Copper functionalization of polypropylene fabric surface in order to use in fog collectors

Polypropylene fabrics were coated with copper particles using electroless plating, screen printing and wire arc spray coating techniques. Surface morphology of the fabrics was studied using optical and scanning electron microscopes (SEM). Furthermore, tensile strength, electrical conductivity, thermal conductivity, air permeability, water contact angle and fog collection efficiency of the coated fabrics were measured and the obtained results were analyzed. SEM micrographs showed that a very thin and uniform layer of copper deposited on the surface of the electroless plated polypropylene fibers. In the printed or spray coated fabrics the copper particles filled the spaces between yarns and fibers. The polypropylene electroless copper plated fabrics showed higher tensile strength, electrical conductivity, air permeability and thermal conductivity when compared with the fabrics coated with copper screen printed and copper spray coated fabrics. Finally, the obtained results showed that copper electroless plating could increase the fog collection efficiency of polypropylene fabrics considerably. As a conclusion, the surface modified copper electroless polypropylene fabrics are good candidates for fog collection in appropriate regions which need further investigations.     

Effects of deposition parameters of electroless copper plating on polyester fabric

Properties of electroless copper-plated polyester fabric mainly depend on the plating bath constituents/conditions. The nickel serves to catalyze the copper deposition when hypophosphite is used as a reducing agent. In this study, the effects of deposition parameters including additive NiSO₄ concentration and pH on microstructure and properties of the electroless copper plating on polyester fabric using hypophosphite as a reducing agent were investigated. The results show that at a higher NiSO₄ concentration, the copper content present in the coating decreases whereas the nickel content increases slightly. On the other hand, the copper content present in the coating increases, whereas the nickel content and phosphorus decreases with respect to the rise of pH. The morphology of the copper deposits show that the particle size increase with respect to the rise of NiSO₄ concentration and pH. The XRD patterns indicate that the copper-plated polyester fabrics are crystalline. In addition, there is a decrease in the surface resistance and an increase in the electromagnetic interference (EMI) shielding effectiveness (SE) with respect to the rise of Ni²⁺ concentration and pH of the solution as a result of gaining a greater weight in the deposits. The results suggest that the copper-plated polyester fabrics have a great potential application as an EMI shielding material.     

Effect of polyester fabric through electroless Ni-P plating

Process for electroless nickel-phosphorous (Ni-P) plating has been investigated as a metallizing treatment technology on polyester fabric. The microstructure and mechanical performance of Ni-P-plated polyester fabric are investigated in this study. Surface modifications of Ni-P-plated polyester fiber were studied by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The changes in weight and thickness of the Ni-P-plated polyester fabric were determined through direct measurements. Systematic investigations, including bending rigidity, tearing strength, tensile strength, elongation at break, air permeability, wettability and absorbency, and anti-static property were conducted on untreated and metallized polyester fabrics. A thorough discussion and quantitative report were made on the specific performance of the Ni-P-plated polyester fabric.     

Fabrication of electromagnetic shielding polyester fabrics with carboxymethyl chitosan-palladium complexes activation

Electromagnetic shielding polyester fabrics were prepared using carboxymethyl chitosan-palladium (CMCS-Pd) complexes as activation solution, followed by electroless nickel plating. CMCS-Pd complexes were prepared by the complexing adsorption between CMCS and Pd²⁺. The effects of reaction time and pH value on the adsorption of Pd²⁺ by CMCS were discussed. The maximum adsorption capacity was calculated as 4.27 mmol/g. CMCS-Pd complexes were characterized by ultraviolet (UV) spectrophotometer and Fourier transform-infrared (FTIR) spectroscopy. The induction time of electroless plating decreased gradually with the increase of Pd²⁺ concentration. The lowest surface resistance 125 mΩ/sq of the treated polyester fabric was obtained when Pd²⁺ concentration in CMCS-Pd complex was 1.5 g/l. The prepared polyester fabrics had excellent electromagnetic shielding effectiveness (SE) of 40–60 dB. The treated polyester fabrics were also characterized by scanning electron microscopy (SEM). Results showed that CMCS-Pd was effective to form an active catalyzed layer on polyester substrate and the 1.5 g/l Pd²⁺ was sufficient to initiate electroless nickel plating reaction. The CMCS-Pd complex activation and electroless nickel plating treatment caused small changes in the polyester fabrics’ tensile strength and air permeability.     

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.     

Enhanced Electromagnetic Interference Shielding Effects of Cobalt-Nickel Polyalloy Coated Fabrics with Assistance of Rare Earth Elements

Co-Ni-P coatings were prepared on ramie fabric by electroless plating with addition of rare earth (RE: Ce, Pr, and Nd). The proposed ultra-low-cost and easy-operated electroless plating method involved successive steps, namely, alkali mercerization, malic acid modification, Co nanoparticles activation, and Co-Ni-P deposition. FT-IR and XPS measurements were utilized to verify the functions of modification and activation procedures. Refined effects of Ce, Pr, and Nd on the structures and morphologies of resulting Co-Ni-P coatings were demonstrated by XRD and FE-SEM measurements. Moreover, by adding tiny dose of RE into the one-pot plating solution, electroless deposition rates were substantially accelerated in all cases. With regard to the resulting fabric-based Co-Ni-P coatings obtained in the presence of RE, not only mechanical durability but also chemical stability were improved. All Co-Ni-P coated fabrics displayed admirable electromagnetic properties and high electromagnetic interference (EMI) shielding effectiveness (SE). Owing to the benefits from RE, EMI SE values of Co-Ni-P shielding fabrics were enhanced with increment of 3-11 dB ranging from 30 to 6000 MHz. Significantly, Co-Ni-P-Nd coated fabric with uniform surface morphology and outstanding corrosion resistance possessed the highest EMI SE of 42.27-66.76 dB.     

The enhanced electrical conductivity of cotton fabrics via polymeric nanocomposites

Enhanced electrical conductivity of cotton fabrics coated with polyaniline (PANI) and PANI/carbon coated Fe (Fe@C) and carbon coated Co (Co@C) metal nanoparticles (NPs) composites were investigated. PANI/metal nanoparticle (NP) composites were fabricated with a surface initialized polymerization method and silanization helped with chemical bonding to cotton. The volume resistivity of the samples and structural characterizations were assessed by relevant methods. The results showed that enhanced electrical conductivity, thermal stability and magnetization were obtained via polymeric nanocomposites (PNC) and all these findings revealed that PANI/metal NP PNC coated cotton fabrics would exhibit good level electromagnetic shielding performance as a function of combined electrical conductivity and magnetization which is the objective of our future studies.     

Comparison between oxygen and nitrogen plasma treatment on adhesion properties and antibacterial activity of metal coated polypropylene fabrics

In this paper, an attempt was made to apply low temperature plasma treatment to improve the adhesion property of polypropylene fabrics. Oxygen and nitrogen plasmas were used for pre-functionalization of polypropylene fabrics. Then treated and untreated samples were coated with copper using direct current magnetron sputtering for 10 minutes. And the effect of oxygen and nitrogen pre-functionalization on adhesion properties between copper particles and polypropylene surface were studied. The textile properties of treated and untreated samples were evaluated by different standard testing methods in terms of both physical and chemical performances. The morphology changes of fabrics after plasma treatment were characterized by scanning electron microscopy. Fourier transform infrared spectroscopy analyses revealed chemical surface modifications occurring after the plasma treatments. Experimental results of the adhesion properties and surface properties are presented for the metal coated-polypropylene samples before and after low pressure plasma treatment, and results are compared. The adhesion properties of the activated samples are determined by abrasion and rubbing tests. The antibacterial counting test was used for determination of antibacterial efficiency of both treated and untreated samples, and durability of antibacterial properties was compared. The adhesion improvement has been related to the formation of different functional groups and changes in the topology of the surface.     

Characteristics of silver-plated silk fabric with plasma pre-treatment

Plasma gases of oxygen and argon were employed for pre-treating silk fabric before conducting electroless silver plating in this study. The effect of plasma pre-treatment with oxygen and argon gases on the electroless silver-plated silk fabric was investigated. Based on the observation of micro-structure using SEM, it was found that there was an increase in the amount of silver particles deposited on the silk fibre surface after plasma pre-treatment. The functional properties of plasmainduced electroless silver-plated silk fabrics were also evaluated. The increase in weight of the silver-plated silk after plasma pre-treatment was determined. When compared, the oxygen plasma treatment could improve the effect of silver plating on the silk fabric. Additionally, anti-static, anti-bacterial, UV protection and water-repellent properties of the silver-plated silk fabric were determined in this study.     

The Effects of Fabric and Conductive Wire Properties on Electromagnetic Shielding Effectiveness and Surface Resistivity of Interlock Knitted Fabrics

Our aim in this study was to investigate the effects of course density, yarn linear density and thickness and type of conductive wire on electromagnetic shielding effectiveness. Metal/cotton conductive composite yarns were produced by the core-spun technique on the ring spinning machine, involving stainless steel, copper and silver coated copper wires with 40 μm, 50 μm, 60 μm thicknesses and Ne10/1 and Ne20/1 count yarns. The interlock fabrics were knitted on a 7G flat knitting machine with the three different machine settings. The EMSE and the surface resistivity of knitted fabrics were measured by the co-axial transmission line method according to the ASTM-D4935-10 standard in the frequency range from 15 to 3000 MHz and by the ASTM D257-07 standard, respectively. It was observed that all fabrics shielded around 95 % of electromagnetic waves at low frequencies, 80 % at medium frequencies and 70 % at high frequencies. Increasing the course density and thickness of conductive wire in interlock knitted fabrics increased the EMSE correspondingly. The knitted fabrics that had been produced with high yarn count showed greater EMSE because there was less isolation. The effect of the metal wire type was highly significant between 15 and 600 MHz.     

Preparation of Copper Nanoparticles Coated Cotton Fabrics with Durable Antibacterial Properties

When copper nanoparticles (Cu NPs) were applied as an antimicrobial agent to finish cotton fabrics, there are two issues should be solved: the oxidization and the weak adsorbability onto cotton fiber surface. In the present work, we developed a new method that can achieve both immobilization and protection of the Cu NPs at the same time. As an effective binder, thioglycolic acid (TGA) was covalently linked to cotton fiber surface via an esterification with the hydroxyl groups of cellulose, then Cu NPs were introduced on the fabric surface in the presence of a protective reagent, citric acid. Due to the doubled stabilization acts of TGA and citric acid, the Cu NPs immobilized on the fabric surface showed an excellent antibacterial effect and outstanding laundering durability. Even after 50 consecutive laundering tests, the modified cotton fabrics still showed satisfactory antibacterial ability against both S. aureus and E. coli, which the bacterial reduction rates are all higher than 96 %. It is believed that this methodology has potential applications in a wide variety of textile productions such as sportswear, socks, and medical textiles.     

Eco-friendly dyeing using natural mordant extracted from <Emphasis Type="Italic">Emblica officinalis G</Emphasis>. Fruit on cotton and silk fabrics with antibacterial activity

Emblica officinalis G. dried fruit tannin was extracted and applied as a natural mordant alone and in combination with metal mordant namely copper sulphate for dyeing on cotton and silk fabrics using natural dyes. The color strength, color-coordinates, wash and light fastness were also evaluated for cotton and silk fabrics with and without mordanting. The pre-mordanted cotton and silk fabrics on dyeing gave better color strength, wash and light fastness than those dyeing obtained without mordanting. The total phenolic content of the extract was calculated. Cotton and silk fabrics resulted in good antibacterial activity using the Emblica officinalis G. mordant. When mordant was used along with 0.5 and 1 % copper sulphate mordant and the activity enhanced and was active up to 20 washes.     

Antibacterial properties and color fastness of silk fabric dyed with turmeric extract

The use of non-toxic and eco-friendly natural dyes on textiles has received much attention due to the increased environmental awareness in order to avoid some hazardous synthetic dyes. In the present study, an eco-friendly approach was developed to impart color and antibacterial properties to silk fabrics dyed with turmeric extract as a non-toxic natural colorant. The natural colorant was extracted from Curcuma Longa rhizome. Copper sulfate, ferrous sulfate and potassium aluminium sulfate were applied in a pre-metallization process as mordanting agents. Antibacterial properties of treated fabrics were evaluated against common pathogenic bacteria, Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). The effects of dye concentration and mordant types on the obtained color hues, antibacterial efficiency and color fastness of the fabrics were investigated. The results indicated that mordanted and dyed fabrics possessed desirable antibacterial properties. Complete antibacterial activity of the treated fabrics was obtained with 3 %owf (on weight of the fabric) copper sulfate. It was also shown that increasing the dye concentration could lead to a more efficient antibacterial activity on the mordanted dyed fabrics. An optimum level of the antibacterial activity was observed in the sample treated with 30 %owf of turmeric. Furthermore, the results of CIE L*, a*, b* values, FTIR, washing, light and rubbing fastnesses of the dyed fabrics were reported. The mordanted dyed silk fabrics exhibited desirable color fastness properties. These studies proved a direct relationship between the degree of antibacterial activity of the fabrics treated with turmeric and the metals ion concentration.     

The antimicrobial characteristic study of acrylic fiber treated with metal salts and direct dyes

Acrylic fabric was treated with direct dyes in combination with copper and zinc sulfates as mordanting agents and then tested for their antimicrobial activity against Gram-positive and Gram-negative bacteria. The metal salts used were also studied for their likely effects on the antimicrobial property of fabrics dyed with C.I. Direct Yellow 12, C.I. Direct Red 23, C.I. Direct Red 31, and C.I. Direct Black 38. Untreated (control) acrylic fabric exhibited no antibacterial behavior whilst dyed and mordanted fabrics revealed considerable antimicrobial properties. It was found that the fabric treated with C.I. Direct Yellow 12 and copper sulfate as mordant achieved the highest antimicrobial activity with good washing fastness. Finally, FT-IR analysis, light, and washing fastnesses of the treated samples were evaluated.     

Electrical Resistivity of Plasma Treated Viscose and Cotton Fabrics with Incorporated Metal Ions

Cellulose fabrics (viscose and cotton) were treated with atmospheric pressure dielectric barrier discharge (DBD) in air. After DBD treatment, samples were characterized and volume electrical resistance was measured under different relative humidity conditions (φ=40-55 %). Results have shown that DBD treatment increases wettability and polar surface functional groups content, which consequently causes a decrease of volume electrical resistivity of cellulose fabrics in measured relative humidity range (φ=40-55 %). Metal ions (silver, copper, and zinc) were incorporated in untreated and plasma treated samples through sorption from aqueous solutions and incorporation of metal ions into plasma treated cellulose samples decreased electrical resistivity even further. Resistivity of cotton and viscose fabrics with incorporated metal ions followed the order Zn²⁺ > Cu²⁺ > Ag⁺. The most pronounced decrease, for entire order of a magnitude, was obtained by modification of cotton fabric with DBD and silver ions, where value of resistivity dropped from GΩ to a several dozens of MΩ.     

Nano-TiO<Subscript>2</Subscript> based multilayer film deposition on cotton fabrics for UV-protection

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.     

Polyester modification through synthesis of copper nanoparticles in presence of triethanolamine optimized with response surface methodology

In this paper, polyester fabric was modified through synthesis and fabrication of Cu/Cu₂O nanoparticles using a facile and cost-effective method at boil by chemical reduction through exhaustion route. Triethanolamine (TEA) was used for aminolysis of polyester fabric and pH adjusting, copper sulfate (CuSO₄) as metal salt, sodium hypophosphite (SHP) as reducing agent and polyvinylpyrrolidone (PVP) as stabilizer. A response surface methodology was also employed to optimize the reaction conditions and study the effects of SHP, PVP and TEA concentrations in the processing. The images of field-emission scanning electron microscopy (FESEM), the patterns of energy-dispersive spectroscopy (EDX) and X-ray diffraction (XRD) patterns confirmed successfully synthesis of Cu and Cu₂O nanoparticles on the polyester fabric. Further, the thermal behavior of the untreated and treated fabrics was studied by using thermogravimetric analysis (TGA) and differential scanning colorimetry (DSC). The treated fabrics indicated good properties regarding wettability and flame-retardant along with high tensile strength.     

Optimization of electroless nickel plating on polyester fabric

Electrical conductivity is an important property of electroless nickel plated fabric. The optimized electroless nickel plating method can provide useful information for textile industries to obtain optimum surface resistance and stable plating. In this study, a screening experiment with factorial design and response surface method (RSM) with central composite design (CCD) was used to optimize the electroless nickel plating on polyester fabric. A two-level full factorial design (FFD) was used to determine the effects of five factors, i.e. the concentrations of nickel sulfate, sodium hypophosphite and sodium citrate, pH and temperature of the plating solution on surface resistance of the electroless nickel plated fabric. It is found that the nickel sulfate concentration and temperature of the plating solution are the most significant variables affecting the surface resistance of electroless nickel plated fabric. The optimum operating condition is finally obtained by using a desirability function. The test for reliability for predicting response surface equations shows that these equations give an excellent fitting to the observed values. In addition, the deposit composition, surface morphology, crystal structure and electromagnetic interference (EMI) shielding effectiveness (SE) were studied. The EMI SE of the nickel plated polyester fabric obtained under the optimal condition is about 60 dB at the frequency ranging from 2 to 18 GHz.     

Assessment of the surface roughness of cotton fabrics through different yarn and fabric structural properties

The effects of some yarn properties (i.e. type, count, twist level, ply number, unevenness and crimp) and fabric constructional properties (i.e. cover, thickness and balance) on surface roughness values of cotton woven fabrics were investigated. A general overview of the results showed that surface roughness values of fabrics were affected from yarn and fabric properties and the effects were related to fabric balance, fabric cover (not cover factor), fabric thickness and crimp values of yarns in fabric structures. Surface roughness values of fabrics decreased as yarn fineness and yarn twist levels increased but as yarn ply number decreased. Also, surface roughness values gradually decreased from open-end yarn constituting fabrics to combed yarn constituting fabrics. Results showed that different properties of yarns caused changes in yarn crimps in fabric structure and also governed the changes in fabric balance, as well as changes in roughness of fabric surfaces. The changing properties of yarns and impact of these properties on fabric construction affected the formation of cotton fabric surfaces from smooth to coarse.     

Mechanism and Analysis of Laccase-mediated Coloration of Silk Fabrics

Laccase provides a mild and eco-friendly alternative for the dyeing of fabrics. In this study, laccase-mediated catalytic oxidation was employed in coloration of silk fabrics, and the color was then assessed. The surfaces of silk fabrics were characterized by scanning electron microscope (SEM), atomic force microscopy (AFM), attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR), and X-ray photoelectron spectroscopy (XPS). Their thermal and crystallization properties were also investigated by differential scanning calorimetry (DSC), thermogravimetry (TG), and Xray diffraction (XRD). The textile softness was evaluated by the bending rigidity (B). In addition, high performance liquid chromatography (HPLC) and ultraviolet-visible (UV-VIS) spectroscopy were employed to analyze hydrolysate of silk fabrics obtained from hydrolysis with hydrochloric acid solution. The results demonstrated that a stable reddish-yellow layer was formed on the surface of silk fabrics by the laccase-mediated coupling of phenol hydroxyl side chains in the silk polypeptide. Moreover, the SEM and AFM observations showed that the surface of colored silk fiber was slick. ATR-FTIR and XPS results demonstrated differences in the C, N, O contents and the functional groups of the uncolored and colored silk fabrics. The DSC, TG, and XRD indicated that the thermal properties of silk fabrics were not affected by laccase and the coupling reaction mainly occurred in the amorphous region. The DMF extraction test further illustrated that covalent bonds were formed between tyrosine residues constituent of silk peptides. Finally, HPLC and UV-VIS results showed that new substances were formed as a result of conjugation between benzene rings.