Use Of Fibers Research Articles

Modeling uniform random distributions of nonwoven fibers for computational analysis of composite materials

This paper considers the random placement of fibers on a square to achieve a desired homogeneous uniform distribution, as required in production of digital twin geometry for computational analysis of composite materials. Six methods of random fiber placement were demonstrated. Bertrand’s paradox for placement of random chords on a circle provided the framework to compare, contrast, and evaluate similar methods for placing fibers on a square. Simulations were performed with chord placement on a circle and fiber placement on a square. Results were evaluated using uniformity of areal line density and fragment size distributions. A combined approach for placement of fibers on a square was developed that achieved homogeneous uniform distribution. A proposed exact solution to achieve the desired uniform distribution was demonstrated. A statistical analysis and data regression demonstrated the homogeneous results achieved by the combined approach and the proposed exact solution. The objectives of this paper were achieved through demonstration of both a combined approach and a proposed exact solution to random fiber placement on a square to achieve homogeneous, uniform distribution of fibers for use in digital twin geometry for computational testing of composite materials.

Effect of Various Chemical Treatments on Physical, Mechanical, Thermal and Morphological Properties of Calotropis Gigantea Bast Fiber

ABSTRACT This paper highlights the chemical surface modifications of Calotropis gigantea (CG) bast fiber for attaining suitable properties as reinforcements in polymeric composites. The effect of chemical modification on its various properties like physical, mechanical, thermal and morphological properties was also discussed in this research. For this purpose the extracted fibers were chemically treated with various chemicals such as sodium hydroxide, potassium permanganate, sodium chlorite and benzoyl chloride. After surface modifications, its density, mechanical property, thermal gravimetry analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and surface morphology were thoroughly investigated. The tensile strength and Young’s modulus of alkali treated CG fiber was found to be 210.39 MPa and 1.77 GPa respectively. The crystallinity index was improved by 25.37% as compared with untreated CG fiber. Finally, it was observed that alkali treated fiber gives better performance and enhances various properties of Calotropis gigantea stem fibers for use as novel reinforcement in composite materials.

Contribution to the Microstructural Study of a Composite Material Based on Carbon Fibers for Use in Orthopedic Prostheses

The use of a carbon fiber composite material to make external prostheses in the form of a femoral socket was the subject of this laboratory study. According to the prior bibliographical studies, this material adapts well to this type of prosthesis. The objective of this research is to study its microscopic structure, in order to verify the good wetting of the fibers by the resin, the good cohesion and molding by infusion. The morphological study of the facies of the parallelepiped-shaped specimens was carried out after cuts perpendicular to the axis of the fiber strands, parallel according to the width and thickness of the specimen. This study was carried out using a scanning electron microscope (SEM), in order to determine, thanks to the typical microstructure of the composite, the various degradations, which appear as a result of the effect of static tension. The laminate used is based on three layers of carbon taffeta fabric and an orthocrylic resin. Tensile tests have been carried out at a speed of 1mm/min with a Zwick/Roell machine with a load cell of 50 kN. This speed was chosen to allow a comparative study with glass fiber specimens, which have been used previously for the production of prostheses, before those made of carbon. The microscopic study allowed to identify the four types of degradation; Matrix fracture, which manifested itself as fault lines, in preferred directions of different sizes. This contributed to interlaminar delamination. The decohesion that contributes to delamination in a different way from that of matrix breakage is visible at different levels. Interlaminar delamination results from the combined effect of matrix breakdown and decohesion and manifests itself as uneven strata. Fiber breakage was manifested by shearing. This study allowed to observing a degradation of the material imposed by static traction. As for the material used in orthopaedics, it has retained good cohesion and meets the requirements of prostheses, despite the defects detected by the microscopic study.

Rapid quantification of cannabinoids in beef tissues and bodily fluids using direct-delivery electrospray ionization mass spectrometry

Hempseed cake is a byproduct of hempseed oil extraction and is potentially a useful source of protein and fiber for use in ruminant diets. However, data are lacking on the appearance and/or clearance of cannabinoids in tissues of animals fed hempseed cake. To this end, a rapid method for quantifying cannabinol (CBN), cannabidiol (CBD), cannabinolic acid (CBNA), cannabidiolic acid (CBDA), cannabigerolic acid (CBGA), cannabichromenic acid (CBCA), cannabidivarin (CBDV), cannabidivarinic acid (CBDVA), tetrahydrocannabinol (THC) and tetrahydrocannabinolic acid (THCA) in cattle tissues, plasma, and urine was developed using rapid screen electrospray ionization mass spectrometry (RS-ESI-MS). Regression coefficients of matrix-matched standard curves ranged from 0.9946 to >0.9999 and analyte recoveries averaged from 90.2 ± 15.5 to 108.7 ± 18.7% across all compounds. Limits of detection and quantification ranged from 0.05 to 2.79 ng · mL−1 and 0.17 to 9.30 ng · mL−1, respectively, while the inter-day relative standard deviation ranged from 5.1 to 15.1%. Rapid screening electrospray ionization mass spectrometry (RS-ESI-MS) returned no false positives for any cannabinoid in plasma, urine, and tissue (liver, skeletal muscle) samples from 6 non-dosed control animals (n = 90 samples; of which 72 samples were plasma or urine and 18 samples were tissues). Across-animal cannabinoid concentrations measured in 32 plasma samples of cattle dosed with ground hemp were quantified by RS-ESI-MS; analytical results correlated well (r 2 = 0.963) with independent LC-MS/MS analysis of the same samples.

On the history of madder (Rubia peregrina L., and Rubia tinctorum L.) in pre-modern Iran and the Caucasus

Abstract For roughly four thousand years the pulverized roots of both wild (Rubia peregrina L.) and cultivated (Rubia tinctorum L.) madder have been used in Asia, North Africa and Europe as a red dye. Madder’s original, natural habitat extended from Iran to the Mediterranean and madder roots were gathered, processed and used long before the plant was systematically cultivated. Although the red dye derived from madder was put to various uses, the dyeing of fibres for use in textiles and carpets was the primary one, and is first attested c. 2000 BC in Mesopotamian cuneiform sources. In Iran madder’s use can be traced from late Antiquity to the modern era, and may have begun as early as the 1st millennium BC. In the 19th century demand for madder in India and Russia was great, spurring large investment in madder cultivation as a cash crop, both in Iran and in the Caucasus. Documents are presented which provide detailed accounts of both madder cultivation and the processing of the roots for the production of dyestuff. The introduction of synthetic dyes in the 1870s largely eradicated the market for madder-based dye in Eurasia and had a profound impact on the carpet industry, in particular.

A membrane-protected micro-solid-phase extraction method based on molecular imprinting and its application to the determination of local anesthetics in cosmetics.

As local anesthetics that are illegally added to cosmetics are harmful to consumer health, it is necessary to establish an efficient method for detecting these substances. Herein, a molecularly imprinted polymer (bupivacaine) was prepared by bulk polymerization and packed into a hollow fiber for use as an extraction phase to fabricate a membrane-protected micro-solid-phase extraction device. The optimal values of the influencing parameters for the microextraction process were as follows: a sample solution pH of 9.0, a loading and washing time of 2 h, and an elution time of 32min. A gas chromatography-mass spectrometry method was established for the determination of local anesthetics and coupled with the microextraction method to successfully detect local anesthetics in cosmetic samples. The calibration curve for the proposed method was linear in the range of 0.4-50mg/L and showed a good correlation coefficient (r2 ). The limits of detection for local anesthetics were in the range of 0.01-0.71mg/L. The molecularly imprinted polymer exhibited good imprinting and selectivity, the micro-solid-phase extraction device was simple and inexpensive and fabrication was reproducible. The combination of molecular imprinting technology, membrane separation, and micro-solid-phase extraction methods used in this study can potentially be applied to pretreat local anesthetics in cosmetic samples.

Retraction Note: Property evaluations of coir fibres for use as reinforcement in composites

The authors have retracted this article. After publication, the authors found that they did not have permission to publish the data used in the article.

Melt-Spun, Cross-Section Modified Polycaprolactone Fibers for Use in Tendon and Ligament Tissue Engineering

Tissue Engineering is considered a promising route to address existing deficits of autografts and permanent synthetic prostheses for tendons and ligaments. However, the requirements placed on the scaffold material are manifold and include mechanical, biological and degradation-related aspects. In addition, scalable processes and FDA-approved materials should be applied to ensure the transfer into clinical practice. To accommodate these aspects, this work focuses on the high-scale fabrication of high-strength and highly oriented polycaprolactone (PCL) fibers with adjustable cross-sectional geometry and degradation kinetics applying melt spinning technology. Four different fiber cross-sections were investigated to account for potential functionalization and cell growth guidance. Mechanical properties and crystallinity were studied for a 24-week exposure to phosphate-buffered saline (PBS) at 37 °C. PCL fibers were further processed into scaffolds using multistage circular braiding with three different hierarchical structures. One structure was selected based on its morphology and scaled up in thickness to match the requirements for a human anterior cruciate ligament (ACL) replacement. Applying a broad range of draw ratios (up to DR9.25), high-strength PCL fibers with excellent tensile strength (up to 69 cN/tex) could be readily fabricated. The strength retention after 24 weeks in PBS at 37 °C was 83–93%. The following braiding procedure did not affect the scaffolds’ mechanical properties as long as the number of filaments and the braiding angle remained constant. Up-scaled PCL scaffolds resisted loads of up to 4353.88 ± 37.30 N, whilst matching the stiffness of the human ACL (111–396 N/mm). In conclusion, this work demonstrates the fabrication of highly oriented PCL fibers with excellent mechanical properties. The created fibers represent a promising building block that can be further processed into versatile textile implants for tissue engineering and regenerative medicine.

Facile One-Pot Method for All Aqueous Green Formation of Biocompatible Silk Fibroin-Poly(Ethylene Oxide) Fibers for Use in Tissue Engineering.

Silk fibroin (SF) fibers are highly regarded in tissue engineering because of their outstanding biocompatibility and tunable properties. A challenge remains in overcoming the trade-off between functioning and biocompatible fibers and the use of cytotoxic, environmentally harmful organic solvents in their processing and formation. The aim of this research was to produce biocompatible SF fibers without the use of cytotoxic solvents, via pressurized gyration (PG). Aqueous SF was blended with poly(ethylene oxide) (PEO) in ratios of 80:20 (labeled SF-PEO 80:20) and 90:10 (labeled SF-PEO 90:10) and spun into fibers using PG, assisted by a range of applied pressures and heat. Pure PEO (labeled PEO-Aq) and SF solubilized in hexafluoro-isopropanol (HFIP) (labeled SF-HFIP) and aqueous SF (labeled SF-Aq) were also prepared for comparison. The resulting fibers were characterized using SEM, TGA, and FTIR. Their in vitro cell behavior was analyzed using a Live/Dead assay and cell proliferation studies with the SaOS-2 human bone osteosarcoma cell line (ATCC, HTB-85) and human fetal osteoblast cells (hFob) (ATCC, CRL-11372) in 2D culture conditions. Fibers in the micrometer range were successfully produced using SF-PEO blends, SF-HFIP, and PEO-Aq. The fiber thickness ranged from 0.71 ± 0.17 μm for fibers produced using SF-PEO 90:10 with no applied pressure to 2.10 ± 0.78 μm for fibers produced using SF-PEO 80:10 with 0.3 MPa applied pressure. FTIR confirmed the presence of SF via amide I and amide II bands in the blend fibers because of a change in structural conformation. No difference was observed in thermogravimetric properties among varying pressures and no significant difference in fiber diameters for pressures. SaOS-2 cells and hFOb cell studies demonstrated higher cell densities and greater live cells on SF-PEO blends when compared to SF-HFIP. This research demonstrates a scalable and green method of producing SF-based constructs for use in bone-tissue engineering applications.

Comparative Behavior of Viscose-Based Supercapacitor Electrodes Activated by KOH, H2O, and CO2.

Activated carbons derived from viscose fibers were prepared using potassium hydroxide, carbon dioxide, or water vapor as activation agents. The produced activated carbon fibers were analyzed via scanning electron microscopy and energy dispersive X-ray spectroscopy, and their porosity (specific surface area, total pore volume, and pore size distribution) was calculated employing physisorption experiments. Activated carbon fibers with a specific surface area of more than 2500 m2 g−1 were obtained by each of the three methods. Afterwards, the suitability of these materials as electrodes for electrochemical double-layer capacitors (supercapacitors) was investigated using cyclic voltammetry, galvanostatic measurements, and electrochemical impedance spectroscopy. By combining CO2 and H2O activation, activated carbon fibers of high purity and excellent electrochemical performance could be obtained. A specific capacitance per electrode of up to 180 F g−1 was found. In addition, an energy density per double-layer capacitor of 42 W h kg−1 was achieved. These results demonstrate the outstanding electrochemical properties of viscose-based activated carbon fibers for use as electrode materials in energy storage devices such as supercapacitors.

Fabrication of Biohybrid Nanofibers by the Green Electrospinning Technique and Their Antibacterial Activity.

The development of bioactive polymer nanofiber sheets based on eco-friendly components is required to meet the needs of various medical applications as well as to preserve the environment. This study aimed to fabricate biohybrid nanofibers based on water-soluble polymers and aqueous extract of myrrh. The myrrh extract was incorporated into poly(vinyl alcohol)/tragacanth gum nanofiber mats (myrrh@PVA/TG) by the green electrospinning technique. Various characteristics of the prepared fibers such as morphology, fiber diameter distribution, crystallinity, and thermal stability were studied. The results confirmed that the morphology of biohybrid nanofibers was uniform without beads and tragacanth gum plays an important role in controlling the average diameter of fibers and the crystallinity. The antibacterial properties of the developed biohybrid nanofibers were investigated against common pathogens of Gram-positive and Gram-negative bacteria by the standard disc diffusion method. A significant antibacterial activity was observed toward bacterial strains after incorporation of aqueous myrrh extract into nanofibers, which increased on increasing the extract ratio. Due to their eco-friendly components and significant antibacterial activity, the prepared biohybrid nanofibers will open new avenues toward incorporating aqueous herbal extracts into degradable polymer fibers for use in many antibacterial applications.

Structure and performance changes of high-modulus and low-shrinkage poly (ethylene terephthalate) industrial fibers under different heat treatment conditions

For different heat treatments, the changes in overall performance features such as tenacity, modulus, load at 5% strain and elongation at a load of 4.0 cN/dtex of high modulus low shrinkage poly (ethylene terephthalate) industrial fibers were compared. The variations in the mechanical behavior were linked to adjustments in the microstructure, as determined by Fourier transform infrared spectroscopy, wide-angle X-ray diffraction and small-angle X-ray scattering. The results confirmed that the tenacity of the fibers is less dependent on the heat treatment conditions, whereas the modulus, load at 5% strain and elongation at a load of 4.0 cN/dtex differ significantly, which could reflect the stability of the fibers in use. The intact crystal structure and the constrained conformation adjustment of molecular chains in amorphous after heat treatment are responsible for the excellent tenacity retention of high modulus low shrinkage poly (ethylene terephthalate) fibers. With a low pre-tension and a higher heating temperature, the molecular chains in the amorphous region relax and disorient, resulting in a lower modulus and load at 5% strain. Instead, in the case of high pre-tension, heat treatment prolongation or temperature increase helps to rearrange the amorphous region into an ordered structure, which can improve the initial modulus and load at 5% strain of the fibers.

High efficiency biomimetic electrospun fibers for use in regenerative medicine and drug delivery: A review

Regenerative medicine is a very promising field for the reconstruction of diseased or defective tissues. Biocompatible materials play an important role in making the synthetic extracellular matrix (ECM) environments as three-dimensional (3D) scaffolds for tissue regeneration. These scaffolds should be able to imitate some aspects of the extracellular matrix. Therefore, electrospun-based fibers that can mimic the main elements of the natural matrix are an inspired strategy for restoring tissue response. Nanofibers are effectively helpful for various medical, tissue engineering, and drug delivery applications due to their high surface area. In this regard, to achieve greater efficiency of nanofibers, their surface is functionalized with different strategies to continuously release various factors in drug delivery and increase cellular response in tissue engineering. This paper contains a comprehensive overview of the application of biomimetic electrospun nanofibers in tissue engineering and drug delivery. The article also focuses on the production, benefits, and applications of various biomimetic fibers that can be used in tissue engineering and drug delivery. In addition, the different techniques used to modify the surface of nanofibers in tissue engineering and drug delivery are briefly discussed.

Producing Spinnable Regenerated Cellulosic Fibers from Palm Fibers for Use in the Textile Industry

The textile industry is considered a major industry worldwide, and some countries use available domestic raw materials for textile manufacturing, being one of many other economic resources. Meanwhile, the Kingdom of Saudi Arabia is at the forefront of States paying great attention to the cultivation of palm trees due to their great importance, which are an indispensable traditional food for a large portion of the population. However, huge quantities of palm’s by-products, especially palm fibers, are constantly wasted, although they can be effectively used to produce textiles of particular end uses such as ropes. This study, therefore, sought to explore the potential of extracting cellulose from palm fibers for use in the textile industry. The study has utilized the experimental approach by applying alkaline to palm fibers so as to extract inherent cellulose. It has also applied mechanical processing to turn cellulose into fibers. Fibers’ physical properties (color, diameter, length), chemical properties (ratios of cellulose, hemicellulose, and lignin), and mechanical properties (tensile strength and elongation of fibers before and after treatment) were all studied. The study has proved that the physical, chemical and mechanical properties of regenerated cellulose fibers extracted from palm fibers are similar to those of other natural fibers such as bamboo and linen, and thus can be used in the textile industry. The study also compared different types of palm trees to determine the one that contains the largest concentration of cellulose. However, it was found that sugar palm fibers contain the highest cellulose concentration of 44% and therefore, it was selected for the application of the study’s theory. The study recommends making use of palm fiber in manufacturing textiles for particular end uses such as ropes, fillings and filters, as well as applying the theory of the study to other plants that have not yet been manipulated.

Silica-Bacterial Cellulose Composite Aerogel Fibers with Excellent Mechanical Properties from Sodium Silicate Precursor.

Forming fibers for fabric insulation is difficult using aerogels, which have excellent thermal insulation performance but poor mechanical properties. A previous study proposed a novel method that could effectively improve the mechanical properties of aerogels and make them into fibers for use in fabric insulation. In this study, composite aerogel fibers (CAFs) with excellent mechanical properties and thermal insulation performance were prepared using a streamlined method. The wet bacterial cellulose (BC) matrix without freeze-drying directly was immersed in an inorganic precursor (silicate) solution, followed by initiating in situ sol-gel reaction under the action of acidic catalyst after secondary shaping. Finally, after surface modification and ambient drying of the wet composite gel, CAFs were obtained. The CAFs prepared by the simplified method still had favorable mechanical properties (tensile strength of 4.5 MPa) and excellent thermal insulation properties under extreme conditions (220 °C and −60 °C). In particular, compared with previous work, the presented CAFs preparation process is simpler and more environmentally friendly. In addition, the experimental costs were reduced. Furthermore, the obtained CAFs had high specific surface area (671.3 m²/g), excellent hydrophobicity, and low density (≤0.154 g/cm3). This streamlined method was proposed to prepare aerogel fibers with excellent performance to meet the requirements of wearable applications.

POTENTIAL OF RICE STRAW AS A NATURAL FIBER MATERIAL FOR COMMERCIAL PRODUCTS

Cellulose is a material used in producing natural fibers, which is more environmentally friendly than synthetic fibers. Rice straw waste contains much cellulose and has potential as natural fiber. However, before the natural cellulose fiber is extracted from the rice straw, it must pass through several processes, such as chemicals or nuclear radiation, especially during the pretreatment process. Furthermore, the resulting natural fibers are utilized to replace synthetic fibers for use as raw materials in manufacturing several commercial products. This review describes a process that can be applied to manufacture natural fibers from rice straw and commercial products made from natural cellulose fibers.

Extraction and characterization of natural cellulosic fiber from fragrant screw pine prop roots as potential reinforcement for polymer composites

AbstractBiodegradable natural plant fiber isolated from the prop roots of fragrant screwpine (FSP) plant has been thoroughly studied as a potential replacement for artificial fiber in light weight bio‐based composite applications. Chemical, physical, Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, differential scanning calorimetry, and thermo gravimetric studies were used to determine the appropriateness of FSP fiber for use as a novel reinforcement. FSP fibers were determined to have a density of 1.3852 g/cm3 and a diameter of 27–280 μm respectively. Good specific strength and bonding qualities are provided by a high cellulose content (73.10 wt%) and a low wax content (0.35 wt%). The tensile strength of raw FSP fiber was 915 ± 195 MPa, the young's modulus was 33 ± 12 GPa, and the average strain to failure rate was 4.59 ± 2.17%. Thermal analysis (TG and DTG) confirmed FSP fiber's thermal stability up to 235°C. The findings revealed that FSP fiber (FSPF) is an excellent alternative for constructing polymer‐based bio‐composites and other high‐value products with both technical and environmental requirements.

Using potential of filament-wound carbon/glass polymeric composites as rocket motor thermal insulation

The study aim is to develop hybrid filament-wound polymeric composites based on flame retardant polyester resin (UPe) and multi-layer structured glass or combined carbon and glass fibers for use as ablative thermal insulation of rocket motor by wet filament winding technique. The composites have a multi-layered structure consisting of two layers of carbon (CF) or glass woven fabric (GF) and one layer of carbon or glass direct roving (CR or GR, respectively), repeated in three cycles. Structural analysis, performed using FTIR spectroscopy and dynamical-mechanical analysis, confirm highly polymerized network. Lower values of the tanδ peak height indicate improved interfacial adhesion between carbon/glass fibers and UPe. The improvements of thermal insulation index of 37% and erosion rate of 38.6% at 180°C are achieved for combined carbon/glass fiber–based composite compared to the neat UPe. Tensile and interlaminar shear properties are investigated according to the fiber orientation and the highest values of tensile and interlaminar shear strengths are obtained for composites with longitudinal orientation, 417.48 MPa and 22.30 MPa, respectively. Compared to the neat UPe, which degrades after 50 s at 3000°C, the composites are stable up to 192 s.

Impact performance of rubber reinforced concrete with waste steel fibres

This study introduces cementitious composite with rubber granulate and waste steel fibres as a new material for construction industry with an enhanced energy absorption capability and impact toughness. Detailed research on physico-mechanical properties of high-performance concrete with waste steel fibres and partial replacement of the aggregates by rubber granulate was performed, with emphasis on impact energy absorption potential. Different aggregate replacement ratios (0–30% wt.) and fibre amount (0–3% wt.) were investigated. The influence of rubber sizes, rubber content and steel fibre content on the mechanical parameters of the rubberized concrete at both quasistatic and dynamic loads was evaluated and discussed. With increasing amount of rubber granulate, the concrete suffered from reduction of its mechanical parameters – compressive and flexural strength, however the energy dissipation capability showed rising trend. This study demonstrated the potential of rubberized concrete with waste steel fibres for use in structures with higher impact resistance requirements.

Analysis of Sorghum Stalks and Fibres for Use in the Production of Low-Cost Housing Materials

Research into low-cost housing solutions, especially for low- and middle-income countries, has grown in recent years. Greater use of natural materials, both mineral and bio-based, offers opportunities for more affordable and sustainable materials and products. In the low- and middle-income countries, residential buildings are too expensive for most people due to the use of the concrete in buildings. Utilisation of agricultural wastes can serve a threefold purpose: (i) minimise the impact of construction products on the environment, (ii) reduce waste, and (iii) decrease the cost. The aim of this study was to investigate fibres and stalks from the sorghum plant as potential additives in low-cost brick production. Analysis of the sorghum fibres and stalks has included microstructural examination using a scanning electron microscope and mercury intrusion porosimetry, together with tensile strength testing of fibres. Fibres and stalks did not undergo chemical pre-treatment. Sorghum stalks and fibres were found to have comparable tensile strength to fibres currently used for brick production, and the methods used to prepare stalks were not found to adversely affect their strengths. Consequently, this research has shown that fibres produced from local agricultural wastes have potential for use in low-cost housing such as one-storey residential load-bearing structures and buildings.