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Functional polymeric membranes with antibacterial properties have gained significant importance in many applications. Silver NPs offer advantage over other materials for their effective antibacterial properties and being safer for humans at low concentrations. The synthesis of silver NPs may not always be environmental friendly and their incorporation in the polymer membranes is usually a multistep process. In this study, PVDF/PVP/AgNPs electrospun membranes were developed in a single step process where silver NPs were synthesized using reducing and stabilizing properties of PVP. The UV-vis spectroscopy confirmed the synthesis of silver NPs in PVP solution by sharp absorption peak at 398 nm. The membranes were loaded with various concentrations of silver NPs (1, 1.5, 2 and 2.5 wt%). The scanning electron microscopy of the developed membranes showed nano fibers of uniform diameter at optimized electrospinning conditions. FTIR spectroscopy also confirmed the successful development of polymeric composite (PVDF/PVP/AgNPs) membranes. The composite membranes demonstrated effective antibacterial properties against Staphylococcus aureus in disk diffusion test. The size of the inhibition halo increased with the concentration of the silver NPs in electrospun membranes. The findings of this study will be helpful in the simple and environmentally friendly development of antibacterial membranes for applications such as air and water filtration.

Hydroxyapatite (HA) coating has received significant attention in the scientific community for the development of implants, and HA coating on titanium oxide (TiO2) nanotubes has shown potential benefits in the improvement of cell proliferation, adhesion, and differentiation. In this study, a HA coating on a TiO2 nanotubular surface was developed to improve the biocompatibility of the titanium (Ti) surface via magnetron sputtering. Scanning electron microscopy (SEM), surface profilometry, and water contact goniometry revealed that HA-coated TiO2 nanotubes influenced the surface roughness (Ra) and hydrophilicity. The XRD and FTIR peaks indicated the presence of crystalline phases of TiO2 (anatase) and HA-coated TiO2 nanotubes after annealing at 500 °C for 120 min. The HA-coated TiO2 nanotubes showed significantly increased Ra and decreased water contact angle (θ) compared to the as-anodized TiO2 nanotubular and bare CP-Ti surfaces. MTS assay using osteoblast-like cells confirmed that the HA-coated TiO2 nanotubular surface provided an enhanced cell attachment and growth when compared to as-anodized TiO2 nanotubular and pure CP-Ti surfaces.

Nowadays needleless electrospinning is a well-known technique to produce polymeric nanofibers on large scale. This study was conducted to see the influence of spinneret polarity on needleless electrospinning. Depending on the type of spinneret polarity, electrospinning led to different fiber morphology, productivity and areal density. The electric field profile in the electrospinning zone was analyzed by using finite element method. It was revealed that the intensity of electric field was higher in the part that was connected with a high voltage electrode. This could be the main reason of variances in fiber diameter, productivity and areal density

To push the upper limit of capacitive materials, the integration of multi-modal capacitive materials has emerged as a potential solution. In this regard, we reported the novel binary composite of self-suspended polyaniline (S-PANI) and multi-walled carbon nanotubes (MWNTs). Compared with conventional polyaniline, S-PANI offers higher porosity and fibrillar polymeric network, which was achieved by doping long-chain protonic acid during in situ polymerization. S-PANI was loaded on oxidized carbon nanotubes (OCNTs) and sulfonated carbon nanotubes (SCNTs) to prepare S-PANI/OCNT and S-PANI/SCNT composite electrodes, respectively. The conductive and exclusive fibrillar S-PANI provide unobstructed channels for charge transport and electrolyte infiltration. Preliminary electrochemical studies revealed that the capacitance of the composite electrode reached 316.8 F g−1 and 345.4 F g−1, and established exceptional capacitance retention rates of 92.8% and 93.7% after 5000 cycles for S-PANI/OCNT and S-PANI/SCNT composite, respectively, making it a potential candidate for imminent energy storage devices.

Technical development in electronic devices is frequently stifled by their insufficient capacity and cyclic stability of energy-storage devices. The nano-structured materials have sensational importance for providing novel and optimized combination to overcome exiting boundaries and provide efficient energy storage systems. Metal hydroxide materials with high capacity for pseudo-capacitance properties have grabbed special attention. Lately, the blend of nickel and cobalt hydroxides has been considered as a favorable class of metallic hydroxide materials owing to their comparatively high capacitance and exceptional redox reversibility. The sulfonated carbon nanotube fluid (SCNTF) was prepared by the ion exchange method to be utilized as the exceptional templates due to astonishing specific surface area, ensuring the maximum utilization of the active material. The CoNi-layered double hydroxides (LDHs)/SCNTF core-shell nanocomposite was prepared by the simple solvothermal method. Structural analysis showed that the composite material had the high conductance of carbon materials, the pseudo-capacitance characteristics of metal hydroxides, and porous structure, which facilitates the ion shuttle when the electrolyte reacts with the active material. Electrochemical analysis results showed that CoNi-LDHs/SCNTF had excellent rate performance, reversible charge-discharge properties and cycle stability. It exhibited an extreme specific capacity of 1190.5 F g−1 at a current density of 1 A g−1; whereas specific capacity remained 953.7 F g−1 at the current density was 10 A g−1. In addition, the capacity retention rate after 5000 charge-discharge cycles at a current density of 20 A g−1 was 81.0%. The results indicated that the CoNi-LDHs/SCNTF core-shell nanocomposite material is cost efficient and an effective substitute in energy storage applications.

2D woven auxetic fabrics (AF) developed by weave design modification provide a continuous, commercial, and low-cost manufacturing process for high strength and stable auxetic structures. However, AFs developed by previous methods have a highly folded surface, which is problematic in printing, laminating, and stitching. For the first time, we studied the auxeticity in a few yarn-based auxetic structures, which provides a uniform surface texture. Reentrant honey-comb geometry was chosen to fabricate auxetic woven fabrics, as such geometry shows the best auxetic nature. Different parameters of auxetic geometry were optimized based on their mechanical response using the statistical tool: gray relational analysis (GRA). The mechanical properties of AFs were compared with conventional (3/1 twill woven) non-auxetic fabric (NAF), having the same specifications. The smaller unit cell (3E) with a reorientation area of 4P showed optimum auxeticity and mechanical properties. The optimized auxetic structure showed superior mechanical properties as compared to conventional fabric. GRA grade of optimized AF was 67.3% higher than the NAF. Most importantly, the tensile strength was 23% higher for optimized AF structure. The bidimensional energy dissipation ability of the AF provides a key advantage in the superior mechanical response.

The man-made fibres have the versatility of required engineered properties. The biodegradability is the need of the day. This study aimed at development of biodegradable starch based fibers using wet extrusion technique. The non-modified natural starch is cost efficient and wet extrusion technique will support bulk production of fibre without any change in chemical structure of material. Multiple additives such as plasticizers and binders were added to the dope solution in different concentrations to study their effect on physical properties, mechanical performance and serviceability of the wet-spun starch fibers. The ranges of additive concentrations in (% wt/v) used to make the dope solutions are as follows: starch; 38–64%, Polyvinyl Alchohol (PVA); 7–23%, glycerol; 18–39% and styrene butadiene styrene (SBS); 0–21%. The developed fibres had linear density in the range of 25 tex–44 tex with fibre diameter of about 247–301 µm. The extruded fibers were characterized for fiber strength, surface morphology, water absorption, and biodegradability. The developed fibres have maximum tenacity of 1.56 cN/tex and water absorbency of 280 g/g. The intended application for these fibres is in medical textiles as wound dressings.

Denim is one of the most popular casual apparel all over the globe due to a variety of available looks, comfort, and convenience. Comfort and performance properties of stretched denim fabrics depend on the elastane content, which can be controlled through the linear density of elastane and draft-ratio in the core of the cotton yarn. Optimization of both of linear density and draft-ratio of elastane for the better performance of denim fabric were focused upon in this study. The results indicated that the elastane content inside the core of yarn affects the dimensional and mechanical properties of denim fabrics. Regression analysis indicated that elastane linear-density and draft-ratio had an almost equal significance on contraction after washing, stretchability, stiffness, skewness, and bow of fabric. However, the elastic properties of fabric were mainly dependent on the elastane draft-ratio. This study will be an endeavor for industry personnel to achieve more durable and dimensionally stable denim fabrics.

Kapok fiber is emerging as a cheaper natural fiber having excellent thermal insulation properties. Recycled polyester/kapok blended needle punched nonwoven waddings are prepared where the effect of...

Some important factors in the design of biomaterials are surface characteristics such as surface chemistry and topography, which significantly influence the relationship between the biomaterial and host cells. Therefore, nanotubular oxide layers have received substantial attention for biomedical applications due to their potential benefits in the improvement of the biocompatibility of the substrate. In this study, a nanotubular layer of titania-niobium pentoxide-zirconia (TiO2-Nb2O5-ZrO2) was developed via anodization on a β-type Ti35Zr28Nb alloy surface with enhanced biocompatibility. Scanning electron microscopy (SEM) and surface profilometry analysis of the anodized nanotubes indicated that the inner diameter (Di) and wall thicknesses (Wt) increased with an increase in the water content of electrolyte and the applied voltage during anodization, while the nanotube length (Ln) increased with increasing the anodization time. TiO2-Nb2O5-ZrO2 nanotubes with different Di, Wt, and Ln showed different surface roughnesses (Ra) and surface energies (γ), which affected the biocompatibility of the base alloy. MTS assay results showed that the TiO2-Nb2O5-ZrO2 nanotubes with the largest inner diameter (Di) of 75.9 nm exhibited the highest cell viability of 108.55% due to the high γ of the surface, which led to high adsorption of proteins on the top surface of the nanotubes. The second highest cell viability was observed on the nanotubular surface with Di of 33.3 nm, which is believed to result from its high γ as well as the optimum spacing between nanotubes. Ra did not appear to be clearly linked to cellular response; however, there may exist a threshold value of surface energy of ∼70 mJ/m2, below which the cell response is less sensitive and above which the cell viability increases with increasing γ. This indicates that the TiO2-Nb2O5-ZrO2 nanotubes provided a suitable environment for enhanced attachment and growth of osteoblast-like cells as compared to the bare Ti35Zr28Nb alloy surface.

Nanoscale surface roughness has conventionally been induced by using complicated approaches; however, the homogeneity of superhydrophobic surface and hazardous pollutants continue to have existing challenges that require a solution. As a prospective solution, a novel bubbled-structured silica nanoparticle (SiO2) decorated electrospun polyurethane (PU) nanofibrous membrane (SiO2@PU-NFs) was prepared through a synchronized electrospinning and electrospraying process. The SiO2@PU-NFs nanofibrous membrane exhibited a nanoscale hierarchical surface roughness, attributed to excellent superhydrophobicity. The SiO2@PU-NFs membrane had an optimized fiber diameter of 394 ± 105 nm and was fabricated with a 25 kV applied voltage, 18% PU concentration, 20 cm spinning distance, and 6% SiO2 nanoparticles. The resulting membrane exhibited a water contact angle of 155.23°. Moreover, the developed membrane attributed excellent mechanical properties (14.22 MPa tensile modulus, 134.5% elongation, and 57.12 kPa hydrostatic pressure). The composite nanofibrous membrane also offered good breathability characteristics (with an air permeability of 70.63 mm/s and a water vapor permeability of 4167 g/m2/day). In addition, the proposed composite nanofibrous membrane showed a significant water/oil separation efficiency of 99.98, 99.97, and 99.98% against the water/xylene, water/n-hexane, and water/toluene mixers. When exposed to severe mechanical stresses and chemicals, the composite nanofibrous membrane sustained its superhydrophobic quality (WCA greater than 155.23°) up to 50 abrasion, bending, and stretching cycles. Consequently, this composite structure could be a good alternative for various functional applications.

Nowadays, synthetic polymers are used in medical applications due to their special biodegradable, biocompatible, hydrophilic, and non-toxic properties. The materials, which can be used for wound dressing fabrication with controlled drug release profile, are the need of the time. The main aim of this study was to develop and characterize polyvinyl alcohol/polycaprolactone (PVA/PCL) fibres containing a model drug. A dope solution comprising PVA/PCL with the drug was extruded into a coagulation bath and became solidified. The developed PVA/PCL fibres were then rinsed and dried. These fibres were tested for Fourier transform infrared spectroscopy, linear density, topographic analysis, tensile properties, liquid absorption, swelling behaviour, degradation, antimicrobial activity, and drug release profile for improved and better healing of the wound. From the results, it was concluded that PVA/PCL fibres containing a model drug can be produced by using the wet spinning technique and have respectable tensile properties; adequate liquid absorption, swelling %, and degradation %; and good antimicrobial activity with the controlled drug release profile of the model drug for wound dressing applications.

Internal Combustion (IC) engines are prevalent in the process sector, and maintaining sufficient Air-Fuel Ratio (AFR) regulation in their fuel system is crucial for enhanced engine performance, fuel economy, and environmental safety. Faults in the AFR system’s sensors cause the engine to shut down, hence, fault tolerance is essential. In order to avoid engine shutdown, this paper offers a novel Active Fault-Tolerant Control System (AFTCS) for air-fuel ratio control of an Internal Combustion (IC) engine in a process plant. In the Fault Detection and Isolation (FDI) unit, the proposed AFTCS uses a nonlinear regression-based observer model for analytical redundancy. The suggested system was simulated in the MATLAB / Simulink environment. The proposed system was tested at two different speeds (300 r/min and 600 r/min) and the results show that the system’s response is within the acceptable bound without compromising the stability. The findings also demonstrate the higher fault tolerance capability for sensor defects of the AFR control system, particularly for the MAP sensor (at 300 r/min) in terms of reduced oscillatory response in comparison to the current literature. Compared to the linear regression-based and Genetic Algorithm (GA) based model, the nonlinear regression-based model results in a more accurate estimation of the faulty sensors. The proposed model is also efficient in terms of computation power and response time.

Synthetic antibiotics have captured the market in recent years, but the side effects of these products are life-threatening. In recent times, researchers have focused their research on natural-based products such as natural herbal oils, which are eco-friendly, biocompatible, biodegradable, and antibacterial. In this study, polyethylene oxide (PEO) and aqueous ginger extract (GE) were electrospun to produce novel antibacterial nanomembrane sheets as a function of PEO and GE concentrations. A GE average particle size of 91.16 nm was achieved with an extensive filtration process, inferring their incorporation in the PEO nanofibres. The presence of the GE was confirmed by Fourier transform infrared spectroscopy (FTIR) through peaks of phenol and aromatic groups. The viscoelastic properties of PEO/GE solutions were analysed in terms of PEO and GE concentrations. Increasing PEO and GE concentrations increased the solution’s viscosity. The dynamic viscosity of 3% was not changed with increasing shear rate, indicating Newtonian fluid behaviour. The dynamic viscosity of 4 and 5 wt% PEO/GE solutions containing 10% GE increased exponentially compared to 3 wt%. In addition, the shear thinning behaviour was observed over a frequency range of 0.05 to 100 rad/s. Scanning Electron Microscopy (SEM) analysis also specified an increase in the nanofibre’s diameter with increasing PEO concentration, while SEM images displayed smooth morphology with beadless nanofibres at different PEO/GE concentrations. In addition, PEO/GE nanomembranes inhibited the growth of Staphylococcus aureus, as presented by qualitative antibacterial results. The extent of PEO/GE nanomembrane’s antibacterial activity was further investigated by the agar dilution method, which inhibited the 98.79% Staphylococcus aureus population at 30% GE concentration.

Development of heating fabrics has a great potential in numerous applications. Heating fabrics can be developed by various approaches each having its own strengths and weaknesses. Incorporating sta...

In this research work, we have studied the dyeing behaviour of fabrics made from ring, rotor and MVS yarns. The discrete structure of respective yarns made by different spinning techniques have significant effect on dyeing behaviour of fabrics. The fabrics were investigated for K/S values of polyester dyed, cotton dyed and polyester+cotton dyed fabrics and their colour fastness to crocking. The analysis of dyeing behaviour revealed that yarn manufacturing technique has substantial effect on the colour strength of their respective fabrics. Due to unique distribution of fibers within the crosssection of yarn, the cotton dyed and polyester+cotton dyed fabrics made from MVS yarns exhibited better K/S values as compared to other fabrics. The fabrics also exhibited a difference in colour fastness to crocking in dry and wet form. The color fastness of fabrics to crocking in dry form were found higher than in wet form. The polyester dyed and polyester+cotton dyed fabrics made from MVS yarns have shown higher color fastness to crocking.

Protection for the respiratory system has become a need of the day due to increased air pollution. Different nonwoven filter media have been incorporated into filtering facepiece respirators (FFRs). However, the performance of these systems could be improved further by the addition of finer nanowebs. The effect of the addition of intermediate media (nanowebs) on the comfort of FFRs also needs to be studied, as comfort can affect the performance of wearer. In this study, electrospun polymeric nanowebs were incorporated between layers of commercially available nonwoven fabrics to improve its filtration performance. The effect of the addition of polymeric webs between the layers of nonwoven filter media on the comfort properties was also studied. It was concluded that the addition of nanowebs remarkably improved the filtration capability of filter media. Also, it was found to have mixed impact on comfort properties of the resultant composite filter media; air permeability was reduced from 58 to 50 mm/s, while the filtration efficiency was improved along with thermal and water vapor permeability. Thermal conductivity was increased from 30.5 to 39 [(W/cm °C) × 104]. Water vapor permeability increased from 1.70 to 2.04 [(g/s mm2) × 108].

Needleless electrospinning is an effective approach to fabricate the nanofibers at high throughput. However, the uniform distribution of nanofibers with finer diameter still needs improvement. In this study, optimization of needleless electrospun polyacrylonitrile (PAN) nanofibers was carried out using an effectively designed toothed wheel spinneret, which improved the nanofiber uniform distribution with finer diameter. Finite element method showed that the electric field norms were highly concentrated at toothed wheel edges. Optimized beadles PAN nanofibers with narrow diameter distribution were obtained at 6 w/v% polymer concentration, 50 kV applied voltage, and 23 cm collecting distance. Highest tensile strength of 100 cN at 7 w/v% concentration showed that the resultant membrane had good mechanical properties. The air permeability of 15 mm/s was obtained at 6 w/v% indicating good insulating behavior of the PAN nanofiber membrane. This study proved that the toothed wheel spinneret has the potential to improve the electrospinning process for the development of uniform nanofibrous membrane at a high production rate.

The nanostructured surface modification of metallic implants is increasingly gaining attention for biomedical applications. Among such nanostructured surfaces, oxide nanotube (NT) structures have r...

This research was aimed at processing of metallic fiber hybrid spun yarns consisting of polyester/stainless steel and viscose/stainless steel staple fibers to achieve better electrical conductivity...

Coatings based on ion-substituted calcium phosphate (Ca-P) have attracted great attention in the scientific community over the past decade for the development of biomedical applications. Among such Ca-P based structures, hydroxyapatite (HA) has shown significant influence on cell behaviors including cell proliferation, adhesion, and differentiation. These cell behaviors determine the osseointegration between the implant and host bone and the biocompatibility of implants. This review presents a critical analysis on the physical vapor deposition magnetron sputtering (PVDMS) technique that has been used for ion-substituted Ca-P based coatings on implants materials. The effect of PVDMS processing parameters such as discharge power, bias voltage, deposition time, substrate temperature, and post-heat treatment on the surface properties of ion-substituted Ca-P coatings is elucidated. Moreover, the advantages, short comings and future research directions of Ca-P coatings by PVDMS have been comprehensively analyzed. It is revealed that the topography and surface chemistry of amorphous HA coatings influence the cell behavior, and ion-substituted HA coatings significantly increase cell attachment but may result in a cytotoxic effect that reduces the growth of the cells attached to the coating surface areas. Meanwhile, low-crystalline HA coatings exhibit lower rates of osteogenic cell proliferation as compared to highly crystalline HA coatings developed on Ti based surfaces. PVDMS allows a close reproduction of bioapatite characteristics with high adhesion strength and substitution of therapeutic ions. It can also be used for processing nanostructured Ca-P coatings on polymeric biomaterials and biodegradable metals and alloys with enhanced corrosion resistance and biocompatibility. STATEMENT OF SIGNIFICANCE: Recent studies have utilized the physical vapor deposition magnetron sputtering (PVDMS) for the deposition of Ca-P and ion-substituted Ca-P thin film coatings on orthopedic and dental implants. This review explains the effect of PVDMS processing parameters, such as discharge power, bias voltage, deposition time, substrate temperature, and post-heat treatment, on the surface morphology and crystal structure of ion-substituted Ca-P and ion-substituted Ca-P thin coatings. It is revealed that coating thickness, surface morphology and crystal structure of ion-substituted Ca-P coatings via PVDMS directly affect the biocompatibility and cell responses of such structures. The cell responses determine the osseointegration between the implant and host bone and eventually the success of the implants.

Safety and critical applications employ fault-tolerant control systems (FTCS) to increase reliability and availability in the event of a failure of critical components. Process facilities may employ these technologies to cut down on production losses caused by equipment failures that occur on an irregular or unscheduled basis. Air–fuel ratio (AFR) adjustment in the fuel system of internal combustion engines (ICE) is crucial for enhancing engine efficiency, saving fuel energy, and safeguarding the environment. This paper proposes a novel hybrid fault-tolerant control system (HFTCS) for controlling the AFR in ICEs that combines the features of both an active fault-tolerant control system (AFTCS) and a passive fault-tolerant control system (PFTCS). The fault detection and isolation (FDI) unit is designed using fuzzy logic (FL) as part of an AFTCS to give estimated sensor values to the engine controller when the sensor becomes faulty. Super-twisting sliding mode control (ST-SMC) is implemented as part of a PFTCS to maintain AFR by adjusting the throttle actuator in the fuel supply line under faulty conditions. Lyapunov stability analysis is also performed to make sure that the system remains stable in both normal and faulty conditions. According to the results in the Matlab/Simulink environment, the suggested system stays robust and stable during sensor faults. In faulty situations, it also maintains the AFR at 14.6 without any degradation, and a comparison with previous studies is carried out. The study shows that the suggested approach is an innovative and highly dependable solution for AFR control in ICEs, preventing engine shutdown and output loss for higher profitability.

Faults frequently occur in the sensors and actuators of process machines to cause shutdown and process interruption, thereby creating costly production loss. centrifugal compressors (CCs) are the most used equipment in process industries such as oil and gas, petrochemicals, and fertilizers. A compressor control system called an anti-surge control (ASC) system based on many critical sensors and actuators is used for the safe operation of CCs. In this paper, an advanced active fault-tolerant control system (AFTCS) has been proposed for sensor and actuator faults of the anti-surge control system of a centrifugal compressor. The AFTCS has been built with a dedicated fault detection and isolation (FDI) unit to detect and isolate the faulty part as well as replace the faulty value with the virtual redundant value from the observer model running in parallel with the other healthy sensors. The analytical redundancy is developed from the mathematical modeling of the sensors to provide estimated values to the controller in case the actual sensor fails. Dual hardware redundancy has been proposed for the anti-surge valve (ASV). The simulation results of the proposed Fault-tolerant control (FTC) for the ASC system in the experimentally validated CC HYSYS model reveal that the system continued to operate in the event of faults in the sensors and actuators maintaining system stability. The proposed FTC for the ASC system is novel in the literature and significant for the process industries to design a highly reliable compressor control system that would continue operation despite faults in the sensors and actuators, hence preventing costly production loss.

Development of conductive yarns for smart textile applications is the most demanding area of research these days. This study was aimed to investigate the effect of yarn constructional parameters, and relative humidity on electromechanical properties of conductive ring spun hybrid yarns. Stainless steel (SS) fibre was blended with polyester and viscose fibre separately on 12% and 24% weight basis to produce hybrid conductive yarns at three different levels of twist factor. The electromechanical properties of yarns were evaluated in response to change in blend type, blend ratio, twist factor, and relative humidity. The content of SS fibre is found to be more effective followed by the twist factor and blend type to govern the linear electrical resistance (LER) of conductive yarns. In addition, on increasing relative humidity, the LER of viscose stainless steel (VS) hybrid yarns are found to drop significantly than that of polyester stainless steel (PS) hybrid yarns.

Auxetic materials expand in at least one dimension, when stretched longitudinally i.e. they have negative Poisson’s ratio. Development of 2D woven auxetic fabrics (AF) is a new approach to develop mechanically stable auxetic textile structures. However, the mechanical response of such emerging structure is still not studied in detail yet, therefore different mechanical properties of 2D woven AF are compared with conventional non-auxetic fabric (NAF). AF was developed by orienting yarns in auxetic honey-comb (AHC) geometry and auxeticity is induced due to such orientation of yarns. AF was developed using conventional (non-auxetic) materials; cotton yarn and elastane cotton yarn in warp and weft dimension respectively, using air jet loom. Structure and auxeticity of AF were analyzed using a digital microscope and its different mechanical properties (tensile strength, tear strength, bursting strength, cut resistance, and puncture resistance) were studied. AF showed superior mechanical properties with a lower initial modulus, which is beneficial for different protective textiles applications like cut resistance gloves, blast resistant curtains, and puncture tolerant elastomeric composites.

Yarn’s surface to metal friction is an important consideration in the subsequent process of knitting and weaving as it influences mainly the ends down rate, fly generation, process efficiency, wear and tear of machine parts, and production rate of the process. These frictional properties are measured in terms of the coefficient of friction of yarn. The effect of cotton type, yarn twist, yarn linear density, process type, and finishing treatment was studied on the surface to the metal friction coefficient of cotton spun yarn using Taguchi experimental design. The experiments were conducted with Pakistani and Indian cotton using combed and carded ring spinning processes. Using Taguchi design of experiment, a total of 36 samples of cotton ring-spun yarns were produced. The coefficient of friction between the yarn’s surface and metal’s surface is measured in compliance with ASTM D3108. The outcome of the Taguchi model to predict the coefficient of friction of yarns with a predefined combination of constituting parameters was further confirmed with nine yarn samples. The frictional characteristics of yarns are found to be influenced by all factors. In addition to the application of wax, the longer fiber length, lower trash count, lower short fiber index, and the optimum level of twist are found advantageous to reduce the yarn coefficient of friction.

The objective of this study was to model the physical and mechanical properties of 100% cotton slub yarns commonly used in denim and other casual wear. Statistical models were developed using central composite experimental design of the response surface methodology. Yarn’s linear density, slub thickness, slub length and pause length were used as the key input variables while yarn strength, elongation, coefficient of mass variation, imperfections and hairiness were used as response/output variables. It was concluded that yarn strength and elongation increased with increase in linear density and pause length, and decreased with increase in slub thickness and slub length. Yarn mass variation and total imperfections increased with increase in slub thickness and pause length, whereas yarn imperfections and hairiness decreased with increase in slub length. It was further concluded that due to statistically significant square and interaction effects of some of the input variables, only the quadratic model instead of the linear models can adequately represent the relationship between the input and the output variables. These statistical models will be of great importance for the industrial personnel to improve their productivity and reduce sampling.

The major concern to the mankind in this generation is clean and green environment. New materials and technologies are developed for everyday purpose products. Biopolymers are widely used in food packaging applications. The food grade film developed with starch and polyvinyl alcohol (PVA) is non-toxic and edible but have low tensile properties. In this study composite structure of corn starch and polyvinyl alcohol with incorporation of coir fiber particle reinforcement was prepared by solution casting method and characterized for their performance properties. Surface modification of coir fiber was done by chemical agents (H 2 O2, NaOCl and KMnO4) with concentration of 0.5% and 1.5% (v/v) of chemicals. Tensile properties and surface/morphological characteristics were evaluated by Universal Testing Machine (UTM) and Scanning Electron Microscopy (SEM) respectively. It was observed that the tensile strength of composite structure was increased by the incorporation of fiber particles. Water absorbency and degradability were also evaluated. It was observed that the tensile strength of composite structure was increased by the incorporation of fiber particles. It was inferred that composite structure with low fiber particle concentration can be utilized in packaging applications due to its better tensile strength.

The proposed research presents significant progress in the photovoltaic performance of quasi-solid state dye-sensitized solar cells (DSSCs) by synthesizing a highly electro-catalytic active activated charcoal decorated functionalized multi-walled carbon nanotube (MWCNT) composite electro-catalyst as a counter electrode (CE). The proposed carbon composite structure was synthesize by facile acid functionalization of MWCNTs followed by the addition of mesoporous activated charcoal, decorating the tubular graphitic structure of the CNTs. The carbon composite paste deposited on FTO glass by a sequential process of doctor blade coating under an air-drying technique. The porous functionalized mesoporous carbon (f-MC) with a dominant oxygen rich surface displays greatly enhanced electro-catalytic activity, low charge transfer resistance (R CT ), and exceptional cyclic stability as compared with pristine CNTs. The DSSC fabricated with f-MC CE demonstrated efficient electrochemical characteristics and photovoltaic performance when fabricated with a high-viscosity quasi-solid electrolyte. The highly conductive and porous carbon structure locates manifold sites for tri-iodide reduction reaction. High mobility of the quasi-solid electrolyte within defect rich (f-MC) surface confirmed a low R CT of (0.60 Ω.cm 2 ), and exhibited superior electrocatalytic activity compared to a conventional platinum (Pt) reference CE. The f-MC CE based DSSCs showed high power conversion efficiency (PCE) of 8.42%, exceeding the Pt reference CE of 8.11%. Based on the facile synthesis of f-MC composites and fabrication of CE, the proposed DSSCs stand out as efficient next generation solar cells.

This research demonstrates the design and operation of a dye-sensitized solar cell (DSSC) with a multi-walled carbon nanotube counter electrode (CE) and a pore-filled membrane consisting of polyvinylidene fluoride-co-hexafluoropropylene (PVdF-co-HFP) as an electrolyte. In this cell, the internal resistance was substantially reduced and the efficiency was found to be as high as 6.04% under 1 sun. For this purpose, a sequence of experiments was carried out to demonstrate that the PVdF-co-HFP membrane possessed superior porosity to absorbed electrolytes and is more compatible with MWCNT CE as compared to the commonly used liquid electrolyte. For a comparison of results, different types of DSSC assemblies composed of MWCNT CEs were fabricated with liquid-, gel- and electrolyte-filled PVdF-co-HFP membranes. Morphological studies showed that the PVdF-co-HFP membrane is a regular and highly porous nano-web which provides optimized interfacial contact with defect-rich MWCNT CE. Detachment of the carbon particles from the CE causes short circuits and lower efficiency of the DSSCs. The proposed DSSC design not only lowers the interfacial charge transfer resistance (RCT = 2.98 Ω) but also reduces the risk of short circuits in the cell. This sustainable and highly efficient DSSC structure provides a new method for the simple fabrication of flexible solar cells and electronic devices.

Metal-oxide based nanostructures, with mixed crystalline phases and high specific surface area, are of great interest due to their excellent performance. Highly porous TiO2 nanofiber-in-nanotube (NF@NT) structures are developed through triaxial electrospinning, followed by the annealing process. A mixed solution of polyvinyl pyrrolidone, tetrabutyl titanate, and di-isopropyl azodiformate are used in the outer and inner layers of the nanofibers, while paraffin oil is used in the middle layer for separation. Mesoporous TiO2NF@NT structure is confirmed through the SEM images. FTIR spectrums reveal the transformation of as-spun polyvinyl pyrrolidone/tetrabutyl titanate/di-isopropyl azodiformate/paraffin oil triaxial nanofiber into TiO2NF@NT after the annealing. XRD results show the maximum mixed phases (anatase and rutile) of TiO2NF@NT at 450 °C. The transformation of anatase to rutile phase increases with increasing the temperature from 450 °C to 700 °C. BET analysis shows that TiO2NF@NT has a higher specific surface area of ~149.67 m2/g compared to the normal TiO2 nanofiber (~62.00 m2/g). TiO2NF@NT performs better photo-degradation of the Sandalfix N.Blue (SNB) under UV-light irradiation than the normal TiO2NFs. Moreover, TiO2NF@NT, calcined at 450 °C temperature, had the highest SNB degradation (88.1%). These mixed-phase triaxial multifunctional structures could be employed in many applications.

Despite the attractive features of existing supercapacitors (SCs), SC devices still exhibit low mass loading, limited working voltage, low specific capacitance, short cycle life, and unsatisfactory energy density. In this study, we introduced novel self-suspended polyaniline (S-PANI) into a combination of manganese dioxide (MnO2) and reduced graphene oxide (RGO) to propose an efficient SC electrode for energy storage applications. The unique addition of lightweight, highly conductive, exceptionally water-soluble, and unique fibrillar structure S-PANI increased the conductivity of composite aerogels and reduced the ionic diffusion resistance of electrode materials. The introduction of S-PANI significantly improved the dispersion of MnO2 particles and enabled MnO2 to give full play to its pseudopotentiability. The MnO2/S-PANI/P-RGO ternary composite aerogel was prepared by the self-assembly hydrothermal technique where different mass ratios of MnO2, S-PANI, and RGO were used and analyzed. Physical analyses showed that MnO2/S-PANI/P-RGO composite aerogels had a 3D porous network structure and MnO2 nanospheres are evenly disseminated on the surface of RGO nanosheets. The flowable S-PANI reduced the solid-solid contact resistance in the electrode. The developed 3D MnO2/S-PANI/P-RGO composite aerogel electrode displayed a specific capacitance of 571 F g−1 at the current density of 1 A g−1 along with the specific capacitance of 413 F g−1 with an increased current density of 40 A g−1 and the capacity retention rate of 72.6 %. Also, the initial capacitance retention of 96.7 % was attained after 10,000 cycles at a current density of 20 A g−1 is attained, displaying significant and long-term stability of the composite aerogel electrode. In summary, MnO2/S-PANI/P-RGO composite aerogels reported in this study are promising in energy storage applications demanding high specific capacitance and cycle life.

Textile fabric based electrodes due to their lightweight, flexibility and cost effectiveness, coupled with the ease of fabrication are recently given a huge attention as wearable energy sources. The current dye sensitized solar cells (DSSCs) are based on Platinized-Fluorinated Tin oxide (Pt-FTO) glass electrode, which is not only expensive, but also rigid and heavyweight. In this work, a highly conductive-graphene coated cotton fabric (HC-GCF) is fabricated with a surface resistance of only 7 Ω sq−1. HC-GCF is used as an efficient counter electrode (CE) in DSSC and the results are examined using photovoltaic and electrochemical analysis. HC-GCF counter electrode shows a negligible change of resistance to bending at various bending positions and is also found extremely resistant to electrolyte solution and washing with water. Cyclic voltammogram, Nyquist and the Tafel plots suggest an excellent electro catalytic activity (ECA) for the reduction of tri-iodide ( I 3 − ) ions. Symmetrical cells prepared using HC-GCF, indicate a very low charge transfer resistance (RCT) of only 1.2 Ω, which is nearly same to that of the Pt with 1.04 Ω. Furthermore, a high photovoltaic conversion efficiency (PCE) of 6.93% is achieved using HC-GCF counter electrode using polymer electrolyte.

Highly conductive mesoporous carbon structures based on multiwalled carbon nanotubes (MWCNTs) and activated charcoal (AC) were synthesized by an enzymatic dispersion method. The synthesized carbon configuration consists of synchronized structures of highly conductive MWCNT and porous activated charcoal morphology. The proposed carbon structure was used as counter electrode (CE) for quasi-solid-state dye-sensitized solar cells (DSSCs). The AC-doped MWCNT hybrid showed much enhanced electrocatalytic activity (ECA) toward polymer gel electrolyte and revealed a charge transfer resistance (RCT) of 0.60 Ω, demonstrating a fast electron transport mechanism. The exceptional electrocatalytic activity and high conductivity of the AC-doped MWCNT hybrid CE are associated with its synchronized features of high surface area and electronic conductivity, which produces higher interfacial reaction with the quasi-solid electrolyte. Morphological studies confirm the forms of amorphous and conductive 3D carbon structure with high density of CNT colloid. The excessive oxygen surface groups and defect-rich structure can entrap an excessive volume of quasi-solid electrolyte and locate multiple sites for iodide/triiodide catalytic reaction. The resultant D719 DSSC composed of this novel hybrid CE fabricated with polymer gel electrolyte demonstrated an efficiency of 10.05% with a high fill factor (83%), outperforming the Pt electrode. Such facile synthesis of CE together with low cost and sustainability supports the proposed DSSCs' structure to stand out as an efficient next-generation photovoltaic device.

Highly dispersed conductive suspensions of multi walled carbon nanotubes (MWCNT) can have intrinsic electrical and electrochemical characteristics, which make them useful candidate for platinum (Pt)-free, dye sensitized solar cells (DSSCs). High energy conversion efficiency of 7.52% is demonstrated in DSSCs, based on enzyme dispersed MWCNT (E-MWCNT) layer deposited on fluorine doped tin oxide (FTO) glass. The E-MWCNT layer shows a pivotal role as platform to reduce large amount of iodide species via electro catalytically active layer, fabricated by facile tape casting under air drying technique. The E-MWCNT layer with large surface area, high mechanical adhesion, and good interconnectivity is derived from an appropriate enzyme dispersion, which provides not only enhanced interaction sites for the electrolyte/counter electrode interface but also improved electron transport mechanism. The surface morphology and structural characterization were investigated using field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), x-ray photoelectron spectroscopy (XPS), Raman spectroscopy and electronic microscopy techniques. Electro catalytic activity (ECA) and electrochemical properties of E-MWCNT counter electrode (CE) were investigated using cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) measurements. The high power conversion efficiency (PCE) of E-MWCNT CE is associated with the low charge transfer resistance ( R CT = 1.39 Ω cm 2 ) and excellent electro catalytic activity on the redox of the iodide/tri-iodide pair, as discovered by the cyclic voltammetry and electrochemical impedance spectroscopy investigations. This facile E-MWCNT configuration provides a concrete fundamental background towards the development of the third generation photovoltaic devices.

Light scattering in dye-sensitized solar cell (DSSC) plays a vital role in extending the traveling distance by confining light propagation within the photoanode and also promotes interaction of incident photons with the dye molecules. A novel strategy was adopted to improve the performance of DSSC with better absorption of solar spectrum both in the visible as well as near IR regions. A double layer photoanode structure with TiO 2 nanoparticles (P25) as main layer and composite of titanium nanotubes (TNTs) and P25 as over-layer was introduced. Three different compositions of TNT/P25 were investigated, and finally an optimized composition with excellent performance was prepared. Performance of cells having composite over-layer was compared with the cells having TNT and conventional bigger particles (G2) over-layers. Composite over-layer structure of 75/25-TNT/P25 showed best photovoltaic performance of 8.52% with J sc of 16.49 mA/cm 2 , which is 7.30% higher than the cells having G2 over-layer and 4.9% higher than the cells having pure TNT over-layer. Different characterization analysis proved that DSSC with optimized composite over-layer structure has significant advantages of better dye adsorption, large surface area, better photo-electron generation, superior electron recombination restraint characteristics, better conductive behavior, better light scattering, and long electron lifetime. Composite over-layer structure is a promising and innovative approach for further improving the efficiency of DSSC and this will be a concrete fundamental background toward the development of the applications of the next generation dye-sensitized solar cells.

Extensive research has been focused on reducing cost of current dye sensitized solar cells (DSSCs) and make them flexible by using versatile materials that could make this energy conversion technique, more economical and increase their applications. In this work, we have demonstrated a low cost, lightweight, Pt and metal-free, flexible, reduced graphene oxide (rGO) coated cotton fabric as textile structured counter electrode (CE) in DSSC. This electrode was prepared with a simple and quick, dip and dry technique, commonly used in textile industry, to adsorb graphene oxide nanosheets (GONs) on cotton fabric which was then chemically reduced, using hydriodic acid to rGO for restoration of π-π conjugation and high electrical conductivity at the surface of cotton fabric. This novel natural fiber-based fabric electrode showed excellent flexibility under different bending angles a I 3 − nd judicious electrocatalytic activity towards reduction of triiodide ( I 3 − ) with a commendable conversion efficiency of 2.52%. This electrode offers advantages of not only saving the cost of Pt itself but also reducing the energy required to activate Pt. Being flexible and light weight, this electrode can be used in variety of applications, including wearable types of DSSCs.

The aim of this study was to investigate the effect of elastane linear density and draft ratio on the physical and mechanical properties of core-spun yarns. Twenty yarn samples were prepared on industrial scale in a spinning mill with two different yarn linear densities, each with different two elastane deniers and five draft ratios. It was found that core-spun yarn’s tenacity, elongation and hairiness are affected not only by the overall yarn linear density but also by the elastane linear density and the draft ratio. However, the effect of elastane linear density and draft ratio was not found to be statistically significant on the yarn mass variations and total imperfections, which are only affected by the overall yarn liner density. A statistically significant interaction for yarn elongation at break was found between the yarn liner density and the elastane linear density concluding that elastane linear density used in the core must be compatible with the overall yarn liner density for attaining the bes...

Textile electrodes are highly desirable for wearable electronics as they offer light-weight, flexibility, cost effectiveness and ease of fabrication. Here, we propose the use of lyocell fabric as a flexible textile electrode because of its inherently super hydrophilic characteristics and increased moisture uptake. A highly concentrated colloidal solution of graphene oxide nanosheets (GONs) was coated on to lyocell fabric and was then reduced in to graphene nanosheets (GNs) using facile chemical reduction method. The proposed textile electrode has a very high surface conductivity with a very low value of surface resistance of only 40 Ω sq −1 , importantly without use of any binding or adhesive material in the processing step. Atomic force spectroscopy (AFM) and Transmission electron microscopy (TEM) were conducted to study the topographical properties and sheet exfoliation of prepared GONs. The surface morphology, structural characterization and thermal stability of the fabricated textile electrode were studied by field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FT-IR), X ray photon spectroscopy (XPS), Raman spectroscopy, Wide angle X ray diffraction spectroscopy (WAXD) and Thermogravimetric analysis (TGA) respectively. These results suggest that the GONs is effectively adhered on to the lyocell fabric and the conversion of GONs in to GNs by chemical reduction has no adverse effect on the crystalline structure of textile substrate. The prepared graphene coated conductive lyocell fabric was found stable in water and electrolyte solution and it maintained nearly same surface electrical conductivity at various bending angles. The electrical resistance results suggest that this lyocell based textile electrode (L-GNs) is a promising candidate for flexible and wearable electronics and energy harvesting devices.

Dye-sensitized solar cell (DSSC) is an attractive renewable energy technology currently under intense investigation. Electrolyte plays an important role in the photovoltaic performance of the DSSCs and many efforts have been contributed to study different kinds of electrolytes with various characteristics such as liquid electrolytes, polymer electrolytes and so on. In this study, DSSC is developed by using quasi-solid electrolyte and a novel procedure is adopted for filling this electrolyte. The quasi-solid-state electrolyte was prepared by mixing Poly ethylene oxide (PEO) and bismaleimide together and constitution was taken as PEO (15 wt%) at various bismaleimide concentrations (1, 3, 5 wt%). The novel procedure of filling electrolyte consists of three major steps (first step: filling liquid electrolyte, second step: vaporization of liquid electrolyte, third step: refilling quasi-solid-state electrolyte). The electrochemical and photovoltaic performances of DSSCs with these electrolytes were also investigated. The electrochemical impedance spectroscopy (EIS) indicated that TiO2/Dye/electrolyte impedance is reduced and electron lifetime is increased, and consequently efficiency of cell has been improved after using this novel procedure. The photovoltaic power conversion efficiency of 6.39% has been achieved under AM 1.5 simulated sunlight (100 W/cm 2 ) through this novel procedure and by using specified blend of polymers.

Textile wearable electronics offers the combined advantages of both electronics and textile characteristics. The essential properties of these flexible electronics such as lightweight, stretchable, and wearable power sources are in strong demand. Here, we have developed a facile route to fabricate multi walled carbon nanotube (MWCNT) coated polyester fabric as a flexible counter electrode (CE) for dye sensitized solar cells (DSSCs). A variety of MWCNT and enzymes with different structures were used to generate individual enzyme-dispersed MWCNT (E-MWCNT) suspensions by non-covalent functionalization. A highly concentrated colloidal suspension of E-MWCNT was deposited on polyester fabric via a simple tape casting method using an air drying technique. In view of the E-MWCNT coating, the surface structure is represented by topologically randomly assembled tubular graphene units. This surface morphology has a high density of colloidal edge states and oxygen-containing surface groups which execute multiple catalytic sites for iodide reduction. A highly conductive E-MWCNT coated fabric electrode with a surface resistance of 15 Ω sq(-1) demonstrated 5.69% power conversion efficiency (PCE) when used as a flexible CE for DSSCs. High photo voltaic performance of our suggested system of E-MWCNT fabric-based DSSCs is associated with high sheet conductivity, low charge transfer resistance (RCT), and excellent electro catalytic activity (ECA). Such a conductive fabric demonstrated stable conductivity against bending cycles and strong mechanical adhesion of E-MWCNT on polyester fabric. Moreover, the polyester fabric is hydrophobic and, therefore, has good sealing capacity and retains the polymer gel electrolyte without seepage. This facile E-MWCNT fabric CE configuration provides a concrete fundamental background towards the development of textile-integrated solar cells.