Open AccessFeature PaperArticle
Structural Evolution of Gossypium hirsutum Fibers Grown under Greenhouse and Hydroponic Conditions
Fibers 2018, 6(1), 11; doi:10.3390/fib6010011 -
Abstract
Cotton is the leading fiber source in the textile industry and one of the world’s most important crops. Despite its economic interest, cotton culture exerts an enormous pressure on natural resources (land and water) and has a negative impact on the environment (abuse
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Cotton is the leading fiber source in the textile industry and one of the world’s most important crops. Despite its economic interest, cotton culture exerts an enormous pressure on natural resources (land and water) and has a negative impact on the environment (abuse of pesticides). Thus, alternative cotton growing methods are urged to be implemented. Recently, we have demonstrated that Gossypium hirsutum (“Upland” cotton) can be grown in a greenhouse (controlled conditions) and hydroponically. Here we report on the elucidation of the structural changes of the Gossypium hirsutum fibers during maturation grown [10, 14, 17, 20, 36 and 51 days post anthesis (dpa)] under a greenhouse and hydroponically, by means of scanning electron microscopy (SEM), Fourier transform infrared spectroscopy with attenuated total reflectance (FT-IR ATR) and thermal gravimetric analysis/differential scanning calorimetry (TGA/DSC). The transition from primary to secondary cell wall growth occurs between 17 and 20 dpa—similarly to the soil-based cultures. However, this new cotton culture offers an advantageous pesticide and soil-free all year-round closed system with efficient water use yielding standardized mature fibers with improved properties (maturity, strength, length, whiteness). Full article
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Open AccessArticle
Influence of Stem Diameter on Fiber Diameter and the Mechanical Properties of Technical Flax Fibers from Linseed Flax
Fibers 2018, 6(1), 10; doi:10.3390/fib6010010 -
Abstract
The continued search for sustainable and eco-friendly materials has led to the integration of bio-fibers, such as flax fiber, as reinforcement in composite materials; however, a wide variation in their diameters and mechanical properties poses a considerable challenge for their incorporation in load
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The continued search for sustainable and eco-friendly materials has led to the integration of bio-fibers, such as flax fiber, as reinforcement in composite materials; however, a wide variation in their diameters and mechanical properties poses a considerable challenge for their incorporation in load bearing and structural bio-composite materials. In this paper, a rigorous experimental investigation was performed using two varieties of linseed flax from two growing locations to determine if the variations observed in ultimate tensile strength, Young’s modulus, failure strain and diameter could be attributed to the diameters of the stems that produced the fibers. Tests were performed in two different facilities and the results were compared and analyzed using Welch’s t-tests. Results showed that samples which differed by stem diameter had statistically significant positive correlation with fiber diameter and negative correlation with tensile strength. No correlations for tensile strength, Young’s modulus or fiber diameter were found in samples with the same stem diameter range that were grown in different locations or were of different varieties, that is the effect of location and variety is not statistically significant. Failure strain did not show any statistical significance with respect to differences in stem diameter and only showed one statistically significant result between both facilities for one of the two growing location comparisons. Full article
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Open AccessBrief Report
Transcriptome Assembly of the Bast Fiber Crop, Ramie, Boehmeria nivea (L.) Gaud. (Urticaceae)
Fibers 2018, 6(1), 8; doi:10.3390/fib6010008 -
Abstract
Ramie (Boehmeria nivea) is a perennial crop valued for its strong bast fibers. Unlike other major bast fiber crops, ramie fiber processing does not include retting, but does require degumming, suggesting distinctive features in pectin and the development and composition of
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Ramie (Boehmeria nivea) is a perennial crop valued for its strong bast fibers. Unlike other major bast fiber crops, ramie fiber processing does not include retting, but does require degumming, suggesting distinctive features in pectin and the development and composition of fibers. A comprehensive transcriptome assembly of ramie has not been made available, to date. We obtained the sequence of RNA transcripts (RNA Seq) from the apical region of developing ramie stems and combined these with reads from public databases for a total of 157,621,051 paired-end reads (30.3 billion base pairs Gbp) used as input for de novo assembly, resulting in 70,721 scaffolds (≥200 base pairs (bp); N50 = 1798 bp). As evidence of the quality of the assembly, 36,535 scaffolds aligned to at least one Arabidopsis protein (BLASTP e-value ≤ 10−10). The resource described here for B. nivea will facilitate an improved understanding of bast fibers, cell wall, and middle lamella development in this and other comparative species. Full article
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Open AccessFeature PaperArticle
Effect of Polypropylene Fibers on Self-Healing and Dynamic Modulus of Elasticity Recovery of Fiber Reinforced Concrete
Fibers 2018, 6(1), 9; doi:10.3390/fib6010009 -
Abstract
This study aims to evaluate self-healing properties and recovered dynamic moduli of engineered polypropylene fiber reinforced concrete using non-destructive resonant frequency testing. Two types of polypropylene fibers (0.3% micro and 0.6% macro) and two curing conditions have been investigated: Water curing (at ~25
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This study aims to evaluate self-healing properties and recovered dynamic moduli of engineered polypropylene fiber reinforced concrete using non-destructive resonant frequency testing. Two types of polypropylene fibers (0.3% micro and 0.6% macro) and two curing conditions have been investigated: Water curing (at ~25 Celsius) and air curing. The Impact Resonance Method (IRM) has been conducted in both transverse and longitudinal modes on concrete cylinders prior/post crack induction and post healing of cracks. Specimens were pre-cracked at 14 days, obtaining values of crack width in the range of 0.10–0.50 mm. Addition of polypropylene fibers improved the dynamic response of concrete post-cracking by maintaining a fraction of the original resonant frequency and elastic properties. Macro fibers showed better improvement in crack bridging while micro fiber showed a significant recovery of the elastic properties. The results also indicated that air-cured Polypropylene Fiber Reinforced Concrete (PFRC) cylinders produced ~300 Hz lower resonant frequencies when compared to water-cured cylinders. The analyses showed that those specimens with micro fibers exhibited a higher recovery of dynamic elastic moduli. Full article
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Open AccessArticle
Interfacial Characterization by Pull-Out Test of Bamboo Fibers Embedded in Poly(Lactic Acid)
Fibers 2018, 6(1), 7; doi:10.3390/fib6010007 -
Abstract
In this work, the apparent shear strength at the interface between a bamboo fiber and the surrounding poly(lactic acid) (PLA) matrix is quantified. A method for processing pull-out test samples within a controlled embedded length is proposed and the details of the test
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In this work, the apparent shear strength at the interface between a bamboo fiber and the surrounding poly(lactic acid) (PLA) matrix is quantified. A method for processing pull-out test samples within a controlled embedded length is proposed and the details of the test procedure are presented, along with a critical discussion of the results. Two series of samples are considered: untreated and mercerized bamboo fibers from the same batch, embedded in the same polyester matrix. Electron and optical microscopy are used to observe the fiber–matrix interface before and after the test, and to identify the failure mode of each sample, especially as regards the occurrence of fibrillation in the fiber bundles. The values of apparent interfacial shear strength are calculated only for regular fibers successfully pulled out from the matrix, and reported with their statistical variations. Mercerization, whose efficiency was proven by Fourier transform infrared (FTIR) spectroscopy, did not appear though to improve the quality of the interface (τapp = 7.0 ± 3.1 MPa for untreated fibers and τapp = 5.3 ± 2.4 MPa for treated fibers). Full article
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Open AccessFeature PaperCommunication
Investigation of the Mechanical Properties of Flax Cell Walls during Plant Development: The Relation between Performance and Cell Wall Structure
Fibers 2018, 6(1), 6; doi:10.3390/fib6010006 -
Abstract
The development of flax (Linum usitatissimum L.) fibers was studied to obtain better insight on the progression of their high mechanical performances during plant growth. Fibers at two steps of plant development were studied, namely the end of the fast growth period
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The development of flax (Linum usitatissimum L.) fibers was studied to obtain better insight on the progression of their high mechanical performances during plant growth. Fibers at two steps of plant development were studied, namely the end of the fast growth period and at plant maturity, each time at three plant heights. The indentation modulus of the fiber cell wall was characterized by atomic force microscopy (AFM) using peak-force quantitative nano-mechanical property mapping (PF-QNM). Changes in the cell wall modulus with the cell wall thickening were highlighted. For growing plants, fibers from top and middle heights show a loose inner Gn layer with a lower indentation modulus than mature fibers, which exhibit thickened homogeneous cell walls made only of a G layer. The influence of these changes in the fiber cell wall on the mechanical performances of extracted elementary fibers was also emphasized by tensile tests. In addition, Raman spectra were recorded on samples from both growing and mature plants. The results suggest that, for the fiber cell wall, the cellulose contribution increases with fiber maturity, leading to a greater cell wall modulus of flax fibers. Full article
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Open AccessEditorial
Acknowledgement to Reviewers of Fibers in 2017
Fibers 2018, 6(1), 5; doi:10.3390/fib6010005 -
Abstract
Peer review is an essential part in the publication process, ensuring that Fibers maintains high quality standards for its published papers[...] Full article
Open AccessFeature PaperArticle
The Fiber Connection Method Using a Tapered Silica Fiber Tip for Microstructured Polymer Optical Fibers
Fibers 2018, 6(1), 4; doi:10.3390/fib6010004 -
Abstract
In this work, an alternative method of coupling light into microstructured polymer fibers is presented. The solution consists in using a fiber taper fabricated with a CO2 laser. The connection is formed by inserting a tapered silica tip into the holes of
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In this work, an alternative method of coupling light into microstructured polymer fibers is presented. The solution consists in using a fiber taper fabricated with a CO2 laser. The connection is formed by inserting a tapered silica tip into the holes of a microstructured polymer fiber. This alternative method is duly characterized and the feasibility of such fiber connection to enable the polymer fiber as a displacement sensor is also demonstrated. Full article
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Open AccessFeature PaperArticle
Effect of Filler Orientation on the Electrical Conductivity of Carbon Fiber/PMMA Composites
Fibers 2018, 6(1), 3; doi:10.3390/fib6010003 -
Abstract
The electrical conductivity of extruded carbon fiber (CF)/Polymethylmethacrylate (PMMA) composites with controlled CF aspect ratio and filler fractions ranging from 0 to 50 vol. % has been investigated and analyzed. The composites were extruded through a capillary rheometer, utilizing either 1-mm or 3-mm
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The electrical conductivity of extruded carbon fiber (CF)/Polymethylmethacrylate (PMMA) composites with controlled CF aspect ratio and filler fractions ranging from 0 to 50 vol. % has been investigated and analyzed. The composites were extruded through a capillary rheometer, utilizing either 1-mm or 3-mm diameter extrusion dies, resulting in cylindrical composite filaments of two different diameters. Since the average CF orientation becomes more aligned with the extrusion flow when the diameter of the extrusion dies decreases, the relationship between conductivity and average fiber orientation could therefore be examined. The room temperature conductivities of the extruded filaments as a function of CF fractions were fitted to the McLachlan general effective medium (GEM) equation and the percolation thresholds were determined to 20.0 ± 2.5 vol. % and 32.0 ± 5.9 vol. % for the 3-mm (with CFs oriented less) and 1-mm (with CFs oriented more) filaments, respectively. It turned out that the oriented CFs in the composite shift the percolation threshold to a higher value, however, the conductivity above the percolation threshold is higher for composites with oriented CFs. A novel approach based on the Balberg excluded volume theory was proposed to explain this counterintuitive phenomenon. Full article
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Open AccessFeature PaperArticle
Flexural Behavior of Hybrid PVA Fiber and AR-Glass Textile Reinforced Geopolymer Composites
Fibers 2018, 6(1), 2; doi:10.3390/fib6010002 -
Abstract
Textile reinforced mortar or concrete, a thin cementitious composite reinforced by non-corrosive polymer textile fabric, was developed and has been researched for its role on repair and strengthening of reinforced concrete (RC) structures. Due to embedment of polymeric textile fabric inside the cementitious
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Textile reinforced mortar or concrete, a thin cementitious composite reinforced by non-corrosive polymer textile fabric, was developed and has been researched for its role on repair and strengthening of reinforced concrete (RC) structures. Due to embedment of polymeric textile fabric inside the cementitious matrix, many researchers argued the superiority of this technology than the externally bonded fiber reinforced polymer (FRP) sheet in RC in terms of prevention of debonding of FRP and durability in fire. However, due to use of cement rich matrix the existing development of textile reinforced concrete (TRC) need to be more environmental friendly by replacing cement based binder with geopolymeric binder. This paper presents a first study on the flexural behavior of alkali resistant glass fiber textile reinforced geopolymer (TRG). In this study, two types of geopolymer binder is considered. One is fly ash based heat cured geopolymer and the other is fly ash/slag blended ambient air cured geopolymer binder. Both geopolymer types are considered in the TRG and the results are benchmarked with the current cement based TRC. The effect of short polyvinyl alcohol (PVA) fiber as hybrid reinforced with alkali-resistant (AR) glass fiber textile on the flexural behavior of above TRC and TRGs is also studied. Results show deflection hardening behavior of both TRGs with higher flexural strength in heat cured TRG and higher deflection capacity at peak load in ambient air cured TRG. The increase in PVA fiber volume fraction from 1% to 1.5% did not show any improvement in flexural strength of both TRGs although TRC showed good improvement. In the case of deflection at peak load, an opposite phenomenon is observed where the deflection at peak load in both TRGs is increased due to increase in PVA fiber volume fractions. Full article
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Open AccessFeature PaperEditorial
FRP for Infrastructure Applications: Research Advances
Fibers 2018, 6(1), 1; doi:10.3390/fib6010001 -
Open AccessFeature PaperCommunication
Composite Oxide Fibres Grown by Internal Crystallisation Method
Fibers 2017, 5(4), 48; doi:10.3390/fib5040048 -
Abstract
The internal crystallisation method (ICM) allows producing bundles containing hundreds and thousands of the fibres of a limited length. It is shown in the present paper that ICM can be used to produce fibres composed of a sapphire matrix and inclusions of calcium
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The internal crystallisation method (ICM) allows producing bundles containing hundreds and thousands of the fibres of a limited length. It is shown in the present paper that ICM can be used to produce fibres composed of a sapphire matrix and inclusions of calcium hexaaluminate. The fabrication of such composite fibres is described in the present paper. An effect of the calcium hexaaluminate inclusions in sapphire fibres is evaluated by testing model composites with brittle molybdenum matrices. The critical stress intensity factors of composite-fibre/molybdenum-matrix specimens are higher than those of specimens reinforced with sapphire fibres. The model specimens reveal non-linear stress/strain behaviour. The results of this work show the effectiveness of composite fibres as a reinforcement for brittle matrices. Full article
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Open AccessFeature PaperArticle
Influence of Cutting Temperature on the Tensile Strength of a Carbon Fiber-Reinforced Polymer
Fibers 2017, 5(4), 46; doi:10.3390/fib5040046 -
Abstract
Carbon fiber-reinforced plastics (CFRP) have seen a significant increase in use over the years thanks to their specific properties. Despite continuous improvements in the production methods of laminated parts, a trimming operation is still necessary to achieve the functional dimensions required by engineering
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Carbon fiber-reinforced plastics (CFRP) have seen a significant increase in use over the years thanks to their specific properties. Despite continuous improvements in the production methods of laminated parts, a trimming operation is still necessary to achieve the functional dimensions required by engineering specifications. Laminates made of carbon fibers are very abrasive and cause rapid tool wear, and require high cutting temperatures. This creates damage to the epoxy matrix, whose glass-transition temperature is often recognized to be about 180 °C. This study aims to highlight the influence of the cutting temperature generated by tool wear on the surface finish and mechanical properties obtained from tensile tests. Trimming operations were performed on a quasi-isotropic 24-ply carbon/epoxy laminate, of 3.6 mm thickness, with a 6 flutes diamond-coated (CVD) cutter. The test specimens of 6 mm and 12 mm wide were obtained by trimming. The reduced width of the coupons allowed amplification of the effect of defects on the measured properties by increasing the proportion of coupon cross-section occupied by the defects. A new tool and a tool in an advanced state of wear were used to generate different cutting temperatures. Results showed a cutting temperature of 300 °C for the new tool and 475 °C for the worn tool. The analysis revealed that the specimens machined with the new tool have no thermal damage and the cut is clean. The plies oriented at −45° presented the worst surface finish according to the failure mode of the fiber. For the worn tool, the surface was degraded and the matrix was carbonized. After cutting, observations showed a degraded resin spread on the machined surface, which reduced the surface roughness and hid the cutting defects. In support of these observations, the tensile tests showed no variation of the mechanical properties for the 12 mm-wide specimens, but did show a 10% loss in mechanical properties for the 6 mm-wide specimens. These results suggest that the thermal defects caused by tool wear affect tensile properties, but only from a certain coupon width below which the machining defects increase their influence on the properties. Full article
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Open AccessArticle
Enhancement Experiment on Cementitious Activity of Copper-Mine Tailings in a Geopolymer System
Fibers 2017, 5(4), 47; doi:10.3390/fib5040047 -
Abstract
Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious
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Copper-mine tailings are the residual products after the extraction of precious copper metal from copper ores, and their storage can create numerous environmental problems. Many researchers have used copper-mine tailings for the preparation of geopolymers. This paper studies the enhancement of the cementitious activity of copper-mine tailings in geopolymer systems. First, copper-mine tailings are activated through mechanical grinding activation. Then, the mechanically activated copper-mine tailings are further processed through thermal activation and alkaline-roasting activation. The cementitious activity index of copper-mine tailings is characterized through the degree of leaching concentration of Si and Al. It was observed that the Si and Al leaching concentration of mechanically activated tailings was increased by 26.03% and 93.33%, respectively. The concentration of Si and Al was increased by 54.19% and 119.92%, respectively. For alkaline-roasting activation, roasting time, temperature and the mass ratio of copper-mine tailings to NaOH (C/N ratio) were evaluated through orthogonal tests, and the best condition for activation was 120 min at 600 °C with a C/N ratio of 5:1. In this study, scanning electron microscopy (SEM), X-ray diffraction (XRD) and infra-red (IR) analysis show that mechanical, thermal and alkaline-roasting activation could be used to improve the cementitious activity index of copper-mine tailings. Full article
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Open AccessArticle
Extruded Monofilament and Multifilament Thermoplastic Stitching Yarns
Fibers 2017, 5(4), 45; doi:10.3390/fib5040045 -
Abstract
Carbon fibre reinforced polymer composites offer significant improvement in overall material strength to weight, when compared with metals traditionally used in engineering. As a result, they are replacing metals where overall weight is a significant consideration, such as in the aerospace and automotive
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Carbon fibre reinforced polymer composites offer significant improvement in overall material strength to weight, when compared with metals traditionally used in engineering. As a result, they are replacing metals where overall weight is a significant consideration, such as in the aerospace and automotive industries. However, due to their laminate structure, delamination is a prime concern. Through-thickness stitching has been shown to be a relatively simple method of improving resistance to delamination. In this paper, monofilament and multifilament fibres of a similar overall diameter were characterised and their properties compared for their suitability as stitching yarns. Dissimilar to other published works which rely on commercially available materials, such as polyparaphenylene terephthalamide, criteria were produced on the required properties and two potentially promising polymers were selected for extrusion. It was found that although the multifilament fibres had a greater ultimate tensile strength, they began to yield at a lower force than their monofilament equivalent. Full article
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Open AccessArticle
Hollow-Core FRP–Concrete–Steel Bridge Columns under Torsional Loading
Fibers 2017, 5(4), 44; doi:10.3390/fib5040044 -
Abstract
This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS) columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP) tube and an inner steel tube, with a concrete shell sandwiched between the two
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This paper presents the behavior of hollow-core fiber-reinforced polymer–concrete–steel (HC-FCS) columns under cyclic torsional loading combined with constant axial load. The HC-FCS consists of an outer fiber-reinforced polymer (FRP) tube and an inner steel tube, with a concrete shell sandwiched between the two tubes. The FRP tube was stopped at the surface of the footing, and provided confinement to the concrete shell from the outer direction. The steel tube was embedded into the footing to a length of 1.8 times the diameter of the steel tube. The longitudinal and transversal reinforcements of the column were provided by the steel tube only. A large-scale HC-FCS column with a diameter of 24 in. (610 mm) and applied load height of 96 in. (2438 mm) with an aspect ratio of four was investigated during this study. The study revealed that the torsional behavior of the HC-FCS column mainly depended on the stiffness of the steel tube and the interactions among the column components (concrete shell, steel tube, and FRP tube). A brief comparison of torsional behavior was made between the conventional reinforced concrete columns and the HC-FCS column. The comparison illustrated that both column types showed high initial stiffness under torsional loading. However, the HC-FCS column maintained the torsion strength until a high twist angle, while the conventional reinforced concrete column did not. Full article
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Open AccessArticle
Strong Light Localization and a Peculiar Feature of Light Leakage in the Negative Curvature Hollow Core Fibers
Fibers 2017, 5(4), 43; doi:10.3390/fib5040043 -
Abstract
In this paper we would like to continue a discussion started in our previous work and devoted to the mechanism of light localization in hollow core microstructured fibers with a noncircular core-cladding boundary. It has been shown in many works that, for waveguide
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In this paper we would like to continue a discussion started in our previous work and devoted to the mechanism of light localization in hollow core microstructured fibers with a noncircular core-cladding boundary. It has been shown in many works that, for waveguide microstructures with different types of core-cladding boundary shape, the positions of the transmission bands’ edges can be predicted by applying the well-known anti–resonant reflecting optical waveguide (ARROW) model. At the same time, the ARROW model cannot explain the strong light localization and guiding at high material loss inside the transmission bands which are observed in negative curvature hollow core fibers, for example. In this paper we want to clarify our previous findings and consider the light localization process from another point of view, namely, by comparing the light leakage process in waveguide microstructures with different shapes of the core-cladding boundary. The results are discussed based on the ARROW model and a new approach associated with the consideration of spatial dispersion occurring under the interaction of the air core mode with the core-cladding boundary. Full article
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Open AccessArticle
Investigation of Mechanical Properties and Morphology of Multi-Walled Carbon Nanotubes Reinforced Cellulose Acetate Fibers
Fibers 2017, 5(4), 42; doi:10.3390/fib5040042 -
Abstract
Cellulose acetate (CA) fibers were reinforced with multi-walled carbon nanotubes (MWCNTs) at 0.5%, 1.0%, 1.5% and 2.0%. Yield strength, ultimate tensile strength, fracture strain and toughness of the nanocomposite fiber increased up to 1.5 wt. % of the carbon nanotube (CNT) loading, however,
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Cellulose acetate (CA) fibers were reinforced with multi-walled carbon nanotubes (MWCNTs) at 0.5%, 1.0%, 1.5% and 2.0%. Yield strength, ultimate tensile strength, fracture strain and toughness of the nanocomposite fiber increased up to 1.5 wt. % of the carbon nanotube (CNT) loading, however, further inclusion (2.0%) of MWCNTs in CA decreased the mechanical properties. Experimental properties were also compared with analytical predictions using a Shear lag model for strength and the rule of mixture for modulus. A solution spinning process, coupled with sonication, mixing, and extrusion, was used to process the CNT-reinforced composite fiber. Scanning electron microscopy (SEM) images of the cross sections of neat CA and CA-MWCNT fibers showed the formation of voids and irregular features. The enhanced interconnected fibrillation in the CNT-reinforced CA samples resulted in improved mechanical properties, which were observed by tensile testing. Fourier transform infrared spectroscopy (FTIR) spectra showed the area under the curve for C–H bonding after the inclusion of CNT. There was no significant shift of wavenumber for the inclusion of MWCNT in the CA matrix, which indicates that the sonication process of the CNT-loaded solution did not degrade the CA bonding structure. Full article
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Open AccessCommunication
Tolnaftate-Loaded PolyacrylateElectrospun Nanofibers for an Impressive Regimen on Dermatophytosis
Fibers 2017, 5(4), 41; doi:10.3390/fib5040041 -
Abstract
Dermatophytosis, topical fungal infection is the most common cause of skin bug in the world, generally underestimated and ignored. It is commonly caused by immensely mortifying and keratinophilic fungal eukaryotes which invade keratinized tissues and generate different tinea diseases in Mediterranean countries. We
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Dermatophytosis, topical fungal infection is the most common cause of skin bug in the world, generally underestimated and ignored. It is commonly caused by immensely mortifying and keratinophilic fungal eukaryotes which invade keratinized tissues and generate different tinea diseases in Mediterranean countries. We herein fabricated nanofibers/scaffolds embedded with thiocarbamate derivative topical antifungal tolnaftatefor the first time to target the complete elimination of dermatophyte at the site of infection. In this regard, variable combinations of biocompatible Eudragit grades (ERL100 and ERS100) were selected to provide better adhesion on the site of dermatophytosis, ample absorption of exudates during treatment, and customized controlled drug release. Surface topography analysis indicated that the fabricated nanofibers were regular and defect-free, comprising distinct pockets with nanoscaled diameters. Characterization and compatibility studies of tolnaftate, polymers, and their nanofibers were performed through ATR-FTIR, TGA, and PXRD. Remarkable hydrophilicity and an excellent swelling index were obtained from a 3:1 ratio of ERL100/ERS100 electrospun D3 nanofibers, which is an essential benchmark for the fabrication of nanofibrous scaffolds for alleviating dermatophytosis. In vitro drug release investigation revealed that a nonwoven nanomesh of nanofibers could control the rate of drug release for 8 h. A microdilution assay exhibited inhibition of more than 95% viable cells of Trichophyton rubrum for 96 h. However, Microsporum species rigidly restricted the effect of bioactive antifungal nanofibers and hence showed resistance. In vivo activity on Trichophyton rubrum infected Swiss albino mice revealed complete inhibition of fungal pathogens on successive applications of D3 nanofibers for 7 days. This investigation suggests potential uses of tolnaftate loaded polyacrylate nanofibers as dressing materials/scaffolds for effective management of dermatophytosis. Full article
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Open AccessReview
Polymer/Carbon Nanotubes (CNT) Nanocomposites Processing Using Additive Manufacturing (Three-Dimensional Printing) Technique: An Overview
Fibers 2017, 5(4), 40; doi:10.3390/fib5040040 -
Abstract
Additive manufacturing (AM)/3D printing (3DP) is a revolutionary technology which has been around for more than two decades, although the potential of this technique was not fully explored until recently. Because of the expansion of this technology in recent years, new materials and
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Additive manufacturing (AM)/3D printing (3DP) is a revolutionary technology which has been around for more than two decades, although the potential of this technique was not fully explored until recently. Because of the expansion of this technology in recent years, new materials and additives are being searched for to meet the growing demand. 3DP allows accurate fabrication of complicated models, however, structural anisotropy caused by the 3DP approaches could limit robust application. A possible solution to the inferior properties of the 3DP based materials compared to that of conventionally manufactured counterparts could be the incorporation of nanoparticles, such as carbon nanotubes (CNT) which have demonstrated remarkable mechanical, electrical, and thermal properties. In this article we review some of the research, products, and challenges involved in 3DP technology. The importance of CNT dispersion in the matrix polymer is highlighted and the future outlook for the 3D printed polymer/CNT nanocomposites is presented. Full article
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