Chemical Composition Of Fibers Research Articles

Influence of Different Retting on Hemp Stem and Fiber Characteristics Under the East of France Climate Conditions

ABSTRACT Historically, for fiber extraction, the stems were immersed in water. However, this method proved far too polluting, leading to its substitution by the dew-retting method in the field. Different retting processes and durations can produce significant differences in hemp stems and fiber characteristics. Both dew- and water-retting methods were carried out on the Santhica 27 cultivar in Eastern France in 2020. An analysis of the stem chemical composition and characteristics has been performed to observe the stem degradation during retting for both methods. Secondly, the analyses of the fiber chemical composition, color, morphological and mechanical properties have been performed to evaluate the impact of retting on the fiber quality. The effect of the retting on the stem and the fiber is observed after 1 week for water-retting and after 4 weeks for dew-retting. For dew-retting, the percentages of fine fiber and cellulose in the fiber bundle increase after 1 week, while the stem chemical composition decreases. Unlike in the dew-retting, the percentage of fine fiber and cellulose in the fiber bundle increases after 4 weeks, while the potassium percentage in the stem, fiber brightness, and fiber tenacity and strain decrease. Finally, after 8 weeks, the fiber properties were found to be similar for both methods.

The Influence of the Chemical Composition of Flax and Hemp Fibers on the Value of Surface Free Energy.

The article presents the exploration of flax and hemp fibers' surface free energy depending on the chemical composition of the fiber, which is closely related to the plant variety and the method of extracting the fiber. For this purpose, tests of the surface free energy (SFE), evaluation of the percentage content of individual fiber components and FTIR analyses were conducted. The research was carried out with the use of fibrous materials prepared in three different ways: 1. To analyze the effect of subsequent stages of flax fibers refining process on chemical composition and SFE, 2. to explore the dependence of fiber SFE on hemp variety, the water-retting hemp fibers were used, 3. To evaluate the influence of the retting method of hemp fibers BIAŁOBRZESKIE variety on SFE, the fibers extracted with the use of dew and water retting were used as the research material. The study confirmed that the content of individual components in the fiber influenced its sorption capacity and therefore determined its hydrophilic properties. The values of Pearson's linear correlation coefficients determined in the statistical analysis proved that the surface free energy was strongly correlated with the content of individual components in the fibers. Understanding the wettability characteristics of bast fibers will allow modeling the properties of products made of these fibers and designing surface modification processes in order to obtain specific functionality of textile products, depending on their intended utilization.

Survey of second harmonic generation in commercial germanium-doped fibers

Seeded optical poling is a promising and simple method to write an effective quadratic coefficient in silica optical fibers doped with germanium. We considered commercial solid core fibers since these fibers could allow for a wide adoption of optical poling. For each fiber, we optimized the poling process and analyzed the second harmonic conversion efficiencies in relation with the fiber chemical composition as obtained resorting to energy-dispersive X-ray spectroscopy. Our comprehensive investigation shows that segments of fibers spanning 20 cm, featuring a germanium content of around 6%, can effectively convert 30 mW of 1064 nm light with efficiencies hovering around 1%.

Optimization of the novel jute retting process to enhance the fiber quality for textile applications

This study introduces an innovative chemical retting approach, systematically optimized via Grey relational analysis, to achieve jute fibers that exhibit desirable characteristics of softness, high tensile strength, and suitability for spinning, with a particular focus on their application in the apparel industry. In this study, the effect of alkali treatment (alkali concentration, temperature and duration of retting) on jute fiber's chemical composition and mechanical characteristics was investigated. Jute fibers were treated at three concentrations (5 %, 10 %, 15 %) of alkali, at three different temperature (30 °C, 60 °C, & 90 °C) and for three different retting duration (12 h, 24 h, & 36 h). The surface morphology and crystallinity of fibers were analyzed using optical microscopy, X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy. The fiber linear density and mechanical characteristics were also tested. The multi-response optimization of all the factors and the responses was investigated using the Grey relational analysis. The results showed that the fiber surface morphology and crystallinity increase with an increase in alkali concentration, retting time, and temperature. Chemical retting treatment also improved the fiber linear density and tensile strength. The finest fibers which were obtained in this research had a linear density of 2.18 Tex with a tenacity of 53.02 cN/tex and elongation of 4.54 %. The spinnable jute fibers were achieved after this treatment with excellent characteristics.

Exploring the Potential of Fique Fiber as a Natural Composite Material: A Comprehensive Characterization Study.

Many studies available in the literature focus mainly on the mechanical characterization of fiber, leaving out other physicochemical and thermogravimetric analyses that allow for establishing its potential as an engineering material. This study characterizes fique fiber for its potential use as an engineering material. The fiber's chemical composition and physical, thermal, mechanical, and textile properties were analyzed. The fiber has a high holocellulose content and low lignin and pectin content, indicating its potential as a natural composite material for various applications. Infrared spectrum analysis revealed characteristic bands associated with multiple functional groups. The fiber had monofilaments with diameters around 10 μm and 200 μm, as determined by AFM and SEM images, respectively. Mechanical testing showed the fiber could resist a maximum stress of 355.07 MPa, with an average maximum strain at which breakage occurs of 8.7%. The textile characterization revealed a linear density range of 16.34 to 38.83 tex, with an average value of 25.54 tex and a regain of 13.67%. Thermal analysis showed that the fiber's weight decreased by around 5% due to moisture removal in the range of 40 °C to 100 °C, followed by weight loss due to thermal degradation of hemicellulose and glycosidic linkages of cellulose ranging from 250 to 320 °C. These characteristics suggest that fique fiber can be used in industries such as packaging, construction, composites, and automotive, among others.

Effect of Grafting Nano-TiO2 on Sansevieria cylindrica Fiber Properties

Natural fibers, which are abundant, environmentally friendly, and biodegradable, are used as a replacement for synthetic fibers. The composite strength can be increased by treating the surfaces of natural fibers with suitable chemicals, which can also improve the interface interaction between fiber and matrix. Application of a coupling agent in chemical treatment is utilized to reinforce the bonding between fiber and matrix. The objective of the study is to determine the influence of silane concentration on the Sansevieria cylindrica fiber properties. The methods included fibers treatment using ethanol and coupling agent as dissolving and TiO2 with concentrations of 0 percent, 0.25 percent, 0.5 percent, 0.75 percent, and 1 percent. The mechanical strength testing was conducted through a single fiber test. Fiber morphology was observed using an electron microscope. FTIR analyzes the change in fiber chemical composition caused by TiO2 addition. As a result, the morphology of S. cylindrica fibers became rougher and showed a rougher surface after a silane concentration of 1 percent, but with the proper concentration, some fiber surfaces provided a good interface. Ti-O bonds are formed at a wavelength of 475 cm-1. The shift in a peak at 400–500 cm-1 indicates Ti-O-Ti group stretching vibrations believed to have originated from TiO2 particles. The mechanical strength increases as the concentration of TiO2 increases, with the highest fiber strength of 284.66 MPa observed at a TiO2 concentration of 1 percent. This represents a 26 percent higher tensile strength compared to the control specimen.

Investigating and Predicting the Effects of Fiber Chemical Composition and Treatment on the Mechanical Properties of Natural Fiber Composites by Response Surface Method

Investigating and Predicting the Effects of Fiber Chemical Composition and Treatment on the Mechanical Properties of Natural Fiber Composites by Response Surface Method

Extraction and Characterization of Novel Natural Fiber from Cryptostegia Grandiflora as a Potential Reinforcement in Biocomposites

ABSTRACT The significant environmental pollution caused by synthetic fibers drew researchers’ attention to the development of eco-friendly reinforcement for composite products. This study seeks to identify an alternative novel natural fiber from the Cryptostegia Grandiflora (CG) plant as a reinforcement material for bio composites. The fiber chemical compositions, X-ray diffraction, Fourier Transform Infrared spectroscopy (FTIR), Scanning Electron Microscopy, Thermo Gravimetric Analysis, and tensile test for single fiber are all examined. The fiber had a cellulose content of 79.20% and a crystallinity index of 62%. Thermo Gravimetric Analysis confirms that Cryptostegia Grandiflora fiber (CGF) can withstand temperatures as high as 230°C. It has a density of 1.02 g/cc and a tensile strength of 791 MPa on average. This novel Cryptostegia Grandiflora fiber will undoubtedly be used as reinforcement material in bio-composite materials.

Effect of a Diet Based on Biotransformed Sorghum on Rabbit Intestinal Morphology and Fecal Fiber Composition

Some of the goals of meat production systems are to improve feed efficiency, reduce costs, provide proper nutrition and avoid metabolic disorders. Hence, the aim of this work was to compare a rabbit diet based on untreated sorghum (T1) with a second one that included the cereal biotransformed by the co-cultivation of two basidiomycetes (T2). Their effects on the cereal, diets, and fecal structural fiber composition, as well as on rabbit intestinal morphology, were evaluated. A completely randomized design was applied, employing 24 New Zealand rabbits (21 days old). The fiber chemical composition results indicated that the sorghum treated with the co-culture had lower amounts of neutral detergent fiber (NDF), acid detergent fiber (ADF), lignin, hemicellulose and cellulose, as did rabbits fed the T2 diet. Decreases in the NDF, ADF and cellulose contents were detected in T2-nourished rabbit excrements at day 21 (p ≤ 0.05), while lignin percentages diminished at days 35 and 49 (p ≤ 0.05). These rabbits also showed longer jejunal and cecal villi (p ≤ 0.05). The results obtained suggest a positive effect on the bioavailability of structural fibers after sorghum fungal co-fermentation, as their content decreased in rabbit fecal matter without damaging the intestinal morphology.

Surface modification of polyimide fibers for high-performance composite by using oxygen plasma and silane coupling agent treatment

In this study, the oxygen plasma and silane coupling agent composite treatment was used to modify the polyimide fiber surface to improve the interfacial properties. The oxygen plasma treatment introduced active groups on the fiber surface, which facilitated the grafting of silane coupling agent to the fiber surface. The surface morphology and chemical composition of fibers were characterized by scanning electron microscope and X-ray photoelectron spectroscopy. The results showed that after plasma treatment, the etching spots on the fiber surface increased with the plasma treatment time, and the surface O atom content, O/C ratio and C–O(H) bond ratio reached the highest value at 27 min plasma treatment. After the composite treatment, the surface Si atomic content reached the highest value after 27 min plasma pretreatment. Moreover, polyimide/polyamic acid unidirectional reinforced composites were prepared. In polyimide/polyamic acid composites, the interfacial shear strength of polyimide fibers first increased and then decreased with plasma treatment time, both in oxygen plasma treatment and in composite treatment, and increased by up to 36.98% and 61.68% respectively compared. In addition, the transverse tensile strength of polyimide/polyamic acid composites increased by 103.73% after composite treatment compared with the pristine specimens.

Evaluation of Original and Enzyme-Modified Fique Fibers as an Azo Dye Biosorbent Material

As natural fibers, low-cost biosorbents have proven to be an effective and clean tool to remove textile dyes from wastewater. In this research, the Reactive Black 5 removal ability of original and enzyme-modified natural fibers were assessed. A fiber extracted from a Colombian fique plant (Furcraea sp.) was employed. The effects of fique fiber protonation with different solvents and dye solution pH on RB5 removal were evaluated. The biosorbent chemical composition was modified using the commercial enzymes pectinase, ligninase, and xylanase. The point of zero charge (PZC) of the original and modified material was measured, and the dye removal capacity of the three enzyme-modified fibers was determined. Fiber protonation with 0.1 M HCl and a dye solution with pH of 2.4 increased the RB5 elimination to 49.1%. The change in the fiber chemical composition led to a reduction in the PZC from 5.5 to a 4.7–4.9 range. Pectinase-pretreated fique fibers presented the highest dye removal of 66.29%, representing a 36% increase in RB5 dye removal. Although the original fique fiber showed RB5 dye removal ability, its enzymatic modification changed the charge distribution on the fiber surface, improving the capture of dye molecules. Enzyme modification can be applied to obtain new functionalities for plant fibers as biosorbent materials.

Continuous Mechanical Extraction of Fibres from Linseed Flax Straw for Subsequent Geotextile Applications

Linseed flax is a multipurpose crop. It is cultivated for its seeds and particularly for its oil. The main contributors for this crop are Canada, France and Belgium. In general, straws of linseed flax are buried in the fields or burnt. However, these solutions are not good practices for the environment and from an economical point of view. In this study, straws of linseed flax (six batches in total) with different dew retting durations and harvesting techniques were studied to possibly use them for producing innovative geotextiles. Two different fibre extraction processes were investigated. A first process (A) involved horizontal breaker rollers and then a breaking card. A second one (B) consisted in using vertical breaker rollers, and an “all fibre” extraction device (fibre opener) followed by sieving. The chemical composition of fibres in parietal constituents appeared to be globally equivalent to the one of textile flax with a pectic content decreasing as a function of the dew retting duration. This contributed to an increase in the cellulose content. The fibre content was situated in a range from 29% to 33%, which corresponds to a good yield for linseed flax fibre. The level of purity can reach values of up to 90% for method A (without extra-sieving) and 96% for method B (with extra-sieving), and the length of the fibres (larger for method A than for method B) and their tensile properties make them suitable for structural geotextile yarn manufacturing.

Carbon fiber-reinforced PEEK in implant dentistry: A scoping review on the finite element method

Objective : The aim of the present study was to perform an integrative systematic review on the stress distribution assessed by finite element analysis on dental implants or abutments composed of carbon fiber-reinforced PEEK composites. Method: An electronic search was performed on PUBMED and ScienceDirect using a combination of the following search terms: PEEK, Polyetheretherketone, FEA, FEM, Finite element, Stress, Dental implant and Dental abutment. Results: The findings reported mechanical properties and the stress distribution through implant and abutment composed of PEEK and its fiber-reinforced composites. Unfilled PEEK revealed low values of elastic modulus and strength that negatively affected the stress distribution through the abutment and implant towards to the bone tisues. The incorporation of 30% carbon fibers increased the elastic modulus and strength of the PEEK-matrix composites although some studies reported no statistic differences in stress magnitude when compared to unfilled PEEK. However, an increase in short carbon fibers up to 60% revealed an enhancement on the stress distribution through abutment and implants towards to the bone tissues. PEEK veneering onto titanium core structures can also be a strategy to control the stress distribution at the implant-to-bone interface. Conclusions: The stiffness and strength of PEEK-matrix composites can be increased by the improvement of the carbon fibers’ network. Thus, the content, shape, dimensions, and chemical composition of fibers are key factors to improve the stress distribution through abutment and implants composed of PEEK-matrix composites.

Characterization of lignocellulosic fibres extracted from agricultural biomass: arecanut leaf sheath

In the present study, long staple lignocellulosic fibres were extracted from the arecanut leaf sheath, an agricultural biomass. The arecanut leaf sheath (ANLS) fibres have been extracted by alkali treatment. The important fibre properties such as fibre length, diameter, density, bundle strength, single fibre strength, moisture content and chemical composition are evaluated and compared with commonly available cellulosic fibres. Chemical nature and structure of ANLS fibre are determined using X-ray diffraction and FTIR techniques. The morphological structure and cross-section of the fibres were studied by scanning electron micrographs. The thermal properties of the fibre are characterized by thermo-gravimetric analysis. The potential of ANLS fibre to be used as a textile and reinforcing material is discussed in detail.

A Method for the Assessment of Textile Pilling Tendency Using Optical Coherence Tomography.

Pilling is caused by friction pulling and fuzzing the fibers of a material. Pilling is normally evaluated by visually counting the pills on a flat fabric surface. Here, we propose an objective method of pilling assessment, based on the textural characteristics of the fabric shown in optical coherence tomography (OCT) images. The pilling layer is first identified above the fabric surface. The percentage of protruding fiber pixels and Haralick’s textural features are then used as pilling descriptors. Principal component analysis (PCA) is employed to select strongly correlated features and then reduce the feature space dimensionality. The first principal component is used to quantify the intensity of fabric pilling. The results of experimental studies confirm that this method can determine the intensity of pilling. Unlike traditional methods of pilling assessment, it can also detect pilling in its early stages. The approach could help to prevent overestimation of the degree of pilling, thereby avoiding unnecessary procedures, such as mechanical removal of entangled fibers. However, the research covered a narrow group of fabrics and wider conclusions about the usefulness and limitations of this method can be drawn after examining fabrics of different thickness and chemical composition of fibers.

Utilization of deep eutectic solvent as a degumming protocol for Apocynum venetum bast

Deep eutectic solvent (DES) pretreatment coupled with alkaline degumming on Apocynum venetum bast was studied for developing an eco-friendly and effective degumming method. A 1:2 mixture of choline chloride and urea was used in a microwave-assisted DES pretreatment optimized to 60 min and 110 °C. The impact of the deep eutectic solvent pretreatment on the properties of produced semi-degummed and refined dry fibers were assessed by examining the fiber chemical composition, surface microstructure, cellulose crystallinity, degree of polymerization, and fiber thermal properties. The combined DES and alkaline degumming treatment effectively removed the gummy matter including hemicellulose and lignin from the A. venetum bast, providing a smooth and clean fiber surface. This combined DES and alkaline degumming treatment also shows the ability to extract amorphous cellulose, leading to an increase of fiber crystallinity and a decrease of the average cellulose molecular weight. The thermal stability of the fibers was improved significantly after the degumming treatment. The refined dry fibers produced by this combined DES-alkaline treatment exhibited comparable chemical and physical properties (e.g. residual gum content, fiber length, fiber fineness, breaking tenacity) compared with traditionally alkali degumming method. These results revealed that DES is a practical and feasible pretreatment protocol for A. venetum bast degumming.

MICROBIAL DEGRADATION OF ANCIENT TEXTILES HOUSED IN THE EGYPTIAN TEXTILE MUSEUM AND METHODS OF ITS CONTROL

All ancient textile materials have a simple chemical composition, mainly cellulose and protein. This organic component increases the susceptibility of textiles to soaking up and retaining wet from the unfavorable conditions of high humidity and temperature, causing microbial deterioration. Microbial deterioration of archaeological textile was studied as a state from the Egyptian Textile Museum; isolation, purification, and identification of the causative microorganisms were occurring, where the most common microorganisms isolated from archaeological textiles were molds. Bio-logical activities of the isolated microorganisms were studied and disinfection of archaeological textile was applied using different methods. The characteristics of test methods and disinfection include their application to historical objects. Historic textiles were analyzed from different perspectives: Stereo microscopes, SEM with EDX, FTIR, as well as fiber structure and fiber chemical composition. The results illustrated that the best concentrations of a specific mic-robicide for the bio-treatment of infected textile materials is Di-chloroxylenol at (1000 ppm). It is sufficient to inhibit all isolated microorganisms, followed by p-chloro-m-cresol at (1000 ppm) concentration, and Sodium azide at (2000 ppm) concentration.

Overview of radiation induced point defects in silica-based optical fibers

Abstract Silica-based optical fibers, fiber-based devices and optical fiber sensors are today integrated in a variety of harsh environments associated with radiation constraints. Under irradiation, the macroscopic properties of the optical fibers are modified through three main basic mechanisms: the radiation induced attenuation, the radiation induced emission and the radiation induced refractive index change. Depending on the fiber profile of use, these phenomena differently contribute to the degradation of the fiber performances and then have to be either mitigated for radiation tolerant systems or exploited to design radiation detectors and dosimeters. Considering the strong impact of radiation on key applications such as data transfer or sensing in space, fusion and fission-related facilities or high energy physics facilities, since 1970′s numerous experimental and theoretical studies have been conducted to identify the microscopic origins of these changes. The observed degradation can be explained through the generation by ionization or displacement damages of point defects in the differently doped amorphous glass (SiO2) of the fiber's core and cladding layers. Indeed, the fiber chemical composition (dopants/concentrations) and elaboration processes play an important role. Consequently, identifying the nature, the properties and the generation and bleaching mechanisms of these point defects is mandatory in order to imagine ways to control the fiber radiation behaviors. In this review paper, the responses of the main classes of silica-based optical fibers are presented: radiation tolerant pure-silica core or fluorine doped optical fibers, germanosilicate optical fibers and radiation sensitive phosphosilicate and aluminosilicate optical fibers. Our current knowledge about the nature and optical properties of the point defects related to silica and these main dopants is presented. The efficiency of the known defects to reproduce the transient and steady state radiation induced attenuation between 300 nm and 2 µm wavelength range is discussed. The main parameters, related to the fibers themselves or extrinsic - harsh environments, profile of use - affecting the concentration, growth and decay kinetics of those defects are also reviewed. Finally, the main remaining challenges are discussed, including the increasing needs for accurate and multi-physics modeling tools.

Chemical resistance of carbon, basalt, and glass fibers used in FRP reinforcing bars

One of the most important fields of research dealing with the use of carbon-, basalt-, and glass-fiber composites in the civil construction industry is their behavior under various chemical exposure conditions. Fiber-reinforced-polymer composites used as internal and external reinforcement in various structural applications can be subjected to widely differing pH situations. This study investigated the chemical durability of various carbon, basalt and glass fibers. The fibers were immersed in four types of solutions with acid, saline, alkaline, and deionized-water conditioning schemes. The fiber mass loss and surface damage along with changes due to chemical reactions were observed through weight-loss measurements and scanning electron microscopy. A criterion was developed to characterize the performance of fibers as very good, good, fair, and poor. This methodology can also be used by manufacturers as a quick quality-control tool for evaluating the chemical resistance of different fibers prior to large-volume production. The results reveal that the carbon fibers exhibited higher chemical resistance than the basalt and glass fibers based on weight loss and evidence of chemical reactions. Moreover, the determination of the fiber chemical composition before and after conditioning in acid and alkaline solutions clearly shows that the E-glass fibers, which are known to contain boron, were very sensitive to chemical corrosion. The ECR-glass fibers showed excellent chemical durability, even better than the basalt fibers.

Important Considerations in Manufacturing of Natural Fiber Composites: A Review

The paper overviews the essential considerations in the manufacturing process of natural fiber composites which influence the performance of biocomposites. The evaluation of thermal properties of composites matrix and natural fiber chemical composition and physical properties appears to be necessary as the initial screening factors before the manufacturing process of biocomposites. On the other hand, considerations on fiber composition, type of manufacturing process and parameter used are seen as other crucial significant factors that need to be focused during the manufacturing of biocomposites. Moreover, the treatment used in the manufacturing process such as alkali treatment and coupling agent utilization should also be highlighted as additional important measures for better performance of biocomposites. In this review, all significant factors that influence the performance outcome of natural fiber composites are highlighted to provide the base-line source of literature for the manufacturing and production of composites sample. It is expected that the findings from the present study could further enhance the performance of natural fiber composites and able to become the preferred alternative or replacement for petroleum-based polymer in various industrial and commercial applications in the future.