Spindle Speed Optimization of a Ring Spinning Machine for Better Surface Irregularity and Hairiness of Yarn and Fabric

정성훈,Sahito, Iftikhar Ali,Arbab, Alvira Ayoub,Jeong, Sung Hoon 한국섬유공학회 2015 한국섬유공학회지 Vol.52 No.1

Producing yarn from natural fibers without creating irregularities in structure or having fibers protruding from the surface, remains the goal of spinners. This is a problem, as structural irregularities such as hairiness affect subsequent fabric manufacturing processes and the aesthetics of the final fabric. This work therefore focused on investigating the effects of varying the spindle speed of a ring spinning frame on the structure of yarn (i.e., its surface regularity and hairiness), its strength and the surface pilling of fabric made from such yarn with a view to optimizing the spindle speed. For this, yarns with counts of 20, 25, and 30 tex were produced at six different spindle speeds ranging from 11,000 to 21,000 rpm with an interval of 2,000 rpm. All other parameters were kept constant, including the draft for a particular count, the type and weight of the traveler, and the diameter of the ring. The results obtained revealed that as the spindle speed was increased to 17,000 rpm, the yarn structure became more regular and less hairy, thereby becoming stronger. Beyond 17,000 rpm, however, both the regularity and strength decreased, with the hairiness continuing to increase with increasing spindle speed. Consequently, the surface pilling of the fabric was found to be optimized when made from yarns produced at a spindle speed of 17,000 rpm.

Facile fabrication and comparative exploration of high cut resistant woven and knitted composite fabrics using Kevlar and polyethylene

Anam Ali Memon,Mazhar H. Peerzada,Iftikhar Ali Sahito,Sadaf Abbassi,정성훈 한국의류학회 2018 Fashion and Textiles Vol.5 No.1

Composite materials offer a number of distinct advantages in a wide range of low and high technology engineering applications. Considering the fact, in this study, a facile fabrication method of highly cut resistant composite fabrics using Kevlar and polyethylene is reported. 100% Kevlar, 100% Polyethylene and 50% Kevlar/50% Polyethylene composite fabrics are fabricated by weaving and knitting techniques. These fabrics were tested for cut index, abrasion, and puncture resistance for comparative exploration. Owing to higher mechanical strength and greater number of interlacements; the woven fabrics demonstrated twice cut resistance in contrast to knitted fabrics. The surface morphology of deformed samples investigated by Scanning Electron Microscopy (SEM) also proved that the woven fabrics of all types offered much resistance towards cutting than the knitted fabrics. Moreover, it is found that greater thickness of fabrics leads to intensification of the cut resistance. Furthermore, the effect of fiber type on cut resistant property of the fabrics was also measured and it was found that the composite fabric exhibited double cut resistance than 100% Kevlar and 100% Polyethylene fabrics. The 50% Kevlar/50% Polyethylene composite woven fabric resisted up to 35 consecutive strokes of sharp steel cutter whereas the knitted fabric completely torn apart at 20 strokes only. Thus, the as synthesized 50% Kevlar/50% Polyethylene composite woven fabric exhibiting superior cut resistance property offer a judicious choice for the preparation of efficient cut resistant fabric for industrial and domestic applications.

Self-assembled nitrogen-doped graphene quantum dots (N-GQDs) over graphene sheets for superb electro-photocatalytic activity

Riaz, Rabia,Ali, Mumtaz,Sahito, Iftikhar Ali,Arbab, Alvira Ayoub,Maiyalagan, T.,Anjum, Aima Sameen,Ko, Min Jae,Jeong, Sung Hoon Elsevier BV * North-Holland 2019 Applied Surface Science Vol.480 No.-

<P><B>Abstract</B></P> <P>Nitrogen-doped graphene quantum dots (N-GQDs) are emerging electroactive and visible light active organic photocatalysts, known for their high stability, catalytic activity and biocompatibility. The edge surfaces of N-GQDs are highly active, however, when N-GQDs make the film the edges are not fully exposed for catalysis. To avoid this issue, the N-GQDs are shaped to branched leaf shape, with an extended network of voids, offering highly active surfaces (edge) exposed for electrocatalytic and photocatalytic activity. The nitrogen doping causes a decrease in the bandgap of N-GQDs, thus enabling them to be superb visible light photocatalyst, for degradation of Methylene blue dye from water. Photoluminescence results confirmed that by a synergistic combination of the highly conductive substrate; Carbon fabric coated graphene sheets (CF-rGO) the recombination of photogenerated excitons is significantly suppressed, hence enabling their efficient utilization for catalysis. Comparatively, uniformly coated N-GQDs showed 49.3% lower photocatalytic activity, owing to their hidden active sites. The degradation was further boosted by 30% by combining the electrocatalytic activity, i.e. electro-photocatalysis of the proposed electrode. The proposed electrode material was analyzed using TEM, FE-SEM, FTIR, AFM, and WA-XRD, whereas the stability of electrode was confirmed by TGA, tensile test, bending test, and in harsh chemical environments. The proposed photo-electrocatalyst electrode is binder-free, stable, flexible and highly conductive, which makes the electrode quite suitable for flexible catalytic devices like flexible solar cells and wearable supercapacitors.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A flexible electrode is fabricated using self-assembled overlayer of Nitrogen doped Graphene Quantum Dots (N-GQDs). </LI> <LI> Self-assembeled highly porous leaflets structure has maximum exposed edge surfaces to accelarate the catalytic reaction. </LI> <LI> The proposed electrode is metal free and is stable at high temperature, harsh chemical environments, and mechanical stresses. </LI> <LI> The surface resistance of the all carbon electrode is only 2.5 Ω sq.<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Nitrogen doped graphene quantum dots (N-GQDs) were self-assembled (with high porosity) on reduced graphene oxide coated carbon fabric to fabricate a highly stable visible light photocatlytically and electrocatalytically active flexible electrode for water treatment.</P> <P>[DISPLAY OMISSION]</P>

Synthesis of highly photo-catalytic and electro-catalytic active textile structured carbon electrode and its application in DSSCs

Memon, Anam Ali,Arbab, Alvira Ayoub,Sahito, Iftikhar Ali,Sun, Kyung Chul,Mengal, Naveed,Jeong, Sung Hoon Elsevier 2017 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.150 No.-

<P><B>Abstract</B></P> <P>Due to the growing need of portable smart devices, textile based solar cells have gained widespread attention in the field of wearable electronics. Here, we have demonstrated facile fabrication of metal free DSSCs by printing cotton, polyester and linen fabric counter electrodes with highly photo catalytic and electro catalytic active mesoporous carbon composite composed of highly conductive acid functionalized multi-walled carbon nanotubes decorated with mesoporous activated charcoal. Different mesoporous carbon structures were formulated by varying the concentration of activated charcoal intercalated in the acid functionalized MWCNT matrix. The mesoporous carbon composite with high level of porosity and oxygen rich surface exhibits low charge transfer resistance and excellent electro-catalytic activity for the reduction of tri-iodide ions. The mesoporous carbon composite exhibited 52% higher photo catalytic activity than the acid modified MWCNT. Besides that, in-depth comparison was carried out in between different kinds of textile fabrics coated with the carbon composite. The slight variation in the microporous structures and surface characteristics of cotton, polyester and linen fabrics led to marginal difference in the electrochemical and photovoltaic performance of DSSCs. High mobility of gel electrolyte within the porous structure of mesoporous carbon and textile fabrics assembly demonstrated low R<SUB>CT</SUB> of 0.82Ω, 0.77Ω and 1.37Ω for cotton, polyester and linen respectively. The obtained photovoltaic conversion efficiency of cotton, polyester and linen based DSSCs using gel electrolyte were 6.06%, 6.26% and 5.80% respectively. The suggested TCO and Pt free DSSC assemblies paved a way to the facile fabrication of textile based DSSC.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Photocatalytic and conductive textile counter electrodes (CEs) were synthesized. </LI> <LI> Cotton, Polyester and Linen fabrics were used as CEs substrate. </LI> <LI> CEs were coated with mesoporous Activated Charcoal intercalated carbon composites. </LI> <LI> Flexible CEs showed a very low charge transfer resistance of 0.77Ω. </LI> <LI> Flexible CEs exhibited a highest conversion efficiency of 6.26%. </LI> </UL> </P>

Synthesis of solution processed f-CNT@Bi₂S₃ hybrid film coated linen fabric as a free-standing textile structured photo catalyst

Memon, Anam Ali,Arbab, Alvira Ayoub,Patil, Supriya A.,Mengal, Naveed,Sun, Kyung Chul,Sahito, Iftikhar Ali,Jeong, Sung Hoon,Kim, Hak Sung Elsevier 2018 Applied catalysis. A, General Vol.566 No.-

<P><B>Abstract</B></P> <P>A unique metallic carbon hybrid film, synthesized with synchronized distribution of bismuth sulfide (Bi<SUB>2</SUB>S<SUB>3</SUB>) and exfoliated multiwall carbon nanotubes (MWCNTs), has been proposed for use as freestanding textile electrodes in photo catalysts. The defect-rich morphology of Bi<SUB>2</SUB>S<SUB>3</SUB> nanowire decorated MWCNT hybrid enhances the photocatalytic activity, electronic properties, cyclic stability, and electron pathways. The proposed f-CNT@Bi<SUB>2</SUB>S<SUB>3</SUB>-hybrid linen fabric electrode demonstrated a defect-rich morphology synchronized with high electrical conductivity. These properties greatly enhanced the photocatalytic activity and electron transfer. The high photocatalytic activity is attributed to the synergistic effect of the high electron affinity of MWCNTs and the structural distortion caused by Bi<SUB>2</SUB>S<SUB>3</SUB> nanowires. Degradation of methylene blue dye was accelerated owing to the elevated activity of Bi<SUB>2</SUB>S<SUB>3</SUB> nanowires, which provides fast absorption of contaminants and reduction of oxidative species. Our proposed system of metallic carbon freestanding textile electrode opens the broad applications of textile-based photochemical devices.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A flexible and highly conductive linen fabric is fabricated. </LI> <LI> The fabric is coated with carbon metallic films by doctor blade technique. </LI> <LI> The electrode is durable and highly photocatalytic active. </LI> <LI> The electrode is stable at various bending positions, against water and electrolyte. </LI> <LI> The surface resistance of the carbon metallic films coated fabric is only 19 Ω sq<SUP>−1</SUP>. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Highly efficient and durable dye-sensitized solar cells based on a wet-laid PET membrane electrolyte

Sun, Kyung Chul,Sahito, Iftikhar Ali,Noh, Jung Woo,Yeo, Sang Young,Im, Jung Nam,Yi, Sung Chul,Kim, Yeon Sang,Jeong, Sung Hoon The Royal Society of Chemistry 2016 Journal of Materials Chemistry A Vol.4 No.2

<▼1><P>Polyethylene terephthalate (PET), a commonly used textile fiber, was used in the form of a wet-laid non-woven fabric as a matrix for electrolytes in dye-sensitized solar cells (DSSCs).</P></▼1><▼2><P>Polyethylene terephthalate (PET), a commonly used textile fiber, was used in the form of a wet-laid non-woven fabric as a matrix for electrolytes in dye-sensitized solar cells (DSSCs). Also functioning as a separator between the photoanode and cathode of a DSSC, this non-woven membrane was prepared by a well-known wet-laid manufacturing process followed by calendaring to reduce the thickness and increase the uniformity of the structure. This membrane can better absorb the electrolyte turning into a quasi-solid, providing excellent interfacial contact between both electrodes of the DSSC and preventing a short circuit. An optimized membrane provides a better and more desirable structure for ionic conductivity, resulting in the improvement of the photovoltaic performance after calendaring. The quasi-solid-state DSSC assembled with an optimized membrane exhibited 10.248% power conversion efficiency (PCE) at 100 mW cm<SUP>−2</SUP>. With the aim of increasing the absorbance, the membrane was also plasma-treated with argon and oxygen separately, which resulted in retention of the electrolyte, avoiding its evaporation, and a 15% longer lifetime of the DSSC compared to liquid electrolytes. The morphology of the membrane was studied by field emission scanning electron microscopy, and the photovoltaic properties and impedance spectroscopy of the cells were studied using polarization curves and electrochemical impedance spectroscopy, respectively. The results suggest that this novel membrane can be used in high-efficiency solar cells, increasing their lifetime without compromising the photovoltaic properties.</P></▼2>

An electrocatalytic active lyocell fabric cathode based on cationically functionalized and charcoal decorated graphite composite for quasi-solid state dye sensitized solar cell

Mengal, Naveed,Arbab, Alvira Ayoub,Sahito, Iftikhar Ali,Memon, Anam Ali,Sun, Kyung Chul,Jeong, Sung Hoon Elsevier 2017 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.155 No.-

<P><B>Abstract</B></P> <P>The state of the art of conductive functional textile woven fabrics have given rise to a demand for textile integrated electrodes. Herein, we report a highly conductive and flexible woven fabric electrode using highly absorbent lyocell fabric as the substrate and cationically functionalized and activated charcoal decorated graphite composite (AC-GC) as the coating film. This (AC-GC) coated lyocell fabric is used as a cathode for quasi-solid state dye sensitized solar cell (Q-DSSCs). Our suggested fabric based cathode shows sufficiently high conductivity and electrocatalytic activity (ECA) compared to platinum (Pt) based reference counter electrode (CE). This efficient CE demonstrates extremely low charge transfer resistance (R<SUB>CT</SUB>) of 1.56Ωcm<SUP>2</SUP> with polyethylene oxide based quasi-solid electrolyte. The cationic charged enriched charcoal decorated graphite planner structure provide more availability of active sites for the reduction of negatively charged tri-iodide ( I 3 - ) ions present in polymeric gel electrolyte. The formation of porous charcoal voids and conductive graphite channels entrap large amounts of gel electrolyte and provide fast diffusion of iodide/tri-iodide ( <SUP> I - </SUP> / I 3 - ) ions. Our organic system of AC-GC coated lyocell fabric based DSSCs assembly demonstrated 7.09% power conversion efficiency (PCE) when fabricated with quasi-solid electrolyte. This AC-GC coated fabric CE is also highly stable in water and electrolyte solution. The adequate electrocatalytic activity and cyclic stability demonstrate that this AC-GC coated fabric can be used to replace expensive Pt CE and can be used in flexible solar cells in future.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Various composites of activated charcoal and enzyme functionalized graphite (AC-GC) were prepared by a facile route. </LI> <LI> Highly porous and electrocatalytic AC-GC coatings were applied on lyocell fabric for preparation of flexible electrode. </LI> <LI> The flexible electrodes showed high stability in water and lithium iodide based electrolyte. </LI> <LI> DSSC based on optimized flexible electrode demonstrated maximum power conversion efficiency of 7.09%. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>Cationic functionalized and activated charcoal decorated graphite coated lyocell fabric cathode is Q-DSSCs, displayed 7.1% efficiency.</P> <P>[DISPLAY OMISSION]</P>

Binder-free Graphene Printed Flexible and Conductive Cotton Fabric for E-textile Applications

Panhwar, Rabia,Soni, Niraj,Sikandar, Aftab,Raza, Ali,Sun, Kyung Chul,Sahito, Iftikhar Ali,Jeong, Sung Hoon,선경철,정성훈 The Korean Fiber Society 2021 한국섬유공학회지 Vol.58 No.3

With the rapid development of the miniaturization and versatility of electronic devices, wireless and flexible properties are playing an increasingly important role in electronics, owing to the rapid increase in power density. Graphene printable devices are in high demand for industrial applications in terms of energy storage and flexible circuit products that are economically viable and can be produced on a large scale. In this study, a flexible binder-free conductive fabric was printed on cotton fabric via flat screen printing. This study involved printing various coats of graphene oxide (GO) followed by chemical reduction using chemical reduction of the printed circuit fabric. The fabric with fifth printed coat showed the least resistance value of 18 Ω/sq. The results also showed that the reduced GO (rGO) printed conductive fabric had excellent washing stability. The successful formation of GO was assessed using atomic force microscopy (AFM) and transmission electron microscopy (TEM) techniques. In addition, the successful reduction of GO to rGO on the GO coated fabric was examined using scanning electron microscopy (SEM), Fourier-transform infrared (FTIR), and X-ray photoelectron spectroscopy (XPS). Additionally, biocompatible water-based and binder-free printing has the potential to open opportunities for the production of next-generation eco-friendly electronic textiles for electronic circuits, sports, healthcare, and military applications.

Electrocatalytic porous nanocomposite of graphite nanoplatelets anchored with exfoliated activated carbon filler as counter electrode for dye sensitized solar cells

Sun, Kyung Chul,Memon, Anam Ali,Arbab, Alvira Ayoub,Sahito, Iftikhar Ali,Kim, Moo Sung,Yeo, Sang Young,Choi, Yeong Og,Kim, Yeon Sang,Jeong, Sung Hoon Elsevier 2018 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.167 No.-

<P><B>Abstract</B></P> <P>A unique graphite nanoplatelet (GnP) composite synthesized with a synchronized distribution of exfoliated activated carbon (AC) filler is proposed for promising Pt-free dye sensitized solar cells. The defect rich morphology of the exfoliated activated carbon filler is designed with graphite nanoplatelets to enhance its electrocatalytic activity and electron pathways, and for this purpose different percentages of AC fillers were incorporated into the GnP matrix. The proposed GnP/AC composite shows a more defect-rich morphology synchronized with high electronic conductivity which greatly enhances the electrocatalytic activity and electron transfer mobility (R<SUB>CT</SUB> of 2.19 Ω). A DSSC fabricated with the proposed GnP/AC composite exhibited a high conversion efficiency rate of 8.478%, similar to that of the Pt electrocatalyst. The high catalytic activity of GnP/AC is attributed to the synergistic effect of the high electron affinity of GnP and the structural distortion caused by the AC filler material. This high-performance catalyst can be a promising material for efficient energy storage and harvesting applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The defect rich morphology of the exfoliated activated carbon filler is designed with graphite nanoplatelets. </LI> <LI> Prepared design showed excellent electrocatalytic activity and electron pathways. </LI> <LI> Prepared composite show a high conversion efficiency of 8.478%, comparable to Pt. </LI> </UL> </P>

An organic route for the synthesis of cationic porous graphite nanomaterial used as photocatalyst and electrocatalyst for dye-sensitized solar cell

Arbab, Alvira Ayoub,Mengal, Naveed,Sahito, Iftikhar Ali,Memon, Anam Ali,Jeong, Sung Hoon Elsevier 2018 ELECTROCHIMICA ACTA Vol.266 No.-

<P><B>Abstract</B></P> <P>An organic synthesis route is proposed to fabricate cationized porous graphite (cpG) for photocatalyst and electrocatalyst nanomaterial. High crystalline structure of graphite possesses few defects and porous channels. In the proposed research, cpG is fabricated by sonicating graphite in cationized enzyme media followed by exfoliating in the activated charcoal filler. The cationic lipase solution distributed positive surface charges over a bare graphitic sheet, and sonication with activated charcoal filler divulges porous channels along graphite exfoliated matrix structure. The charcoal doping in graphite was modified with the different charcoal content percentage ranging from 0 to 100%. The cationized porous graphite (cpG) material possess high surface area, pore volume and conductivity leads to high photoresponse and electrocatalytic reaction. As photocatalyst, the proposed graphite provide fast degradation of methylene blue dye observed by UV–Vis spectrophotometer. As cathode for dye-sensitized solar cell (DSSCs), cpG provides high electrocatalytic activity with low charge transfer resistance (R<SUB>CT</SUB> = 0.95Ω) and high photovoltaic performance with 9.59% efficiency. The positive charge distribution over graphite sheet attracts plenty of negative iodide ions present in the electrolyte, provide fast reduction-oxidation reaction. Furthermore, porous charcoal filler doping accepts a large amount of gel electrolyte, and fasten interfacial reaction between electrolyte and CE. This cost-effective cationized porous graphite (cpG) nanomaterial can provide new ways towards sustainable energy resources.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An organic route for the synthesis of cationized porous graphite (cpG) nanomaterial is proposed. </LI> <LI> cpG used as photo catalyst and electro catalyst for DSSCs. </LI> <LI> cpG shows excellent degradation of methylene blue dye at very low time interval. </LI> <LI> cpG demonstrated low R<SUB>CT</SUB> of 0.95Ω with high photovoltaic performance. </LI> <LI> cpG cathode outperform Pt. electrode and exhibit 9.59% PCE of DSSCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>