on which they are deposited and adhered, such as various air filtration media. Air filtration media can include a plurality of fibers to which a plurality of metallic nanoparticle agglomerates are adhered. The metallic nanoparticle agglomerates can include a plurality of fused, partially fused, or unfused metallic nanoparticles associated with one another on the surface of the plurality of fibers. Suitable metallic nanoparticles for facilitating biocidal activity against various pathogens, such as viruses and bacteria, can include copper nanoparticles and / or silver nanoparticles. Face masks, inline filters, and air filtration systems can integrate the air filtration media.

The invention provides a solar cell and a photovoltaic module, and belongs to the technical field of solar cells. The solar cell comprises: a cell body having a first surface and a second surface opposite to each other; the plurality of current collection electrodes are positioned on the second surface of the battery body, and the plurality of current collection electrodes are alternately arranged at intervals according to different polarities; wherein the collector electrode is made of copper, and at least one copper nanoparticle is arranged on the first surface of the battery body. The copper nanoparticles on the front surface of the battery body can absorb and reflect short-wave ultraviolet light harmful to the battery body, so that performance degradation and material aging of the battery are delayed.

This invention discloses a method for fabricating a near-zero temperature coefficient thin-film pressure sensor with a wide temperature range. The purpose of this invention is to address the common problem of insufficient environmental adaptability in existing flexible thin-film sensors, particularly the significant performance degradation under extreme temperature conditions. This invention proposes a wide-temperature-range intrinsically self-compensating flexible pressure sensor based on a PVDF / CFT / Cu composite sensing material thin film. This sensor achieves a near-zero temperature coefficient of resistance for the composite material by synergistically introducing carbon fiber tubes with negative temperature coefficients and copper nanoparticles with positive temperature coefficients into the flexible PVDF matrix and dynamically controlling their ratio, thereby constructing a temperature self-compensation mechanism at the material level. This invention provides an effective material solution for developing next-generation high-reliability, wide-temperature-range adaptive flexible sensing systems.

A scaffold for bone-tissue engineering includes a mesh and a coating on the mesh. The mesh includes a plurality of offset layers of filaments of polyester. The coating covers the mesh and includes magnesium hydroxide / copper oxide nanoparticles suspended in gelatin. A method of constructing the scaffold comprises combining magnesium hydroxide / copper oxide nanoparticles with a gelatin solution and coating a polyester mesh with the combined magnesium hydroxide / copper oxide nanoparticle and gelatin solution.

The present application relates to a kind of cationic polymer coated copper-based catalyst and its preparation method and application, belong to catalyst technical field.The preparation method of the present application includes the following steps: S1, 5-bromo indigo and 5-bromo indole-2-ketone are reacted in acid solution to obtain 5,5 '-dibromo isoindigo;S2, 5,5 '-dibromo isoindigo, potassium hydroxide and 1,4-dibromobutane are dissolved in organic solvent to carry out reaction to obtain N,N-dibutyl-5,5-dibromo isoindigo;S3, N,N-dibutyl-5,5-dibromo isoindigo, trimethylamine hydrochloride and base are reacted in solvent to obtain double quaternary ammonium dibromo isoindigo;S4, copper nanoparticles suspension is added to the double quaternary ammonium dibromo isoindigo solution to carry out self-assembly reaction, and cationic polymer coated copper-based catalyst is obtained.The catalyst exhibits excellent electrocatalytic carbon dioxide reduction performance in acidic electrolytic system, and can be highly selective to prepare ethanol.

Disclosed herein are glass-ceramics that may include a phase assemblage including: 35 wt % to 60 wt % of a petalite crystalline phase; 20 wt % to 60 wt % of a lithium disilicate crystalline phase; and 5 wt % to 20 wt % of a residual amorphous glass phase. The glass-ceramics may further include copper metal nanoparticles dispersed in the residual amorphous glass phase. The glass-ceramics may appear red in color and comprises transmittance color coordinates in CIE LAB color space of: L* greater than or equal to 0 and less than or equal to 100; a* greater than or equal to −23 and less than or equal to 62; and b* greater than or equal to −10 and less than or equal to 60.5 at an article thickness of 0.55 mm for a CIE illuminant D65 under SCI UVC conditions and a 10 degree observer angle.

The invention discloses copper paste and a preparation method and application thereof. The copper paste comprises copper powder, resin, a curing agent, a dispersing agent, a reducing copper precursor and a solvent. The reducing copper precursor is a reducing copper complex or a mixture composed of copper salt and a reducing agent; the reductive copper complex is composed of copper ions and reductive ligands; the reducing ligand is selected from one or more than two of organic acid and phenolic compounds containing reducing groups; the reducing agent is selected from one or more than two of organic acid containing reducing groups and phenolic compounds. According to the copper slurry disclosed by the invention, the reducing copper precursor is introduced and is dissolved in the organic phase, and uniform and fine copper nanoparticles are generated in situ in the curing process and are embedded among resin or copper powder particles, so that a conductive path is increased, a tunneling potential barrier among the resin is reduced, and the conductivity is increased.

The invention relates to copper nanoparticles and a preparation method and application thereof, the copper nanoparticles are obtained by dispersing a copper source, a dispersing agent and a reducing agent as raw materials in n-butyl alcohol and performing redox reaction through a reflux heating method, and the n-butyl alcohol is used as a solvent and the reducing agent. The method for modifying the copper nanoparticles by taking the n-butyl alcohol as the reducing agent is provided for the first time, the preparation method is simple, the requirement is low, and the process is green and environment-friendly. The prepared n-butyl alcohol modified copper nanoparticles can be applied to preparation of an electrochemical luminescence (ECL) immunosensor, and the detection sensitivity is high.

The invention provides a method for rapidly detecting pesticide residues in fruits and vegetables, and belongs to the field of pesticide analysis and detection. The method comprises the following steps: mixing a copper nanoparticle / reduced graphene oxide / chitosan composite material, acetylcholin esterase, choline oxidase and a cross-linking agent glutaraldehyde solution for reaction to obtain a double-enzyme functionalized nano composite material; dispensing a chitosan solution on the surface of a working electrode of a screen-printed electrode, drying to form a film, and covalently modifying the surface of the electrode with the bienzyme functionalized nano composite material through a cross-linking agent glutaraldehyde to obtain a sensing electrode; according to the method, acetylcholine is taken as a substrate, a sensing electrode is used, a chronoamperometry is adopted, inhibition ratios of pesticide standard substance solutions with different known concentrations to electrode response current are detected, and a standard curve between the pesticide concentration and the current inhibition ratio is established; and calculating the pesticide residue concentration in the fruit and vegetable sample to be detected according to the current inhibition ratio of the liquid to be detected and the standard curve. Therefore, the sensitivity and accuracy of pesticide residue detection in fruits and vegetables are improved.

This invention relates to an air-to-water system and its absorbent gel. The preparation method of the absorbent gel includes: dispersing carboxymethyl cellulose in deionized water until a transparent solution is formed; adding copper oxide nanoparticles to the transparent solution and ultrasonically dispersing them uniformly to obtain a CuO / CMC pretreatment solution; adding hydroxypropyl methylcellulose to the CuO / CMC pretreatment solution and stirring until fully swollen to form a precursor solution; adding lithium chloride to the precursor solution and stirring until fully foamed to obtain a foam gel; and finally drying the foam gel to obtain the absorbent gel. The absorbent gel of this invention has low preparation cost, can rapidly and efficiently absorb / desorb moisture, and can be assembled into an independent passive water production system, thus adapting to a wider range of applications in arid regions.

The invention discloses a graphene aluminum-based composite enameled wire and a preparation method thereof, and belongs to the technical field of metal-based composites.The preparation method comprises the steps that firstly, Cu-rGO anchored by copper nanoparticles is prepared; secondly, carrying out hydroxylation and sulfhydrylation surface modification on the aluminum powder; then, Cu-rGO, zirconium-aluminum alloy powder and the modified aluminum powder are mixed, and a reinforcement is evenly anchored on the surface of the aluminum powder through the S-Cu specific coordination effect; and finally, carrying out vacuum hot pressed sintering, hot extrusion, cold drawing and painting. According to the preparation method, the strategy of first coordination anchoring and then in-situ interface reconstruction is adopted, in the high-temperature sintering process, a chemically-bonded gradient transition interface is formed, and the wettability and combination problems of graphene and an aluminum matrix are solved; and meanwhile, the Zr element in the zirconium-aluminum alloy is subjected to in-situ precipitation in the aluminum matrix through solid diffusion to form an Al3Zr reinforced phase which is dispersively distributed, the phase can effectively pin the grain boundary, and the high-temperature creep resistance of the material is remarkably improved.

This invention discloses an ultra-small size copper nanoparticle powder and a green and controllable synthesis method. This invention pioneers a novel reaction pathway combining "one-step direct reduction with alkaline ascorbic acid" with three-stage programmed temperature control. By precisely controlling the reaction temperature and rate from monomer formation to nucleation and final growth stages, it achieves the green and controllable synthesis of ultra-small size copper nanoparticle powder with an average particle size of less than 80 nanometers. This invention eliminates the need for a secondary reducing agent such as ferrous sulfate, resulting in a simpler process that meets green production requirements, reduces environmental treatment costs, and offers strong controllability, making it suitable for large-scale industrial production. The prepared copper powder has a metal-based purity of ≥99.9%, high sintering activity, and a sintering temperature 30-80℃ lower than conventional copper powder. It has significant application value in high-density PCB interconnects, third-generation semiconductor packaging, high-precision 3D printing, photovoltaic pastes, flexible displays, and wearable devices.

The application provides a preparation method of copper nanoparticles, which comprises the following steps: preparing a copper source complexing agent solution; preparing a surface modifier dispersion; fully mixing a reducing agent, the copper source complexing agent solution and the surface modifier dispersion, and performing an oxidation-reduction reaction; and obtaining a copper nanoparticle mixed solution after the reaction is completed, and then performing solid-liquid separation through centrifugation to obtain the copper nanoparticles. The preparation method of the copper nanoparticles provided by the application adopts a one-step chemical synthesis method to prepare copper nanoparticles with a bimodal particle size distribution by using a combination of strong and weak reducing agents. Small copper nanoparticles are gathered around large copper nanoparticles to form composite copper nanoparticles, and the surface of the copper nanoparticles is coated with an organic ligand which is easy to desorb. The composite structure of the copper nanoparticles exhibits good low-temperature sintering performance, and the sintering structure after sintering has high compactness, thereby meeting the requirements of low-temperature sintering and high-temperature service in the application of power electronic chip interconnection.

The application discloses an electrocatalytic composite material of MXene loaded with copper phosphide nanoparticles as well as a preparation method and application thereof, and comprises the following steps: (1) dispersing MXene, a copper precursor, a phosphorus precursor and anhydrous sodium citrate in deionized water, continuously stirring until completely dissolved, adjusting pH by sodium hydroxide, and preparing a mixed solution; (2) under the environment of inhaled inert gas, adding sodium borohydride solution drop by drop into the mixed solution, and stirring intensively; when the reduction reaction is completed, centrifuging, washing and freeze-drying the obtained solid-liquid mixture, and finally obtaining P-Cu@MX composite material. The composite material is used as an electrocatalyst, is coated on the surface of a conductive material, forms a high-efficiency catalytic electrode, and constructs a reactor, so that the co-reduction of NO3 ‑ and CO2 into urea can be realized.

This invention discloses a reactive oxygen species (ROS)-responsive nanocomposite for targeting and repairing damaged endothelium, its preparation, and its application, belonging to the field of nanomedicine technology. The nanocomposite comprises a physalicylate-copper nanoparticle core and a P-selectin-targeting polypeptide linked to the core surface via thiol-copper affinity. The physalicylate-copper nanoparticle core is prepared by coordination of physalicylate and copper ions to form a primary complex, followed by ascorbic acid reduction. This composite nanosystem can specifically recognize and accumulate in the blood vessels and peritubular regions of the kidney injury area, releasing Cu in response to high concentrations of ROS in an inflammatory environment. 2+ Together with HBT, it simultaneously achieves antioxidant and anti-inflammatory functions, promotes angiogenesis and repair, and inhibits the release of inflammatory factors and macrophage infiltration and activation, effectively blocking the fibrosis process. This system has a well-defined structure and strong targeting, and can effectively rebuild microvessels, reduce inflammation, and block the process of renal fibrosis, providing a highly efficient and precise new nanomedicine strategy for the anti-fibrotic treatment of kidney diseases.

The invention discloses a functional coating for the surface of an orthopedic implant material as well as a preparation method and application thereof, the coating comprises core-shell structure nanoparticles, copper oxide nanoparticles with the particle size of 200nm are taken as a core, and a compound of polydopamine and baicalein is taken as a shell. The preparation method comprises the following steps: dissolving baicalein in ethanol, dispersing copper oxide nanoparticles in water, mixing to obtain a suspension, adding dopamine hydrochloride, adjusting to alkalinity, and immersing the implant material matrix for reaction. The coating is applied to an orthopedic implant material for preventing and treating periprosthetic infection, and the core-shell structure of the coating can realize continuous release of baicalein and intelligent response release of copper ions in an acidic infection environment, so that the synergistic effect of early-stage antibacterial immune regulation and late-stage enhanced antibacterial is exerted; the compound has multiple functions of long-acting antibiosis, biofilm resistance, promotion of M2 polarization of macrophages and reduction of bone destruction.

The invention relates to a FeMo bimetallic alkene modified multi-dimensional heterojunction preparation method, which relates to the photovoltaic technical field, and comprises the following steps: 1) forming a pyramid-shaped suede on the surface of a silicon wafer through an alkaline solution etching method; 2) dropwise adding a copper nitrate solution on the textured silicon wafer, drying, and annealing in hydrogen and argon atmospheres to prepare CuNPs; (3) preparing a FeMo bimetallic alkene film by adopting a wet chemical method; and 4) placing the textured silicon / copper nanoparticle / graphene film structure on a spin coater, dropwise adding FeMo bimetallic alkene colloid, uniformly spin-coating, drying, and annealing in an argon atmosphere to obtain the FeMo bimetallic alkene modified multi-dimensional heterojunction. According to the preparation method of the FeMo bimetal alkene modified multi-dimensional heterojunction, the sunlight reflectivity is remarkably reduced, the capture efficiency of the silicon substrate on wide-spectrum sunlight is greatly improved, the localized distribution of photon-generated carriers is optimized, and a full-chain performance improvement basis from light capture to charge separation is provided for an efficient photovoltaic device.

One embodiment of the present invention pertains to copper microparticles that have a tap density of 2.8 g / cm3 or more and a specific surface area of 1-5 m2 / g, and in which, in a number-based particle diameter histogram, the particle diameter D10 at a cumulative frequency of 10% and the particle diameter D90 at a cumulative frequency of 90% satisfy the condition D90 / D10≤3.7.<sp / > Another embodiment of the present invention also pertains to a copper microparticle dispersion containing the copper microparticles. Another embodiment of the present invention also pertains to a copper microparticle production method including maintaining a mixture, which contains a copper raw material compound, a reducing agent, a dispersant agent, and a solvent having an SP value of 8-18, at a prescribed temperature lower than the boiling point of the solvent for at least 1 minute in order to reduce the copper raw material compound.

The present invention relates to a method for modifying a reverse osmosis thin-film composite (TFC) membrane, the polyamide active layer of which is modified by incorporating polyamine groups, polyphosphonic groups and copper nanoparticles / ions via a chemical modification process. This modified composite membrane exhibits high biofouling resistance, which makes it suitable for use in seawater and brackish water desalination.

The application belongs to the technical field of nanomaterials, and discloses a temperature-sensitive CS hydrogel loaded with a PtCu@ZIF-8 nanoenzyme with sterilization performance and a preparation method thereof. The nanoenzyme comprises a metal organic framework and metal nanoparticles encapsulated in the metal organic framework; the metal nanoparticles comprise platinum nanoparticles and copper nanoparticles. The application provides a nanoenzyme (denoted as a PtCu@ZIF-8 nanoenzyme), which is a peroxidase-like three-metal organic framework. By doping Pt and Cu into ZIF, the nanoenzyme has excellent peroxidase activity and excellent affinity for hydrogen peroxide, and has extremely strong sterilization capacity by being used in cooperation with hydrogen peroxide.

The invention discloses a strong-sunscreen high-breathability cool-feeling copper ammonia texture fabric and a preparation method thereof, and relates to the technical field of copper ammonia texture fabrics, the preparation method comprises the following steps: adding viscose fibers into a nonionic surfactant solution for ultrasonic treatment to obtain pretreated viscose fibers; adding the pretreated viscose fibers into the cationization treatment liquid, standing and baking to obtain cationization viscose fibers; adding cationized viscose fibers into the alginate solution, dip-coating at room temperature, and airing at room temperature to obtain alginate coated viscose fibers; adding the alginate-coated viscose fibers into the copper nanoparticle precursor solution, and carrying out heating reaction to obtain modified viscose fibers; blending and tatting the modified viscose fibers and polyester staple fibers to obtain a tatted fabric; adding the woven fabric into the cation post-treatment liquid, and carrying out two-time dipping and two-time rolling to obtain a post-treatment fabric; and soaking the post-treated fabric in deionized water, preheating, adding a palladium chloride solution, and carrying out heat preservation reaction to obtain the copper ammonia texture fabric.