Surface characterization of sputter silver-coated polyester fiber

The present study concerns modification of surface of polyester fiber by magnetron sputtering using a silver (Ag) target. A detailed characterization of the silver-coated polyester fiber was investigated by scanning electron microscopy (SEM), X-ray diffraction technique (XRD) and X-ray photoelectron spectroscopy (XPS). The results revealed the remarkable changes in the surface morphology and microstructure of silver film on polyester fiber after sputtering for 10 and 30 min respectively. The SEM results showed that the silver particles were uniformly and densely deposited on the surface of polyester fiber. The XRD pattern of silver coated fabric showed that silver film is polycrystalline structure and dominated by the very strong (220) peak. Depth profiling results of silver coated fabric by XPS indicated that mainly metallic silver is existed throughout the whole depth region.     

Comparative Performance of Copper and Silver Coated Stretchable Fabrics

The present work described the development of multifunctional, electrically conductive and durable fabrics by coating of silver and copper particles using a dipping-drying method. The particles were directly grown on fabric structure to form electrically conductive fibers. Particles were found to fill the spaces between the microfibers, and were stacked together to form networks with high electrical conductivity. The electrically conductive fabrics showed low resistance with high stretch ability. The utility of conductive fabrics was analyzed for electromagnetic shielding ability over frequency range of 30 MHz to 1.5 GHz. The EMI shielding was found to increase with increase in concentration of copper and silver particles. Furthermore, the heating performance of the copper and silver coated fabric was studied through measuring the change in temperature at the surface of the fabric while applying a voltage difference across the fabric. The maximum temperature (119°C for silver and 112°C for copper) were obtained when the applied voltage was 10 V. Moreover, the role of deposited particles on antibacterial properties was examined against pathogenic bacteria such as Staphylococcus aureus and Escherichia coli. At the end, the durability of coated fabrics was examined against several washing cycles. The fabrics showed good retention of the particles, proved by small loss in the conductivity of the material after washing.     

Surface characterization of aromatic thermotropic liquid crystalline fiber deposited by nanostructured silver

Nanostructured silver thin films were sputtered onto the aromatic thermotropic liquid crystalline fibers of Vectran by magnetron sputtering technology. Plasma treatment was used as pre-treatment in order to improve the deposition of the coating layer. Surface morphology of the coated fibers was examined by scanning electron microscopy (SEM) and atomic force microscopy (AFM). A full energy dispersive X-ray analysis (EDX) was used to detect the elemental composition of the material. Its conductivity and mechanical properties were measured and analyzed as well. The study revealed that a very thin conductive silver deposition exhibited high electrical conductivity as well as less influence on the mechanical properties of the pre-treated Vectran fiber. The plasma treatment could improved the deposition of the coating layer, but the surface roughness caused by plasma treatment also affected the surface conductivity. It was found that the surface resistivity could reach very low value of 1.66×10⁻³ Ω·cm after sputtering deposition for 30 min.     

Surface modification of polyester fibers by thermal reduction with silver carbamate complexes

In this study, the surface of polyester fiber was modified by means of thermal treatment with a silver carbamate complex. We used scanning electron microscopy (SEM), an X-ray diffraction technique (XRD), and X-ray photoelectron spectroscopy (XPS) to allow a detailed characterization of the silver-coated polyethylene terephthalate (PET) fibers. The results revealed remarkable changes in the surface morphology and microstructure of the silver film after thermal reduction. On SEM, the silver nanoparticles (AgNPs) were seen to be uniformly and densely deposited on the fiber surface. The XRD pattern of the silver-coated fiber indicated that the film has a crystalline structure. A continuous layer of AgNPs, between 30 and 100 nm in size, was assembled on the PET fibers. The PET/Ag composite was found to impart high conductivity to the fibers, with an electrical resistivity as low as 0.12 kΩ·cm.     

Application of silver nanoparticles to cotton fabric as an antibacterial textile finish

A novel nano-silver colloidal solution was prepared in one step by mixing AgNO₃ aqueous solution and an amino-terminated hyperbranched polymer (HBP-NH₂) aqueous solution under vigorous stirring at room temperature. All results of Dynamic Light Scattering (DLS), Transmission Electron Microscopy (TEM) and UV/Visible Absorption Spectrophotometry indicated that silver nanoparticles had been formed in colloidal solution. Cotton fabric was treated with nano-silver colloid by an impregnation method to provide the cotton fabric with antibacterial properties. The whiteness, silver content, antibacterial activity and washing durability of the silver-treated fabrics were determined. The results indicated that the silver-treated cotton fabric showed 99.01 % bacterial reduction of Staphylococcus aureus and 99.26 % bacterial reduction of Escherichia coli while the silver content on cotton was about 88 mg/kg. The antimicrobial activity of the silver-treated cotton fabric was maintained at over 98.77 % reduction level even after being exposed to 20 consecutive home laundering conditions. In addition, the results of scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) confirmed that silver nanoparticles have been fixed and well dispersed on cotton fabrics’ surface and the major state of the silver presented on the surface was Ag⁰.     

Reduction of 4-nitrophenol to 4-aminophenol over sonoimmobilized silver/reduced graphene oxide nanocomposites on polyester fabric

The current paper is aimed to compare different arrangement of Ag nanoparticles within silver/reduced graphene oxide (Ag/rGO) nanocomposites on the polyester fabric. rGO sheets cannot be dispersed in the water for long time however, thin layer surfactant-free Ag/rGO nanocomposites were immobilized on the surface of polyester. This leads to attain the preserved array of nanocomposites for a long time. TEM, FESEM/EDX, XRD, XPS, cyclic voltammetry, catalytic activity and electrical resistivity were used to characterize Ag/rGO nanocomposites coated polyester fabric. Interestingly, sonoimmobilization of Ag/GO produced an even coating layer of nanocomposites on the polyester fabric. The prepared fabric can be used as a high active and stable nanocatalyst for reduction of 4-nitrophenol (4-NP) in water at room temperature. The created flexible and light fabric showed low electrical resistance and high catalytic activity, wherein sonoimmobilization of Ag/rGO treated samples indicated highest catalytic activity as 4-NP solution completely reduced to 4- AP with assistance of 2×4 cm2 treated polyester after 25 min. On the other hand, introducing sonoprepared silver nanoparticles among graphene nanosheets led to significant lowering of electrical resistivity from 43 kΩ/square in mechanical stirring methodto 2 kΩ/square using ultrasound.     

Application of silver nanoparticles as an antibacterial mordant in wool natural dyeing: Synthesis,antibacterial activity,and color characteristics

Madder is a natural colorant which is commonly applied with metal salts as a mordant to improve its affinity to fibers and color fastness. Madder produces an insoluble complex or lake in the presence of metal ions on mordanted fabric. In this study, wool fabric was pretreated with AgNPs (silver nanoparticles) as a mordant, then dyed with madder. The wool fabric samples were examined by scanning electron microscopy (SEM) and their colorimetric characteristics were evaluated. The formation of spherical silver nanoparticle was confirmed using UV-Visible spectroscopy, SEM images, and elemental analysis. The average size of synthesized silver nanoparticles on the surface of wool fibers is around 73 nm. The dyed wool samples were pretreated with different concentration of Ag⁺ ions or AgNPs, which showed higher color strength value compared to untreated dyed wool fabric. This pretreatment also presented good antibacterial activity.     

Conductive aramid fiber with Ni-Cu composite coating prepared using the metalation swelling method

Conductive aramid fiber with nickel-copper composite coating is prepared by consecutive steps of metalation swelling, sensitization, activation, nickel electroless deposition, and copper electroless deposition, respectively. The metalation swelling of aramid fiber makes the follow-up sensitization and activation feasible. The as-prepared samples are characterized by SEM, TEM, XRD and XPS. After metalation swelling, the aramid fibers look like cotton fibers with numerous nano-scale pits of 50–300 nm in diameter. Pd metal as nuclei for Ni crystal growth with the size of 10±5 nm is originated from Pd²⁺, which can be reduced to Pd⁰ by Sn²⁺. The Ni-Cu composite coating of 1-µm thickness has polycrystalline structure. And the electrical resistance of conductive Ni-Cu aramid fiber is 0.035 Ω/cm. The synthesis mechanism of the conductive aramid fiber with Ni-Cu composite coating is given.     

Antibacterial effect of carbon nanofibers containing Ag nanoparticles

Silver nanoparticles imbedded in polyacrylonitrile (PAN) nanofibers and converted into carbon nanofibers by calcination was obtained in a simple three-step process. The first step involves conversion of silver ions to metallic silver nanoparticles, through reduction of silver nitrate with dilute solution of PAN. The second step involves electrospinning of viscous PAN solution containing silver nanoparticles, thus obtaining PAN nanofibers containing silver nanoparticles. The third step was converting PAN/Ag composites into carbon nanofibers containing silver nanoparticles. Scanning electron microscopy (SEM) revealed that the diameter of the nanofibers ranged between 200 and 800 nm. Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) showed silver nanoparticles dispersed on the surface of the carbon nanofibers. The obtained fiber was fully characterized by measuring and comparing the FTIR spectra and thermogravimetric analysis (TGA) diagrams of PAN nanofiber with and without imbedded silver nanoparticles, in order to show the effect of silver nanoparticles on the electrospun fiber properties. The obtained carbon/Ag composites were tested as gram-class-independent antibacterial agent. The electrosorption of different salt solutions with the fabricated carbon/Ag composite film electrodes was studied.     

Bending properties of carbon/glass and carbon/aramid fabric composites with various stacking structures by the VARTM method

In this paper, the bending properties of woven carbon/glass and carbon/aramid fabric-reinforced polymer laminates is studied using a combination of experimental analysis and fracture observation. Six types of each hybrid composite were manufactured by lamination of the carbon/aramid fabric and carbon/glass fabric using VARTM. Bending behaviors were fundamentally evaluated for the six types of monolithic composites laminated by the same fabric. The objective was to achieve a good bending strength by effective combination of composite structures using limited amounts of a raw material. It was shown that the bending property was different, depending on the type of fiber, lamination structure, and the number of layers.     

Tunable functional properties on polyester fabric using simultaneous green reduction of graphene oxide and silver nitrate

Here, a novel method is introduced to create tunable properties on the polyester fabric through diverse chemical modifications. The polyester fabric was primarily modified with NaOH or ethylenediamine to enhance the surface activity. This will produce diverse chemical groups on the polyester fabric surface including carboxylate, hydroxyl and amine groups. The fabric was treated with grahene oxide through exhaustion method. The silver nitrate was then added and simultaneously reduced with grapheme oxide using ascorbic acid and ammonia to produce reduced graphen oxide/silver nanocomposites (rGO/Ag) on the fabric surface. The synthesized nanocomposites were characterized by TEM and Raman spectra. The presence and uniform distribution of the nanocomposites on the fabric surface was also confirmed by SEM images and EDX patterns. The electrical resistivity was varied on the raw and modified polyester fabric due to the diverse formation of the graphene nanosheets network on the fabric surface. More Ag particles were formed on the surface of the alkali hydrolyzed polyester whereas more graphene nanosheets deposited on the aminolyzed polyester fabric. Also the hydrolyzed polyester fabric exhibited higher antibacterial properties with the lowest silver nitrate in the processing solution. The aminolyzed fabric showed a lower electrical resistance than the hydrolyzed and raw fabrics with the same amount of GO in the procedure bath. The aminolyzed polyester fabric indicated higher affinity towards GO produced higher antibacterial properties before reduction and without silver nitrate however lower electrical resistance obtained after reduction comparing with other samples.     

Electrospun grape seed polyphenols/gelatin composite fibers contained silver nanoparticles as biomaterials

GSP/gelatin composite nanofiber membranes containing silver nanoparticles were successfully fabricated as a novel biomaterial by electrospinning. The silver nanoparticles (AgNPs) were synthesized with the grape seed polyphenols (GSP) as reducing agent in aqueous solution of gelatin, and then the GSP/gelatin/AgNPs mixed solution was electrospun into nanofibers at 55 °C. The scanning electron microscopy (SEM) confirmed that the composite fibers were uniform and the average fiber diameter ranged between 150 nm and 230 nm with an increase in applied potentials from 14 kV to 22 kV. And the transmission electron microscopy (TEM) showed that silver nanoparticles distributed individually in the fibers with the average particle size of about 11 nm. Furthermore, the ultraviolet visible spectrophotometer (UV-vis spectroscopy) test demonstrated that all of Ag⁺ converted to Ag⁰ when the concentration of gelatin was 24 wt% and the mass ratio of GSP to AgNO₃ was about 5:2. The antibacterial activities of the fiber membranes against E.coli and S.aureus were measured via a shake flank test and demonstrated good performance after the importation of silver nanopaticles. Cytotoxicity testing also revealed that fiber membranes contained silver nanoparticles had no cyto-toxic. All the results indicated that the GSP was effective for the formation and stabilization of silver nanoparticles in composite nanofibers mats which had the potential for applications in antimicrobial tissue engineering and wound dressing.     

The application of gas plasma technologies in surface modification of aramid fiber

Gas plasma technologies have been utilized to improve the surface properties of fibers in many applications from textiles to fiber-reinforced composites since the 1960s. This review discusses the feasibility and characteristics of gas plasma technologies applied to aramid fiber. The influence of various plasma treatments on the chemical and mechanical properties of aramid fibers as well as fiber-reinforced composites is described. The moisture regain is emphasized to achieve good bonding between aramid fibers and polymer matrix and to enhance the surface modification of aramid fiber and mechanical properties of the composites. More sophisticated technologies such as plasma-initiated graft polymerization are also discussed to highlight very recent developments.     

Stab-resistant property of the fabrics woven with the aramid/cotton core-spun yarns

Aramid fibers are mainly used for industrial applications and human body protection against ballistic threats. But they are used mostly in forms of composites. And fabrics woven with a high yarn count offer a moderate protection performance against the knife stabbing due to the low shear strength. This research is focused on investigating the effect of the aramid core-spun yarns on the stab resistance of the woven fabrics. With the aramid core-spun yarns with core to sheath weight ratio of 1 to 2.5 the armor specimens having different fabric densities were prepared and the knife edge impact test was conducted. On the impact energy of the knife at the level 1 according to the NIJ standard, the drop tower test results demonstrated that fabric density of the armor specimens affected the stab resistance significantly. The penetration depth of the impactor through the armor specimens was associated with the thickness and mass of the armor sample in different ways. Being the stab resistance introduced by considering the penetration depth of the impactor via thickness and weight per surface area, the effects of the fabric conditions on the anti-stabbing property could be systematically analyzed and turned out that there was an optimal level of the fabric density, showing the most effective stab resistance.     

Effect of Silver Particle size on color and Antibacterial properties of silk and cotton Fabrics

In this study silver nanoparticles with different particle sizes and hence colors were synthesized on silk and cotton fabrics through reduction of silver nitrate. Particle sizes of the silver colloids were measured by dynamic light scattering (DLS). The structure and properties of the treated fabrics were characterized by scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD), and UV-Vis reflectance spectroscopy. Various characteristics of the treated fabrics including antibacterial activities against a Gram positive (Staphylococcus aureus) and a Gram negative (Escherichia coli) bacteria, color effect, wash and light fastness, water absorption, fabric rigidity, and UV blocking properties were also assessed. The results indicated that the treated fabrics displayed different colors in the presence of silver nanoparticles with different particle sizes and exhibited good and durable fastness properties. Also, the size of the silver particles had a tangible effect on antibacterial activity of treated fabrics and its antibacterial performance was improved by decreasing the size of particles. Moreover, this process imparted significantly UV blocking activity to fabric samples.     

Effect of surface treatment on the structure and properties of para-aramid fibers by phosphoric acid

The surface of para-aramid fiber was modified by phosphoric acid solutions (H3PO4) based on an orthogonal experimental design and analysis method. Statistical results indicate that treatment temperature is the most significant variable in the modification processing, while treatment time was the least important factor. The structure and morphology of the modified fiber were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), X-ray diffraction instrument (XRD), and scanning electron microscope (SEM). The results showed that some polar groups were introduced into the molecular structure of aramid fibers and the physical structure of the treated fibers was not etched obviously. The interfacial properties of aramid fiber/epoxy composites were investigated by the single fiber pull-out test (SFP), and the mechanical properties of aramid fibers were investigated by the tensile strength test. The results showed that the interfacial shear strength (IFSS) of aramid/epoxy composites was remarkably improved and the breaking strength of aramid fibers was not affected appreciably after surface modification.     

Reactive dyeing of meta-aramid fabrics photografted with dimethylaminopropyl methacrylamide

Aramid fibers have been known to difficult to dye with conventional dyes and dyeing techniques because of its extremely high crystallinity and compactness. In order to make the aramid fibers dyeable to a bright color in deep shade, meta-aramid fabrics were photografted under continuous UV irradiation with dimethylaminopropyl methacrylamide (DMAPMA) and benzophenone as a monomer and a hydrogen-abstractable photoinitiator respectively. Several factors affecting the photografting treatment of the meta-aramid fabrics were investigated including monomer and photoinitiator concentrations. ATR, ESCA and SEM analysis indicated significant alterations on the chemical structure and atomic composition of the photografted fabric surface and the fabric surface was covered with the grafted polymers. While the pristine meta-aramid fabrics showed no appreciable dyeability to the α-bromoacrylamide type reactive dyes, the grafted aramid fabrics showed the remarkably enhanced dyeability to the reactive dyes, which was proportional to the graft yield indicating the covalent bond formation between the dyes and the secondary amino groups in the grafted DMAPMA. In case of C.I. Reactive Red 84, a K/S value of 14.8 can be obtained with the grafted meta-aramid fabrics with a graft yield of 7.6 % (w/w). Also and the color fastness properties of the dyed fabrics was excellent in the conditions of washing, rubbing and solar irradiation.     

Synthesis of self-crosslinking fluorinated polyacrylate soap-free latex and its waterproofing application on cotton fabrics

Fluorinated polyacrylate latexes are preferably candidates for the textile water repellent finishes as a result of their special surface property and especially economical, low-toxic characteristics compared to fluorinated polyacrylate solutions. The benefits of soap-free latex prepared from reactive surfactants are now well known. We herein used a reactive emulsifier, ammonium allyloxtmethylate nonylphenol ethoxylates sulfate (DNS-86), to prepare novel self-crosslinking fluorinecontaining polyacrylate soap-free latex (FMBN) with core-shell structure by co-polymerization of dodecafluoroheptyl methacrylate (DFMA), methyl methacrylate (MMA), butyl acrylate (BA), and N-methylolamide (NMA), and then treated the cotton fabric with FMBN. Results showed that the as-prepared latex particles had the uniform spherical core-shell structure with an average diameter of 116 nm. FMBN could form a smooth resin film on the treated fabric/fiber surface under Field emission scanning electron microscopy (FESEM) observation, but some protuberances appeared on that surface from Atomic force microscopy (AFM) image. X-ray photoelectron spectroscopy (XPS) analysis indicated the fluoroalkyl groups tended to enrich at the film-air interface. Hydrophobicity of the FMBN treated fabric was superior to that of the fabrics treated by general emulsion and the non-crosslinking one. In addition, the above three latexes didn’t influence whiteness of the treated fabrics at all. However, they all, and in especial two self-crosslinking latexes would make the treated fabrics stiffer compared to non-crosslinking one.     

Antibacterial properties of PLA nonwoven medical dressings coated with nanostructured silver

In this paper, magnetron sputtering was applied to deposit nano-structured silver films on the surfaces of polylactic acid (PLA) nonwovens, which were used in medical dressings. The influence of the coating thickness of the nano-structured sliver films on the antibacterial property of the nonwovens was studied. The antibacterial properties of the medical dressings were measured by shake flask test. The surface morphology of nano-structured silver films and the grain sizes of silver agglomerates were analyzed by atomic force microscope (AFM). Energy dispersive X-ray (EDX) was employed to analyze the surface elemental compositions. The study revealed that the antibacterial properties were improved as the film thickness increased. AFM images of the coated samples indicated that as the sputtering time prolonged, the film thickness was increased, the film became compacter, and the specific area of the film was also increased. Thus, the release rate of silver ions increased, leading to the improved antibacterial property. It was found that the reduction percentage of both tested bacteria-Staphylococcus aureus and Escherichia coli reached 100 % as the coating thickness exceeded 1 nm.     

Properties of basic dyes on polyacrylonitrile treated m-aramid fabrics

Treatment of polyacrylonitrile (PAN) onto m-aramid fabric was carried out by pad-dry-cure method using dimethylformamide (DMF) dissolved acrylic fiber solution. The obtained PAN treated m-aramid fabric was dyed using exhaustion method with basic dyes. The effect of PAN treatment on fabric stiffness property was acceptable with acrylic fiber solutions ranging from 1 wt% to 4 wt%. Whilst, more than 4 wt% PAN treated fabrics exhibited undesirable stiffness. The dyeing results showed that PAN treated m-aramid fabrics exhibited a significant increase in color strength when compared to untreated fabric, arising from an increase in anionic dye sites (styrene SO₃ ^? group). Wash fastness was comparable to that of untreated fabric, indicating the strong interaction between dye molecules and the PAN. Rubbing fastness of treated fabrics was not affected by treatments with PAN concentrations lower than 4 wt%. Further increase in PAN concentration led to poorer rubbing fastness property due to the problem of surface dyeing. For light fastness, the PAN treatment failed to improve the light fastness property which is the main disadvantage of basic dyeing of aramid fabric. Finally, in case of PAN treatments with the range of 1 wt% to 4 wt%, the flame retardancy property of PAN treated m-aramid fabrics was found not affected by the percent add-on. However, above 4 wt% PAN treatment, the flame retardancy performance became deteriorated.