Giovanna Rizzo, Roberto Buccione, Marilena Dichicco, Rosalda Punturo, Giovanni Mongelli
A multi-analytical study on serpentinites in the ophiolite units (Calabria-Basilicata boundary, southern Apennines) was carried out on samples collected from a serpentinite quarry, locally called “Pietrapica”, which sitsin the Pollino UNESCO Global Geopark. Optical microscopy observations revealed the petrographic characteristics, ICP-MS was used to assess the chemical composition while EMPA mineral chemistry, Raman spectroscopy and X-Ray Powder Diffraction and were used altogether to trace the mineral composition of the rocks. Petrography revealed that serpentinites from Pietrapica quarry are essentially composed of serpentine group minerals, amphibole and carbonate minerals with lower abundances of talc and Cr-spinel. Raman spectroscopy and X-ray powder diffraction analysis clearly allowed to establish that carbonate minerals, serpentine and amphibole-like minerals, are the dominant phases, followed by 2:1 phyllosilicate. Electron probe microanalyses were carried out on different minerals in serpentinites samples including serpentine, amphibole, chlorite, clinopyroxene, magnetite, talc, quartz and titanite which are often associated with carbonate veins. Bulk geochemistry is dominated by major oxides SiO2, MgO and Fe2O3 while the most abundant trace elements are Ni and Cr. Chemical analysis showed that some heavy metals in the studied serpentinites such as Ni and Cr, are beyond the maximum admissible limits for Italian normative for public, private and residential green as well as for commercial and industrial use representing a potential environmental concern. Anyway, some of these heavy metals have been recently listed by Europe as critical raw materials and therefore, the Pietrapica abandoned quarry could represent a new resource considering their economic potentiality.
{"title":"Petrography, Geochemistry and Mineralogy of Serpentinite Rocks Exploited in the Ophiolite Units at the Calabria-Basilicata Boundary, Southern Apennine (Italy)","authors":"Giovanna Rizzo, Roberto Buccione, Marilena Dichicco, Rosalda Punturo, Giovanni Mongelli","doi":"10.3390/fib11100081","DOIUrl":"https://doi.org/10.3390/fib11100081","url":null,"abstract":"A multi-analytical study on serpentinites in the ophiolite units (Calabria-Basilicata boundary, southern Apennines) was carried out on samples collected from a serpentinite quarry, locally called “Pietrapica”, which sitsin the Pollino UNESCO Global Geopark. Optical microscopy observations revealed the petrographic characteristics, ICP-MS was used to assess the chemical composition while EMPA mineral chemistry, Raman spectroscopy and X-Ray Powder Diffraction and were used altogether to trace the mineral composition of the rocks. Petrography revealed that serpentinites from Pietrapica quarry are essentially composed of serpentine group minerals, amphibole and carbonate minerals with lower abundances of talc and Cr-spinel. Raman spectroscopy and X-ray powder diffraction analysis clearly allowed to establish that carbonate minerals, serpentine and amphibole-like minerals, are the dominant phases, followed by 2:1 phyllosilicate. Electron probe microanalyses were carried out on different minerals in serpentinites samples including serpentine, amphibole, chlorite, clinopyroxene, magnetite, talc, quartz and titanite which are often associated with carbonate veins. Bulk geochemistry is dominated by major oxides SiO2, MgO and Fe2O3 while the most abundant trace elements are Ni and Cr. Chemical analysis showed that some heavy metals in the studied serpentinites such as Ni and Cr, are beyond the maximum admissible limits for Italian normative for public, private and residential green as well as for commercial and industrial use representing a potential environmental concern. Anyway, some of these heavy metals have been recently listed by Europe as critical raw materials and therefore, the Pietrapica abandoned quarry could represent a new resource considering their economic potentiality.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135966109","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Roman Nikolaevich Yastrebinsky, Vyacheslav Ivanovich Pavlenko, Anna Viktorovna Yastrebinskaya, Andrey Ivanovich Gorodov, Anastasia Vladislavovna Akimenko
This research is aimed at obtaining boron-containing nanotubular chrysotile fibers with increased neutron absorption capacity. The possibility of using an organosilicon modifier based on tetraethoxysilane to increase the hydrothermal stability of chrysotile, as well as the strength of nanoreinforced composites based on a cement binder is considered. The mechanisms for the synthesis of heat-resistant nanotubular fibers of the composition Mg6(OH)8SiB4O10, which have a chrysotile structure, have been established. To increase the hydrothermal stability of chrysotile, crystalline hydrate phases were localized inside nanotubes using amorphous silica formed as a result of hydrolysis of silicon alkoxide under hydrothermal conditions in an alkaline environment. The modification of chrysotile via amorphous silica increases its hydrothermal stability by 97 °C. It is shown that the introduction of an organosilicon modifier based on tetraethoxysilane into the composition of Portland cement composite material leads to an increase in the structural strength and density of the composite due to the activation of silicate formation processes in the cement matrix, especially under hydrothermal conditions. The experiments showed that the strength of silicon alkoxide-modified samples of composite material increased by 34%.
{"title":"Application of Organosilicon Modifier Based on Tetraethoxysilane for the Production of Heat-Resistant Chrysotile Fibers and Reinforced Cement Composites","authors":"Roman Nikolaevich Yastrebinsky, Vyacheslav Ivanovich Pavlenko, Anna Viktorovna Yastrebinskaya, Andrey Ivanovich Gorodov, Anastasia Vladislavovna Akimenko","doi":"10.3390/fib11100080","DOIUrl":"https://doi.org/10.3390/fib11100080","url":null,"abstract":"This research is aimed at obtaining boron-containing nanotubular chrysotile fibers with increased neutron absorption capacity. The possibility of using an organosilicon modifier based on tetraethoxysilane to increase the hydrothermal stability of chrysotile, as well as the strength of nanoreinforced composites based on a cement binder is considered. The mechanisms for the synthesis of heat-resistant nanotubular fibers of the composition Mg6(OH)8SiB4O10, which have a chrysotile structure, have been established. To increase the hydrothermal stability of chrysotile, crystalline hydrate phases were localized inside nanotubes using amorphous silica formed as a result of hydrolysis of silicon alkoxide under hydrothermal conditions in an alkaline environment. The modification of chrysotile via amorphous silica increases its hydrothermal stability by 97 °C. It is shown that the introduction of an organosilicon modifier based on tetraethoxysilane into the composition of Portland cement composite material leads to an increase in the structural strength and density of the composite due to the activation of silicate formation processes in the cement matrix, especially under hydrothermal conditions. The experiments showed that the strength of silicon alkoxide-modified samples of composite material increased by 34%.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"71 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136094252","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Javier González-Benito, Miguel A. Lorente, Dania Olmos, Ana Kramar
In this work, materials with potential biomedical applications constituted by fibrous poly(ethylene oxide), PEO, are prepared by solution blow spinning (SBS). The SBS setup has a cylindrical collector for which the rotational speed and size are varied to study its effect on the final morphology of the materials. The morphology is inspected using field emission scanning electron microscopy and studied using image analysis. As a result, many doubts were generated because of the use of different methods of image analysis, therefore a simpler and more conventional method using Image J open-source software was used to ensure the accuracy of the final interpretation. It is shown that fiber size and orientation depend on the linear speed associated with the surface of the collector more than on its rotational speed; therefore, it can be said that the morphology of materials prepared by SBS will depend on the size, shape, and rotational speed of the collector. When the linear speed of the cylindrical collector increases, fibers get thinner, less entangled, and more oriented. It is clear, therefore, that the linear speed of material collection by solution blow spinning is a very important parameter of processing to control the final morphology of materials manufactured by that method. Since morphology can affect the final properties of the materials the simple variation of the linear speed might have important implications on their final performance for different biomedical applications.
{"title":"Solution Blow Spinning to Prepare Preferred Oriented Poly(ethylene oxide) Submicrometric Fibers","authors":"Javier González-Benito, Miguel A. Lorente, Dania Olmos, Ana Kramar","doi":"10.3390/fib11090079","DOIUrl":"https://doi.org/10.3390/fib11090079","url":null,"abstract":"In this work, materials with potential biomedical applications constituted by fibrous poly(ethylene oxide), PEO, are prepared by solution blow spinning (SBS). The SBS setup has a cylindrical collector for which the rotational speed and size are varied to study its effect on the final morphology of the materials. The morphology is inspected using field emission scanning electron microscopy and studied using image analysis. As a result, many doubts were generated because of the use of different methods of image analysis, therefore a simpler and more conventional method using Image J open-source software was used to ensure the accuracy of the final interpretation. It is shown that fiber size and orientation depend on the linear speed associated with the surface of the collector more than on its rotational speed; therefore, it can be said that the morphology of materials prepared by SBS will depend on the size, shape, and rotational speed of the collector. When the linear speed of the cylindrical collector increases, fibers get thinner, less entangled, and more oriented. It is clear, therefore, that the linear speed of material collection by solution blow spinning is a very important parameter of processing to control the final morphology of materials manufactured by that method. Since morphology can affect the final properties of the materials the simple variation of the linear speed might have important implications on their final performance for different biomedical applications.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136129539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Athanasia K. Thomoglou, Jagadesh Palanisamy, Maristella E. Voutetaki
When a seismic load is applied horizontally or laterally on unreinforced masonry walls (URM), the walls behave in two different ways, viz., in-plane (IP) and out-of-plane (OoP). This review beneficially provides a literature overview of the most cited research papers on Scopus, and the database is evaluated with VOSviewer software for scientometric analysis. This review paper delves into the practical applications of various types of reinforcement for masonry walls, specifically focusing on four commonly used systems: externally bonded strengthening techniques using fiber-reinforced polymers (FRP), steel-reinforced grout (SRG), fabric-reinforced cementitious mortar (FRCM), and textile-reinforced mortars (TRM). The main objective of the paper is to explore the efficacy of these reinforcement techniques in strengthening masonry walls, and to provide a comprehensive overview of their respective advantages and limitations. A further detailed study of the extent of the literature is performed about the effect of the different strengthening systems on the mechanical properties of different categories of masonry walls like a cement block, stone, and clay brick are described and categorized. The efficiency of OoP strengthening can depend on various factors, such as the types of masonry units, the rendering mortar, the type of strengthening system, the bond between the different materials interfaces, the geometry of the wall, and the loading conditions. By utilizing the practical method of Dematel (Decision-making trial and evaluation laboratory) analysis, this review can delve deeply into the impact of various factors and precisely identify the crucial components of the cause-and-effect connection. The results indicate that the bond between material interfaces is the critical factor. This meticulous and structured review offers valuable perspectives for researchers and engineers, showcasing current research trends and presenting potential avenues for future exploration.
当地震荷载水平或横向施加在无筋砌体墙(URM)上时，墙体表现为两种不同的方式，即面内(IP)和面外(OoP)。本文综述了Scopus上被引次数最多的研究论文，并使用VOSviewer软件对数据库进行了科学计量分析。这篇综述论文深入探讨了各种类型的砌体墙加固的实际应用，特别关注四种常用的系统:外部粘结加固技术，使用纤维增强聚合物(FRP)，钢增强浆液(SRG)，织物增强水泥砂浆(FRCM)和纺织增强砂浆(TRM)。本文的主要目的是探讨这些加固技术在加固砌体墙方面的效果，并对各自的优点和局限性进行全面的概述。对不同强化体系对不同类别砖石墙(如水泥块、石材和粘土砖)机械性能的影响进行了进一步的详细研究，并对其进行了描述和分类。面向对象加固的效率取决于各种因素，如砌体单元的类型、渲染砂浆、加固系统的类型、不同材料界面之间的粘结、墙壁的几何形状和加载条件。通过运用Dematel (Decision-making trial and evaluation laboratory，决策试验与评价实验室)分析的实用方法，本综述可以深入挖掘各种因素的影响，准确识别因果关系的关键组成部分。结果表明，材料界面间的结合是影响材料性能的关键因素。这篇细致而有组织的综述为研究人员和工程师提供了有价值的观点，展示了当前的研究趋势，并为未来的探索提供了潜在的途径。
{"title":"Review of Out-of-Plane Strengthening Techniques of Unreinforced Masonry Walls","authors":"Athanasia K. Thomoglou, Jagadesh Palanisamy, Maristella E. Voutetaki","doi":"10.3390/fib11090078","DOIUrl":"https://doi.org/10.3390/fib11090078","url":null,"abstract":"When a seismic load is applied horizontally or laterally on unreinforced masonry walls (URM), the walls behave in two different ways, viz., in-plane (IP) and out-of-plane (OoP). This review beneficially provides a literature overview of the most cited research papers on Scopus, and the database is evaluated with VOSviewer software for scientometric analysis. This review paper delves into the practical applications of various types of reinforcement for masonry walls, specifically focusing on four commonly used systems: externally bonded strengthening techniques using fiber-reinforced polymers (FRP), steel-reinforced grout (SRG), fabric-reinforced cementitious mortar (FRCM), and textile-reinforced mortars (TRM). The main objective of the paper is to explore the efficacy of these reinforcement techniques in strengthening masonry walls, and to provide a comprehensive overview of their respective advantages and limitations. A further detailed study of the extent of the literature is performed about the effect of the different strengthening systems on the mechanical properties of different categories of masonry walls like a cement block, stone, and clay brick are described and categorized. The efficiency of OoP strengthening can depend on various factors, such as the types of masonry units, the rendering mortar, the type of strengthening system, the bond between the different materials interfaces, the geometry of the wall, and the loading conditions. By utilizing the practical method of Dematel (Decision-making trial and evaluation laboratory) analysis, this review can delve deeply into the impact of various factors and precisely identify the crucial components of the cause-and-effect connection. The results indicate that the bond between material interfaces is the critical factor. This meticulous and structured review offers valuable perspectives for researchers and engineers, showcasing current research trends and presenting potential avenues for future exploration.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135010752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This article studies the flexural behavior of thin-walled specimens with square hollow sections fabricated using fused deposition modeling (FDM). The specimens were 3D printed from an ABS filament reinforced with aramid fibers. Four wall thicknesses were analyzed. The strength data were collected during three-point flexural tests. There are visible, clear differences in the flexural properties between the X- or Y-oriented specimens and those printed in the Z direction, and they vary up to 70%. It was also found that the flexural strength was dependent on the G-codes controlling the print head’s motion, path, and position. For specimens with a thickness up to 1.4 mm, the infill pattern was linear, whereas 1.8 mm and 2 mm specimens needed a stitch, which had some negative effects on the strength properties.
{"title":"Flexural Properties of Thin-Walled Specimens with Square Hollow Sections 3D Printed from ABS Reinforced with Aramid Fibers","authors":"Jerzy Bochnia, Tomasz Kozior, Mateusz Musialek","doi":"10.3390/fib11090077","DOIUrl":"https://doi.org/10.3390/fib11090077","url":null,"abstract":"This article studies the flexural behavior of thin-walled specimens with square hollow sections fabricated using fused deposition modeling (FDM). The specimens were 3D printed from an ABS filament reinforced with aramid fibers. Four wall thicknesses were analyzed. The strength data were collected during three-point flexural tests. There are visible, clear differences in the flexural properties between the X- or Y-oriented specimens and those printed in the Z direction, and they vary up to 70%. It was also found that the flexural strength was dependent on the G-codes controlling the print head’s motion, path, and position. For specimens with a thickness up to 1.4 mm, the infill pattern was linear, whereas 1.8 mm and 2 mm specimens needed a stitch, which had some negative effects on the strength properties.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135258923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Dora Pugliese, Valerio Alecci, Rosa Romano, Gianfranco Stipo, Mario De Stefano, Antonio Nanni
Usually, energy and structural improvements for historic masonry buildings are addressed separately using distinct methods and protocols. This paper covers an integrated assessment of new composite materials to reduce the seismic vulnerability of historic masonry buildings while complying with sustainable conservation requirements, emissions’ reduction, and energy savings. Firstly, this study focused on selecting suitable thermal mortars that could serve as the base material for the innovative composite. Subsequently, the mechanical characteristics of these mortars were examined by subjecting them to compressive and three-point bending tests. Dynamic thermo-hygrometric simulations were conducted using commercially available software to check the energy performance of the composite material when used on walls of existing masonry buildings. The thermal mortar that exhibited the most favorable mechanical and thermal properties was subsequently reinforced with a basalt fabric. A composite sample was assembled and subjected to direct tensile testing to determine its stress–strain behavior.
{"title":"Innovative and Sustainable Composite Material for the Seismic and Energetic Upgrade of Historic Masonry Buildings","authors":"Dora Pugliese, Valerio Alecci, Rosa Romano, Gianfranco Stipo, Mario De Stefano, Antonio Nanni","doi":"10.3390/fib11090076","DOIUrl":"https://doi.org/10.3390/fib11090076","url":null,"abstract":"Usually, energy and structural improvements for historic masonry buildings are addressed separately using distinct methods and protocols. This paper covers an integrated assessment of new composite materials to reduce the seismic vulnerability of historic masonry buildings while complying with sustainable conservation requirements, emissions’ reduction, and energy savings. Firstly, this study focused on selecting suitable thermal mortars that could serve as the base material for the innovative composite. Subsequently, the mechanical characteristics of these mortars were examined by subjecting them to compressive and three-point bending tests. Dynamic thermo-hygrometric simulations were conducted using commercially available software to check the energy performance of the composite material when used on walls of existing masonry buildings. The thermal mortar that exhibited the most favorable mechanical and thermal properties was subsequently reinforced with a basalt fabric. A composite sample was assembled and subjected to direct tensile testing to determine its stress–strain behavior.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134914118","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flávio A. Marter Diniz, Tim Röding, Mohamed Bouhrara, Thomas Gries
Carbon fibers (CF) and their composites (CC) are one of the world’s most promising and avant-garde high-performance materials, as they combine excellent mechanical characteristics with high weight reduction potential. Polyethylene (PE) is the perfect alternative precursor for CF as it combines widespread availability, low cost, high carbon content, and, most importantly, precursor fibers that can be produced via melt-spinning. PE-based CF production involves a challenging and time-consuming diffusion-limited chemical stabilization step. The work presented in this article tackles the challenge of reducing the chemical stabilization process time by converting a bicomponent island-in-the-sea fiber, consisting of PA6 as sea matrix and HDPE as island material, into an ultra-thin PE-precursor fiber. The produced precursor fiber is then successfully converted into an ultra-thin PE-based CF through sulfonation and subsequent carbonization in a continuous set-up. The resulting CF has a smooth surface with no observable surface defects and a filament diameter of around 3 µm. The successful conversion to ultra-thin CF is shown in both batch and continuous processes. Additionally, a reduction in sulfonation reaction time from 4 h to 3 h is achieved.
{"title":"The Production of Ultra-Thin Polyethylene-Based Carbon Fibers out of an “Islands-in-the-Sea” (INS) Precursor","authors":"Flávio A. Marter Diniz, Tim Röding, Mohamed Bouhrara, Thomas Gries","doi":"10.3390/fib11090075","DOIUrl":"https://doi.org/10.3390/fib11090075","url":null,"abstract":"Carbon fibers (CF) and their composites (CC) are one of the world’s most promising and avant-garde high-performance materials, as they combine excellent mechanical characteristics with high weight reduction potential. Polyethylene (PE) is the perfect alternative precursor for CF as it combines widespread availability, low cost, high carbon content, and, most importantly, precursor fibers that can be produced via melt-spinning. PE-based CF production involves a challenging and time-consuming diffusion-limited chemical stabilization step. The work presented in this article tackles the challenge of reducing the chemical stabilization process time by converting a bicomponent island-in-the-sea fiber, consisting of PA6 as sea matrix and HDPE as island material, into an ultra-thin PE-precursor fiber. The produced precursor fiber is then successfully converted into an ultra-thin PE-based CF through sulfonation and subsequent carbonization in a continuous set-up. The resulting CF has a smooth surface with no observable surface defects and a filament diameter of around 3 µm. The successful conversion to ultra-thin CF is shown in both batch and continuous processes. Additionally, a reduction in sulfonation reaction time from 4 h to 3 h is achieved.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136362369","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. Kazemi, A. Fazli, Jean Philippe Ira, D. Rodrigue
This study proposes a simple approach to separate most rubber particles from recycled tire fibers (RTFs) and to determine their rubber content using thermogravimetric analysis (TGA)/calcination. Furthermore, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and Fourier transform infrared spectroscopy (FTIR) analyses are used to investigate the separation process and materials compositions. Afterwards, a series of composites based on recycled post-consumer low-density polyethylene (rLDPE) with clean fiber (CF) and residual ground rubber particles (GR) is prepared at different filler concentrations (0–30%) via extrusion compounding before using compression molding and injection molding for comparison. In all cases, injection molding leads to higher strength and modulus but lower elongation at break. The results show that incorporating 30 wt.% of CF into rLDPE yields a remarkable improvement in tensile strength (15%), tensile modulus (192%) and flexural modulus (142%). On the other hand, the incorporation of up to 30 wt.% of GR results in a reduction in both tensile strength and flexural modulus by 15%, confirming the critical role of the cleaning process for RTF in achieving the best results.
{"title":"Recycled Tire Fibers used as Reinforcement for Recycled Polyethylene Composites","authors":"H. Kazemi, A. Fazli, Jean Philippe Ira, D. Rodrigue","doi":"10.3390/fib11090074","DOIUrl":"https://doi.org/10.3390/fib11090074","url":null,"abstract":"This study proposes a simple approach to separate most rubber particles from recycled tire fibers (RTFs) and to determine their rubber content using thermogravimetric analysis (TGA)/calcination. Furthermore, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDAX), and Fourier transform infrared spectroscopy (FTIR) analyses are used to investigate the separation process and materials compositions. Afterwards, a series of composites based on recycled post-consumer low-density polyethylene (rLDPE) with clean fiber (CF) and residual ground rubber particles (GR) is prepared at different filler concentrations (0–30%) via extrusion compounding before using compression molding and injection molding for comparison. In all cases, injection molding leads to higher strength and modulus but lower elongation at break. The results show that incorporating 30 wt.% of CF into rLDPE yields a remarkable improvement in tensile strength (15%), tensile modulus (192%) and flexural modulus (142%). On the other hand, the incorporation of up to 30 wt.% of GR results in a reduction in both tensile strength and flexural modulus by 15%, confirming the critical role of the cleaning process for RTF in achieving the best results.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48141806","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, the different effects of weave structure on the comfort properties of fabrics and the mechanical properties of fiber-reinforced composites were investigated. Fabrics were developed using one type of material (flax spun yarn) in the warp direction and three different materials (flax, sisal and cotton spun yarn) in the weft directions. Four different types of weaves (plain, twill, matt and mock leno) were produced in each type of material. Twelve specimens were produced on a sample weaving machine. These fabrics with multiweave combinations give the wearer a comfort zone for sportswear and outdoor applications. These fabrics maintain the temperature of wearers in extreme weather conditions. But these weaves have different effects when interlaced with different types of weft yarns. Air permeability, overall moisture management, stiffness and thermal resistance were investigated for these fabric specimens. The hybrid fabric produced with pure flax warp and weft cotton/sisal exhibited the highest value of air permeability, overall moisture management capability and thermal resistance followed by flax–sisal and flax–flax. The hybrid fabric produced with the mock leno weave also presented a higher value of air permeability compared to the twill, mat and plain weaves. Bending stiffness was observed to be higher in those fabrics produced with flax/sisal compared to pure flax and flax–cotton. The outerwear fabric produced with a blend of flax yarn in the warp and cotton/sisal spun yarn in the weft exhibited improved properties when compared to the fabric produced with flax/sisal and pure flax yarns. In composites, flax/flax showed enhanced mechanical properties, i.e., tensile and flexural strength. In other combinations, the composites with longer weaves possessed prominent mechanical characteristics. The composites with enhanced mechanical properties can be used for window coverings, furniture upholstery and sports equipment. These composites have the potential to be used in automotive applications.
{"title":"Enhancing the Thermal Comfort of Woven Fabrics and Mechanical Properties of Fiber-Reinforced Composites Using Multiple Weave Structures","authors":"Zafar Arshad, Salman S. Alharthi","doi":"10.3390/fib11090073","DOIUrl":"https://doi.org/10.3390/fib11090073","url":null,"abstract":"In this study, the different effects of weave structure on the comfort properties of fabrics and the mechanical properties of fiber-reinforced composites were investigated. Fabrics were developed using one type of material (flax spun yarn) in the warp direction and three different materials (flax, sisal and cotton spun yarn) in the weft directions. Four different types of weaves (plain, twill, matt and mock leno) were produced in each type of material. Twelve specimens were produced on a sample weaving machine. These fabrics with multiweave combinations give the wearer a comfort zone for sportswear and outdoor applications. These fabrics maintain the temperature of wearers in extreme weather conditions. But these weaves have different effects when interlaced with different types of weft yarns. Air permeability, overall moisture management, stiffness and thermal resistance were investigated for these fabric specimens. The hybrid fabric produced with pure flax warp and weft cotton/sisal exhibited the highest value of air permeability, overall moisture management capability and thermal resistance followed by flax–sisal and flax–flax. The hybrid fabric produced with the mock leno weave also presented a higher value of air permeability compared to the twill, mat and plain weaves. Bending stiffness was observed to be higher in those fabrics produced with flax/sisal compared to pure flax and flax–cotton. The outerwear fabric produced with a blend of flax yarn in the warp and cotton/sisal spun yarn in the weft exhibited improved properties when compared to the fabric produced with flax/sisal and pure flax yarns. In composites, flax/flax showed enhanced mechanical properties, i.e., tensile and flexural strength. In other combinations, the composites with longer weaves possessed prominent mechanical characteristics. The composites with enhanced mechanical properties can be used for window coverings, furniture upholstery and sports equipment. These composites have the potential to be used in automotive applications.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42202901","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Koptev, Alexander E. Zaprialov, A. Kosolapov, A. Denisov, M. Muravyeva, S. Semjonov, S. Muravyev, A. Kim
Broadband supercontinuum (SC) fiber sources covering the mid-IR range have many significant applications, largely due to their compactness, reliability, and ease of use. However, most of the existing SC fiber sources cannot boast of either high reliability or a wide bandwidth. Thus, supercontinuum sources based on silica fibers are robust, but are not capable of generating SC in the mid-IR range. Sources based on soft glasses (tellurite, chalcogenide, etc.) generate broadband SC in the mid-IR range but are not used commercially, due to the poor mechanical and chemical characteristics of such fibers. In this work, we propose a new approach consisting of cascade generation of a supercontinuum sequentially in a silica photonic crystal fiber (PCF) and a germanate fiber. Using a standard ytterbium chirped-pulse amplification (CPA) laser system for pumping, we have demonstrated a supercontinuum in the range of 450–2950 nm in PCF and germanate fiber firmly connected by a standard fusion splicing technique. Further optimization of the cascade pump will make it possible to create a compact and reliable all-fiber SC source from the visible to mid-IR range.
{"title":"Visible to Mid-IR Supercontinuum Generation in Cascaded PCF-Germanate Fiber Using Femtosecond Yb-Fiber Pump","authors":"M. Koptev, Alexander E. Zaprialov, A. Kosolapov, A. Denisov, M. Muravyeva, S. Semjonov, S. Muravyev, A. Kim","doi":"10.3390/fib11090072","DOIUrl":"https://doi.org/10.3390/fib11090072","url":null,"abstract":"Broadband supercontinuum (SC) fiber sources covering the mid-IR range have many significant applications, largely due to their compactness, reliability, and ease of use. However, most of the existing SC fiber sources cannot boast of either high reliability or a wide bandwidth. Thus, supercontinuum sources based on silica fibers are robust, but are not capable of generating SC in the mid-IR range. Sources based on soft glasses (tellurite, chalcogenide, etc.) generate broadband SC in the mid-IR range but are not used commercially, due to the poor mechanical and chemical characteristics of such fibers. In this work, we propose a new approach consisting of cascade generation of a supercontinuum sequentially in a silica photonic crystal fiber (PCF) and a germanate fiber. Using a standard ytterbium chirped-pulse amplification (CPA) laser system for pumping, we have demonstrated a supercontinuum in the range of 450–2950 nm in PCF and germanate fiber firmly connected by a standard fusion splicing technique. Further optimization of the cascade pump will make it possible to create a compact and reliable all-fiber SC source from the visible to mid-IR range.","PeriodicalId":12122,"journal":{"name":"Fibers","volume":" ","pages":""},"PeriodicalIF":3.9,"publicationDate":"2023-08-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48859293","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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