Nonwoven Fiber Research Articles

Mechanical characterization of Abutilon Indicum fiber nonwoven fabric epoxy composite materials

The effect of nonwoven Abutilon Indicum fiber content (20, 25, 30, 35, and 40 wt%) on the structure (FTIR, SEM) and selected mechanical and thermal (TGA) properties of epoxy resin was investigated. The best mechanical properties were obtained with a fiber content of 35 wt%. The tensile strength of the composite was about 40 MPa, the flexural strength over 60 MPa, and the compressive strength about 48 MPa. Moreover, the composite showed the fracture energy about 0.44 J.

A facile energy-efficient approach to prepare super oil-sorbent thin films

Oil spills on water surface and shoreline have caused significant water pollution, and one of the ways to deal with them is to use oil sorbents. An effective sorbent provides high oil uptake and retention values, high selectivity, super-fast uptake kinetics, and sufficient mechanical strength to ensure practical application under different conditions. In this regard, synthetic sorbents made up of graphene, carbon nanotubes, and polymers in the form of aerogels, thin films, pads, and non-woven fibers have been widely explored. However, none of them addresses all the attributes of an ideal oil sorbent. Aerogels provide extremely high uptake values, but they are so light that it is difficult for the end user to handle them. On the other hand, thin films and non-woven fibers can quickly absorb oil but suffer from low uptake capacity with low retention values. Similarly, commercial oil sorbent pads have sufficient mechanical strength, but low uptake capacity compared to aerogels. Herein, we present a super oil sorbent with a porous structure using a facile energy-efficient approach. The as-prepared sorbent comprises a porous thin film with micropores and macro-cavities, resulting in super-fast uptake kinetics and a high oil uptake value of 85 g/g. Moreover, tensile test results confirm sorbent’s effectiveness in spill response. Lastly, our unique design does not involve expensive hydrophobic functionalization and thus utilizes lower embodied energy and generates lower carbon footprints.

Aging of PLA/NR electrospun fibers under the influence of UV-irradiation, water and soil environment

Research in the field of the influence of environmental factors on composite materials based on polyesters is very relevant, as such materials are gaining more and more use in various industries and agriculture. This paper presents the results of the influence of UV-irradiation, water and soil on PLA/NR nonwoven fibers. The content of NR was 5-15 wt.%. It was found that the presence of NR over 10 wt. % inhibits photolysis. After 300 hours of irradiation, the melting point of 100% PLA decreases more significantly than in composites with NR. The IR-spectroscopy method confirmed the occurrence of the process of photooxidative degradation in fibrous samples. Biodegradation in soil proceeds more actively in PLA/NR fibrous composites than in pure PLA. Apparently, an increase in the proportion of the amorphous phase in the composites and the bioavailability of rubber contribute to this process.

Seawater-degradable, tough, and fully bio-derived nonwoven polyester fibres reinforced with mechanically defibrated cellulose nanofibres

PHBH incorporated with cellulose nanofibers was fabricated as a completely bio-derived bioplastic with high seawater degradability and mechanical properties by electrospinning Pickering emulsions.

Conversion of discarded industrial PPS non-woven fabric into heteroatoms co-doped honeycomb-like hierarchical porous carbon for superior performance supercapacitor

To achieve carbon peaking and carbon neutrality, it is important to develop a circular economy. Among them, the pollution control of solid waste is a key direction. Herein, an environmentally-friendly method has been proposed to convert the discarded industrial polyphenylene sulfide (PPS) non-woven fabric fiber into value-added hierarchical porous carbon (HPC) for superior performance supercapacitor. Pre-treatment by oxidation and nitrification, combined with activation process and carbonization, the well-organized honeycomb-like carbon material ONS-HPC-0.5 is obtained with the ultrahigh specific surface area (3112.2 m2 g−1), abundant heteroatoms oxygen (10.85 atom%), nitrogen (4.93 atom%) and sulfur (5.33 atom%) codoped and hierarchical porous structure. Owing to the structure advantages, the ONS-HPC-0.5 electrode delivers high specific capacitance of 301 F g−1 at 0.5 A g−1, superior rate characteristic and electrochemical stability in alkaline electrolyte. Notably, the assembled ONS-HPC-0.5//ONS-HPC-0.5 symmetric supercapacitor achieves the remarkable energy density of 21.87 Wh kg−1 with power density of 450 W kg−1, which not only demonstrates this material promising application in supercapacitor industry, but also opens up a new circular economy model for the recycling of industrial solid waste.

Bending Strength of Apus Bamboo Fiber Reinforced Asphalt Composite Materials as Small Ship

Bamboo is generally widely used as a material or construction material in homes. However, the use of bamboo as a raw material for shipbuilding is not yet available. To make bamboo as a material in shipbuilding, the bamboo is assembled or made into a composite to meet class standards as a material for shipbuilding. In this study, the composites used were apus bamboo fiber and asphalt. The method of making the composite uses the hand lay-up method with variations of 1 layer of reinforcement, 3 layers of reinforcement, and 5 layers of reinforcement. The dimensions of the test specimen size refer to ASTM D 790-3 which is then carried out by bending tests to determine the strength of the material due to loading and the elasticity of the material. Furthermore, the results of the bending test will be analyzed using the Anova method and compared with the standard material class in ship construction. Results Asphalt composite material with apus bamboo fiber has the highest bending test value of 27,068 Mpa and the lowest bending test value of 25,998 Mpa. Based on these results, it is stated that the Bamboo reinforced asphalt (BRA) material has not been able to match and even exceed the Bamboo reinforced plastic (BRP) material in the woven, non-woven and random fiber variants. It is influenced by the diameter, and the strength of the shape between the fiber and the matrix.

Protease Immobilization in Solution-Blown Poly(ethylene oxide) Nanofibrous Nonwoven Webs

Enzyme-functionalized solution-blown nonwoven (EFSBN) fibers were produced by a single-step solution blow spinning method that utilizes high-velocity gas to simultaneously extrude the codissolved polymer–solvent–enzyme spinning solution and evaporate solvent at mild conditions to form a nanofibrous web with preserved enzyme activity. A broad concentration range of 0.6–7.4 wt % protein of subtilisin A protease from Bacillus licheniformis was successfully entrapped by poly(ethylene oxide) (PEO) during solution blow spinning nonwoven web production. The presence of enzyme protein in the solid nanofibers was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Time of flight-secondary ion mass spectroscopy and laser confocal microscopy revealed the immobilized enzymes were mainly positioned inside the fibers and homogeneously distributed throughout the webs. Scanning electron microscopy showed that the fiber shape and diameter of PEO nanofibers containing enzymes were irregular compared to PEO-only nanofibers. Residual enzyme activity in the webs was measured by redissolving fibers in buffer and comparing the released enzyme activity to nonimmobilized free enzyme using a casein substrate-based assay. Immobilized protease (1.3% (w/w) protein in solid dry nanofiber webs) retained more than 90% of the free enzyme activity. Protease immobilized in solid nanofiber webs exhibited long storage stability at ambient (∼22 °C) and 4 °C temperature storage conditions, with more than 60% remaining catalytic activity after 300 days compared to the initial activity. Immobilized protease had equally good thermal stability as a stabilized liquid commercial protease, both retaining above 95% of their initial activity after treatment for 12 h at 65 °C. In contrast, the same liquid protease diluted in buffer lost activity within 2 h at that temperature. The nondusting, readily aqueous-soluble EFSBN solid materials are easy to handle and have good storage stability compared to liquid products.

Strong, Tough, and Adhesive Polyampholyte/Natural Fiber Composite Hydrogels.

Hydrogels with high mechanical strength, good crack resistance, and good adhesion are highly desirable in various areas, such as soft electronics and wound dressing. Yet, these properties are usually mutually exclusive, so achieving such hydrogels is difficult. Herein, we fabricate a series of strong, tough, and adhesive composite hydrogels from polyampholyte (PA) gel reinforced by nonwoven cellulose-based fiber fabric (CF) via a simple composite strategy. In this strategy, CF could form a good interface with the relatively tough PA gel matrix, providing high load-bearing capability and good crack resistance for the composite gels. The relatively soft, sticky PA gel matrix could also provide a large effective contact area to achieve good adhesion. The effect of CF content on the mechanical and adhesion properties of composite gels is systematically studied. The optimized composite gel possesses 35.2 MPa of Young's modulus, 4.3 MPa of tensile strength, 8.1 kJ m-2 of tearing energy, 943 kPa of self-adhesive strength, and 1.4 kJ m-2 of self-adhesive energy, which is 22.1, 2.3, 1.8, 6.0, and 4.2 times those of the gel matrix, respectively. The samples could also form good adhesion to diverse substrates. This work opens a simple route for fabricating strong, tough, and adhesive hydrogels.

A Remarkable Photocatalyst Filter for Indoor Air Treatment

A crucial environmental public health risk is air pollution caused by organic contaminants, bio-aerosols, and fine particulate matter (PM2.5–10). A multi-purpose photocatalyst filter with photocatalytic nitrogen-doped titanium dioxide (PNT) incorporated into non-woven polymer fibers (NWPF) with wide applications is focused on in detail in this work. Loading of PNT on NWPF is carried out by the simple dip coating method. Para-xylene is selected as the target pollutant for the removal of organic contaminants. Higher removal efficiency of p-xylene (94.2%) is achieved under fluorescent daylight. The filtration efficiency of PNT is also evaluated to capture PM2.5–10, which is increased with higher loading content of PNT. At a high air flow rate, the filtration efficiency of the photocatalyst PNT/NWPF is 97.33%, whereas the efficiency of the pristine NWPF is 91.1%. Moreover, the PNT/NWPF filter exhibits excellent antibacterial activity (99.9%) under visible light irradiation, but the pristine NWPF filter has negligible destruction effects on pathogens. These results clearly indicate that a PNT-coated NWPF filter would be an outstanding multi-purpose material for indoor air purification systems.

Potent Antibacterial Composite Nonwovens Functionalized with Bioactive Peptides and Polymers (Adv. Mater. Interfaces 33/2022)

Antibacterial Fabrics In article number 2201061, Eduardo Barbieri, Stefano Menegatti, and colleagues present scalable methods to produce antibacterial fabrics by functionalizing nonwoven fiber mats with antimicrobial peptides and polymers. Microgels are photo-crosslinked on nonwovens fibers and utilized to load and release peptides. Selected fabrics affording sustained release of peptides show antibacterial activity against bacteria Staphylococcus aureus and Escherichia coli, with no adverse effect on human skin cells.

Development of high-strength green composites based on ramie sliver and cellulose acetate resin

In the present study, the tensile properties of a single ramie fiber and the adhesion of ramie and a resin were compared at 170, 180, 190, 200, 210 and 220 °C. The results revealed that the most suitable temperature for the formation of a unidirectional composite is 190 °C. The tensile properties of the non-woven ramie fiber fabric, woven ramie fiber fabric, ramie fiber yarns, or sliver reinforced composites were tested and compared, and their structures were analyzed by X-ray computed tomography. The results revealed that sliver was the most suitable reinforcing material for unidirectional composites. We also know that the tensile strength and tensile modulus increased as the fiber volume content increased, and the relationships between them were linear.

Shear Bond Strength of Polypropylene Fiber in Orthodontic Adhesive on Glazed Monolithic Zirconia.

This study aims to compare shear bond strength (SBS) and mode of failure (MOF) between ceramic and metal orthodontic brackets on glazed monolithic zirconia using non-woven polypropylene fiber adhesive. Sixty glazed and sintered zirconia blocks were divided into six groups and attached with orthodontic brackets as follows: CS, ceramic bracket with silane; CB, ceramic bracket with bonding agent; CBS, ceramic bracket with bonding agent and silane; MS, metal bracket with silane; MB, metal bracket with bonding agent; and MBS, metal bracket with bonding agent and silane. There was a statistically significant difference in mean SBS values (p < 0.001). The CS group showed the highest SBS value (23.42 ± 3.88 MPa). On the other hand, the lowest was found in the MB group, which was not statistically different from the CB group (3.26 ± 0.76 and 5.09 ± 1.50 MPa, respectively). The MS, MBS, and CBS groups showed no statistical difference compared to each other (15.57 ± 4.01, 13.23 ± 5.47, and 12.77 ± 4.43 MPa, respectively). SBS is highest when a ceramic bracket with silane is bonded to glazed monolithic zirconia.

Cellulose Fibre Degradation in Cellulose/Steel Hybrid Geotextiles under Outdoor Weathering Conditions.

Risks from rockfall and land sliding can be controlled by high-tensile steel nets and meshes which stabilise critical areas. In many cases, a recultivation of the land is also desired. However, high-tensile steel meshes alone are not always sufficient, depending on the location and the inclination of the stabilised slope, to achieve rapid greening. Cellulose fibres exhibit high water binding capacity which supports plant growth. In this work, a hybrid structure consisting of a nonwoven cellulose fibre web and a steel mesh was produced and tested under outdoor conditions over a period of 61 weeks. The cellulose fibres are intended to support plant growth and soil fixation, and thus the biodegradation of the structure is highly relevant, as these fibres will become part of the soil and must be biodegradable. The biodegradation of the cellulose fibres over the period of outdoor testing was monitored by microscopy and analytical methods. The enzymatic degradation of the cellulose fibres led to a reduction in the average degree of polymerisation and also a reduction in the moisture content, as polymer chain hydrolysis occurs more rapidly in the amorphous regions of the fibres. FTIR analysis and determination of carboxylic group content did not indicate substantial changes in the remaining parts of the cellulose fibre. Plant growth covered geotextiles almost completely during the period of testing, which demonstrated their good compatibility with the greening process. Over the total period of 61 weeks, the residual parts of the biodegradable cellulose web merged with the soil beneath and growing plants. This indicates the potential of such hybrid concepts to contribute a positive effect in greening barren and stony land, in addition to the stabilising function of the steel net.

Multifunctional non-woven fabrics based on interfused MXene fibers

MXene-based fibers are expected to have the hopeful potential for manufacturing multifunctional fabrics with permeability, lightweight, remarkable electrical conductivity, and outstanding mechanical properties. However, the weak interaction between fibers limits the performance of the fabrics, and researchers are still seeking a suitable solution and easily scalable production methods. Here a green and novel wet-assembly approach is proposed for producing non-woven MXene fiber fabrics (MFFs) constructed by random-oriented and well-connected interfused MXene fibers. The as-prepared fabrics are porous and lightweight while exhibiting high electrical conductivity (708 S cm−1). A maximum specific electrical conductivity is achieved with a relatively low density (0.24 g cm−3), even superior to individual MXene fibers. Moreover, the MFFs exhibit outstanding electromagnetic interference (EMI) shielding effectiveness of 75.0 dB at a thickness of 107 μm, exceptional Joule heating (up to 370 °C at a voltage of 3.5 V), and excellent photothermal conversion abilities, showing their great potential as high-performance and multifunctional fabrics in EMI shielding, wearable intelligent garments, and personal heating applications.

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.

Development and characterization of DTMS treated nettle fiber nonwovens for oil spill removal applications

In this work, nonwoven oil sorbent from nettle fiber was developed by changing the hydrophilic surface of nettle fiber to a hydrophobic surface by dodecycltrimethoxysialne (DTMS) treatment. Change in the surface structure of the fiber due to DTMS treatment was confirmed by SEM analysis. Fourier transform infrared analyses showed clear evidence of successful incorporation of DTMS on nettle fiber. The oil sorption capacities of diesel oil and crude oil were 31.39 and 41.89 g/g, respectively, which were found to be considerably higher than commercial oil sorbents. The pseudo first order and pseudo second order kinetic equations were employed to obtain the sorption rate constants and equilibrium sorption capacity. The results showed that the process fits the pseudo second-order kinetic model better for oil sorption than the pseudo first-order kinetic model. Also, the sorption capacities of the unmodified and modified samples were estimated by analyzing the isotherm data using Langmuir and Freundlich adsorption isotherm models. The results show that fitting via the Langmuir isotherm model produced a higher correlation coefficient than fitting via the Freundlich isotherm model. DTMS treated nettle nonwoven fabrics also showed good buoyancy characteristics under both static and dynamic conditions. Due to high oil sorption ability, reusability, and environmental responsiveness, the developed nonwoven oil sorbent can be considered as a potential substitute for organic synthetic fiber for oil spill removal applications.

Nonwoven Membranes with Infrared Light-Controlled Permeability.

This study presents the development of the first composite nonwoven fiber mats (NWFs) with infrared light-controlled permeability. The membranes were prepared by coating polypropylene NWFs with a photothermal layer of poly(N-isopropylacrylamide) (PNIPAm)-based microgels impregnated with graphene oxide nanoparticles (GONPs). This design enables "photothermal smart-gating" using light dosage as remote control of the membrane's permeability to electrolytes. Upon exposure to infrared light, the GONPs trigger a rapid local increase in temperature, which contracts the PNIPAm-based microgels lodged in the pore space of the NWFs. The contraction of the microgels can be reverted by cooling from the surrounding aqueous environment. The efficient conversion of infrared light into localized heat by GONPs coupled with the phase transition of the microgels above the lower critical solution temperature (LCST) of PNIPAm provide effective control over the effective porosity, and thus the permeability, of the membrane. The material design parameters, namely the monomer composition of the microgels and the GONP-to-microgel ratio, enable tuning the permeability shift in response to IR light; control NWFs coated with GONP-free microgels displayed thermal responsiveness only, whereas native NWFs showed no smart-gating behavior at all. This technology shows potential toward processing temperature-sensitive bioactive ingredients or remote-controlled bioreactors.

Effect of fique fibers and its processing by-products on morphology, thermal and mechanical properties of epoxy based biocomposites

This work examines the morphology, mechanical and thermal properties of biocomposites based on epoxy resin-EP and fique (Furcraea andina), a native crop of South America. The EP-fique biocomposites were prepared using fique powder-FP an industrial waste generated during fique processing, nonwoven fique fiber mats-NWF and unidirectional fique fiber mats-UF oriented at 0° and 90°. The addition of fique into EP matrix restricts EP macromolecule chains movement and enhance the thermal stability of EP. SEM images showed that fique form used (powder or fiber) and mat arrangement can generate changes in the biocomposites morphology. Mechanical characterization show that fique powder and fique fibers oriented at 90° acts as fillers for the epoxy matrix while the fique fibers oriented at 0° reinforce EP matrix increasing the tensile and flexural modulus up to 5700 and 1100% respectively and tensile and flexural strength up to 277% and 820% in comparison with neat EP. The obtained results can increase the interest in researching and developing products from fique Powders and other natural fibers processing byproducts thus reducing the abundance of waste in soil and landfills and environmental concerns and suggest that the EP-fique biocomposites are promising to be used in the automotive sector.

Analysis of silica and silicon carbide abrasives characteristics on denim wear

AbstractThis paper presents the development of certain abrasives based on selected industrial wastes and gives an idea of their postuse behavior. These abrasives are manufactured using two methods: pulverization and coating. For these purposes, we used cellulosic nonwoven fibers as reinforcement, three types of resin (polyurethane, acrylic, and polyester) as a matrix, and abrasive grains of silicon carbide (SiC) and silica to obtain the abrasive character. We report the wear of the developed materials by abrasion, the evaluation of their roughness, the influence of the type of the abrasive grains, and their sizes on the wear performances. Scanning electron microscopy was performed to show the morphology of abrasives. The weight loss of abrasives was measured by thermogravimetric analysis and its derivative. Fourier‐transform infrared spectroscopy allows the chemical characterization and identification of abrasive grains. Under the same test conditions, experimental results indicate that silica‐based abrasives exhibit higher surface roughness and abrasion wear rate than SiC‐based abrasives.

Immobilization of strontium aluminate nanoparticles onto plasma-pretreated nonwoven polypropylene fibers by screen-printing toward photochromic textiles

Polypropylene fibers have been applied in various fields, such as automotives, plastic furniture, medical devices, and food packaging. Polypropylene fibers are characterized by low-cost, high flexural and impact strength, as well as high resistant to chemicals, moisture, fade, electricity and fatigue. However, polypropylene fiber is inherently resistant to stain because they have no active dyeing sites on their surface. Therefore, it has been impossible to dye polypropylene fibers after extrusion. In the current study, we introduce a novel strategy toward the production of photoluminescent nonwoven polypropylene fabrics by plasma-assisted screen-printing with rare-earth doped strontium aluminate nanoparticles. Aqueous-based phosphor-binder printing paste was applied directly onto nonwoven polypropylene textiles. The superhydrophobic properties of the phosphor-printed nonwoven polypropylene textile substrates were enhanced with increasing the phosphor ratio in the printing paste. Both of ultraviolet protection and antibacterial activity of the phosphor-printed nonwoven polypropylene fabrics were also considered. The produced colorless photoluminescent layer displayed an emission band at 515 nm after being excited at 371 nm. The phosphor-printed fabrics exhibited various colorimetric shades, including off-white beneath daylight and green beneath ultraviolet lamp, as proved by photoluminescence spectra and CIE Lab properties. The comfortability was inspected by testing both of air-permeability and bend length to indicate good flexibility and breathability. The phosphor nanoparticles were studied for their morphological properties to display diameters of 4–9 nm. The spectroscopic findings of the phosphor-printed nonwoven polypropylene were explored. The colorfastness was studied to indicate high durability. The phosphor-printed fabrics showed good reversibility and fatigue-resistance.