Reduction In Fiber Diameter Research Articles

Extraction and characterization of cellulose from agricultural waste of hemp (<i>Cannabis sativa)</i> and parthenium (<i>Parthenium hysterophorus)</i>

The current study focused on the extraction of cellulose from two selected plants, hemp (Cannabis sativa) and parthenium (Parthenium hysterophorus). The research successfully isolated high-purity cellulose from both plants using a chlorination and alkaline extraction process. A higher yield (%) (38.4 ± 0.18) was obtained from hemp compared to parthenium (22 ± 0.82). Characterization techniques were used to probe the structure and properties of the extracted cellulose. Fourier transform infrared spectroscopy analysis revealed functional groups characteristic of cellulose, while X-ray diffraction confirmed its highly crystalline structure in both samples. Scanning electron microscopy provided valuable insights into the cellulose morphology, indicating a smoother surface and reduced fiber diameter after treatment due to the removal of noncellulosic components. The research paved the way for the development of eco-friendly bioproducts utilizing cellulose from hemp and parthenium, promoting a more sustainable future.

Carbon fibres: Effect of various thermo-oxidative environments on structural and performance damage, both alone and in composites

This study examines the effects of heat and fire on the physical, mechanical and electrical properties of carbon fibre and those in carbon fibre reinforced composites (CFRCs). Carbon fibres were exposed to controlled heating (thermogravimetric analysis (TGA) and a tube furnace) in inert and air (oxygenated) environments and simulated fire (cone calorimetry at 35–75 kW m−2 and jet fire (propane burner) of 116 kW m−2) atmospheres. In inert atmospheres there was a minimal effect on the properties of carbon fibres, but in an oxygenated environment, significant oxidation began at temperatures ≥550 °C, resulting in a reduction in fibre diameter, which reduced further with increasing temperature and exposure duration. Tensile strength and electrical conductivity of carbon fibre decreased with reduction in fibre diameter. CFRCs exposed to 75 kW m−2 in a cone calorimeter and direct flame in a propane burner (116 kW m−2) showed varying degrees of oxidation in CFRC plies, with surface ply fibres experiencing more oxidation and consequent reductions in fibre diameter and tensile properties compared to fibres in underlying plies, where oxidation was limited due to restricted oxygen availability. Fibres exposed to the propane burner exhibited notable damage, including pitting and internal oxidation. Despite this, the overall electrical properties of residual carbon fibres did not significantly decrease, indicating that they still pose an electrical hazard if exposed during a high heat or fire event.

Dual-layer nanofibrous PCL/gelatin membrane as a sealant barrier to prevent postoperative pancreatic leakage

Post-operative pancreatic leakage is a severe surgical complication that can cause internal bleeding, infections, multiple organ damage, and even death. To prevent pancreatic leakage and enhance the protection of the suture lining and tissue regeneration, a dual-layer nanofibrous membrane composed of synthetic polymer polycaprolactone (PCL) and biopolymer gelatin was developed. The fabrication of this dual-layer (PGI-PGO) membrane was achieved through the electrospinning technique, with the inner layer (PGI) containing 2% PCL (w/v) and 10% gelatin (w/v), and the outer layer (PGO) containing 10% PCL (w/v) and 10% gelatin (w/v) in mixing ratios of 2:1 and 1:1, respectively. Experimental results indicated that a higher gelatin content reduced fiber diameter enhanced the hydrophilicity of the PGI layer compared to the PGO layer, improved the membrane’s biodegradability, and increased its adhesive properties. In vitro biocompatibility assessments with L929 fibroblast cells showed enhanced cell proliferation in the PGI-PGO membrane. In vivo studies confirmed that the PGI-PGO membrane effectively protected the suture line without any instances of leakage and promoted wound healing within four weeks post-surgery. In conclusion, the nanofibrous PGI-PGO membrane demonstrates a promising therapeutic potential to prevent postoperative pancreatic leakage.

Dynamic behavior and mechanistic analysis in filtration of dilute particulate suspensions through nanofibrous membrane

Nanofibrous membranes have garnered significant interest in membrane filtration due to their high porosity, small pore sizes, and complex interconnected pore structures. Although many studies focus on size exclusion in surface filtration, the filtration behavior and mechanisms for particles smaller than the pore size have been relatively underexplored. In this study, membrane filtration using nanofibrous membranes was employed to elucidate the filtration behavior and mechanisms for polystyrene latex suspensions with particles smaller than the pore size. The results indicated that reducing fiber diameter decreases the pore size and enhances particle rejection, with particle retention occurring within the intricate three-dimensional nanofiber pore network. In contrast, the effect of the membrane’s basis weight was less significant compared to fiber diameter. This observation can be attributed to the concept of effective thickness; once this thickness is exceeded, particles are prevented from penetrating deeper into the membrane. The filtration model was analyzed using Hermans-Bredée blockage filtration theory and cake filtration theory, considering the mass of trapped particles within the membranes. The model characterizes the filtration process as initially following standard blocking, progressing to cake filtration once a sufficient number of pores become clogged.

Fabrication and Characterization of Polycaprolactone-Baghdadite Nanofibers by Electrospinning Method for Tissue Engineering Applications.

This work investigates the essential constituents, production methods, and properties of polycaprolactone (PCL) and Baghdadite fibrous scaffolds. In this research, electrospinning was used to produce fiber ropes. In this study, the Baghdadite powder was synthesized using the sol-gel method and incorporated into PCL's polymeric matrix in formic acid and acetic acid solvents. The present work examined PCL-Baghdadite fibrous scaffolds at 1%, 3%, and 5 wt% for morphology, fiber diameter size, hydrophilicity, porosity, mechanical properties, degradability, and bioactivity. The introduction of Baghdadite nanopowder into pure PCL scaffolds reduced fiber diameter. The wetting angle decreased when Baghdadite nanopowder was added to fibrous scaffolds. Pure PCL reduced the wetting angle from 93.20° to 70.53°. Fibrous PCL scaffolds with Baghdadite nanopowder have better mechanical characteristics. The tensile strength of pure PCL fibers was determined at 2.08 ± 0.2 MPa, which was enhanced by up to 3 wt% by adding Baghdadite nanopowder. Fiber elasticity increased with tensile strength. Baghdadite at a 5% weight percentage reduced failure strain percentage. Fibers with more Baghdadite nanopowder biodegrade faster. Adding Baghdadite ceramic nanoparticles resulted in increased bioactivity and caused scaffolds to generate hydroxyapatite. The results show that Baghdadite PCL-3 wt% fibers have promising shape, diameter, and mechanical qualities. After 24 h, L-929 fibroblast cell viability was greater in the scaffold with 3% Baghdadite weight compared to the pure PCL. PCL-3 wt% Baghdadite fibers generated hydroxyapatite on the surface and degraded well. Based on the above findings, PCL fibers having 3 wt% of Baghdadite are the best sample for tissue engineering applications that heal flaws.

Enhancing electrochemical properties of bacterial cellulose-derived carbon nanofibers through physical CO2 activation

Carbon nanofiber (CNF) derived from carbonization of bacterial cellulose (BC), with a unique three-dimensional porous nanostructure, has received significant interest in electrochemical applications. In this study, CNF samples were physically activated in CO2 at different temperatures and durations. Raman spectroscopy and FTIR analysis showed that CO2 activation caused hexagonal lattice defects, disorder, and oxygen-related functional groups in an amorphous carbon structure. CNF surface morphology changed after physical activation, reducing fiber diameter to 55 nm and introducing mesopores. Through activation temperature and time adjustments, surface area (870.1 m2/g) and micropore surface area (535.6 m2/g) and pore volume (0.2148 cm3/g) increased. EDX elemental analysis showed that activated CNF had a carbon concentration of > 90 %, while XPS analysis showed surface functional groups like C-C (sp2) and C-C (sp3) hybridization, which could improve electrolyte ion adsorption and accessibility. Electrochemical properties improved owing to CO2 activation. The optimal activation condition of 800 ℃ for 60 min resulted in the highest specific area capacitance of 552 mF cm−2 at 1 mA cm−2. This activated CNF electrode retained capacitance nearly unchanged up to 3,000 cycles. It also achieved the highest energy density of 76.7 mWh cm−2 at 500 mW cm−2. This study demonstrates the efficacy of CO2 physical activation for enhancing the electrochemical properties of CNF electrodes. The findings also highlight the importance of tailoring activation conditions, providing valuable insights for the design of advanced energy storage materials.

Fenton-Based Treatment of Flax Biomass for Modification of Its Fiber Structure and Physicochemical Properties

The availability of a sustainable technique for degumming lignocellulose fibers is a challenge for the fiber processing industry. Removal of non-cellulosic content from lignocellulose fibers is essential for improving their mechanical and chemical properties, which makes the fibers more suitable for various applications. Herein, a catalytic Fenton-based oxidation process was employed to isolate microcellulose fibers from raw flax fibers. Various complementary methods such as FT-IR/NMR spectroscopy and TGA were used to obtain insight into the thermal behavior of the treated fibers. The morphology of the fibers was studied using Scanning Electron Microscopy (SEM), whereas the surface chemical properties of the fibers was evaluated by a dye-based adsorption method, along with a potentiometric point-of-zero-charge method. To obtain fibers with suitable properties, such as uniform fiber diameter, several Fenton reaction parameters were optimized: pH (7), reaction time (15 h), iron sulfate (2 wt.%), and hydrogen peroxide (10 wt.%). The results indicate that, under the specified conditions, the average diameter of the raw fibers (12.3 ± 0.5 µm) was reduced by 58%, resulting in an average diameter of 5.2 ± 0.3 µm for the treated fibers. We demonstrate that the treated fibers had a lower dye adsorption capacity for methylene blue, consistent with the smoother surface features of the treated fibers over the raw flax fibers. Overall, this study contributes to utilization of the Fenton reaction an efficient oxidation technique for the production of lignocellulose fibers with improved physicochemical properties, such as reduced fiber diameter distribution, in contrast with traditional alkali-based chemical treatment.

Centrifugally spun hydroxyapatite/carbon composite nanofiber scaffolds for bone tissue engineering

In recent years, advancements in tissue engineering have demonstrated the potential to expedite bone matrix formation, leading to shorter recovery times and decreased clinical challenges compared to conventional methods. Therefore, this study aims to develop composite carbon nanofibers (CNFs) integrated with nano-hydroxyapatite (nHA) particles as scaffolds for bone tissue engineering applications. A key strategy in achieving this objective involves harnessing nanofibrous structures, which offer a high surface area, coupled with nHA particles expected to accelerate bone regeneration and enhance biological activity. To realize this, polyacrylonitrile (PAN)/nHA nanofibers were fabricated using the centrifugal spinning (C-Spin) technique and subsequently carbonized to yield CNF/nHA composite structures. Scanning Electron Microscopy (SEM) confirmed C-Spin as a suitable method for PAN and CNF nanofiber production, with nHA particles uniformly dispersed throughout the nanofibrous structure. Carbonization resulted in reduced fiber diameter due to thermal decomposition and shrinkage of PAN molecules during the process. Furthermore, the incorporation of nHA particles into PAN lowered the stabilization temperature (by 5 °C–20 °C). Tensile tests revealed that PAN samples experienced an approximately 80% increase in ultimate tensile strength and a 187% increase in modulus with a 5 wt.% nHA loading. However, following carbonization, CNF samples exhibited a 50% decrease in strength compared to PAN samples. Additionally, the addition of nHA into CNF improved the graphitic structure. The incorporation of nHA particles into the spinning solution represents a viable strategy for enhancing CNF bioactivity.

Investigating the impact of thymol/ɤ-cyclodextrin concentrations on the properties of electrospun PLA/PVP nanofibers for packaging applications

This study focuses on the modification of Polylactic acid (PLA)/polyvinylpyrrolidone (PVP) nanofibers using thymol-loaded cyclodextrin (TC) to optimize their suitability for applications in food science and packaging. The researchers conducted a comprehensive investigation into the impact of TC concentration on the nanofiber morphology, chemistry, and functionality. Scanning electron microscopy (SEM) analysis revealed that the modification with TC led to a reduction in fiber diameter and an increase in bead formation compared to the unmodified nanofibers. Fourier transform infrared spectroscopy (FTIR) analysis confirmed chemical alterations resulting from TC incorporation. The mechanical properties of the nanofibers were significantly enhanced with increasing TC content, as demonstrated by increased tensile strength and reduced elongation. This indicates improved mechanical strength and resilience of the nanofibers. Furthermore, the modified nanofibers exhibited notable improvements in antioxidant and antibacterial activities. They demonstrated remarkable antibacterial efficacy against both E. coli and S. aureus. This suggests that the incorporation of TC enhanced the antimicrobial properties of the nanofibers. Thymol release from the nanofibers reached its peak at a TC concentration of 10 %. This indicates that the release of thymol can be optimized by adjusting the TC content in the nanofibers. Overall, the results of this study demonstrated improved properties such as moisture management, mechanical properties, and antimicrobial activity in the modified nanofibers. These findings highlight the suitability of TC-modified nanofibers for various applications in the food industry, particularly in food science and packaging.

Aligned polycaprolactone/polyaniline electrospun nanofibers for directing neural stem cell differentiation and neuron arrangement

The use of engineered biomimetic substrates combined with neural stem cells (NSCs) constitutes a promising approach to develop reliable in vitro models of the nervous tissue. The fabrication of scaffolds with suitable compositional, topographical, and electrical properties is crucial for directing neural cell adhesion, differentiation, and arrangement. Herein, we propose the development of electroconductive polycaprolactone/polyaniline (PCL/PANI) electrospun mats as functional substrates for NSC culture. A rotating drum collector was employed to obtain fibers with aligned geometry. According to the results, the increase in alignment contributed to the reduction of fiber diameter and the increase of scaffold mechanical properties in terms of elastic modulus and tensile strength. In vitro experiments demonstrated the ability of PCL/PANI membranes to support NSC attachment and growth, as well as significantly foster neuronal differentiation. Furthermore, the presence of an aligned pattern was shown to effectively influence the arrangement of NSC-derived neurons, confirming the potential of this substrate for the design of a physiologically relevant culture platform for in vitro investigation of the nervous tissue.

Tailoring of Gelatin-Chitosan Nanofibers Functionalized with Eucalyptus Essential Oil via Electroblowing for Potential Food Packaging and Wound Dressing Applications

In recent years, new approaches to fabricating nanofiber networks for potential applications in wound dressing and food packaging have been in the spotlight. This study aimed to produce functional webs based on gelatin, chitosan, and eucalyptus essential oil using the electro-blowing method instead of traditional spinning methods such as electrospinning. The resultant nanofiber webs exhibit promising morphological characteristics, including reduced fiber diameters, enhanced air permeability, and improved thermal stability. The integration of chitosan and eucalyptus essential oil overcomes limitations associated with gelatin, offering enhanced mechanical properties, antibacterial efficacy, and potential attributes for wound healing and food packaging. The combination of gelatin and chitosan contributes to biodegradability and biocompatibility, crucial for developing materials compatible with the natural environment. The addition of eucalyptus essential oil provides an additional layer of antimicrobial protection, aligning with sustainability goals in wound care and active food packaging. A comprehensive analysis encompassing SEM morphologies, fiber diameters, air permeability, FTIR spectra, TGA thermograms, and contact angle measurements establishes a thorough understanding of the fabricated nanofiber webs’ characteristics. Despite the favorable properties exhibited by the developed nanofiber webs for wound healing and food packaging applications, the incorporation of eucalyptus essential oil resulted in a reduction in tensile strength and elongation ratios. This observation highlights the necessity for further optimization and fine-tuning of the formulation to strike a balance between antimicrobial benefits and mechanical properties. Distinguished by its unique combination of gelatin, chitosan, and eucalyptus essential oil, this research contributes to the advancement of nanofiber technology, expanding knowledge in the field and paving the way for the development of advanced materials with enhanced therapeutic properties for wound healing and food packaging.Graphical

Submicron PAN and nanofiber CTA air filters: Fabrication, optimization, and performance

This study investigates the fabrication, optimization, and performance of submicron polyacrylonitrile (PAN) and nanofiber cellulose triacetate (CTA) air filters produced through electrospinning. PAN fibers with diameters ranging from 379 to 804 nm were generated from PAN/DMF solutions, while genuine CTA nanofibers (65–102 nm) were successfully produced using a recycled CTA polymer and a binary solvent system (DMSO/TCM). The effects of electrospinning parameters, including solution concentration (10–12 wt% for PAN, 8 wt% for CTA), applied voltage (10–16 kV), tip-to-collector distance (16–24 cm), solution supply rate (0.08–0.10 mL/hr), and binary solvent ratio (7:1 to 20:1 DMSO/TCM), on fiber morphology and diameter were systematically examined. Reducing PAN solution concentration and increasing applied voltage effectively decreased fiber diameter, enhancing filtration efficiency. Filtration performance tests revealed that CTA nanofibers outperformed PAN submicron fibers, exhibiting higher quality factors (0.043–0.046 Pa−1) due to their smaller fiber diameters and increased fiber packing density. Decreasing CTA solution supply rate and increasing DMSO/TCM ratio reduced fiber diameter and increased packing density. Longer spinning collection times improved filtration efficiency but increased thickness and pressure drop. The optimization of electrospinning parameters proved crucial for controlling fiber diameter and achieving enhanced filtration efficiency, particularly at the most penetrating particle size (MPPS), which usually covers the ultrafine particle size range. This study provides valuable insights into the development of high-performance air filtration media through the optimization of electrospinning parameters and the utilization of recycled materials.

Effects of macro basalt fibers on the tensile behavior of ultra-high performance concrete

Macro basalt fibers (MBF), which is also named as basalt fiber reinforced polymer (BFRP) minibar, is a novel kind of fiber manufactured with BFRP. This work studied the effects of MBF on the tensile behavior of ultra-high performance concrete (UHPC) and proposed some MBF optimization recommendations based on the experimental results. Nine kinds of UHPC with MBFs and two kinds of UHPC with steel fibers or polypropylene (PP) fibers were designed for the tests of fiber distribution, density, compressive and tensile behavior. According to test results, UHPC with MBFs showed a more ideal fiber distribution compared to UHPC with steel fibers and PP fibers. For the samples with MBFs, UHPC with 3 % twisted MBFs had the highest compressive strength, tensile strength and ultimate tensile strain, which were 138.9 MPa, 8.14 MPa and 1714 με, respectively. Compared to UHPC with steel fibers, UHPC with MBFs had slightly lower density and mechanical properties, but a similar stain-stress relationship. Thereby, the linear-exponential softening model was adopted to show the tensile stain-stress relationship of UHPC with MBFs. Based on the test results, three recommendations for optimizing MBF, which contained reducing fiber diameter for larger aspect ratio, optimizing fiber shape for higher fiber-UHPC bonding behavior and increasing the fiber modulus, were proposed to improve the mechanical properties of UHPC with MBFs.

Optimization of Polycaprolactone and Type I Collagen Scaffold for Tendon Tissue Regeneration.

Introduction Collagen synthesis is vital for restoring musculoskeletal tissues, particularly in tendon and ligamentous structures. Tissue engineering utilizes scaffolds for cell adhesion and differentiation. Although synthetic scaffolds offer initial strength, their long-term stability is surpassed by biological scaffolds. Combining polycaprolactone (PCL) toughness with collagen in scaffold design, this study refines fabrication via electrospinning, aiming to deliver enduring biomimetic matrices for widespread applications in musculoskeletal repair. Methods Electrospinning employed four solutions with varied collagen and PCL concentrations, dissolved in chloroform, methanol, and hexafluoro-2-propanol. Solutions were combined to yield 60 mg/mL concentrations with different collagen/PCL ratios. Electrospinning at 12-14kV voltage produced scaffolds, followed by vacuum-drying. Collagen coating was applied to PCL and 15% collagen/PCL scaffolds using a 0.1% collagen solution. SEM characterized fiber morphology, tensile testing was conducted to determine the mechanical properties of the scaffold, and Fourier-transform infrared (FTIR) spectroscopy analyzed scaffold composition. Atomic force microscopy (AFM) analyzed the stiffness properties of individual fibers, and a finite element model was developed to predict the mechanical properties. Cell culture involved seeding human bone marrow mesenchymal stem cells onto scaffolds, which were assessed through Alamar Blue assay and confocal imaging. Results Various scaffolds (100% PCL, PCL-15% collagen, PCL-25% collagen, PCL-35% collagen) were fabricated to emulate the extracellular matrix, revealing collagen's impact on fiber diameter reduction with increasing concentration. Tensile testing highlighted collagen's initial enhancement of mechanical strength, followed by a decline beyond PCL-15% collagen. FTIR spectroscopy detected potential hydrogen bonding between collagen and PCL. A finite element model predicted scaffold response to external forces which was validated by the tensile test data. Cell viability and proliferation assays demonstrated successful plating on all scaffolds, with optimal proliferation observed in PCL-25% collagen. Confocal imaging confirmed stem cell integration into the three-dimensional material. Collagen coating preserved nanofiber morphology, with no significant changes in diameter. Coating of collagen significantly altered the tensile strength of the scaffolds at the macro scale. AFM highlighted stiffness differences between PCL and collagen-coated PCL mats at the single fiber scale. The coating process did not significantly enhance initial cell attachment but promoted increased proliferation on collagen-coated PCL scaffolds. Conclusion The study reveals collagen-induced mechanical and morphological alterations, influencing fiber alignment, diameter, and chemical composition while emphasizing scaffolds' vital role in providing a controlled niche for stem cell proliferation and differentiation. The optimization of each of these scaffold characteristics and subsequent finite element modeling can lead to highly repeatable and ideal scaffold properties for stem cell integration and proliferation.

Shear wave propagation in a fiber-laden viscoelastic waveguide under prestress: Inverse modeling challenges

The functional role of skeletal muscle and the hierarchal microstructure and arrangement of fibers within it results in anisotropy and inhomogeneity in both material properties and imposed stresses. Dynamic elastography reconstruction methods for estimating muscle tissue viscoelastic properties that are based on assumptions of homogeneity, isotropy and only bulk wave motion may produce inaccurate estimates. Biases may be introduced in reconstruction by homogenizing muscle with axially aligned fibers and approximating it as transversely isotropic. The significance of these biases, and their interplay with imposed stresses and confounding waveguide effects due to small cross-sectional dimensions, is quantified with a series of numerical finite element and experimental elastography studies on cylindrically-shaped fiber-laden muscle phantoms, with varying fiber dimensions. Specifically, numerical simulations of elastography are conducted on 4-, 60- and 113-fiber models with the aligned fiber cross-sectional area fixed (reduced fiber diameter as fiber count increases) and comprising approximately 40% of the cross-sectional area of the cylindrical phantom that is also undergoing tensile axial pre-loading. Fiber elastic moduli twice that of connective tissue are considered. Experimental studies of the 4-fiber model are used to validate the numerical model. [Funding support: NSF 1852691 and NIH AR071162]

A novel antioxidant and antimicrobial food packaging based on Eudragit ®/collagen electrospun nanofiber incorporated with bitter orange peel essential oil

A novel nanofiber for potential use in food packaging was developed by blending Eudragit ® (Eu) and collagen (Co) at varying ratios. Among these blends, Eu/Co nanofiber with a 70:30 ratio was identified as the optimal composition due to its bead-free morphology, fine fiber diameter (279.6 nm), high tensile stress (6.9 MPa), desirable water contact angle (WCA) of 72.18°, low water vapor transmission rate (WVTR) of 423.51 g/m2 × 24 h, and favorable porosity (65.4%). To further enhance its properties, bitter orange peel essential oil (BE) (up to 100 μL/mL) was incorporated into the optimal blend, resulting in a reduced fiber diameter (211.6 nm), increased tensile stress (8.5 MPa), and enhanced porosity (73.5%). Moreover, BE induced potential antimicrobial and antioxidant activities in the nanofibers, effectively inhibiting the growth of E. coli and S. aureus bacteria while scavenging up to 50% of DPPH radicals, respectively. Importantly, none of the nanofiber samples exhibited cytotoxicity toward Human umbilical vein endothelial cells (HUVEC) over a 72-h period, demonstrating their biocompatibility. These findings highlight the suitability of Eu and Co-based nanofibers enriched with bioactive compounds like BE for use in food packaging applications.

Cold atmospheric plasma modified polycaprolactone solution prior to electrospinning: A novel approach for improving quercetin-loaded nanofiber drug delivery systems

In this study, we present a novel approach for enhancing the performance of Quercetin-loaded nanofiber drug delivery systems through the modification of Polycaprolactone (PCL) solution using Cold Atmospheric Plasma (CAP) prior to electrospinning. CAP treatment was applied to PCL solutions for varying durations, namely, 0.5, 1, and 3 min. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) collectively demonstrate that CAP application and QU loading induce morphological changes in nanofibers, facilitating the creation of drug delivery systems with modified fiber diameters, devoid of bead formation. CAP treatment duration correlates with varying fiber diameters, with the longest treatment (3 min) producing the largest fibers (1324 ± 387 nm). Concurrently, the incorporation of quercetin (QU) into the PCL nanofibers resulted in reduced fiber diameter. These observations emphasize the pivotal role of CAP modification in tailoring nanofiber size and morphology. Notably, minimal peak shifts indicate no significant molecular structure changes in PCL nanofibers compared to PCL solutions, assuring the absence of unwanted chemical modifications or degradation during electrospinning. Furthermore, specific QU peaks are undetectable in Fourier-transform infrared (FTIR) spectra, suggesting dispersed or amorphous QU molecules within the nanofibers. Additionally, X-ray diffraction (XRD) results demonstrate that CAP treatment does not alter the crystalline structure of the PCL nanofiber drug delivery system. Crystalline planes of PCL remain unchanged, affirming stability under CAP treatment conditions. Water contact angles indicate that CAP treatment affects nanofiber hydrophobicity, with shorter CAP treatment times rendering more hydrophilic surfaces. Cumulative QU release percentages vary, with PCL/CAP-0.5-QU exhibiting the highest release at 56 ± 2.2 %, surpassing unmodified PCL/QU. Moreover, cell viability remains comparable or slightly increased when QU is incorporated into CAP-treated PCL nanofibers, suggesting potential mitigation of cytotoxic effects induced by CAP treatment. The combination of QU and CAP treatment enhances cancer cell viability reduction, QU release from nanofibers, and drug loading efficiency in a synergistic manner.

Effects of Fiber Treatment and Humidity on the Mechanical, Fracture Toughness, Dynamic and Thermal Properties of Grewia Optiva Natural Fiber Reinforced Epoxy Composites

Abstract The effects of relative humidity, and fiber treatment on the mechanical properties of Grewia Optiva natural fibres reinforced composites were studied. The results revealed that the fiber reinforcement composition with Benzoyl peroxide treatment on NaOH pretreated fiber (BP) shows optimum results at 90% relative humidity. The corresponding experimental results of the tensile strength (MPa), % elongation, flexural strength (MPa), impact strength (kJ/m2), and fracture toughness (MPa vm) were 260.895, 5.230, 52.572, 33.226, and 2.565 respectively. The surface response method yielded the optimum properties with D value as 0.768 and properties variation between 1 to 6%. TGA analysis shows a considerable amount of variation in the rate of degradation after the chemical treatment of fibers. Decrease in the damping factor and increase in glass transition temperature due to chemical treatment shows increased fiber matrix interfacial bonding and cross linking. SEM images show that BP treatment is more suitable than NaOH treatment to remove the undesirable elements from the fiber surface and higher surface roughness to obtain better bonding between fibre and matrix. The fiber diameter reduction due to BP and NaOH treatment is about 57 %, and 52.62 % as compared to untreated fiber.

The modeling of meso-structure of fiber/particle composites and its influence on ETC under different inner pressure: A comprehensive study by RNMG-LBM

Fiber/Particle composites (FPCs) have garnered increasing attention as promising insulation materials in the energy field. Establishing a suitable composite model that can be used to investigate each component is essential. In this paper, the random non-contact multi-phase generation (RNMG) method was proposed for generating the meso-structure of FPCs. Furthermore, a comprehensive investigation was conducted using the Lattice Boltzmann Method (LBM) to quantify the influence mechanisms of various physical parameters, including inner pressure, aspect ratio, and particle diameter, as well as orientation angle, on the effective thermal conductivity (ETC) of FPCs. The validity of the RNMG-LBM was examined by comparing its results with experimental data. The simulation results demonstrated that reducing the particle diameters from 5 nm to 2 nm in FPCs leads to decreased pore sizes. Consequently, this reduces the sensitivity of FPCs to pressure fluctuations in the range of 10−1 Pa–105 Pa. Moreover, a physical parameter, called the orientation angle, was introduced to describe and explore the relationship between heat flux orientation and fiber orientation. The findings revealed that when the fiber was oriented perpendicular to the heat flux direction, it exhibited the lowest ETC among the orientation angles ranging from 0° to 90°. In addition, both the diameter and aspect ratio of fiber impacted its thermal properties. It's suggested controlling the aspect ratio below 20 and reducing fiber diameter as much as possible will significantly decrease the ETC of FPCs. The conclusions are valuable for optimizing the manufacturing process of FPCs and further improving their insulation capacity.

Driving fiber diameters to the limit: nanoparticle-induced diameter reductions in electrospun photoactive composite nanofibers for organic photovoltaics

Electrospun photoactive nanofibers hold significant potential for enhanced photon absorption and charge transport in organic photovoltaics. However, electrospinning conjugated polymers with fiber diameters comparable to exciton diffusion lengths for efficient dissociation, is difficult. Previously, spinning sub-100 nm poly(3-hexylthiophene) (P3HT) fibers has required the auxiliary polymer, poly(ethylene oxide) (PEO), and large antisolvent additions. Therefore, its success differs considerably across donor polymers, due to variable antisolvent addition limits before precipitation. Herein, plasmonic nanoparticle infusion into P3HT nanofibers is used to modulate viscosity and deliver a novel and unrivaled strategy to achieve reduced fiber diameters. Following PEO removal, the fibers measure 55 nm in diameter, 30% lower than any previous report – providing the shortest exciton diffusion pathways to the heterojunction upon electron acceptor infiltration. The nanoparticle-containing nanofibers present a 58% enhancement over their pristine thin-film counterparts. ~17% is ascribed to plasmonic effects, demonstrated in thin-films, and the remainder to along-fiber polymer chain alignment, introduced by electrospinning. The anisotropy of light absorbed when polarized parallel versus perpendicular to the fibers increases from 0.88 to 0.62, suggesting the diameter reduction improves the alignment, resulting in greater electrospinning-induced enhancements. Controlled by the electrospinning behavior of PEO, our platform may be adapted to contemporary donor-acceptor systems.Graphical A dramatic reduction in the diameters of electrospun photoactive nanofibers is achieved by introducing nanoparticles, offering shorter exciton pathways towards the heterojunction in nanofibrous OPVs. Thinner fiber diameters enhance the alignment of the polymer chains along the fiber, manifesting in greater photon absorption. Alongside plasmonic effects, the dual-mode enhancement within the fibers offers 58% additional light harvesting versus their thin-film counterparts.