Comparative Performance of Copper and Silver Coated Stretchable Fabrics

Azam Ali,Vijay Baheti,Jiri Militky,Zaman Khan,Syed Qummer Zia Gilani 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

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 oC for silver and 112 oC 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.

Metal Coating on Ultrafine Polyester Non-woven Fabrics and Their Ageing Properties

Azam Ali,Vijay Baheti,Jiri Militky,Zaman Khan,Guocheng Zhu 한국섬유공학회 2019 Fibers and polymers Vol.20 No.7

The presented research work proposed a simple technique to metalize the milife fabric (very fine thickness) withsilver coating. The polyester fabrics were firstly sensitized with copper, and then silver plating was performed on the surface. The presence of silver over the fabric was observed by scanning electron microscope and respective EDX spectra. Thechange in the electrical conductivity, electromagnetic shielding and joule heating properties were examined for differentelectroplating time. The electrically conductive fabrics showed low electrical resistance with high EMI shielding overfrequency range of 30 MHz to 1.5 GHz. To have an idea about the durability of electrical conductivity under stretch load, the75 cycles of stretch and release were carried out. Furthermore, the heating performance of silver plated fabric was studiedthrough measuring the change in temperature at the surface of the fabric while applying a voltage difference across the fabric. Lastly, the effect of ageing parameters like washing, oxidation and sulfidation were examined on the functional and comfortproperties (i.e. thermal conductivity and stiffness) of conductive fabric.

Bio-Composites Reinforced with Natural Fibers: Comparative Analysis of Thermal, Static and Dynamic-Mechanical Properties

Rajesh Mishra,Jakub Wiener,Jiri Militky,Michal Petru,Blanka Tomkova,Jana Novotna 한국섬유공학회 2020 Fibers and polymers Vol.21 No.3

In the present study, flax, jute and glass woven fabric samples were developed as reinforcement for compositeswith bio-epoxy resin. Flax fabrics were developed with plain weave, twill weave (different areal densities) and unidirectional(UD) structure. Jute fabrics were woven with three different structures i.e. plain, matt and twill respectively. For comparisonpurpose, glass woven fabric with plain weave and 3D orthogonal weave were used in this study. Static mechanical propertieslike flexural strength and impact resistance were studied. Dynamic mechanical properties were investigated by DMA 40XTRMI equipment.. Thermal conductivity has been studied for all composite samples. It is observed that the static mechanicalproperties of glass fabrics reinforced composites are superior but the flax & jute fabric reinforced composites are moreflexible. The specific flexural strength as well as specific impact strength of the flax & jute fabric reinforced composites arecompetitive. The dynamic mechanical properties are comparable to that of glass fabric reinforced composites. They can beused in relatively lower load bearing applications as they are a sustainable source of materials for bio-composites whichreduce the environmental burden and reduce the manufacturing cost.

Development of Multilayered Nanocomposites for Applications in Personal Protection

Jana Novotna,Vijay Baheti,Blanka Tomkova,Jiri Militky,Jan Novak 한국섬유공학회 2018 Fibers and polymers Vol.19 No.6

The aim of the presented research was to study the influence of surface layer material on improvement of impact, dielectric, EMI shielding and sound absorption properties of sandwich composites. The sandwich composite structure consisted of Kevlar or Carbon woven fabric at the surface layer, recycled high loft nonwoven in the center and a mixture of carbon particles/epoxy matrix as a binder to hold the surface layer and core together. The carbon particles were incorporated in epoxy in order to improve failure mechanism and enhance dielectric properties or electromagnetic shielding of sandwich composites. The biggest improvements on impact properties of sandwich composites were obtained when Kevlar fabric was used as surface layer. However, surface layer of carbon fabric was found to provide better dielectric properties and improve EMI shielding of sandwich composites against Kevlar fabric surface layer.

Multifunctional nanofiber membrane with anti-ultraviolet and thermal regulation fabricated by coaxial electrospinning

Shuoshuo Wang,Wubin Chen,Lina Wang,Juming Yao,Guocheng Zhu,Baochun Guo,Jiri Militky,Mohanapriya Venkataraman,MING ZHANG 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.108 No.-

Ultraviolet radiation is extremely harmful to humans and often occurs in high-temperature weather. Thedevelopment of intelligent textiles based on UV protection and thermal regulation is paramount. In thisresearch, we use coaxial electrospinning technology to prepare anti-ultraviolet smart thermo-regulatingnanofiber membranes. The zinc oxide (ZnO) and octadecane were incorporated into nanofibers with thepolyacrylonitrile (PAN)/ZnO as sheath and the octadecane as core successfully. The composite nanofibershave excellent comprehensive properties, the highest melting enthalpy is 111.38 J/g, and the UPF value is86.21. This multifunctional nanofiber membrane has broad prospects in outdoor products, electroniccomponent protection, and military products.

Flame Retardancy, Physiological Comfort and Durability of Casein Treated Cotton Fabrics

Sajid Faheem,Vijay Baheti,Nazia Nahid,Maros Tunak,Jakub Wiener,Jiri Militky 한국섬유공학회 2019 Fibers and polymers Vol.20 No.5

The present work was aimed to develop the flame retardant textiles for prevention of second-degree burn injuriesfrom low intensity heat flux accidents. The different concentration of casein suspension was applied on cotton fabrics andtheir thermo-oxidative properties, flame retardant behavior as well as physiological comfort were examined. From thermogravimetric analysis, the percentage increase in char residue indicated improvement in thermo-oxidative properties. Themaximum improvement in flame retardant behavior was found in case of 30 w/v % casein suspension due to higherproduction of thermally stable char. Their SEM micrographs also showed the formation of stronger and coherent char withpresence of local intumescence. Furthermore, for estimating small differences in burn length and burn area, the flamepropagation was studied in detail using the image analysis. The lower concentration of casein below 20 w/v % was found toprovide adequate flame retardancy with acceptable physiological comfort and mechanical properties. Finally, the short termdurability of casein treatment was verified under the effect of washing and ageing conditions.

Nanofibrous membranes with antibacterial and thermoregulatory functions fabricated by coaxial electrospinning

Zhuofan Qin,Shuoshuo Wang,Lina Wang,Juming Yao,Guocheng Zhu,Baochun Guo,Jiri Militky,Mohanapriya Venkataraman,MING ZHANG 한국공업화학회 2022 Journal of Industrial and Engineering Chemistry Vol.113 No.-

Bacteria, viruses, and temperatures change can affect the preservation of food and medicines, so it is necessaryto develop an intelligent textile for antibacterial and thermal regulation. In this paper, we usedcoaxial electrospinning technology to achieve antibacterial thermo-regulating intelligent textiles. Thepolyacrylonitrile (PAN)/curcumin is the sheath, and n-octadecane is the core. The composite fiber hasexcellent comprehensive properties. When the curcumin concentration is 10 wt%, the antibacterial effectis the best, and the bacteriostatic rate is 100%. When the core feed rate is 0.25 mL/h, the latent heat canreach 123.94 J/g. The multifunctional textiles have potential application value in the clothing fabrics,preservation and storage quality of functional foods, biomedical products, and other fields.

Highly antibacterial electrospun double-layer mats for preventing secondary wound damage and promoting unidirectional water conduction in wound dressings

Runnan Xu,MING ZHANG,Juming Yao,YAN WANG,Yafeng Ge,Dana Kremenakova,Jiri Militky,Guocheng Zhu 한국공업화학회 2023 Journal of Industrial and Engineering Chemistry Vol.119 No.-

The efficient absorption of wound exudate and the prevention of soft tissue infection are major concernsin wound repair. Good antibacterial agents and unique wound dressing structures can effectively reducewound infection, thereby accelerating wound healing. In some double-layer asymmetric wound dressings,antimicrobial agents are incorporated in the hydrophilic layer, and only a small fraction of theantimicrobial agent penetrates the hydrophobic fibre layer towards the interior of the wound. Therefore, in this study, we chose curcumin (Cur.)/cellulose acetate (CA) as the hydrophobic inner layer. Not only does this effectively allow Cur. to make contact with the lining of the wound but it also preventsthe wound from sticking. However, the mechanical properties of a single CA/Cur. layer are not ideal. Using polyacrylonitrile as the outer hydrophilic substrate improves the fibre mat mechanical properties. In addition, to further improve the hydrophilicity, the water contact angle was reduced by introducing ahydrophilic group (2-hydroxypropyl-b-cyclodextrin, b-CD) and changing the fibre roughness (nano-TiO2). Thus, wound dressings with high biocompatibility, excellent antibacterial properties, and unidirectionalwater conduction were constructed for preventing secondary wound damage. In terms of performance, ittook 40 minutes for water to enter the hydrophilic fibre layer from the hydrophobic fibre layer (the watercontact angle decreased from 121.24 to 85.42), and it took 25 minutes for water to completely enter thefibre mats (the water contact angle decreased from 85.42-0), which is effective for draining wound exudate. In terms of antibacterial properties, the antibacterial rates of Cur. (8 wt%) against Escherichia coliand Staphylococcus aureus were 82.4% and 92.57%, respectively. The Cur./CA@PAN/b-CD/TiO2 bilayerasymmetric nanofibrous mats mimic the semipermeability of the extracellular matrix (ECM) and havehigh biocompatibility, which is effective for preventing secondary wound damage. It can be used as alow-cost, high-performance wound dressing with medical material potential.