Fibers

4 pages, 166 KiB

Open AccessEditorial

Acknowledgment to the Reviewers of Fibers in 2022

by Fibers Editorial Office

Fibers 2023, 11(1), 11; https://doi.org/10.3390/fib11010011 - 16 Jan 2023

Viewed by 926

Abstract

High-quality academic publishing is built on rigorous peer review [...] Full article

11 pages, 4513 KiB

Open AccessArticle

Investigation of Fiber-Based Bag Filter Coated with Metal Oxides for Dust Adsorption

by Marichelvam Mariappan Kadarkarainadar and Geetha Mariappan

Fibers 2023, 11(1), 10; https://doi.org/10.3390/fib11010010 - 13 Jan 2023

Cited by 2 | Viewed by 1873

Abstract

The production of cement increases every year, which leads to the emission of dust/gas/ particulate matter. The emission of unfiltered dust would create a significant environmental impact. Hence, it is the responsibility of industries to control the emission of dust. Air filters and [...] Read more.

The production of cement increases every year, which leads to the emission of dust/gas/ particulate matter. The emission of unfiltered dust would create a significant environmental impact. Hence, it is the responsibility of industries to control the emission of dust. Air filters and electrostatic precipitators (ESP) play a significant role in controlling pollutants. Synthetic filter media which are dangerous to our environment are widely used in most industries. The disposal of synthetic filters is an arduous task as the biodegradability of synthetic materials is poor. Hence, it is essential to develop an eco-friendly air filter material. In this paper, a new type of bag filter was designed by using natural sisal fiber as filtering media. The biodegradability of sisal fiber is better than the synthetic polyester media and also sisal fiber is less expensive. The natural fibers were coated with zinc oxide and iron oxide nanoparticles to improve the dust adsorption rate. Various tests were conducted as per standards to validate the performance of the filler media. The results were impressive. Hence, the proposed sisal fiber-based filter media can be used in cement industries for dust adsorption to minimize the environmental impact. Full article

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14 pages, 2645 KiB

Open AccessArticle

Improving the Performance of Lightweight Crumb Rubber Mortar Using Synthetic, Natural, and Hybrid Fiber Reinforcements

by S. M. Iqbal S. Zainal, Debbie Mattius, Zulhelmi Baba, Ahmad Nurfaidhi Rizalman and Farzad Hejazi

Fibers 2023, 11(1), 9; https://doi.org/10.3390/fib11010009 - 12 Jan 2023

Cited by 5 | Viewed by 2058

Abstract

The global market for tires is ever-growing, and partially replacing sand with crumb rubber (CR) as fine aggregates in concrete could reduce environmental pollution. However, the main barrier to the complete usage of recycled tire crumbs in construction is the deterioration effect of [...] Read more.

The global market for tires is ever-growing, and partially replacing sand with crumb rubber (CR) as fine aggregates in concrete could reduce environmental pollution. However, the main barrier to the complete usage of recycled tire crumbs in construction is the deterioration effect of CR on the mechanical properties of cement-based composites. Therefore, this paper attempts to improve the fresh and hardened properties of crumb rubber mortar (CRM) by incorporating polypropylene-polyethylene synthetic fibers with coconut and kenaf natural fibers as reinforcements. A total of 18 mix designs were developed with varying fiber combinations and rubber crumb replacement. Subsequently, parametric studies with chemical admixture were conducted at 3, 7, and 28 days to improve the flowability and resulting mechanical properties of the fiber-reinforced CRM. According to the results, the single and hybrid fibers positively improved the mechanical properties of cement mortar at 5–15% CR replacement. It can be concluded that adding single and hybrid fibers enhanced the performance of cement mortar modified with tire crumb rubber aggregates by providing varying degrees of improvement. Full article

(This article belongs to the Special Issue Fiber-Reinforced Polymers and Fiber-Reinforced Cement-Based Mortars in Repair/Strengthening Methods of Masonry and Reinforced Concrete Structural Members)

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9 pages, 4624 KiB

Open AccessCommunication

Electrochemical Oxidation of Pb II Using Carbon Electrodes Doped with Nanocellulose-FeOx

by Araceli G. Gomez-Rojas, Luis Alejandro Macclesh del Pino-Perez, Carlos Fernando Castro-Guerrero, Claudia Esmeralda Ramos-Galvan and Ana Beatriz Morales-Cepeda

Fibers 2023, 11(1), 8; https://doi.org/10.3390/fib11010008 - 12 Jan 2023

Cited by 1 | Viewed by 1438

Abstract

With TEMPO oxidation, it was possible to incorporate iron nanostructures into a cellulose nanofiber matrix. FTIR spectra showed the functional groups present in the films. The combination of both iron and CNF confers to the films good electrochemical activity; the electrochemical characterization (CV) [...] Read more.

With TEMPO oxidation, it was possible to incorporate iron nanostructures into a cellulose nanofiber matrix. FTIR spectra showed the functional groups present in the films. The combination of both iron and CNF confers to the films good electrochemical activity; the electrochemical characterization (CV) showed that they present stability in the reduction process at a potential of 0–1 V, with the materials with 5% and 10% being the most active. The Pb reduction process shows that the 5% film is the material with the highest oxidizing capacity. Full article

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21 pages, 14123 KiB

Open AccessArticle

Experimental Investigation of the Influence of Metallic Coatings on Yarn Pull-Out Behavior in Kevlar^® Fabrics

by Julie Roark, Frank D. Thomas, Subramani Sockalingam, Julia Kempf, Dan Christy, Derek Haas, Daniel J. O’Brien, Kris J. Senecal and Scott R. Crittenden

Fibers 2023, 11(1), 7; https://doi.org/10.3390/fib11010007 - 11 Jan 2023

Cited by 1 | Viewed by 1573

Abstract

This work reports yarn pull-out studies of commercially available Kevlar^® KM2+ individual yarns coated with metallic layers (copper, aluminum, aluminum nitride and silver) via a directed vapor deposition process. The uncoated control and metal-coated Kevlar^® yarns are hand-woven into fabric swatches [...] Read more.

This work reports yarn pull-out studies of commercially available Kevlar^® KM2+ individual yarns coated with metallic layers (copper, aluminum, aluminum nitride and silver) via a directed vapor deposition process. The uncoated control and metal-coated Kevlar^® yarns are hand-woven into fabric swatches for quasi-static pull-out experiments. To perform these experiments, a yarn pull-out fixture is custom-designed and fabricated to apply transverse pre-tension to the fabric. Three levels of transverse pre-tensions are studied at 100 N, 200 N, and 400 N. The results showed that both peak pull-out force and energy absorption during the pull-out process increase with increase in transverse pre-tension. All the metal-coated groups showed an approximately 200% increase in peak pull-out force and a 20% reduction in tenacity compared to uncoated control. Furthermore, all the metal-coated groups showed an increase in energy absorption, with aluminum-coated yarns showing the highest increase of 230% compared to control. These results suggest enhanced frictional interactions during yarn pull-out in metal-coated yarns compared to uncoated control as evidenced by the surface roughness profile of individual fibers and inter-yarn frictional calculations. Full article

(This article belongs to the Special Issue Polymer Fibers and Composites)

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16 pages, 10623 KiB

Open AccessArticle

CFD Comparison of the Influence of Casting of Samples on the Fiber Orientation Distribution

by Oksana Goidyk, Mark Heinštein and Heiko Herrmann

Fibers 2023, 11(1), 6; https://doi.org/10.3390/fib11010006 - 10 Jan 2023

Viewed by 1411

Abstract

The main goal of this research is to show that even a small deviation from the prescribed casting method EN 14651 causes a difference in fiber orientation distribution in sample beams. A further goal is to investigate the difference in the fiber orientation [...] Read more.

The main goal of this research is to show that even a small deviation from the prescribed casting method EN 14651 causes a difference in fiber orientation distribution in sample beams. A further goal is to investigate the difference in the fiber orientation between bottom and side layers, which would carry the tensile load in the in-situ situation (bottom layer) compared to testing according to EN 14651 (side layer). Nowadays, the development of the proper numerical simulations that aim to visualize the casting process of the fresh concrete flow is a promising challenge in the construction industry. To be able to predict the orientation and spatial distribution of the short fibers using numerical tools may significantly simplify the investigations of the fibered composite materials. This paper compares simulations of different casting methods of the fiber concrete mixture with various flowabilities. The casting of the testing specimen was simulated in different ways: the filling of the formwork according to EN 14651, from the center only and from one edge of the formwork using computational fluid dynamics. The influence of different casting methods in combination with four specific sets of the rheological parameters on the final fiber orientation distribution is discussed. The presented outcomes of the simulations demonstrate that even a minor change in the casting procedure can significantly alter the final characteristics of the material. Full article

(This article belongs to the Special Issue Mechanics of Fiber Reinforced Cementitious Composites)

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15 pages, 5323 KiB

Open AccessArticle

Extraction and Physico-Chemical Characterization of Pineapple Crown Leaf Fibers (PCLF)

by Vivek Johny, Ajith Kuriakose Mani, Sivasubramanian Palanisamy, Visakh Kunnathuparambil Rajan, Murugesan Palaniappan and Carlo Santulli

Fibers 2023, 11(1), 5; https://doi.org/10.3390/fib11010005 - 06 Jan 2023

Cited by 14 | Viewed by 4656

Abstract

Apart from the widely discussed pineapple leaf fibers, normally referred to as PALF, fibers from other parts of the plant also exist, particularly those in the fruit crown, which are known as pineapple crown leaf fibers (PCLF). In this work, PCLF were characterized [...] Read more.

Apart from the widely discussed pineapple leaf fibers, normally referred to as PALF, fibers from other parts of the plant also exist, particularly those in the fruit crown, which are known as pineapple crown leaf fibers (PCLF). In this work, PCLF were characterized using thermogravimetric analysis (TGA), Fourier transform IR spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and atomic force microscopy (AFM). The results indicated that the properties of PCLF do not greatly differ from those observed for PALF. In particular, a cellulose content of over 67% was observed, with approximately 76% crystallinity. The main degradation phenomena of the fibers took place between 230 and 380 °C, peaking at 324 °C, which is in line with observations in other fibers which have similar cellulose and crystalline contents. There was 13.4% residue at 680 °C. Bare mechanical retting of PCLF, although not allowing a full and thorough degumming, which would only be achieved through more aggressive chemical treatment, enabled aspect ratios of over 10³ to be obtained. This indicates some potential for their application as short fibers in composites. In this respect, the considerable roughness of PCLF when compared to other leaf-extracted fibers, and in particular when compared to PALF, could suggest an ability to obtain a sufficiently sound fiber–matrix interface. Full article

(This article belongs to the Special Issue Plant Fibers II)

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20 pages, 5050 KiB

Open AccessArticle

Experimental and Statistical Study of the Effect of Steel Fibers and Design Strength on the Variability in Repeated Impact Test Results

by Ahmmad A. Abbass, Sallal R. Abid, Ali I. Abed and Sajjad H. Ali

Fibers 2023, 11(1), 4; https://doi.org/10.3390/fib11010004 - 30 Dec 2022

Cited by 5 | Viewed by 1762

Abstract

The ACI 544-2R repeated impact test is known as a low-cost and simple qualitative test to evaluate the impact strength of concrete. However, the test’s main deficiency is the high variability in its results. The effect of steel fibers and the compressive strength [...] Read more.

The ACI 544-2R repeated impact test is known as a low-cost and simple qualitative test to evaluate the impact strength of concrete. However, the test’s main deficiency is the high variability in its results. The effect of steel fibers and the compressive strength of concrete on the variability in repeated impact test results was investigated experimentally and statically in this study. Two batches from four mixtures were prepared and tested for this purpose. Hooked-end steel fibers were utilized in the fibrous mixtures. The mixtures NC, NC-SF0.5 and NC-SF1.0 were normal strength mixtures with 0, 0.5 and 1.0% of steel fibers, respectively, while HC was a plain high-strength mixture. The impact tests were conducted using an automatic testing machine following the setup of the ACI 544-2R repeated impact test. The impact numbers at cracking (N1) and at failure (N2) were recorded for both batches of the four mixtures. The results were also analyzed using the normal probability and Weibull distribution tests. The test results showed that the fibers increased the impact results at the cracking stage and significantly increased the failure impact resistance. Adding 0.5 and 1.0% of steel fibers increased the N1 by up to 66 and 111%, respectively, and increased the N2 by 114 and 374%, respectively. The test results also showed that duplicating the design compressive strength from 40 to 80 MPa increased the impact resistance by up to approximately 190%. The test results revealed no clear trend of an effect of steel fibers and compressive strength on the variability in the test results. Full article

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11 pages, 1861 KiB

Open AccessFeature PaperArticle

Liquid Crystal Coated Yarns for Thermo-Responsive Textile Structures

by Deña Mae Agra-Kooijman, Md Mostafa, Mourad Krifa, Linda Ohrn-McDaniel, John L. West and Antal Jákli

Fibers 2023, 11(1), 3; https://doi.org/10.3390/fib11010003 - 24 Dec 2022

Cited by 2 | Viewed by 2216

Abstract

We have developed a prototype of breathable thermochromic textile ideal for sensor applications, e.g., medical thermography. The textile was woven/knitted from polyester filaments pre-coated with thermochromic liquid crystal (TLC) ink, in lieu of coating the TLC ink on the woven/knitted textile. This process [...] Read more.

We have developed a prototype of breathable thermochromic textile ideal for sensor applications, e.g., medical thermography. The textile was woven/knitted from polyester filaments pre-coated with thermochromic liquid crystal (TLC) ink, in lieu of coating the TLC ink on the woven/knitted textile. This process brings us closer to achieving breathable thermochromic textiles while enhancing the versatility of the textile. A combination of precoated yarns can be preselected according to the desired thermochromic properties of the textile. Swatches from both knitted and handwoven fabrics showed excellent reversible thermochromic property showing color from red to blue as the temperature is raised from 26 to 32 °C, consistent with the unincorporated TLC ink. Full article

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15 pages, 4754 KiB

Open AccessArticle

Polymer-Modified Cellulose Nanofibrils Cross-Linked with Cobalt Iron Oxide Nanoparticles as a Gel Ink for 3D Printing Objects with Magnetic and Electrochemical Properties

by Jakob Benedikt Mietner, Sebastian Willruth, Rajesh Komban, Christoph Gimmler, Bilal Nehmeh and Julien R. G. Navarro

Fibers 2023, 11(1), 2; https://doi.org/10.3390/fib11010002 - 21 Dec 2022

Cited by 3 | Viewed by 2274

Abstract

This paper presents a strategy to convert hydrophilic cellulose nanofibrils (CNF) into a highly cross-linked hydrophobic network with inorganic nanoparticles to develop a gel ink suitable for gel 3D printing. The CNF were chemically modified initially through a single-electron transfer-living radical polymerization (SET-LRP) [...] Read more.

This paper presents a strategy to convert hydrophilic cellulose nanofibrils (CNF) into a highly cross-linked hydrophobic network with inorganic nanoparticles to develop a gel ink suitable for gel 3D printing. The CNF were chemically modified initially through a single-electron transfer-living radical polymerization (SET-LRP) of stearyl acrylate (SA) in the presence of the surface-modified cobalt iron oxide (CoFe₂O₄, CFO) nanoparticles. The modified CFO nanoparticles provide their multifunctional properties, such as magnetic and electrochemical, to the CNF hybrid network and, at the same time, act as cross-linking agents between the nanocellulose fibrils, while the grafted poly-stearyl acrylate (PSA) introduces a strong hydrophobicity in the network. A suitable gel ink form of this CNF–PSA–CFO material for gel 3D printing was achieved together with a certain solvent. Some test structure prints were directly obtained with the CNF–PSA–CFO gel and were used to evaluate the consolidation of such 3D objects through solvent exchange and freeze-drying while also keeping the magnetic and electrochemical properties of CFO in the CNF-based composite intact. The pristine CNF and CFO particles and the CNF–PSA–CFO were characterized by FTIR, SEM, XPS, TGA, VSM, and CV measurements. Full article

(This article belongs to the Topic Cellulose and Cellulose Derivatives)

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19 pages, 6041 KiB

Open AccessArticle

Development of Thin Films from Thermomechanical Pulp Nanofibers of Radiata Pine (Pinus radiata D. Don) for Applications in Bio-Based Nanocomposites

by Judith Vergara-Figueroa, Oswaldo Erazo, Héctor Pesenti, Paulina Valenzuela, Arturo Fernández-Pérez and William Gacitúa

Fibers 2023, 11(1), 1; https://doi.org/10.3390/fib11010001 - 20 Dec 2022

Cited by 2 | Viewed by 1802

Abstract

The main objective of this study was to develop cellulose nanofibers from the thermomechanical pulp (TMP) of Radiata Pine (Pinus radiata D. Don), and for this, a one-step micro-grinding process was used. The newly developed material was called thermomechanical pulp nanofibers (TMP-NF). [...] Read more.

The main objective of this study was to develop cellulose nanofibers from the thermomechanical pulp (TMP) of Radiata Pine (Pinus radiata D. Don), and for this, a one-step micro-grinding process was used. The newly developed material was called thermomechanical pulp nanofibers (TMP-NF). In the first instance, a determination of the constituents of the TMP was carried out through a chemical characterization. Then, TMP-NFs were compared with cellulose nanofibers (CNF) by morphological analysis (Scanning Electron Microscopy, SEM, and Atomic Force Microscopy, AFM), X-ray Diffraction (XRD) and Fourier-Transform Infrared Spectroscopy with Attenuated Total Reflection (FTIR-ATR). In addition, films were developed from TMP-NF and CNF using a vacuum filtration manufacturing method. For this study, 0.10, 0.25, 0.50, and 1.00% dry weight of CNF and TMP-NF were used as continuous matrices without organic solvents. The films were characterized by determining their morphological, physical, surface properties, and mechanical properties. The main results showed that morphological analysis by SEM and AFM for the fractionated sample indicated a fiber diameter distribution in the range of 990-17 nm and an average length of 5.8 µm. XRD analysis showed a crystallinity index of 90.8% in the CNF, while in the TMP-NF, it was 71.2%, which was foreseeable. FTIR-ATR analysis showed the functional groups of lignin and hemicellulose present in the TMP-NF sample. The films presented apparent porosity values of 33.63 for 1.00% solids content of CNF and 33.27% for 0.25% solids content of TMP-NF. The contact angle was 61.50° for 0.50% solids content of CNF and 84.60° for 1.00% solids content of TMP-NF. Regarding the mechanical properties, the modulus of elasticity was 74.65 MPa for CNF and 36.17 MPa for TMP-NF, and the tensile strength was 1.07 MPa for CNF and 0.69 MPa for TMP-NF. Although the mechanical properties turned out to be higher in the CNF films, the TMP-NF films showed improved surface characteristics as to surface hydrophobic and apparent porosity. In addition, the easy and rapid obtaining of TMP nanofibers makes it a promising material that can be used in biologically based nanocomposites. Full article

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Fibers, Volume 11, Issue 1 (January 2023) – 11 articles

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