Crystalline Fibers Research Articles

Immobilization of urea on beads based on OPEFB cellulose-alginate via blending to fabricate sustained release fertilizer

Transforming oil palm empty fruit bunches (OPEFB) waste into value-added cellulose as a reinforcement agent for eco-friendly slow-release fertilizer (SRF) composites is a strategy to achieve clean and sustainable production. OPEFB cellulose was isolated by alkalization (10 % w/v NaOH) for 1 h and bleaching (30 % v/v H2O2) for 1.5 h. The treatment increased the cellulose content to 80.88 %, reduced the non-cellulosic component, and improved the fiber crystallinity to 58.40 %. The hydrogel composite was cross-linked by blending urea in an OPEFB cellulose fiber (w/w) (0 %, 0.5 %, and 1 %) and sodium alginate (3 % w/w). Then, the wet beads were freeze-dried to fabricate SRF composites. Each material was evenly dispersed in the matrix, had a porous structure, and could bind total nitrogen up to 20.0 %, confirmed by the Kjeldahl method. Adding cellulose increased crystallinity (significant at 1 % w/w cellulose), decreased bulky density (significant at 0.5 % and 1 % w/w cellulose), increased swelling capacity (significant at 0.5 % w/w cellulose), and water-retention capacity. Reinforced composite with 0.5 % (w/w) cellulose released nitrogen into the soil (Fickian diffusion) following the Higuchi model (R2 = 0.957) with K = 0.0394 and equilibrium at around t1/2 = 1.8 h. Changing SRF composite properties are likely related to the porous structure loaded with urea crystals.

Tensile and Crystallization Behavior of Melt‐Spun Fibers Derived From Poly(Butylene Terephthalate‐Co‐2,6‐Naphthalate) Copolyester

ABSTRACTIn this study, a series of poly(butylene terephthalate‐co‐2,6‐naphthalate) (PBTN) copolymers was synthesized via a one‐step polycondensation process. These PBTN copolymers demonstrate excellent thermal stability and semi‐crystalline behavior, with the enthalpy of melting values exceeding 17 J g−1. Crystallization kinetics analysis revealed that the copolymers exhibit significantly higher crystallization rates than neat poly(butylene terephthalate) (PBT) and poly(butylene naphthalate) (PBN), making them well‐suited for fiber production. The copolymers were melt‐spun, followed by a post‐drawing process at a ratio of 2.0, to enhance fiber strength. By adjusting the 2,6‐naphthalene dicarboxylate (NDC) content, the mechanical properties and crystallinity of the PBTN fibers were fine‐tuned. Tensile testing revealed that the copolymer fiber containing 50 mol% NDC, post‐drawn at a ratio of 2.0, exhibits superior toughness, with maximum tenacity and elongation values of 3.13 g den−1 and 69.3%, respectively.

Advancing bamboo fiber reinforcement: A novel approach using eco-friendly plant ash alkali treatment

This study aimed to enhance the engineering performance of bamboo fibers for use in composite materials by employing a sustainable plant ash alkali treatment. The primary objective was to improve the tensile strength, crystallinity, and thermal stability of bamboo fibers, which are known for their high specific strength, low density, and biodegradability but suffer from poor compatibility with hydrophobic matrices. The study involved treating bamboo fibers with varying concentrations of plant ash solutions (5 %, 10 %, 20 %, and 30 % by mass fraction) and comparing the results with those from conventional NaOH treatment (5 % and 10 %). The results showed that plant ash treatment at a 20 % concentration significantly improved tensile strength by 14.16 % compared to untreated fibers, increased the crystallinity index to 74.31 %, and enhanced thermal stability, retaining more residual mass at high temperatures than NaOH-treated fibers. These improvements are attributed to the reduction in fiber polarity and better preservation of fiber structure. The findings suggest that plant ash, as a cost-effective and eco-friendly alternative to NaOH, can significantly enhance the mechanical and thermal properties of bamboo fibers, making them suitable for use in environmentally sustainable composite materials in construction, and other industries.

Designing an all-laser processing and operating microheater conceptual device for medical applications

Obstructive sleep apnea (OSA) is a prevalent condition affecting a significant portion of the population, with a reported prevalence of 33% and 19% in males and females, respectively. OSA is associated with an increased risk of sudden death, with studies suggesting nearly double the risk compared to individuals without OSA. The condition is characterized by frequent sleep disruptions due to airway collapse, often at the level of the tongue or soft palate. Current treatment approaches primarily rely on radiofrequency (RF) ablation for tissue volume reduction. While effective, this technique can cause significant collateral damage and postoperative pain due to extensive burning of surrounding tissues. To avoid such drawbacks, in this work it is proposed and discussed the features of a possible conceptual all-laser-processing and operating device that can produce localized heat affected zones, with the possibility to monitor the local temperature during the procedure. The device is based on the eutectic composition of the system Al2O3-YAG, with double doping Nd3+ and Cr3+ crystalline fiber tip, which is prepared by the Laser-Heated Pedestal Growth technique on a sapphire single crystal fiber end. The results showed that the tip, although highly Nd3+-doped, follows the Jackson-Hunt relation for binary eutectic compounds. The lifetime of the luminescence produced by the Cr3+ doping, emitted by the eutectic tip, can act as a temperature sensor for the device in the range of 30 to 100 °C.

In-Situ Oxidized MXene Dopes for Enhanced Sensitivity of PVDF Piezoelectric Nanogenerators in Morse Code Transmission and Photocatalysis Applications

The surface functionalization of MXenes with controlled termination groups alters various properties and expands its versatility. Here, we report a partially oxidized MXene-incorporated polyvinylidene difluoride (PVDF) fibrous piezo-nanogenerator mats termed as MOP performing functions of biomechanical energy harvesting, self-powered tactile sensing, and piezo-assisted photocatalyst application. In comparison with neat PVDF, MOP piezo nanogenerators (PENG) with 5 wt% dope (MOP(5)-PENG) show significant improvement in the output performance delivering an output voltage, current, and power density of 14.4 V, 1.6 μA, and 1.5 μW cm-2, respectively. The device reveals a high sensitivity of 3.7 V/KPa to tactile perceiving, which was applied for digital information transmission. The addition of oxidized MXene increases not only the β crystallinity of fibers but also their dielectric property which was attributed to the semi-conductive TiO2 formed during in-situ oxidation process. Moreover, the composite fibers can be employed as piezo-photocatalyst (PPC) for the degradation of Rhodamine B dye. The synergetic effect of light and piezoelectric action significantly improved the kinetics of degradation. A heterojunction formed between TiO2 and MXene further boosted the separation of photo-generated species and produced more active species for effective degradation up to 98%.

Isolation and extraction of microcellulose from Alpine galanga fiber

Bleaching and alkalization techniques enhance cellulose isolation and extraction, leading to higher yields and improved quality, but may cause inconsistencies in production and quality.This study investigates the extraction, characterization, and thermal properties of Alpine galanga fiber (AGF), a byproduct of traditional Indonesian herbal medicine. Utilizing hydrothermal bleaching and alkali treatments, the cellulose content in AGF was significantly enhanced, achieving a purity of up to 73%. These treatments effectively removed contaminants, improved fiber crystallinity as shown by X-ray diffraction (XRD) analysis, and enhanced surface features observed through scanning electron microscopy (SEM). Thermogravimetric analysis (TGA) identified several stages of thermal decomposition, with treated fibers exhibiting increased thermal resistance. The findings indicate that bleaching and alkalization techniques enhance the yield, quality, and chemical properties of AGF, highlighting its potential for industrial applications. Further optimization and focused investigations are recommended to fully exploit AGF in the development of biocomposites and environmentally friendly materials.

Continuous Phase Separation Induced Tough Hydrogel Fibers with Ultrahigh Conductivity for Multidimensional Soft Electronics

AbstractConductive hydrogel fibers exhibit great potential in soft robots, bioelectronics, and human–machine interfaces due to the unique combination of electrical conductivity, high water content, tissue‐like mechanical properties, and 1D structure. Despite significant advances in hydrogel technologies, the typical conductive hydrogel fibers show low conductivity (<10 S cm−1), weak mechanical properties, and water stability, which makes it challenging to satisfy the requirements of practical applications. Here, a facile strategy is proposed to construct hydrogel fibers with ultrahigh conductivity and toughness by exploiting the synergistic effects of freezing‐thawing, salting‐out, and drying‐annealing. The continuous phase separation induced by the combined processes results in hierarchical structures, promoting the formation of interconnected conductive networks and increasing the fiber's crystallinity and crystal domain size. The prepared conductive hydrogel fibers exhibited ultrahigh conductivity (≈958 S cm−1), excellent mechanical properties (strength (≈6.2 MPa), stretchability (>300%), and toughness (≈10 MJ m−2)), high water content (≈75%), outstanding water stability, and fatigue resistance properties. In addition, the processibility of conductive hydrogel yarns and fabrics are demonstrated and their potential application in bioelectronics. Overall, this work presents a preparation strategy for conductive hydrogel fibers, which will facilitate the advancement of soft electronics and may inspire structural construction in other polymers.

Logarithmic and Archimedean organic crystalline spirals

Crystals can be found in many shapes but do not usually grow as spirals. Here we show that applying a non-uniform layer of a polymer blend onto slender centimeter-size organic crystals prestrains the crystals into hybrid dynamic elements with spiral shapes that respond reversibly to environmental variations in temperature or humidity by curling. Exposure to humidity results in partial uncurling within several seconds, whereby a logarithmic-type spiral crystal is transformed into an Archimedean one. Conical helices obtained by lateral pulling of the spirals can wind around solid objects similar to plant tendrils or lift suspended objects with a positive correlation between the actuator’s elongation and the cargo mass. The morphological, kinematic, and kinetic attributes turn these hybrid materials into an attractive platform for flexible sensors and soft robots, while they also provide an approach to morph crystalline fibers in non-natural spiral habits inaccessible with the common crystallization approaches.

Chain rigidity controlled aggregation ability and solid-state microstructures for efficient stretchable conjugated polymer films

Stretchable conjugated polymer films with good electrical performance under mechanical deformation are highly desirable for soft electronics. However, the mechanical and electrical properties of these films, particularly in conjugated polymer:elastomer blends, are not fully understood at molecular level. This study explores the relationships among molecular structure, aggregation ability, film microstructure, and the electrical/mechanical properties of three diketopyrrolopyrrole -based conjugated polymers (P1, P2, P3) with decreasing backbone rigidity and their corresponding polymer:elastomer blends. The most flexible polymer P3 shows strong aggregation, which forms highly crystalline fibers to produce fragile neat film and produces large isolated crystallites restricting charge transport in blend film. As chain rigidity increases, the P1 and P2 polymers show weaker aggregation, and produce smaller crystallites in neat films with enhanced ductility. P1 and P2 based blend films display nanocrystallites polymer networks with dispersed elastomer domains. As a result, we achieved near-constant charge mobility before and after stretching under 50 % strain for P2-based blend films with well-controlled pathways for both charge transport and energy dissipation. This study demonstrates the critical role of backbone rigidity in regulating the properties of stretchable conjugated polymer films, paving the way for more reliable and deformable materials in soft electronics.

The effects of UV aging process on the structure and properties of high-tenacity poly(ethylene terephthalate) industrial fiber

The high-tenacity poly(ethylene terephthalate) (HT PET) industrial fibers (1100 dtex/192f) were fixed in position with a constant fiber length and subjected to accelerated artificial ultraviolet exposure with temperature of 50 °C to assess their degradation mechanism. The structural evolutions were evaluated using a combination of ex-situ wide-angle X-ray diffraction (WAXD), ex-situ small angle X-ray scattering (SAXS), Fourier transform infrared spectroscopy (FTIR), and intrinsic viscosity tests based on the relaxed aged samples after different aging process. The results indicate that the structures and properties evolutions of HT PET industrial fiber under UV aging process can be categorized into three stages. In the pre-aging stage (t ≤ 0.5d), the fiber experiences a slight decline in tenacity and thermal shrinkage properties due to the combined impact of UV radiation and heat treatment. Subsequently, in the mid-aging stage (0.5d < t ≤ 28d), a notable decrease in the fiber's elongation at break is observed, accompanied by visible macroscopic defects arising from photo-oxidative aging on the fiber surface after 16 days of exposure. While the fiber's unit cell and atomic positions remains stable on atomic scale, the lamellar thickness and long period witness a significant reduction owing to high-orientation molecular breakages in the mesophase region. Moreover, rearrangement of molecular chains leads to a reduction in the tilting angle. In the late-aging stage (t > 28d), the degradation rate of mechanical and thermal shrinkage properties of the fiber decelerates, alongside a decline in intrinsic viscosity. These results suggest that the fiber's crystallinity remains unchanged post UV aging, with the deterioration in mechanical properties of HT PET industrial fiber primarily attributed to molecular degradation during UV exposure.

Cross‐referenceable microscopic and micro‐spectroscopic analysis of fiber reinforced thermoplastics

AbstractThis study aims at the assessment of damage on crystallinity of fiber reinforced thermoplastic (FRTP) composites resulting from mechanical polishing to demonstrate a novel methodology enabling comprehensive crystalline structural characterization. Investigating the crystalline structure is relevant for understanding the relationship with the mechanical properties. In a previous study, FRTPs have successfully been processed to the thickness of 5 μm or below via an innovative polishing strategy, which for the first time visualized the crystalline morphologies by polarized optical microscopy. Analyzing these sections via micro‐Raman and micro‐infrared spectroscopies facilitate the quantification of these structure. However, no study reports on the correct interpretation of FRTP data appropriately considering the damage resulting from mechanical polishing to date. Herein, we report fundamental knowledge on this aspect via detailed Raman micro‐spectroscopic investigations to demonstrate our novel strategy. Four types of FRTPs with major matrix resins (GF/PBT, CF/PA6, CF/PEEK and GF/PP) were analyzed and the damage on both polished cross‐sections, prepared by traditional process, and the thin sections was confirmed to be approx. 1%–2% crystallinity, which solidified the credibility of the obtained analytical data. Then, the newly established methodology of ‘cross‐referenceable microscopic and micro‐spectroscopic analyses for FRTPs’ was applied for comprehensive crystalline structural characterization.Highlights Cross‐sectioning and thin‐sectioning of FRTPs. Evidencing of damage on the crystallinity resulting from mechanical polishing. Equations to convert Raman spectral data into crystallinity. Strategy for considering the anisotropy of Raman measurements. Practical application of novel microscopic and micro‐spectroscopic strategies.

Enhancing the Mechanical Properties of Regenerated Cellulose through High-Temperature Pre-Gelation

This paper investigates the effects of pre-gelation on cellulose dissolved in LiCl/DMAc solutions to enhance the properties of regenerated cellulose materials. This study focuses on characterizing the crystallinity, molecular orientation, and mechanical performance of cellulose fibers and hydrogels prepared with and without pre-gelation treatment. X-ray diffraction (XRD) analysis reveals that crystallinity improvement from 55% in untreated fibers to 59% in fibers pre-gelled for 3 and 7 days, indicating a more ordered arrangement of cellulose chains post-regeneration. Additionally, XRD patterns show improved chain alignment in pre-gelled fibers, as indicated by reduced full width at half the maximum of Azimuthal scans. Mechanical testing demonstrates a 30% increase in tensile strength and a doubling of the compression modulus for pre-gelled fibers compared to untreated fibers. These findings underscore the role of pre-gelation in optimizing cellulose material properties for applications ranging from advanced textiles to biomaterials and sustainable packaging. Future research directions include further exploration of the structural and functional benefits of pre-gelation in cellulose processing and its broader implications in material science and engineering.

Atomistic simulations of polysaccharide materials for insights into their crystal structure, nanostructure, and dissolution mechanism

AbstractCrystalline polysaccharides are abundant in nature and can be transformed into highly functional materials. However, the molecular basis for the formation of higher-order structures remains unclear. Computer simulation is an advanced tool for modeling macromolecular structures, and the atomistic simulations provide valuable information on the crystalline polysaccharides. Fiber deformation, crystalline transition, and novel nanostructures of cellulose were characterized through molecular dynamics simulations and density functional theory calculations of models of molecular chain sheets extracted from the crystal structure of the cellulose polymorphs. Extended ensemble molecular dynamics simulations were applied to analyze the artificial crystal structure of non-natural amylose analog polysaccharides, revealing the hexagonal packing of double helices through the self-assembly of molecular chains dispersed in aqueous solution. Dissolution simulations of the cellulose and chitin crystalline fibers revealed that the anions of ionic liquids, with their solvation power, played a key role in the cleavage of intermolecular hydrogen bonds in the crystal structure, whereas the cations contributed to irreversible molecular chain dispersion. The good correlation between the actual solubility of polysaccharides and the predicted number of intermolecular hydrogen bonds prompted the development of a platform that combined simulations and machine learning for high-throughput screening of solvents for cellulose and chitin.

Electrical and dynamic mechanical analysis of kenaf fiber reinforced epoxy composites hybridized with acacia concinna powder

The objective of this work is to create and analyze composites made of kenaf fibers and epoxy polymer, which are strengthened by the addition of Acacia concinna pod (ACP) powder. These composites are intended for use in electrical insulation applications. The study investigated the impact of alkali treatment using a 6% NaOH solution on kenaf fiber. The effects were analyzed in relation to the dielectric and dynamic mechanical properties, while also considering the addition of different quantities of ACP powder (0%, 4%, and 8%). The composites were produced using the hand layup method, and the dielectric constant, dissipation factor, storage modulus, loss modulus, and damping factor were assessed. The study demonstrated that NaOH-treated kenaf fiber composites displayed considerably lower dielectric constant values than untreated composites, due to increased fiber crystallinity and decreased moisture absorption. Dynamic Mechanical Analysis (DMA) found that untreated composites had greater storage modulus and glass transition temperature (Tg) due to reduced segmental motion at the fiber-matrix interface. SEM research indicated better fiber-matrix bonding in treated composites, with decreased voids and robust interlocking, notably in those containing 4% Acacia concinna (ACP) filler. These findings show that NaOH treatment substantially enhances the performance of hybrid composites for electrical insulating applications.

Simultaneously enhancing strength and toughness of coir fiber through NaOH and sodium alginate treatment

Coir fibers are commonly subjected to alkali treatment to eliminate impurities and tune their mechanical properties. However, this process can damage the fibers’ microstructures, posing a challenge in significantly enhancing both strength and toughness simultaneously. Herein, we successfully enhanced both strength and toughness of coir fibers through a combined treatment with NaOH and sodium alginate aqueous solution. Coir fibers treated with 5 wt% NaOH solution, followed by 0.5 wt% sodium alginate solution, exhibit a tensile modulus of 2475.0 MPa, a tensile strength of 126.4 MPa, and a toughness of 30.7 MJ/m³, representing improvements of 57.1 %, 72.7 %, and 116.2 %, respectively, compared to the raw fibers. Mechanistic studies revealed that NaOH treatment effectively removes pectin, hemicellulose and lignin from coir fibers but introduces numerous defects. Sodium alginate can repair these defects by forming hydrogen bonds with the rich oxygen-containing group of coir fibers. The combined treatment also increases the crystallinity of coir fibers from 30.3 % for the raw fibers to 44.1 % by removing a large number of amorphous substances. Additionally, the combined treatment reduces the microfibril angle from ∼63.6° to ∼46.6° by elongating the helix structure and filling the gaps between helical fibers. Our cost-effective strategy not only promotes the applications of coir fibers but also provides guidance for the modification of other natural plant fibers.

Two‐stage annealing method for short carbon fiber‐reinforced nylon 6 in fused filament fabrication

AbstractThe mechanical properties of short carbon fiber‐reinforced nylon 6 (CF‐PA6) components formed by fused filament fabrication (FFF) are significantly affected by the process parameters of additive manufacturing and heat treatment. In this study, the effects of printing speed, carbon fiber aspect ratio, and annealing temperature on fiber orientation were investigated by observation of single‐layer‐single‐fiber samples. Furthermore, a two‐stage annealing process was proposed to increase the tensile modulus of CF‐PA6 based on the correlation analysis results between the degree of fiber alignment and the variation of tensile modulus. According to the calculation of the Pearson correlation coefficient, the tensile modulus was highly correlated with the degree of fiber alignment under different printing speeds and fiber aspect ratios. The variation in tensile modulus and fiber orientation was also consistent when the annealing temperature was lower than the crystallization temperature. Conversely, the variation of tensile modulus and fiber orientation were opposite, as the annealing temperature was higher than the crystallization temperature because of the influence of crystallinity. Through increasing the degree of fiber alignment and crystallinity of the parts, the proposed two‐stage annealing method could increase the tensile modulus of the parts to 9.0 GPa, which was 16.81% higher than that of single‐temperature annealing.Highlights The effects of annealing temperature, carbon fiber aspect ratio and printing speed on fiber orientation were illustrated. The relationship between the degree of fiber alignment and the variation of tensile modulus was established. The proposed two‐stage annealing method, considering fiber orientation and crystallinity, significantly increased the tensile modulus of CF270‐PA6 parts from 7.7 to 9.0 GPa. The quantitative analysis of the fiber orientation is realized by the statistical analysis of the plane fiber orientation angle of the single‐layer‐single‐fiber sample.

In Situ Growth of Highly Compatible Cu2O-GO Hybrids Via Amino-Modification for Melt-Spun Efficient Antibacterial Polyamide 6 Fibers.

Polyamide 6 (PA6) fiber has the advantages of high strength and good wear resistance. However, it is still challenging to effectively load inorganic antibacterial agents into polymer substrates without antimicrobial activity. In this work, graphene oxide is used as a carrier, which is modified with an aminosilane coupling agent (AEAPTMS) to enhance the compatibility and antimicrobial properties of the inorganic material, as well as to improve its thermal stability in a high-temperature melting environment. Cuprous oxide-loaded aminated grapheme (Cu2O-GO-NH2) is constructed by in situ growth method, and further PA6/Cu2O-GO-NH2 fibers are prepared by in situ polymerization. The composite fiber has excellent washing resistance. After 50 times of washing, its bactericidal rates against Bacillus subtilis and Escherichia coli are 98.85% and 99.99%, respectively. In addition, the enhanced compatibility of Cu2O-GO-NH2 with the PA6 matrix improves the orientation and crystallinity of the composite fibers. Compared with PA6/Cu2O-GO fibers, the fracture strength of PA6/Cu2O-GO-NH2 fibers increases from 3.0 to 4.2 cN/dtex when the addition of Cu2O-GO-NH2 is 0.2wt%. Chemical modification and in situ concepts help to improve the compatibility of inorganic antimicrobial agents with organic polymers, which can be applied to the development of medical textiles.

Effect of temperature and relative humidity on the moisture recovery and specific resistance of yak hair fiber

This study measured the moisture regain and specific resistance values of yak hair fiber in a humidified environment to provide a theoretical basis for the development and utilization of yak hair fiber in the fields of textile, electronics and manufacturing. The effects of temperature and relative humidity on moisture absorption and electrical resistance of yak hair fiber were measured, and the effects of ambient temperature and humidity on the moisture regain and specific resistance of yak hair fiber were evaluated when using a new type of water-cooled textile air conditioner as a humidifying device, and the amino acid structure and crystallinity were compared between yak hair fiber and wool fiber. The experimental results show that temperature and relative humidity have a greater effect on the moisture regain rate and specific resistance value of the fiber, and the higher the temperature and relative humidity, the higher the moisture regain rate of yak hair fiber and the lower the specific resistance. When the temperature was 30 °C and the relative humidity was 85%, the fiber had the lowest specific resistance value and the highest moisture return rate. In terms of amino acid species, there is not much difference in chemical structure between yak hair fiber and wool fiber. The crystallinity of yak hair fiber is lower than that of wool fiber.

Effect of alkali treatment on new lignocellulosic fibres from the stem of the Aster squamatus plant

This research aims to examine the physical, structural and chemical properties of Aster Squamatus (AS) fibres, which are commonly found in Algeria, Brazil, France and the West Indies. In this work, we assess their appropriateness as reinforcing fillers to fabricate components for polymer composites principally designed for lightweight applications. To accomplish this objective, an extraction of fibres from plants modification of AS fibres and characterization of both untreated fibres (UASFs) and alkali-treated AS fibres (TASFs) are conducted. We analysed the crystallinity, chemical composition, thermal characteristics, and mechanical properties of AS fibres as per standard methods. It's clear from chemical treatment that amorphous components were successfully eliminated from the AS fibres, including hemicellulose, lignin, and wax. Consequently, the fibres' thermal, physical, and mechanical characteristics including Young's modulus, tensile strength, crystalline index, and surface roughness were substantially enhanced. It was determined that the fibres possessed a thermal stability of around 250 °C, with the maximal degradation temperature rising from 372.50 to 375.35 °C. The maximum stress rose from 183.24 ± 25.27 to 302.00 ± 24.91 MPa, the Young's modulus increased from 11.08 ± 1.1 to 18.53 ± 1.45 GPa, and the crystallinity index increased from 43% to 45%. Two-parameter Weibull statistics showed a strong link between experimental data and mechanical features of the twenty samples. We concluded from this work that AS plant fibres can serve as a robust reinforcing material in polymer composites for various applications.

Controlled Release of Curcumin and Hypocrellin A from Electrospun Poly(l-Lactic Acid)/Silk Fibroin Nanofibers for Enhanced Cancer Cell Inhibition.

Nanofibers have emerged as a highly effective method for drug delivery, attributed to their remarkable porosity and ability to regulate drug release rates while minimizing toxicity and side effects. In this study, we successfully loaded the natural anticancer drugs curcumin (CUR) and hypocrellin A (HA) into pure poly(l-lactic acid) (PLLA) and PLLA-silk protein (PS) composite nanofibers through electrospinning technology. This result was confirmed through comprehensive analysis involving SEM, FTIR, XRD, DSC, TG, zeta potential, and pH stability analysis. The encapsulation efficiency of all samples exceeded 85%, demonstrating the effectiveness of the loading process. Additionally, the drug release doses were significantly higher in the composites compared to pure PLLA, owing to the enhanced crystallinity and stability of the silk proteins. Importantly, the composite nanofibers exhibited excellent pH stability in physiological and acidic environments. Furthermore, the drug-loaded composite nanofibers displayed strong inhibitory effects on cancer cells, with approximately 28% (HA) and 37% (CUR) inhibition of cell growth and differentiation within 72 h, while showing minimal impact on normal cells. This research highlights the potential for controlling drug release through the manipulation of fiber diameter and crystallinity, paving the way for wider applications of electrospun green nanomaterials in the field of medicine.