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1.
A new application of conventional electroless nickel plating to improve the interfacial properties of PBO fibers was reported. The relationship between surface morphology and interfacial properties of nickel-plated PBO fiber was explored. The continuous nickel coating consisted of nickel and phosphorus elements determined by Energy dispersive spectrometer (EDS) and transmission electron microscope (TEM), exhibiting high adhesive durability. The influence of bath temperature and plating time on the crystal structure, microstructure and mechanical properties of nickel-plated PBO fibers was systematically investigated. X-ray diffractometer (XRD) results revealed that the crystal structure among nickel-plated PBO fibers did not show differences. Scanning electron microscope (SEM) and Atomic force microscope (AFM) images showed that the process parameters had a great influence on surface morphology and roughness of nickel-plated PBO fibers, which could directly affect the interfacial properties of nickel-plated PBO fibers. Single fiber pull-out testing results indicated that the interfacial shear strength (IFSS) of PBO fibers after electroless nickel plating had a significant improvement, which reached maximum at 85 °C for 20 min. Single fiber tensile strength of nickel-plated PBO fibers was slightly lower than that of untreated one. Thermo gravimetric analysis (TGA) indicated that nickel-plated PBO fiber had excellent thermal stability.  相似文献   

2.
In the research self-cleaning coatings based on photocatalytically active nano titanium dioxide (TiO2) were prepared. When applied directly to cellulose fiber surfaces, TiO2 coatings form weak bonds with fibers. Therefore 3-glycidooxypropyl-trimethoxysilane was used as a coupling agent. It had been applied on the surface of cellulose fibers before the TiO2 coating was performed. In this case, the silane is in the interface region, where it can be most effective as an adhesion promoter. Silane coupling agents have unique chemical and physical properties not only to enhance bond strength, but more importantly to prevent de-bonding at the interface during composite aging and use as well. The coupling agent provides a stable bond between two otherwise poorly bonding surfaces. Surface properties of these coatings have been examined, such as surface morphology and surface microstructure. TiO2 nanoparticles were irreversibly attached to the surface of monodisperse silica (SiO2) spheres and to the surface of Lyocell fibers coated with an epoxy-containing silane coupling agent. Analysis using scanning electron microscopy showed uniform distribution of nanoparticles in the resulting coatings. Fourier transform infrared spectroscopy revealed changes in the surface microstructure occurring after different modifications. In addition, the influence of photocatalytic activity on the mechanical properties of Lyocell fibers was determined. In addition to that, the results indicated that SiO2 and the coupling agent provide a protection against high oxidizing power of TiO2 under exposure to daylight irradiation.  相似文献   

3.
Depositing of TiO2 nanoparticles on cellulose fiber surface has potential technological applications in the field of photocatalysis. With this motivation, multilayers composed of lignosulfonates (LS) and TiO2 nanoparticles were constructed on cellulose fiber surface via layer-by-layer (LBL) self-assembly technique. X-ray photoelectron spectroscopy (XPS), zeta potential measurement and atomic force microscopy (AFM) were used to characterize the LS/TiO2 multilayers on cellulose fiber surface. Moreover, the photocatalytic activities of modified cellulose fibers (decomposition of methyl orange and antibacterial test) were investigated. The decomposition efficiency of methyl orange for a (LS/TiO2)5 multilayer modified cellulose fibers was 74.7 % under 5 h UV irradiation. Photocatalytic decomposition efficiency of methyl orange by LS/TiO2 multilayer modified cellulose fibers under the same UV irradiation time increased linearly with the number of bilayers. Antibacterial tests results revealed that the cellulose fibers modified with LS/TiO2 multilayers exhibited excellent antibacterial activity against E.coil. The degree of E.coil growth inhibition for a (LS/TiO2)5 multilayer modified cellulose fiber reached as high as 93 %. In addition, the effect of LS/TiO2 multilayers on properties of handsheets made from modified cellulose fibers was also considered. The air permeability of the handsheet prepared from fibers modified with TiO2/LS multilayers had 6.1–24.3 % higher compared with that of handsheet prepared from original fibers. The wetting properties measurement results demonstrated that the water contact angle of handsheet oscillated with the increasing number of layers depended on building block which was in the outermost layer.  相似文献   

4.
High performance fibers have distinguished properties such as high tensile strength, good thermal and chemical resistance, dimensional stability, lightweight, and high electrical conductivity. Due to these superior properties, high performance fibers made it to the scene of broad range of applications such as aerospace, automotive, windmill, fiber reinforced composites, high strength tethers, tendons for scientific balloon, tension structures, protective clothing, and marine. Examples of such fibers are Zylon®, Kevlar®, and Vectran®. However, the fibers lose their strength significantly upon exposure to Ultraviolet (UV) and visible light. In this research, UV protective films from extruded low density polyethylene (LDPE) loaded with different content of UV stabilizers (TiO2 nanoparticles and White PE CC®) were investigated. To assess the degree of UV blockage of each extruded protective film, their transmittance to UV and visible (UV-VIS) light was measured. Additionally, Zylon® braids were sheathed with the protective films and the strength of the braids and yarns raveled from braids was measured before and after UV exposure for different number of days. LDPE loaded with White PE CC® and 10 % TiO2 showed the least transmittance to UV-VIS and their yarns and braids exhibited highest strength retention after exposure to artificial UV. Strength retention of braids was higher than that of individual yarns due to weak link effect and braid structure assistant.  相似文献   

5.
Carbon fibers were coated with E51 plus Methacryl-POSS together in an attempt to improve the interfacial properties between carbon fibers and unsaturated polyester resins matrix. Atomic force microscopy (AFM), scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were performed to characterize the changes of carbon fiber surface. AFM results show that the coating of E51 plus POSS significantly increased the carbon fiber surface roughness. XPS indicates that silicon containing functional groups obviously increased after modification. Dynamic mechanical analysis was carried out to investigate the surface energy of carbon fiber. Force modulation atomic force microscopy (FMAFM) and Interlaminar shear strength (ILSS) were used to characterize the interfacial properties of the composites. ILSS was increased by 21.9 % after treatment.  相似文献   

6.
Nano-TiO2 based multilayer nanocomposite films were fabricated on cationically modified woven cotton fabrics by layer-by-layer molecular self-assembly technique. Cationization process was used to obtain cationic surface charge on cotton fabrics. Attenuated total reflectance Fourier transform infrared spectroscopy analyses were used to verify the presence of cationic surface charge and multilayer films deposited on the fabrics. Scanning electron microscope micrographs of poly(sodium 4-styrene sulfonate)/TiO2, nano polyurethane/TiO2, and TiO2/poly(diallyldimethylammonium chloride) multilayer films deposited on cotton fabrics were taken. With nano-TiO2 based multilayer film deposition, the protection of cotton fabrics against UV radiation is enhanced. The UV protection durability of the self-assembled multilayer films deposited on the cotton fabrics was analyzed after 10 and 20 washing cycles at 40 °C for 30 min. Air permeability and whiteness value analysis were performed on the untreated and multilayer film deposited cotton fabrics. The effect of layer-by-layer deposition process on tensile strength properties of the warp and weft yarns was determined.  相似文献   

7.
TiO2/NBR-PVC hollow fibers were spinned by NBR casting solution blended PVC with nano-titanium dioxide (TiO2). The effect of NBR-PVC hollow fiber damping and mechanical properties aroused by loading TiO2 were studied. Results showed that the hollow fibers loaded TiO2 increased in tensile strength, storage modulus, stiffness and glass transition temperature, while decreased in tanδpeak and breaking tensile elongation. The damping of the TiO2/NRR-PVC hollow fiber were not only linked to the dosage of TiO2, but also related to the degree of dispersion in matrix.  相似文献   

8.
Multi-functional comonomer from pentaerythritol (PE) and terephthaloyl chloride (TPC) was synthesized and used for polymerization of poly(p-phenylene benzobisoxazole) (PBO) copolymer. PBO copolymer fibers were prepared from PBO copolymers using a dry-jet wet spinning. The tensile strength of PBO copolymer fibers was higher than that of PBO, and showed 42 % increase at 0.5 mol% loading of comonomer. The tensile modulus of PBO copolymer fiber at 0.5 mol% loading showed 192 % increase compared to PBO fiber. The compressive strength of PBO copolymer fiber had values between 0.46 GPa and 0.6 GPa with the comonomer content. 64-114 % increase in compressive strength of PBO copolymer fibers was observed compared to PBO fiber.  相似文献   

9.
In order to improve the interfacial adhesion property between Poly(p-phenylene benzobisoxazole) (PBO) fiber and epoxy, the surface modification effects of PBO fiber under dielectric barrier discharge treatments in different time were investigated. The samples were tested for surface morphology, functional groups, surface wettability and interfacial shear strengths (IFSS) in epoxy using scanning electron microscope, Fourier transform infrared spectroscopy, water contact angle measurements and Micro-bond pull out tests, respectively. The results indicated that fiber surface morphology after plasma treatment was rougher than untreated one. Some polar groups were introduced on fiber surface in plasma treatment. Moreover, surface wettability and the IFSS between fiber and epoxy had much improvement after plasma treatment, the contact angle decreased with the treatment time increasing and reached the lowest value when the treated time was 60 s, and the IFSS was improved by 117.3 %. On the other hand, no significant difference in single fiber tensile test was observed between treated and untreated fibers when the processing time was shorter than 75 s, but the tensile strength declined by more than 10 % after 75 s treatment as a result of the excessive plasma etching.  相似文献   

10.
We reported the controlled surface morphologies and the cell culture of polyelectrolyte multilayer coated nylon 6 fibrous mats with different number of layers. Polyelectrolyte multilayer coated nylon 6 fibers were successfully prepared by an alternative deposition of alginic acid sodium salt and chitosan via a Layer-by-Layer (LbL) electrostatic self-assembly. The surface morphology, stiffness, and hydrophilicity of polyelectrolyte multilayer coated nylon 6 fibrous mats could be finely tuned by regulating the number of polyelectrolyte nanocoating. It was observed that the morphology of polyelectrolyte multilayer coated nylon 6 fibers was uniform and smooth, indicating a dense and harder nanocoating of polyelectrolytes onto nylon 6 fibers. Compared to pure nylon 6 fibrous mat (tensile strength ～10.6±1 MPa), the tensile strength of polyelectrolyte coated nylon 6 fibrous mats was largely increased to 35.2±2 MPa for 5 bilayers coated fiber mats. In addition, it was found that at an initial stage after 1 day of cell culturing, the electrospun nylon 6 fibrous mats coated with 5 bilayer of alginic acid and chitosan show the highest cell affinity (good adhesion), while the electrospun nylon 6 fibrous mats coated with 10 bilayer show the lowest cell affinity. After cell seeding for 3 days, it was observed that rate of proliferation is enhanced by increasing the number of bilayer up to 3 bilayers (good proliferation), and then drastically decreased with further increasing the number of bilayer.  相似文献   

11.
We report the preparation of polybenzoxazole (PBO) fiber from polyhydroxyamide (PHA) precursor fiber which is free from strong acid such as polyphosphoric acid. We prepared the PHA fibers with different spin-draw ratios (SDRs) using a wet-spinning method and the PBO fibers with an SDR of 3.5 (SDR-3.5 PBO fibers) were prepared by various heat-treatment temperatures, and investigated their morphology, crystalline structure, and mechanical properties. The simultaneous thermogravimetric analysis-mass spectrometry (STA-MS) and field-emission scanning electron microscopy (FE-SEM) results confirmed that the diameter of the SDR-3.5 PBO fiber was much smaller than that of the SDR-3.5 PHA fiber, due to the release of water during the thermal cyclization reaction which forms the PBO structure. The wide-angle Xray diffraction (WAXD) pattern of the SDR-3.5 PBO fiber heat-treated at 350 °C (SDR-3.5 PBO 350 fiber) showed two peaks, at 2θ=14.83 ° and 24.38 °, and the diffraction angles dropped with increasing heat-treatment temperature. In addition, the initial modulus and tensile strength of the SDR-3.5 PBO fiber heat-treated at 550 °C (SDR-3.5 PBO 550 fiber) were found to be 19.1 GPa and 449.2 MPa, which were much higher than those of the SDR-3.5 PHA fiber, 9.3 GPa and 227.0 MPa, respectively.  相似文献   

12.
PET fabric was first modified with silane coupling agent KH-560, and then was loaded with a layer of nano-scaled TiO2 particles using tetrabutyl titanate as precursor by low temperature hydrothermal method, followed by dyeing with Disperse Blue 56. The morphology, crystalline phase, chemical modification, thermal stability and optical property of PET fiber before and after treatments were studied by scanning electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy, thermal gravimetric and diffuse reflectance spectrum techniques. The properties of tensile, air permeability, luster, ultraviolet (UV) protection, photocatalytic activity, K/S value and color fastness were also measured. It was found that compared with the TiO2-coated fabric without modification with KH-560, the loading of TiO2 nanoparticles on the surface of the TiO2-coated fabric modified with KH-560 was obviously improved. The pure anatase TiO2 nanoparticle was grafted onto the fiber surface. The onset decomposition temperature increased. The absorbing capability to ultraviolet radiation was enhanced. The properties of tensile, air permeability, luster, K/S value and color fastness changed slightly. The UV protection ability and photodegradation of methyl orange under UV illumination were enhanced to some extent.  相似文献   

13.
The surface topography, tensile properties, and thermal properties of ramie fibers were investigated as reinforcement for fully biodegradable and environmental-friendly ‘green’ composites. SEM micrographs of a longitudinal and cross-sectional view of a single ramie fiber showed a fibrillar structure and rough surface with irregular cross-section, which is considered to provide good interfacial adhesion with polymer resin in composites. An average tensile strength, Young’s modulus, and fracture strain of ramie fibers were measured to be 627 MPa, 31.8 GPa, and 2.7 %, respectively. The specific tensile properties of the ramie fiber calculated per unit density were found to be comparable to those of E-glass fibers. Ramie fibers exhibited good thermal stability after aging up to 160°C with no decrease in tensile strength or Young’s modulus. However, at temperatures higher than 160°C the tensile strength decreased significantly and its fracture behavior was also affected. The moisture content of the ramie fiber was 9.9%. These properties make ramie fibers suitable as reinforcement for ‘green’ composites. Also, the green composites can be fabricated at temperatures up to 160°C without reducing the fiber properties.  相似文献   

14.
Conductive polyaniline (PAn)/poly(ethylene terephthalate) (PET) composite fibers were prepared by chemical polymerization of aniline in the presence of PET fibers using benzoyl peroxide (Bz2O2) in organic solvent/aqueous hydrochloric acid mixtures. The effects of polymerization conditions such as organic solvent/water ratio, oxidant, aniline and hydrochloric acid concentrations and temperature were investigated on the amount of PAn deposited on PET fiber and the electrical surface resistance of composite fibers. The maximum PAn content and the lowest electrical surface resistance of composite fibers were observed at HCl concentrations of 0.5 mol L−1. The properties of PAn/PET composite fibers such as density, diameter, tensile strength and breaking elongation were also investigated in comparison with those of pure PET. Characterization of conductive composite fibers was carried out by FTIR, TGA, SEM techniques, surface resistance measurements, and cross section images taken by optical microscope.  相似文献   

15.
The high light reflection of multilayer TiO2/SiO2 film was prepared on the fabric by the sol-gel process. The size of titania and silica particles in hydrosol was analyzed by Nanosizer, and the morphology of TiO2/SiO2 multilayer film on the fabric was characterized by SEM. The reflection spectra of the samples were tested accordingly, and it showed that the reflection of the fabric coated by multilayer film was higher than that of the monolayer film. Moreover, the reflection increased with the increase of layer number. For sunlight fastness testing, the fabric color changed less with the increase of layer number, which showed the multilayer film on the fabric can improve the light resistance of the fabric. The mechanical property, the bending property and air permeability testing results showed that there was little change for the coated fabric compared with the original fabric.  相似文献   

16.
Nylon 6 fabric with self-cleaning properties was prepared by corona discharge pre-treatment and coating with TiO2 nanoparticles (NPs) using pad-dry-cure technique. The self-cleaning property was studied by discoloration of methylene blue (MB), ketchup, tea and coffee stains from the corona+TiO2 treated nylon-6 fabric. Color difference (ΔΕ*), reflectance (R) and K/S of MB stain were investigated by diffuse reflectance spectrophotometry. The MB stain was almost completely removed from the corona+TiO2 treated nylon surface after 24 h under UV light/daylight irradiation. Both of these phenomena (corona and TiO2) led to an increase in the discoloration of stains under UV and daylight irradiations. The EDS analysis showed an increase in the concentration of deposited TiO2 NPs coating after corona treatment. The FE-SEM images revealed that the surface of nylon 6 was coarser after the corona treatment. Also, the FE-SEM micrographs exhibited that a uniform layer of TiO2 NPs was formed on the corona treated nylon fabric. The corona+TiO2 treated nylon illustrated antibacterial activity against E. coli and B. subtillis microorganisms. The EDS and FE-SEM analysis confirmed that after 5 washing cycles, the amount of TiO2 NPs was higher on the surface of corona+TiO2 treated nylon than that of the fabric only treated with TiO2 without corona pretreatment. This result justifies that the corona+TiO2 treated nylon fabric with appropriate self-cleaning property can be applied cost-effectively in the textile industry.  相似文献   

17.
Kevlar fibers were treated in three kinds of coupling agents’ solutions by Co60 γ-ray co-irradiation. After the treatment, the interlaminar shear strength (ILSS) values of Kevlar fibers/epoxy composites were all improved. Surface elements of the fibers were determined by energy dispersive X-ray microanalysis (EDX). X-ray photoelectron spectroscopy (XPS) indicated that the oxygen/carbon ratio of the treated fibers was increased and Fourier transform infrared (FT-IR) spectrum confirmed the increase in the polar groups at the fiber surface. The tensile strength of the fibers was evaluated by statistical analysis using the Weibull distribution. The wettability of the fiber surface was also enhanced by the treatment. The possible mechanisms of γ-ray co-irradiation treatment are proposed by the radical reactions. The results indicated that γ-ray co-irradiation technique modified the physicochemical properties of Kevlar fibers and improved the interfacial adhesion of its composites.  相似文献   

18.
Wool and alpaca fibers were coated with polypyrrole by vapor-phase polymerisation method. The changes in frictional and tensile properties of the single fibers upon coating with the conductive polymer are presented. Coating a thin layer of polypyrrole on the alpaca and wool fibers results in a significant reduction in the fiber coefficient of friction, as the conducting polymer layer smooths the protruding edges of the fiber scales. It also reduces the directional friction effect of the fibers. Depending on the type of fiber, the coating may slightly enhance the tensile properties of the coated fibers.  相似文献   

19.
In this study, a new finishing technique is introduced through treatment of wool fabric with graphene/TiO2 nanocomposite. Graphene oxide/titanium dioxide nanocomposite first applied on the wool fabric by hydrolysis of titanium isopropoxide in graphene oxide suspension and then this coating chemically converted by sodium hydrosulfite to graphene/TiO2 nanocomposite. The homogenous distribution of the graphene/TiO2 nanocomposite on the fiber surface was confirmed by field emission scanning electron microscopy (FE-SEM), Energy-dispersive X-ray spectroscopy (EDS) and X-ray mapping. X-ray diffraction patterns proved the presence of titanium dioxide nanoparticles with a crystal size of 127 Å on the treated wool fabric. Also, the defect analysis based on X-ray photoelectron spectroscopy (XPS) established the composition of the nanocomposite. Other characteristics of treated fabrics such as antibacterial activity, photo-catalytic self-cleaning, electrical resistivity, ultraviolet (UV) blocking activity and cytotoxicity were also assessed. The treated wool fabrics possess significant antibacterial activity and photo-catalytic self-cleaning property by degradation of methylene blue under sunlight irradiation. Moreover, this process has no negative effect on cytotoxicity of the treated fabric even reduces electrical resistivity and improves UV blocking activity.  相似文献   

20.
In this study, fire-retardant polyester fibers (FRPFs), which are hollow and have a 3D-crimp shape, were processed using nonwoven manufacturing technology to create fire-retardant fibrous material. The content of low-T m fibers (10, 20, 30, 40, 50 %) and number of layers of loose nonwoven sheet (1, 2, 3, 4, 5 layers) were changed to determine tensile strength and elongation, thermal conductivity, air permeability and the limiting oxygen index. The purposes of this study are to develop a manufacturing procedure for convenient installation of thermal insulation material and improve the application of fiber materials in thermal insulation. Experimental results demonstrate that, due to the loose nonwoven sheet combined with needle punching nonwoven sheets, tensile strength FRPFs increased to 100 %. The contents of the polyester low-melting-temperature fiber and the number of combined layers affected thermal conductivity results. In the test for the limit oxygen index, the optimal sample was manufactured using 7.78 dtex FRPFs, 10 % PET low-melting-temperature fiber and 5 layers of loose nonwoven sheet. The limit oxygen index is 35.  相似文献   

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