Browsing by Author "Wanasekara, ND"

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item: Article-Full-text
All-organic, conductive and biodegradable yarns from core-shell nanofibers through electrospinning
(RSC Advance, 2020) Weerasinghe, VT; Dissanayake, DGK; Tissera, ND; Wijesena, RN; Wanasekara, ND; Perera, WPTD
Electrically conductive and biodegradable materials are desired for a range of applications in wearable electronics to address the growing ecological problem of e-waste. Herein, we report on the design and fabrication of all-organic, conductive and biodegradable nanofibrous core–shell yarn produced by in situ polymerization of aniline on the surface of electrospun poly(ε-caprolactone) nanofibers. The effect of concentration of aniline monomer on the morphology and resistivity of deposited polyaniline layer was investigated. The electrical resistance changed almost instantaneously with the strain for multiple stretch and recovery cycles. This rapid and sensitive response to mechanical loading and unloading is promising to validate the possibility of using the conductive yarns as strain sensors for monitoring human motion. Increasing the number of plies of yarn to three resulted in a three-fold reduction of the resistance. The twisted plied yarns were incorporated into fabric by stitching to demonstrate their use as a wearable electrode for capacitive sensors. This approach presents an early step in realizing all-organic conductive biodegradable nanofibrous yarns for biodegradable smart textiles.
item: Conference-Full-text
Chitosan-graphene oxide composite membrane for methylene blue removal
(IEEE, 2022-07) Dissanayake, NSL; Pathirana, MA; Wanasekara, ND; Nandasiri, GK; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
Textile wastewater accommodates many toxic organic contaminants which could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, nondegradable, cationic dye which is reportedly found in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. This study reports an investigation of methylene blue removal using a composite membrane fabricated using chitosan and graphene oxide. The fabricated composite membrane was characterized using Scanning Electron Microscopy, FTIR Spectroscopy, Raman Spectroscopy, UV vis spectroscopy, and X ray Diffraction. The isotherm modelling conducted confirmed a maximum adsorptive capacity of 179 mg/g which was well fitted with the Langmuir isotherm model indicating a homogenous monolayer adsorption.
item: Article-Full-text
Chitosan-graphene oxide dip-coated polyacrylonitrile-ethylenediamine electro spun nanofiber membrane for removal of the dye stuffs methylene blue and congo red
(Multidisciplinary Digital Publishing Institute, 2023) Pathirana, MA; Dissanayake, NSL; Wanasekara, ND; Mahltig, B; Nandasiri, GK
Textile wastewater accommodates many toxic organic contaminants that could potentially threaten the ecosystem if left untreated. Methylene blue is a toxic, non-biodegradable, cationic dye that is reportedly observed in significant amounts in the textile effluent stream as it is widely used to dye silk and cotton fabrics. Congo red is a carcinogenic anionic dye commonly used in the textile industry. This study reports an investigation of methylene blue and Congo red removal using a chitosan-graphene oxide dip-coated electrospun nanofiber membrane. The fabricated nanocomposite was characterized using Scanning Electron Microscopy (SEM), FT-IR Spectroscopy, Raman Spectroscopy, UV-vis Spectroscopy, Drop Shape Analyzer, and X-ray Diffraction. The isotherm modeling confirmed a maximum adsorptive capacity of 201 mg/g for methylene blue and 152 mg/g for Congo red, which were well fitted with a Langmuir isotherm model indicating homogenous monolayer adsorption.
item: Conference-Full-text
Copper nanoparticle synthesis on plasma treated poly(lactic) acid nonwoven fabrics
(IEEE, 2022-07) Rathnayaka, NC; Nandasiri, GK; Wanasekara, ND; Rathnayake, M; Adhikariwatte, V; Hemachandra, K
The demand for antibacterial fabric surfaces is increasing day by day. With the covid-19 pandemic situation, there is attention to antibacterial and antiviral nonwoven fabrics which can be used towards the development of personal protective wear. To reduce the environmental pollution caused by disposable and non-biodegradable polymer-made personal protective wear can be replaced by biodegradable polymers like poly(lactic) acid (PLA), which is quite similar to polypropylene, but biodegradable. In this study, the non-thermal plasma treatment method is used to increase the surface reactivity of the PLA nonwoven polymer surface. On the activated nonwoven surface copper nanoparticles are in-situ synthesized by chemical treatments. After 30 minutes of plasma treatment, better copper nanoparticle distribution and higher yield were achieved. Fourier transformed infrared spectroscopy (FTIR) and Scanning Electron Microscopy (SEM) were used to characterize the treated PLA nonwoven fabric surfaces.
item: Conference-Extended-Abstract
Development of a nanocomposite membrane for organic dye removal
(Department of Textile and Apparel Engineering, 2023-08-31) Pathirana, MA; Dissanayake, NSL; Nandasiri, GK; Wanasekara, ND; Mahltig, B; Niles, SN; Nandasiri, GK; Pathirana, M; Madhurangi, C
Contaminated wastewater poses a significant threat to both the ecosystem and human health. The annual production of commercial dyes exceeds 7x105 tonnes, with the textile industry being responsible for two-thirds of the consumption [1]. Moreover, an estimated 10-20% of the manufactured dye is annually released into the effluent stream [2]. Previous literature indicates that adsorption offers promising solutions to organic dye removal owing to its simplicity and cost-effectiveness. Adsorption is fundamentally defined as the process through which ions, atoms and molecules are retained on solid surfaces via physical or chemical bonding. The literature extensively covers adsorbents designed for individual removal of either anionic or cationic dyes. However, research on techniques for simultaneous removal of both types of dyes is limited. As anionic and cationic dye molecules contain charges, adsorption can initiate through the formation of electrostatic bonding.
item: Conference-Abstract
Flame retardant synthetic fabrics by low pressure plasma technology
Jayasinghe, Y; Jayaweera, C; Botheju, R; Ariyasinghe, M; Gunasekera, U; Wanasekara, ND
This article focuses on the development of a flame retardant coating for synthetic knitted fabrics using the low-pressure plasma technology. Hexamethyldisiloxane (HMDS)was used to enhance the flame retardant property of the polyester knitted fabrics. The treated fabrics also exhibited hydrophobic properties. The role of oxygen flow rate on flame retardancy and hydrophobicity was investigated by varying the oxygen flow rate from 0sccm to 100sccm. Degree of flammability was determined by the ignition status and flame spread time if ignited. It has been found that at least an oxygen flow rate of 60 sccm was required to stop the ignition of fabrics after exposure time of 5 seconds to the flame. The elemental analysis confirmed the presence of silicon groups on the surface. Durability of coating was determined by subjecting the samples to multiple cycles of washing. It is envisaged that this work on plasma enabled hydrophobicity and flame retardancy will open up new avenues to achieve functional properties on synthetics fabrics.
item: Conference-Extended-Abstract
Investigating loss of wicking properties due to hard washing of the fabric used for top layer of the period underwear
(Department of Textile and Apparel Engineering, 2023-08-31) Ayesha, KAD; Dissanayake, HDJC; Niles, SN; Nandasiri, GK; Wanasekara, ND; Nandasiri, GK; Niles, SN; Pathirana, M; Madhurangi, C
A period panty consists of three layers, a moisture wicking layer to transfer liquid away from the skin, absorbent layer to absorb liquid, and a protective layer to prevent leaking or staining [1]. The moisture wicking layer is made from a French terry material which has high wicking properties with a one-way transfer structure, allowing it to absorb the liquid and prevent it from returning to the surface. However, it has been observed that this wicking layer tends to lose its wicking properties after two LTD 30 hard washes. (One LTD 30 wash is approximately equal to twenty-five washes defined in AATCC 135 standard) When wicking properties of the top layer are lost, the liquid does not pass through to the absorbent layer, instead the liquid remains on the fabric surface. This will impair the functionality of the product and significantly reduce the comfortability of the wearer. Therefore, it is vital to find a solution to this issue to increase the durability of the product and to meet the requirements of the customer.
item: Conference-Full-text
Investigating the feasibility of applying spin coating method for textiles
(IEEE, 2020-07) Dissanayake, N; Abeysundara, S; Wanasekara, ND; Edussooriya, C; Weeraddana, CUS; Abeysooriya, RP
Spin coating method is widely used to coat material surfaces with a thin coating in the electronic industry. However, the use of spin coating in textile surfaces is challenging due to high porosity and the hydrophilicity of textile materials. Here, the use of spin coating on textile surfaces was thoroughly investigated. This method is advantageous due to simplicity and relative ease of the process and ability to obtain thin and uniform coating. The experiments are carried using Titanium Dioxide as the coating material and the suitable fabric type is selected from Polyamide/Elastane and Cotton/ Polyester/ Elastane. The effect of an array of spin coating parameters such as rotational velocity, fiber type, concentration of solution and the binding agent was examined. Surface characterization, elemental analysis, air permeability and moisture management experiments were carried out to determine the coverage and effectiveness of the coating. It was found that the spin coating of Titanium Dioxide using Polyurethane as the binding agent onto Cotton/ Polyester/ Elastane blended, knitted fabric exhibits good adhesion and durability. Furthermore, it is recommended to use 3500 revolutions per minute with 0.5% concentration of TiO2 solution to achieve optimum coverage of the coating.
item: Conference-Extended-Abstract
Investigation of the thermal and physical properties of fabrics produced by metallic-polymer hybrid yarns
(Department of Textile and Apparel Engineering, 2023-08-31) Karunaratne, C; Jayasundara, N; Wanasekara, ND; Niles, SN; Nandasiri, GK; Pathirana, M; Madhurangi, C
Majority of the smart devices contain touch screens and the majority of them are based on capacitance and conductivity. This type of touch screens are developed by utilizing a matrix of rows and columns of conductive electrodes and small current is provided to electrodes to produce an even electrostatic field[ 1]. However, electrically insulating materials such as textile fabrics, cannot actuate touch screens as these types of materials are incapable of changing the electrostatic field.
item: Conference-Full-text
Modeling surface conductivity in a sweat analyzing wearable smart textile platform
(IEEE, 2021-07) Medagedara, MH; Peiris, TS; Wanasekara, ND; Adhikariwatte, W; Rathnayake, M; Hemachandra, K
Wearable self-health monitoring devices are a contemporary necessity with modern life-style and health implications of this decade. Current devices have transitioned to non-invasive sampling due to benefits including minimal possibility of infections, convenience, no requirement for storage, and physiological safety of neo-natal and geriatric patients. Sweat, in this regard, is of importance as the variations in the sweat composition have been validated as bio markers of different diseases. Corresponding variations in the surface resistivity as the sweat composition is changed, has been introduced in this novel research with a synergistic approach, based on developing a conductive sweat sensing and analyzing textile platform. The relationship between the macro porosity of the proposed textile platform and the measured surface conductivity values has been mathematically modeled and presented in this paper. A simulation of the mathematical model concluded that variations in the localized surface area for sweat accumulation and the fabric weight of the textile platform has minimal effect on the performance of the wearable sweat monitoring platform, while a satisfactorily measurable surface conductivity value can be obtained at sweat concentration levels in the order 0.01M.
item: Article-Full-text
Removal of methylene blue and congo red using a chitosan–graphene oxide-electrosprayed functionalized polymeric nanofiber membrane
(2023) Dissanayake, NSL; Pathirana, MA; Wanasekara, ND; Mahltig, B; Nandasiri, GK
Untreated textile effluent may contain toxic organic pollutants that can have negative impacts on the ecosystem. Among the harmful chemicals present in dyeing wastewater, there are two frequently used organic dyes: methylene blue (cationic) and congo red (anionic). The current study presents investigations on a novel two-tier nanocomposite membrane, i.e., a top layer formed of electrosprayed chitosan–graphene oxide and a bottom layer consisting of an ethylene diamine functionalized polyacrylonitrile electrospun nanofiber for the simultaneous removal of the congo red and methylene blue dyes. The fabricated nanocomposite was characterized using FT-IR spectroscopy, scanning electron microscopy, UV-visible spectroscopy, and Drop Shape Analyzer. Isotherm modeling was used to determine the efficiency of dye adsorption for the electrosprayed nanocomposite membrane and the confirmed maximum adsorptive capacities of 182.5 mg/g for congo red and 219.3 mg/g for methylene blue, which fits with the Langmuir isotherm model, suggesting uniform single-layer adsorption. It was also discovered that the adsorbent preferred an acidic pH level for the removal of congo red and a basic pH level for the removal of methylene blue. The gained results can be a first step for the development of new wastewater cleaning techniques.
item: Article-Full-text
Scalable textile manufacturing methods for fabricating triboelectric nanogenerators with balanced electrical and wearable properties
(American Chemical Society, 2022) Gunawardhana, KRS; Wanasekara, ND; Wijayantha, KG; Dharmasena, RD
Triboelectric nanogenerators (TENGs) are foreseen as a leading candidate to harvest mechanical energy from ambient sources such as human body movements. However, wearable TENGs, which are used for this purpose, require adequate wearability for long durations, in addition to sufficient electrical outputs. So far, it has been difficult to achieve this through the predominantly plastic-based wearable TENGs constructed using conventional nanogenerator fabrication methods. This Article evaluates the use of textile materials and scalable fabrication techniques to develop TENGs targeting balanced electrical and wearable properties. The fabrication process is conducted using yarn-coating, dip-coating, and screen-printing techniques, which are common textile manufacturing methods, and converted into fabrics using flat-bed knitting, resulting in TENGs with improved wearable and electrical performances. The electrical properties (open circuit voltage (Voc), short circuit current (Isc), and short circuit charge (Qsc)) and wearable properties (air permeability, stretch and recovery, and moisture management) of these structures are evaluated, during which the yarn-coated TENG resulted in maximum electrical outputs recording Voc ≈ 35 V, Isc ≈ 60 nA, and Qsc ≈ 12 nC, under mild excitations. In terms of wearability, the yarn-coated TENG again performed exceptionally during the majority of tests providing the best moisture management, air permeability (101 cm3/cm2/s), and stretch (∼75%), thus proving its suitability for wearable TENG applications.