Uniform Fiber Research Articles

Electrospinning of LaB6/PEDOT:PSS/PEO Fiber Composites of Unique Morphologies.

We present a direct electrospinning fabrication technique for the manufacture of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/poly(ethylene oxide) (PEDOT:PSS/PEO) polymer fibers containing embedded cubic lanthanum hexaboride (LaB6) particles. We focus on the impact of relative humidity on the formation of uniform polymer fibers and show that a relative humidity of 5% is optimal, resulting in an average fiber thickness of 266 ± 88 nm. As the relative humidity is increased, the fibers contain beads as a consequence of Rayleigh instabilities. The addition of lanthanum hexaboride cubic particles to the polymer solution before electrospinning results in the encapsulation of the LaB6 particles inside the fibers. We investigate the effect of LaB6 particle size on morphology and observe that particles of ∼500 nm yield a fiber-cube-fiber morphology, while 2 μm particles result in fewer embedded cubes along the length of the polymer fibers. This phenomenon likely arises from electrodynamic interactions between the LaB6 particles in the polymer solution and the electric field lines generated during electrospinning between the spinneret and the collector. Our results display the versatility of the electrospinning technique in the fabrication of unique polymer/hexaboride composite fibers.

Gallic acid functionalized silk fibroin/gelatin composite wound dressing for enhanced wound healing

As the incidence of chronic wounds increases, the requirements for wound dressings are rising. The specific aim of this study is to propose a novel gallic acid (GA) functionalized silk fibroin (SF) and gelatin (Gel) composite wound dressing in which GA is used as an antibacterial and wound healing substance. Via electrospinning, SF, Gel, and GA mixed solutions could be conveniently fabricated into a composite nanofiber mat (SF-Gel-GA), consisting of uniform fibers with an average diameter around 134.57 ± 84 nm. The internal mesh structure of SF-Gel-GA provides sufficient drug loading capacity, proper moisture permeability, and proper degradation rate. SF-Gel-GA presents excellent biocompatibility. NIH-3T3 fibroblast cells could adhere and spread stably on the SF-Gel-GA surface with slightly promoted proliferation. In the presence of SF-Gel-GA, the growth of both Gram-positive and Gram-negative bacteria, includingStaphylococcus aureusandPseudomonas aeruginosa, is significantly inhibited in both plate and suspension cultures. A cutaneous excisional mouse wound model proves the efficient ability of SF-Gel-GA to promote wound healing. Compared with pure SF dressing and commercial Tegaderm Hydrocolloid3Mdressing, the wound closure rate with SF-Gel-GA treatment is significantly improved. The histological assessments further demonstrate SF-Gel-GA could facilitate collagen deposition, neovascularization, and epithelialization at wound sites to promote wound healing. In conclusion, a novel SF-Gel-GA composite wound dressing with efficient wound healing activities have been developed for chronic wound treatment with broad healing potential.

Highly Intrinsic Thermal Conductivity of Aramid Nanofiber Films by Manipulating Intermolecular Hydrogen Bonding Interactions

AbstractLightweight, flexible, and thermostable thermally conductive materials are essential for enhancing heat dissipation efficiency in advanced electronics. The development of intrinsic thermally conductive polymers is the key to expanding the space for improving the thermal conductivity of polymer‐based thermal management materials. In order to balance the thermal conductivity and mechanical performance of bulk polymers, thermally conductive aramid nanofiber (ANF) films are assembled by manipulating the proton‐donating ability of solvents. Compared to water as a conventional proton donor, ethanol‐induced multi‐scale structures composed of dense hydrogen bonding interaction, large grain size, and uniform fiber topology endow the resulting ANF films with enhanced intrinsic thermal conductivity up to 5.05 W m−1 K−1 with a 34% increase, salient mechanical performance with the tensile strength of 181.4 MPa, and exceptional thermal stability higher than 500 °C. These outstanding properties of ANF films provide many possibilities for the preparation of polymer‐based thermally conductive materials.

Development and characterization of antibacterial marine extract-infused cellulose acetate nanofibers as wound dressings for combatting multidrug-resistant wound infections

Wound infections caused by multidrug-resistant bacteria pose a significant challenge globally in healthcare. Traditional wound dressings often lack efficacy against these resilient pathogens, necessitating the exploration of innovative approaches to combat infections and promote wound healing. This study was designed to investigate a novel wound dressing marine extract-infused electrospun cellulose acetate nanofibers (CANF) with particular emphasis on combating multidrug-resistant bacteria. Cellulose acetate (CA) solution was blended with marine extract (Heteroxenia Fuscescens soft coral, H. Fu) before the formation of electrospun nanofibers. The antibacterial activities of H. Fu extract and the prepared nanofiber mats were explored against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Staphylococcus epidermidis. Results displayed that H. Fu extract has a robust antibacterial action against tested bacteria. Different concentrations of H. Fu (0.05 g, 0.1 g, 0.2 g, and 0.3 g) were added to CA solutions, and named as H. Fu-1@CANF, H. Fu-2@CANF, H. Fu-3@CANF and H. Fu-4@CANF, respectively. The obtained results from SEM analysis demonstrated the smooth and uniform fibers. As observed, the results also domenstrated that the addition of H. Fu with specific concentrations (0.05 g, 0.1 g, 0.2 g) has no significant impact on the smooth properties of the formed nanofibers. Increasing the concentration of H. Fu (0.3 g) leads to the formation of nanofibers coated with huge beads. The contact angle values of CANF, H. Fu-1@CANF, H. Fu-2@CANF, and H. Fu-3@CANF were 33.3°, 57.1°, 60.8° and 62.9°, respectively. The prepared nanofiber samples were tested for their inhibitory impact on bacterial survival counts using the disc diffusion method. Important results from the study include the observation that H. Fu-3@CANF exhibited the largest zones of inhibition (ZOI) with diameters of 35 ± 0.25 mm for P. aeruginosa, 32 ± 0.65 mm for A. baumannii, 28 ± 0.14 mm for S. aureus, and 27.6 ± 0.48 mm for S. epidermidis. Additionally, the H. Fu-2@CANF sample demonstrated strong antibacterial activity, with ZOI diameters of 32 ± 0.56 mm, 29 ± 0.81 mm, 26 ± 0.27 mm, and 25.4 ± 0.28 mm for the respective bacteria. The Microtox® assay further evaluated the toxicity levels of the nanofiber mats, revealing that while all samples exhibited some toxicity, the H. Fu-3@CANF sample had the lowest toxicity profile. These findings highlight the potential of H. Fu-loaded nanofibers, particularly H. Fu-3@CANF, for broad-spectrum antibacterial applications. The study underscores the importance of incorporating bioactive compounds into nanofiber mats to enhance their antimicrobial properties, making them suitable candidates for medical and environmental applications requiring effective bacterial eradication.

Electrospun hydrophilic PAN/CO/TA composite nanofibrous membrane for adsorbing Cu(II) in water

In this paper, a novel polyacrylonitrile (PAN)/collagen (CO)/tannic acid (TA) composite nanofiber membrane for the adsorption of Cu(II) in water was prepared. The nanofibrous membranes were characterized by Fourier transform infrared (FTIR), scanning electron microscopy (SEM), thermogravimetric (TG), and water contact angle (WCA) techniques, and their adsorption performance on Cu(II) in water was tested. The results showed that incorporating CO improved the hydrophilic performance of the membranes, and the contact angle of PAN/CO decreased from 60.57° to 39.16° with the increase of CO content, which exhibited good hydrophilicity. Moreover, CO effectively crosslinked TA, so that TA was well fixed on the surface of the fiber membrane, and the resulting PAN/CO/TA composite nanofiber membrane had good fiber morphology, uniform fiber diameter distribution, with an average diameter of 292.22 nm, and good adsorption performance for Cu(II), up to 133.26 mg/g. The adsorption kinetics fitting showed that the adsorption mechanism was mainly electrostatic adsorption and chelation of Cu(II) by phenoxy anion. PAN/CO/TA and PAN/CO/TA/Cu nanofiber membranes showed bacteriostatic effects on E. coli and S. aureus, with PAN/CO/TA/Cu nanofiber membranes being particularly effective, with the average inhibition bands for E. coli and S. aureus being 7.50 mm and 10.05 mm, respectively. The distribution of the electric field during the spinning process was also simulated by finite element analysis in this study. Since TA is a natural polymer of plant origin and CO is of animal origin, it provides an environmentally friendly and cost-effective method to remove Cu(II) from water.

Electrospun Polylactic Acid/Polyethylene Glycol/ Silicate‐Chlorinated Bioactive Glass Composite Scaffolds for Potential Bone Regeneration

ABSTRACTThe integration of bioglass with polymers in tissue engineering scaffolds holds promise for enhancing bone regeneration. This study explores the fabrication and characterization of composite scaffolds comprising polylactic acid (PLA)/polyethylene glycol (PEG) fibers incorporated with silicate‐chlorinated bioglasses (45S5 and 58S). Electrospinning was utilized to produce the scaffolds, followed by physical–chemical and in vitro evaluations. Scanning electron microscopy (SEM) revealed uniform fiber formation, with bioglass incorporation observed in the composite groups. Bioglass incorporation led to a significant reduction in fiber diameter. Thermogravimetric analysis (TGA) estimated bioglass content, with 58S exhibiting the highest incorporation. Contact angle measurements indicated enhanced hydrophilicity in bioglass‐containing groups. In vitro, bioactivity assessment in simulated body fluid (SBF) demonstrated apatite formation potential and the pH variance indicates a slightly alkaline to neutral condition. Cell culture studies revealed robust cellular adhesion and metabolic activity across all groups, with no cytotoxic effects observed. Overall, these findings suggest the potential of PLA/PEG bioglass composite scaffolds for bone tissue engineering applications.

An ultrastructure analysis of the developing human anterior cruciate ligament tibial enthesis.

This study aimed to investigate the ultrastructural anatomy of the developing ACL tibial enthesis. We hypothesized that enthesis architecture would progressively mature and remodel, eventually resembling that of the adult by the early postnatal stage. Five fresh-frozen human pediatric cadaveric knees aged 1-36 months underwent anatomical dissection to harvest the ACL insertion and underlying tibial chondroepiphysis. The samples were prepared for scanning electron microscopy (SEM) to examine the ultrastructural anatomy of the enthesis and underwent histological staining for circular polarized light (CPL) and light microscopy imaging. SEM analysis of the 1- and 8-month-old samples revealed a shallow interdigitation between the dense fibrous (ligamentous) tissue and unmineralized chondrogenic tissues, with a minimal transition zone. By 11-month, a more complex transition zone was present. By age 19- and 36-month-old, a progressively more complex and defined fibrocartilage zone was observed. CPL analysis revealed distinct collagen fiber continuity, alignment, and organization changes over time. By 19 and 36 months, the samples exhibited complex fiber arrangements and a progression toward uniform fiber orientation. Similarly, histological analysis demonstrated progressive remodeling of the enthesis with increasing age. Our results suggest that the ACL enthesis of the developing knee begins to mimic that of an adult as early as 19 months of age, as a more complex transition between ligamentous and chondro-epiphyseal tissue can be appreciated. We hypothesize that the observed changes are likely due to mechanical loading of the enthesis with the onset of weightbearing. Future investigations of ACL reconstruction and repair will benefit from improved understanding of the chondro-epiphyseal/ACL regions.

Characterisation of fibre distribution uniformity in steel fibre-reinforced concrete under microwave-induced heating during casting

Traditional active microwave thermography (AMT) tests for hardened steel fibre-reinforced concrete (SFRC). The surface temperature of SFRC derived from AMT cannot fully characterise the distribution of steel fibres in the SFRC. This study proposes a microwave-induced heating method combined with temperature sensors (MI-TS) to estimate the fibre dispersion of an SFRC mixture during casting. The principles and testing process are discussed, and a numerical model is developed to evaluate the temperature distribution of the SFRC mixture following microwave exposure. Through MI-TS and numerical models, the temperature in the SFRC mixture with uniform fibre distribution, fibre clustering and fibre sinking is investigated, and the results are compared with those obtained by AMT and destruction technology to evaluate the feasibility of the proposed method. The results show that in the same specimen, the temperature difference between areas with similar fibre content falls in a very narrow range (e.g., 3.5–4.5 °C for a 100 × 100 × 100 mm specimen exposed to 600 W of microwave irradiation for 180 s). When the fibre content in a given area is more than 0.5 vol%, a large temperature difference forms between this and other areas. When the equivalent fibre content of the specimen is ignored, the temperature difference between the two areas is directly proportional to the difference in fibre content. Therefore, the area that shows differences in fibre clustering and fibre content can be easily determined found based on the temperature difference derived from MI-TS.

PVC/CNT Electrospun Composites: Morphology and Thermal and Impedance Behavior.

Due to their mechanical robustness and chemical resistance, composite electrospun membranes based on polyvinyl chloride (PVC) are suitable for sensor applications. Aiming to improve the electrical characteristics of these membranes, this work investigated the effects of the addition of carbon nanotubes (CNTs) to PVC electrospun membranes, in terms of morphology and thermal and impedance behavior. Transmission electron microscopy images evidenced that most of the nanotubes were encapsulated within the fibers and oriented along them, while field-emission scanning electron micrographs revealed that the membranes consisted of uniform fibers with an average diameter of 339 ± 31 nm, regardless of the addition of the carbon nanotubes. With respect to the neat resin, the addition of nanotubes caused a significant lowering of the glass transition temperature (up to 20 °C) and a marked change in the second degradation step of PVC. Nyquist plots from electrical impedance spectra showed a charge transfer resistance (RCT) of 38 and 40 MΩ for neat PVC and PVC/CNT 3 wt.% membranes, respectively, indicating that, in the dry state, the encapsulation of CNTs in the fibers and the high porosity of the membranes prevented the formation of a percolation network, increasing the electrical resistance. In the wet state, however, there was a greater change in the impedance behavior, decreasing the resistance RCT to 4.5 and 1.1 MΩ, for neat PVC and PVC/CNT 3 wt.% membranes, respectively. The results of this study, showing a significant variation in impedance behavior between dry and wet membranes, are relevant for the development of various types of sensors based on PVC composites.

Effect of Triton X-100 surfactant concentration on the wettability of polyethylene-based separators used in supercapacitors

Polyethylene-based separators are generally unsuitable for aqueous supercapacitors due to their poor wettability with the electrolyte, which impedes ion transport. However, incorporating Triton X-100 (2-[4-(2,4,4-trimethylpentan-2-yl)phenoxy]ethanol) into the aqueous sulfuric acid (H2SO4) electrolyte improves the wettability of polyethylene and facilitates ionic movement through its pores. In this study, Triton X-100 was added to 1.0 M H2SO4 at various concentrations (0.122%–1.210% V/V) to evaluate its impact on supercapacitor performance. Supercapacitors were assembled using activated carbon-filled carbon cloth electrodes, each of the above electrolytes and polyethylene sheet separators. Scanning electron microscopy revealed that the carbon cloth exhibited a uniform fiber distribution and high surface area for activated carbon integration. The polyethylene separator displayed a porous structure with an average pore size of 165 ± 35 nm. Triton X-100 significantly reduced the water contact angle from 101.5° (without surfactant) to 30.2° (with 1.21% V/V Triton X-100), enhancing polyethylene’s wettability. This change from hydrophobic to hydrophilic characteristics enabled the formation of an electrical double layer at the separator/electrolyte interface, improving ionic transport. However, higher Triton X-100 concentrations increased the electrolyte's viscosity, which impeded ion movement. The highest specific capacitance of 55.3 F/g (at a scan rate of 0.005 V s−1) was achieved with 0.488% V/V Triton X-100. The specific capacitance varied with surfactant concentration in a complex manner, influenced by micelle formation and precipitation. These findings were corroborated by cyclic voltammetry and AC impedance spectroscopy.

Optimization of Polyvinylidene Fluoride/Polyvinyl Alcohol Electrospun using Taguchi Method for Tissue Engineering Application

Composite nanofibers for tissue engineering applications were prepared with polyvinylidene fluoride and polyvinyl alcohol via a horizontal electrospinning process. The effect of the processing parameters (polymer concentration, voltage, feed rate and tip-to-collector distance) on the fibre diameter was studied using L9 orthogonal arrays of the Taguchi Method, S/N ratio, and ANOVA to produce uniform and finest fibre. The optimum parameters were at 90 wt% PVDF ratios for polymer concentration, applied voltage at 10 kV, feed rate at 0.5 mL/h and tip-to-collector distance at 15 cm. The PVDF/PVA electrospun compromises 171.60 nm nanofiber diameter with homogenous morphology and no bead formed. MTT and live/dead kit assay analysis toward human (HSF) cells confirmed the potential of the PVDF/PVA electrospun to be used as an alternative tissue template to allow new cell or tissue formation in the future.

Development and characterization of nitazoxanide-loaded poly(ε-caprolactone) membrane for GTR/GBR applications

ObjectiveGuided tissue/guided bone regeneration (GTR/GBR) membranes are widely used for periodontal bone regeneration, but their success depends on a bacteria-free environment. Systemic antibiotic treatment often proves inadequate, moreover, the increasing prevalence of antibiotic resistance in oral infections exacerbates this challenge. This study aimed to fabricate antibacterial membranes using a new class of antibiotics for local drug delivery, to eradicate infections and promote tissue regeneration. MethodsMembranes loaded with nitazoxanide (NTZ) were fabricated via electrospinning using poly(ε-caprolactone) (PCL) with varying concentrations of NTZ (0 %, 2.5 %, and 5 % w/w) relative to the polymer weight. Morphochemical of NTZ-loaded membranes were assessed using scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) and Fourier Transform Infrared spectroscopy (FTIR). Mechanical properties were evaluated using universal testing machine and NTZ release profile from membranes was determined by spectrophotometer (λmax = 444) for 14 days. Antimicrobial efficacy against periodontal pathogens, cell compatibility and mineralization were evaluated using periodontal ligament stem cells (PDLSCs). ResultsOptimized spinning parameter maintained a uniform fiber diameter and successful loading of NTZ was confirmed by SEM-EDS and FTIR. NTZ incorporation did not significantly affect mechanical properties, whereas the drug release kinetics showed an initial burst, followed by sustained release over 14 days. NTZ-loaded membranes demonstrated antibacterial activity against Aggregatibacter actinomycetemcomitans (Aa) and Fusobacterium nucleatum (Fn). Importantly, the presence of NTZ showed minimal cell toxicity; however, it reduced the mineralization potential compared with that of the pure PCL membrane, which increased over time. SignificanceTaken together, these findings established that NTZ-loaded membranes could be promising barrier membrane to counteract microbial environment and aid periodontal bone regeneration.

Analysis of Bare Uniform Fiber Bragg Grating Sensor for Measuring Strain on the Landing Gear of the LSU-02 Unmanned Aircraft

Analysis of Bare Uniform Fiber Bragg Grating Sensor for Measuring Strain on the Landing Gear of the LSU-02 Unmanned Aircraft

Bacterial Cellulose Production within a Circular Economy Framework: Utilizing Organic Waste.

Bacterial cellulose (BC) has emerged as a sustainable biomaterial with diverse industrial applications. This paper examines BC production through a circular economy framework, focusing on organic waste as a primary feedstock. It compares static and agitated cultivation methods for BC production, highlighting their advantages and limitations. Static cultivation using Gluconacetobacter xylinum yields high-quality cellulose films but is constrained by lower yields and longer incubation times. Agitated cultivation accelerates production but may affect fiber uniformity. This paper emphasizes sustainability by exploring organic waste materials such as coffee grounds, tea leaves, and food scraps as cost-effective nitrogen and carbon sources. These materials not only lower production costs but also support circular economy principles by converting waste into valuable products. BC produced from these waste sources retains key properties, making it suitable for applications in the textile and other industries. In addition, BC production can align with vegan principles, provided that all additives and processing methods are free of animal-derived components. The paper discusses BC's potential to replace synthetic fibers in textiles and reduce environmental impact. Case studies show successful BC integration into textile products. In conclusion, this paper calls for more research to optimize BC production processes and explore new industrial applications. Using organic waste in BC production can help industries adopt sustainable practices, reduce environmental footprints, and create high-value materials.

Production and Characterization of Electrospun Chitosan, Nanochitosan and Hyaluronic Acid Membranes for Skin Wound Healing.

The development of new wound dressings made from biomaterials, which offer a better cost-benefit ratio and accelerate the healing process, is increasing nowadays. Various biopolymers can be electrospun to form functional membranes for wound healing. Therefore, in this study, chitosan and nanochitosan membranes with or without hyaluronic acid were prepared using the electrospinning technique, characterized and evaluated in the healing of skin wounds in rats. Chitosan and nanochitosan solutions, with or without hyaluronic acid, were prepared at concentrations of 1%-4% using PEO (polyethylene oxide) and subjected to the electrospinning process to obtain membranes characterized by scanning electron microscopy (SEM), mechanical tests, and antimicrobial activity. The healing effect of the membranes was evaluated by monitoring the area of the lesions, contraction of the wounds, histologic analysis, and induction of pro-inflammatory cytokine (IL-1 α and TNF-α) production in rats. The nanochitosan and nanochitosan membranes with hyaluronic acid achieved greater fiber diameter and uniformity, resistance, elasticity, and thermal stability, in addition to good adhesion to the wound bed and permeation capacity. Despite not presenting antimicrobial activity in vitro, they contributed to the production of pro-inflammatory interleukins in the animals tested, provided physical protection, reduced the wound area more markedly until the seventh day of the evaluation, with an acceleration of the healing process and especially when functionalized with hyaluronic acid. These results indicate that the membranes may be promising for accelerating the healing process of chronic wounds in humans.

Electrospun poly(ε-caprolactone)/poly(glycerol sebacate) aligned fibers fabricated with benign solvents for tendon tissue engineering.

The electrospinning technique is a commonly employed approach to fabricate fibers intended for various tissue engineering applications. The aim of this study is to develop a novel strategy for tendon repair through the use of aligned poly(ε-caprolactone) (PCL) and poly(glycerol sebacate) (PGS) fibers fabricated in benign solvents, and further explore the potential application of PGS in tendon tissue engineering (TTE). The fibers were characterized for their morphological and physicochemical properties; amniotic epithelial stem cells (AECs) were used to assess the fibers teno-inductive and immunomodulatory potential due to their ability to teno-differentiate undergoing first a stepwise epithelial to mesenchymal transition, and due to their documented therapeutic role in tendon regeneration. The addition of PGS to PCL improved the spinnability of the polymer solution, as well as the uniformity and directionality of the so-obtained fibers. The mechanical properties were in the range of most TTE applications, specifically in the case of PCL/PGS 4:1 and 2:1 ratios. Compared to PCL alone, the same ratios also allowed a better AECs infiltration and growth over 7 days of culture, and triggered the activation of tendon-related genes (SCX, COL1, TNMD) and the expression of tenomodulin (TNMD) at the protein level. Concerning the immunomodulatory properties, both PCL and PCL/PGS fibers negatively affected the immunomodulatory profile of AECs, up-regulating both anti-inflammatory (IL-10) and pro-inflammatory (IL-12) cytokines over 7 days of culture. Overall, PCL/PGS 2:1 fibers fabricated with benign solvents proved to be the most suitable composition for TTE application based on their topographical cues, mechanical properties, biocompatibility, and teno-inductive properties.

ZIF-67 Assists ultra-high piezoelectric output based on PVDF flexible nanogenerator

As smart electronics and self-powered devices continue to evolve, the emergence of piezoelectric polymers has sparked significant research interest. In this pioneering project, we have successfully synthesized ZIF-67 particles/tetrabutylammonium hexafluorophosphate (TBAHP)/polyvinylidene fluoride (PVDF) tree-like nanofiber structures for the first time, which was characterized by a large number of branching nanofibers (down to 5 nm) and a uniform diameter trunk fiber (about 400 nm). And the synergistic interaction between these two distinct additives yields exceptional multifunctional properties. By optimizing the quantities of ZIF-67 and TBAHP, we enhanced the β-phase content and piezoelectric performance of PVDF through diameter refinement, interface coupling enhancement, and the introduction of a micro-capacitance mechanism. Notably, the improvements surpassed those achieved with a single additive. Specifically, the piezoelectric energy harvester fabricated using TBAHP/PVDF-TLNMs doped with 0.5 wt% ZIF-67 exhibited an output current of 4.25 μA and a peak voltage of 17.32 V, marking an increase of approximately 1187 % and 831 %, respectively, over pure PVDF nanofiber membranes. Furthermore, the device demonstrated sensitivity to motor movements and effectively harvested energy from diverse bodily motions.

Study of the electrospun PVDF fibrous membrane in capturing particulate matters in smoke by the synergy between GO and CNWs

The filtration capability can be effectively adjusted by involving the incorporation of fillers into filter materials. Here, we present a promising filter material for capturing particulate matters in smoke, a polyvinylidene fluoride (PVDF) fibrous membrane modified by cellulose nanowhisker (CNWs) and graphene oxide (GO), which was prepared by a facile electrospinning method. GO with oxygen-containing groups can improve the capability of capturing particle owing to its excellent adsorption performance. CNWs with highly ordered crystalline regions can alter the dimension and properties of PVDF fibers. The synergistic effect of GO and CNWs enabled uniform fiber diameter, higher porosity, and better filtration property as compared with that of pristine PVDF membranes. Experimental results demonstrated a significant improvement in the filtration efficiency of PVDF fibrous membranes after blending with GO and CNWs. The filtration data showed that the filtration efficiency (95.58%) of GO/CNWs/PVDF membrane was higher than that (87.68%) of CNWs/PVDF membrane and that (86.36%) of PVDF membrane. The reusability for capturing pollutants showed that the fibrous membrane could keep a certain filtration capability (93.85%) after 5 cycles. Computational results suggested there was an interaction between GO and smoke pollutants (monoterpene) and the addition of GO play an effect on the filtration efficiency of fibrous membranes. These results showed that GO/CNWs/PVDF fibrous membranes was ideal filter materials for air pollutant.

Genome-wide association study of fiber quality traits in US upland cotton (Gossypium hirsutum L.).

A GWAS in an elite diversity panel, evaluated across 10 environments, identified genomic regions regulating six fiber quality traits, facilitating genomics-assisted breeding and gene discovery in upland cotton. In this study, an elite diversity panel of 348 upland cotton accessions was evaluated in 10 environments across the US Cotton Belt and genotyped with the cottonSNP63K array, for a genome-wide association study of six fiber quality traits. All fiber quality traits, upper half mean length (UHML: mm), fiber strength (FS: gtex-1), fiber uniformity (FU: %), fiber elongation (FE: %), micronaire (MIC) and short fiber content (SFC: %), showed high broad-sense heritability (> 60%). All traits except FE showed high genomic heritability. UHML, FS and FU were all positively correlated with each other and negatively correlated with FE, MIC and SFC. GWAS of these six traits identified 380 significant marker-trait associations (MTAs) including 143 MTAs on 30 genomic regions. These 30 genomic regions included MTAs identified in at least three environments, and 23 of them were novel associations. Phenotypic variation explained for the MTAs in these 30 genomic regions ranged from 6.68 to 11.42%. Most of the fiber quality-associated genomic regions were mapped in the D-subgenome. Further, this study confirmed the pleiotropic region on chromosome D11 (UHML, FS and FU) and identified novel co-localized regions on D04 (FU, SFC), D05 (UHML, FU, and D06 UHML, FU). Marker haplotype analysis identified superior combinations of fiber quality-associated genomic regions with high trait values (UHML = 32.34mm; FS = 32.73gtex-1; FE = 6.75%). Genomic analyses of traits, haplotype combinations and candidate gene information described in the current study could help leverage genetic diversity for targeted genetic improvement and gene discovery for fiber quality traits in cotton.

Fabrication of Laminated Electrospun Fire˗Resistant Phosphorylated Poly(Vinylalcohol) Membrane for Enhanced Firefighter Safety

AbstractThe current study focuses on the creation of breathable and fire˗retardant fibrous membranes using phosphorylated poly(vinylalcohol) (PPVA) via the electrospinning method, with a specific interest in their application for structural firefighter clothing. Poly(vinylalcohol) (PVA) was phosphorylated to enhance its inherent flame resistance. Optimization of reaction conditions, including time and temperature, was conducted to achieve a solution suitable for electrospinning. The flame resistance of PPVA was confirmed through vertical flammability tests, with thermogravimetric analysis indicating a significant increase in carbonaceous char formation during PPVA decomposition compared to unmodified PVA. The limiting oxygen index also exhibited a notable increase from PVA to PPVA. Furthermore, the study established optimal operating conditions for producing uniform fibers, considering parameters such as polymer concentration, feed rate, tip to collector distance, and applied potential difference. The PPVA membrane demonstrated superior water vapor transmission rates compared to PVA, indicating enhanced breathability. The entire fabrication process utilized an environmentally friendly water‐based solvent. Additionally, a moisture‐cum‐thermal barrier layer (MCTB) was developed by laminating the PPVA fibrous membranes with microporous polytetrafluoroethylene and further with needle punch‐spunlaced OPAN fabric. Experimental assessments of the MCTB layer revealed satisfactory breathability and thermal performance, surpassing the standard requirements of 35 cal/cm2 for structural firefighting configuration.