Polyethylene terephthalate (PET) accounts for a significant portion of textile waste, and recycling strategies for this material have attracted much attention. This study proposes a facile and innovative PET recycling method applicable to environmental remediation that involves the conversion of dyed PET fabric waste into a value-added fabric. Herein, a template-based synthesis approach capable of growing a UiO-66 metal-organic framework (MOF) directly on a dyed PET fabric is reported.
View Article and Find Full Text PDFWastewater treatments using photocatalysts and metal-organic frameworks (MOFs) have gained increasing importance due to their catalytic reactions leading to the decomposition of dyes and organic pollutants without generating secondary pollutants. This work aims at developing an advanced photocatalytic fabric by conceiving a heterojunction of NH-MIL-88B (Fe/Co) (n-type) and AgPO (p-type) and increasing the electrical conductivity to facilitate charge transfer at the heterojunction. Of particular interest is the design of a conductive Z-scheme heterophotocatalytic fabric by implementing polypyrrole (PPy) between the heterocatalysts and to investigate the role of the heterojunction and increased conductivity in the generation of reactive species and the photocatalytic mechanism.
View Article and Find Full Text PDFWith an increased need of wastewater treatment, application of photocatalysts has drawn growing research attention as an advanced water remediation strategy. Herein, a floating photocatalytic fabric in a woven construction was developed for removal of Rhodamine B (RhB) in water. For an efficient photocatalytic reaction, AgI nanoparticles were grown on the surface of UiO-66-NH crystals in a layered structure, forming a heterojunction system on a cotton yarn, and this was woven with polypropylene yarn.
View Article and Find Full Text PDFMushroom chitin membranes with controllable pore structures were fabricated through a simple process with naturally abundant mushrooms. A freeze-thaw method was applied to alter the pore structures of the membranes, which consist of chitin fibril clusters within the glucan matrix. With tunable pore size and distribution, mushroom chitin membranes could effectively separate stable oil/water emulsions (dodecane, toluene, isooctane, and chili oil) with various chemical properties and concentrations and particle contaminants (carbon black and microfibers) from water.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2022
Protective equipment for detecting bacterial contamination has been in high demand with increasing interest in public health and hygiene. Herein, a fiber-based visually indicating bacteria sensor (VIBS) embedded with iodonitrotetrazolium chloride is developed for the general purpose of detecting live bacteria, and its chromogenic effectiveness is investigated for Gram-negative and Gram-positive . The developed color intensity is measured by the light absorption coefficient to the scattering coefficient (/) based on the Kubelka-Munk equation, and the colorimetric sensitivities of different membranes are examined by calculating the limit of detection (LOD) and the limit of quantification (LOQ).
View Article and Find Full Text PDFEfforts have been made for sustainable development of adsorbents to purify organic contaminants from wastewater. In this study, a MIL-100(Fe) based textile that acts as a reusable adsorbent and photocatalytic agent was developed by synthesizing MIL-100(Fe) onto a cotton fabric by the layer-by-layer (LBL) process using water-based solutions. As the number of LBL cycles increased, the add-on's of MIL-100(Fe) showed a drastic increase up to 8 cycles, then showed gradual increases with further treatments.
View Article and Find Full Text PDFAs rapid industrial growth spawns severe water contamination and a far-reaching impact on environmental safety, the development of a purification system is in high demand. Herein, a visible light-induced photocatalytic adsorbent membrane was developed by growing a porous metal-organic framework (MOF), MIL-100(Fe) crystals, onto electrospun polyacrylonitrile (PAN) nanofibers, and its purification capability by adsorption and the photocatalytic effect was investigated. As water-soluble organic foulants, a cationic dye, rhodamine B (RhB), and an anionic dye, methyl orange (MO), were employed, and the adsorption/desorption characteristics were analyzed.
View Article and Find Full Text PDFThis study explores a novel approach of multiscale modeling and simulation to characterize the filtration behavior of a facepiece in varied particulate conditions. Sequential multiscale modeling was performed for filter media, filtering facepiece, and testing setup. The developed virtual models were validated for their morphological characteristics and filtration performance by comparing with the data from the physical experiments.
View Article and Find Full Text PDFMetal-organic framework (MOF), an emerging class of porous hybrid inorganic-organic crystals, has been applied for various environmental remediation strategies including liquid and air filtration. In this study, the role of the zeolite imidazole framework-8 (ZIF-8) was explored on the charge trapping ability and its contribution to capturing the targeted pollutants of NaCl nanoparticles and SO gas. Poly(lactic acid) fibers with controlled surface pores were electrospun using water vapor-induced phase separation, and the fiber surface was uniformly coated with ZIF-8 crystals via an growth method.
View Article and Find Full Text PDFConcerns have been ramping up with regard to the propagation of infectious droplets due to the recent COVID-19 pandemic. The effects of filter microstructures and ambient air flows on droplet dispersion by sneezing are investigated by a fully coupled Eulerian-Lagrangian computational modeling with a micro-to-macroscale bridging approach. Materials that are commonly applied to face masks are modeled to generate two different virtual masks with various levels of filtration efficiency, and the leakage percentages through the unsealed nose and cheek areas were set to 11% and 25%, respectively.
View Article and Find Full Text PDFBacteria adhesion on the surface is an initial step to create biofouling, which may lead to a severe infection of living organisms and humans. This study is concerned with investigating the textile properties including wettability, porosity, total pore volume, and pore size in association with bacteria adhesion. As model bacteria, Gram-negative, rod-shaped and the Gram-positive, spherical-shaped were used to analyze the adhesion tendency.
View Article and Find Full Text PDFFor environmental protection from exposure to airborne toxic gases, metal organic frameworks (MOFs) have drawn great attention as gas adsorbent options, with their advantages in chemical tailorability and large porosity. To develop a fiber-based gas filter that is effective against SO gas, zeolite imidazole framework-8 (ZIF-8) was applied to polypropylene nonwoven by various methods. Among the tested methods, the sol-gel impregnation method showed the highest ZIF-8 loading efficiency.
View Article and Find Full Text PDFIn the outbreak of COVID-19, the extended wear of single-use, disposable respirators was inevitable due to limited supplies. As a respirator is front-line protection against particulate matter, including bioaerosol and droplets, a comprehensive understanding for the reuse strategy is needed. In this study, eight different disinfection methods commonly applied for the reuse of respirators were compared for their influence on the filtration and bactericidal/bacteria removal performance, with in-depth discussion on the cause of effects.
View Article and Find Full Text PDFThe buildup of pressure drop with mass loading of particles aggravates the breathing resistance and energy consumption of filters. This study investigated the role of intra- and interlayer space of filter media on the pressure drop development with continued particle loading. Five basic morphologies, including microfibers, nanofibers, microbeads-on-strings, and a mix of those morphologies were fabricated via electrospinning.
View Article and Find Full Text PDFMechanoluminescence (ML), which emits light upon external mechanical stress, was applied to fibrous composites. Herein, ML particles were incorporated into poly(vinylidene fluoride) (PVDF) and polyacrylonitrile (PAN) electrospun webs to prepare ML/PVDF and ML/PAN composite fabrics. The produced fabrics were treated with O and CF plasma to modify the wetting properties, then the effects of composite wettability on the light-emitting response in dry and wet conditions were investigated.
View Article and Find Full Text PDFWith increasing air pollution and sporadic outbreaks of epidemics, there is ramping attention on the filtration devices. The main constituents of airborne pollutants are particulate matters of solid particles, liquid aerosol, bioaerosol/bio-droplets, and gas/vapor. With the growing demand for high-performance filters, novel materials and functionalities are being developed applying advanced technologies.
View Article and Find Full Text PDFElectret filters as opposed to mechanical filters display the enhanced ability to capture airborne particles with the electrostatic attraction. However, the environmental aging during shelf-life or use may cancel its benefit by dissipating the charges. This work investigates the polymeric attributes influencing the charge decay and the electrostatic filtration of electret filters, employing polymers with different dielectric constants () and wettability.
View Article and Find Full Text PDFPolymers (Basel)
November 2019
The study aims at lowering the pressure drop and extending the service life at a given set of filter materials implementing a space between the filter layers. As design factors, the web-to-web space was implemented by inserting either a bulk air gap or porous spacer web between the filter webs. The effect of spacing, either by the air gap or by the spacer web, on the pressure drop reduction was apparent for 4-layer constructions, and the effect was greater at the higher face velocity.
View Article and Find Full Text PDFQuantification of bacteria adhered on porous, multi-layered fibers is a challenging task. The goal of this study is to compare different assessment procedures on counting textile-adhered bacteria, and to guide relevant analytical techniques. Three different methods were compared in measuring the amount of () adhered to polymeric film and fibrous nonwovens.
View Article and Find Full Text PDFWith the growing concern about the health impacts associated with airborne particles, there is a pressing need to design an effective filter device. The objective of this study is to investigate the effect of plasma-based surface modifications on static charges of electrospun filter media and their resulting filtration performance. Polystyrene (PS) electrospun web (ES) had inherent static charges of ~3.
View Article and Find Full Text PDFParticulate airborne pollutants are a big concern to public health, and it brings growing attention about effective filtration devices. Especially, particulate matters smaller than 2.5 µm can reach the thoracic region and the blood stream, and the associated health risk can be exacerbated when pathogenic microbials are present in the air.
View Article and Find Full Text PDF