Synthesis Of Nanofibers Research Articles

Synthesis and characterization of novel electrospun nanofibers based on taro starch: influence of solvent and isolation agent on morphology and diameter

AbstractThe utilization of natural polymers in producing electrospun nanofibers has received significant attention due to their biocompatibility, sustainability and diverse range of applications. This research focuses on synthesizing electrospun nanofibers derived from taro starch isolated from tubers. The investigation utilized SEM to examine the structure and size of the electrospun nanofibers. Formic acid and dimethyl sulfoxide solvents were tested to determine the most efficient solvent system for synthesizing taro starch nanofibers. The results demonstrated that the taro starch nanofibers can be effectively synthesized when using formic acid as the primary solvent. The study also investigated the impact of altering the volumetric ratio of formic acid to water on nanofiber morphology and size, finding that a lower formic acid fraction produced smooth fibers while a higher fraction resulted in fused fibers. The electrospinnability was further evaluated by comparing the effects of different isolation agents—distilled water and sodium metabisulfite—during the isolation process. The isolation agent significantly affected the fiber diameter, with notable differences observed in the smoothness of taro starch nanofibers at starch solution concentrations of 13, 15 and 17 wt%. Overall, the results of the study showed that the formation of taro starch fibers was influenced by the type of solvent, the volume fraction of the solvent to water, and the starch isolation agent. Successful fabrication of nanofibers from taro starch and its optimization parameters can contribute to the development of environmentally friendly nanofiber materials and offer a variety of applications in biomedicine, food and environmental engineering, such as tissue engineering, wound dressing, drug delivery, functional food delivery and food packaging. © 2024 Society of Chemical Industry.

Homochiral Covalent Organic Frameworks with Superhelical Nanostructures Enable Efficient Chirality‐Induced Spin Selectivity

AbstractDespite significant advancements in fabricating covalent organic frameworks (COFs) with diverse morphologies, creating COFs with superhelical nanostructures remains challenging. We report here the controlled synthesis of homochiral superhelical COF nanofibers by manipulating pendent alkyl chain lengths in organic linkers. This approach yields homochiral 3D COFs 13‐OR with a 10‐fold interpenetrated diamondoid structure (R=H, Me, Et, nPr, nBu) from enantiopure 1,1′‐bi‐2‐naphthol (BINOL)‐based tetraaldehydes and tetraamine. COF‐13‐OEt exhibits macroscopic chirality as right‐handed and left‐handed superhelical fibers, whereas others adopt spherical or non‐helical morphologies. Time‐tracking shows a self‐assembly process from non‐helical strands to single‐stranded helical fibers and intertwined superhelices. Ethoxyl substituents, being of optimal size, balance solvophobic effects and intermolecular interactions, driving the formation of superhelical nanostructures, with handedness determined by BINOL chirality. The superhelical nature of these materials is evident in their chiral recognition and spin‐filter properties, showing significantly improved enantiodiscrimination in carbohydrate binding (up to six times higher enantioselectivity) and a remarkable chiral‐induced spin selectivity (CISS) effect with a 48–51 % spin polarization ratio, a feature absent in non‐helical analogs.

Cross‐Scale Interface Engineering for Fabricating Super‐Strong and Super‐Tough Aramid nanofiber film

AbstractPoly (p‐phenylene terephthalamide) (PPTA), known for its exceptional mechanical properties under the brand name Kevlar, finds extensive use in high‐performance applications despite the challenges it presents in processing and integration with other materials. Existing top–down methods for preparing PPTA composites result in significantly reduced strength (<200 MPa) and toughness (<10 MJ·m−3) due to insufficient interfacial interactions, limiting their application. Here, a cross‐scale interface engineering strategy is reported for fabricating super‐strong and super‐tough PPTA composite films. At the microscale, a synergistic crosslinking strategy of physical entanglement and hydrogen bonding to crosslink PPTA nanofibers is employed. At the macroscale, the network using a cyclic freeze–thaw and the stretch‐drying method is reinforced. The PPTA nanofiber composite film is super‐strong (854.6 MPa), super‐tough (106.2 MJ·m−3), and has a high‐temperature resistance (300 °C). Moreover, the bottom–up approach enables the direct synthesis of PPTA nanofibers, significantly reducing the preparation time from 7 days to 0.5 h. Furthermore, it is demonstrated that the composite film can be integrated into a robust and intelligent sensing‐display device that responds to external mechanical and heat injuries for firefighter's protection. This work provides an efficient strategy for fabricating high‐performance PPTA composites, paving the way for their practical use as durable protective materials.

One-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and CNFs onto Ni foam: Supercapacitor performance with enhanced electrochemical properties

This study reported one-pot hydrothermal synthesis of 3D garland BiOI, spherical ZnO, and carbon nanofibers (CNFs) onto Ni foam substrate with improved supercapacitor performance and enhanced electrochemical properties. The synthesized nanocomposites exhibited high specific capacitance (SC) of 1073 g−1 at a current density of 1 A/g and excellent cycling stability with 88.6% retention of original capacity after 5000 cycles in 2M KOH aqueous solution. The findings highlight the potential of 3D materials for use as electrode materials in advanced supercapacitor applications due to their high energy storage capabilities.

Confined Gelation Synthesis of Flexible Barium Aluminate Nanofibers as a High-Performance Refractory Material.

Barium aluminate (BAO) ceramics are highly sought after as a kind of high-temperature refractory material due to their exceptional thermal stability in both vacuum and oxygen atmospheres, but their inherent brittleness results in rapid hardening, imposing a negative impact on the overall construction performance. Here, we report a strategy to synthesize flexible BAO nanofibers with a needle-like structure through confined-gelation electrospinning followed by in situ mineralization. The confined gelation among the colloidal particles promotes the formation of precursor nanofibers with high continuity and a large aspect ratio. The resulting flexible BAO nanofiber membranes are bendable, stretchable, and can even be woven, exhibiting a softness (12 mN) that is lower than that of tissue paper (27 mN). Additionally, they are capable of withstanding hundreds to thousands of continuous buckling and bending at 50% deformation without tearing. More importantly, the low emissivity of the flexible BAO nanofiber membranes ensures excellent thermal insulation at 1300 °C while preserving structural integrity and performance stability. In this sense, our strategy can be easily scaled up to produce flexible yet tough oxide ceramic membranes for a wider range of applications.

In-Situ synthesis of 2D nanozymes-coated cellulose nanofibers on paper-based chips for portable detection of biothiols

BackgroundSimple, fast and low-cost paper-based analytical devices (PADs) have a good application prospect for point-of-care detection of GSH. However, effective immobilization of functional nanomaterials onto cellulose, as a critical factor in the construction of PADs, presents numerous difficulties and challenges. ResultsIn this study, we have developed an exceptionally straightforward and environmentally friendly synthetic approach by using ovalbumin (OVA) as a bio-mineralization template for the preparation of MnO2 nanosheets. The MnO2 nanosheets produced in the solution phase exhibited excellent intrinsic nano-enzyme activity and biodegradability. The OVA-MnO2 nanosheets can effectively oxidize Amplex red in the absence of H2O2, enabling sensitive detection of GSH with a linear range of 5 nM-10 μM and a detection limit as low as 2.8 nM. Furthermore, we utilized this method to facilitate in situ synthesis of OVA-MnO2 nanosheets directly on paper substrates. This approach eliminates the need for conventional stirring and centrifugation steps, greatly simplifying the fabrication process while reducing material usage and time expenditure. Characterization of the chemical composition and morphology confirmed the intimate growth of the 2D nano-enzymes on the cellulose fibers. Utilizing smartphone capabilities, the OVA-MnO2 nanosheet-modified PAD enabled instrument-free detection of GSH, demonstrating high sensitivity (0.74 μM) and a wide linear response range (1-1000 μM). SignificanceThe synthesis of MnO2 nanosheets directly on cellulose substrates substantially streamlines the modification workflow of PADs and reduces detection costs, offering new avenues for clinical diagnostics of relevant diseases.

Sintesis dan Karakterisasi Solid Polymer Electrolyte (SPE) Berbasis Nanofiber Selulosa untuk Menunjang Baterai Litium Berdensitas Tinggi dan Ramah Lingkungan

Lithium battery as one of the energy storage has two important elements, namely electrodes and electrolyte. Electrolyte is a part of the battery element that has undergone many developments. In this study, the manufacture of electrolytes in the form of Solid Polymer Electrolyte (SPE) was carried out by utilizing the abundant availability of nata de coco. The nanofibrous cellulose structure in Bacterial Cellulose (BC) nata de coco has the advantages of good porosity, flexibility in surface functionality, compact porous structure that provides abundant ion pathways and hetero atoms (oxygen atoms) with free electron pairs that facilitate ionic conduction. The SPE synthesis process was carried out by varying the soaking time of nata de coco in ethanol, namely 1, 2 and 3 days to determine the structure with optimal results. FTIR characterization results show the synthesis of cellulose nanofiber has the same groups as commercial cellulose groups in the form of O-H, C-H, C=O and C-O. CV characterization results show the SPE electrolyte has good redox properties, especially in the 2-day variation with the highest specific capacitance. The EIS test showed the lowest resistance in the 1-day variation sample with a conductivity of 0.017 ohm-1.

Synthesis of bifunctional copolymeric nanofibers with selective extracting U(VI) from the solution and antibacterial property

Facing the problem of future nuclear fuel shortage, developing high-performance adsorbent materials is key. In this work, the amidoxime group/imidazole functionalized ionic liquid copolymer fibers containing bromide salts, and fluoroborate salts (namely P(AO/VEIMBr)8 and P(AO/VEIMBF4)6) were prepared by a one-pot method and free radical polymerization, hydroxyl amination reaction and electrostatic spinning, and characterized by SEM, FT-IR, and 1 H NMR. The influence of solid-liquid ratio, ionic strength, and adsorption time on the adsorption performance was investigated by batch adsorption experiments. In the meanwhile, the adsorption kinetics and thermodynamic processes of U(VI) on the copolymer fibers was also studied. Adsorption mechanism of U (VI) on polymer fibers was explored by XPS spectroscopic analysis combined with DFT method. Finally, the antimicrobial properties of the copolymer fibers were tested. The experimental results showed that the polymer nanofibers synthesized for U(VI) has a fast adsorption, high adsorption capacity at ionic strength close to seawater, and excellent reusability. The adsorption process conformed to the pseudo-second-order kinetic model and Langmuir model, which indicated that chemical adsorption and monolayer adsorption are dominant for adsorption U(VI) on the polymer nanofibers, and exhibits the highest Uranium adsorption capacity (76.92 mg/g and 81.96 mg/g at pH=8.1+0.1, respectively). XPS result showed the amine nitrogen and oxime oxygen in the amidoxime functional group were coordinated with uranyl(VI) ions. The antibacterial experiments showed that the copolymer fibers have antimicrobial properties and the antibacterial rate is over 90 %. Therefore, the nanofibers may be a promising material for extracting uranium from the weak alkaline wastewater or seawater.

Temperature-controlled synthesis of novel boron nanofibers by laser ablation technique

The synthesis of boron nanofibers (BNFs) at different temperatures using the double-pulsed laser ablation (DPLA) technique were reported. Q-switched Nd: YAG laser with 532 and 1064 nm dual beam wavelengths of laser used to ablate a solid boron target. A vapor–solid process at a furnace temperature and pressure supported boron 'nanofibers' growth with the active metal catalysts of 1 % Ni and 1 % Co in a quartz tube furnace in flowing argon (Ar) gas. The crystalline phase purity of the synthesized BNFs at 950, 1050, and 1150 °C were determined by X-ray diffraction (XRD), and the results from XRD confirm that each BNF is preferentially grown in the c-axis (100) direction of alpha boron (α-B). Electron microscopy revealed that each BNF exhibit a length of 1–5 μm and a diameter width of 5–100 nm, while the elemental chemical compositional nature of the BNFs is identified from energy dispersive X–ray spectroscopy (EDX). Image analysis shows the average diameter of each BNF synthesized to be 23.10, 19.13, and 16.09 nm. The lattice distance of each BNF is found to be 0.40, 0.39, and 0.38 nm, respectively. Fingerprint Raman spectroscopy revealed the fundamental vibrational modes of BNFs at Eg and A1g.

Synthesis and characterization of cu-doped ZnO nanofibers for ethanol vapor sensing

Synthesis and characterization of cu-doped ZnO nanofibers for ethanol vapor sensing

Advances in the Fabrication, Properties, and Applications of Electrospun PEDOT-Based Conductive Nanofibers.

The production of nanofibers has become a significant area of research due to their unique properties and diverse applications in various fields, such as biomedicine, textiles, energy, and environmental science. Electrospinning, a versatile and scalable technique, has gained considerable attention for its ability to fabricate nanofibers with tailored properties. Among the wide array of conductive polymers, poly(3,4-ethylenedioxythiophene) (PEDOT) has emerged as a promising material due to its exceptional conductivity, environmental stability, and ease of synthesis. The electrospinning of PEDOT-based nanofibers offers tunable electrical and optical properties, making them suitable for applications in organic electronics, energy storage, biomedicine, and wearable technology. This review, with its comprehensive exploration of the fabrication, properties, and applications of PEDOT nanofibers produced via electrospinning, provides a wealth of knowledge and insights into leveraging the full potential of PEDOT nanofibers in next-generation electronic and functional devices by examining recent advancements in the synthesis, functionalization, and post-treatment methods of PEDOT nanofibers. Furthermore, the review identifies current challenges, future directions, and potential strategies to address scalability, reproducibility, stability, and integration into practical devices, offering a comprehensive resource on conductive nanofibers.

Synthesis and in vitro evaluation of cross-linked tragacanthin nanofibers as implants for delivery of cisplatin to hepatocellular carcinoma

There is growing interest in the use of electrospun polymeric nanofibers in drug delivery systems due to their remarkable surface-to-volume ratio, which enhances the processes of drug loading, specific cell binding and proliferation. The preferred polymers for drug delivery must be biocompatible and biodegradable. Gum tragacanth is one of the materials of choice for drug delivery. This work aimed at cross-linking the tragacanthin, the water-soluble fraction of gum tragacanth, with glutaraldehyde, synthesis of the cross-linked nanofibers and evaluating their properties to encapsulate and deliver a drug using caffeine as a model drug in the first place. The nanofibers were then loaded with cisplatin and evaluated against HepG2 cell line. The drug-loaded nanofibers (dia. 0.841 μm) were prepared by electrospinning using glutaraldehyde as the cross-linker and glycerol as a plasticizer and characterized by scanning electron microscopy, Fourier transform-infrared spectroscopy, electronic spectroscopy, 1HNMR, powder X-ray diffraction analysis, and thermogravimetric analysis. They released the encapsulated drugs in a sustained manner at pH 7.4 over 4.5 days (∼275 h with ∼80 % release) following Higuchi (cisplatin) and Hixon-Crowell (caffeine) kinetics. In a cytotoxicity assay against HepG2 cell line the cisplatin-loaded nanofibers exhibited enhanced activity compared to that with the standard cisplatin and in the caspase activity assay it activated caspase 3 to a higher extent and 8 and 9 to double the extent (4-fold) of cisplatin, suggesting a higher apoptotic activity by the nanoformulation than the standard cisplatin. Thus, nanoformulation appeared to be a potential candidate for treating hepatocellular carcinoma as an implant.

Synthesis of innovative Daphne mucronata extract/Cu-MOF/PVA-PVP nanofiber as high-performance anticancer and antimicrobial agent

Nanofibers’ unique physical properties include mechanical strength, compressive strength, and high specific surface area, making them highly valuable and significant. Nanofiber can be containing nano compounds such as metal nano oxides, metal–organic framework, etc., as well as plant extracts. Plant extracts have had a special place in human life since the past and used in traditional medicine. The synthesis of new nanofibers containing plant extracts and metal–organic framework was the idea that we focused on it. For this purpose, Daphne mucronata extract and copper metal–organic framework, considering the high biological properties were used. For the synthesis of Daphne mucronata extract/Cu-MOF/PVA-PVP nanofiber, electrospinning method and polyvinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) were used. The final product’s structure was examined and verified using XRD (X-Ray diffraction analysis), EDAX (Energy dispersive X-ray analysis), CHNO EA (Carbon, hydrogen, nitrogen, and oxygen elemental analysis), SEM (Scanning electron microscope images), BET (Brunauer-Emmett-Teller theory), FT-IR (Fourier transform infrared spectroscopy), contact angle (Hydrophilic properties), mechanical strength and compressive strength. The specific surface area of the synthesized nanofiber and the diameter size of the synthesized particles were observed to be area 1102 m2/g and 80 nm, respectively. High hydrophilic properties (29°), high flexural strength (17.3 N/mm2), and high compressive strength (65.7 N/mm2) were among other characteristics of the synthesized nanofiber. Biological properties of the synthesized nanoparticle, such as anti-skin cancer, anti-bacterial, and anti-fungal properties, were tested. In the anticancer study, IC50 was 21 μg/mL, and in the antimicrobial studies (antibacterial and antifungal activity), the MIC was between 2 μg/mL and 64 μg/mL. Thus, the synthesized nanofiber can be incorporated as a bioactive compound in the medical industry, such as being utilized as bioactive medical bandages after other tests have been completed.

Homochiral Covalent Organic Frameworks with Superhelical Nanostructures Enable Efficient Chirality-Induced Spin Selectivity.

Despite significant advancements in fabricating covalent organic frameworks (COFs) with diverse morphologies, creating COFs with superhelical nanostructures remains challenging. We report here the controlled synthesis of homochiral superhelical COF nanofibers by manipulating pendent alkyl chain lengths in organic linkers. This approach yields homochiral 3D COFs 13-OR with a 10-fold interpenetrated diamondoid structure (R = H, Me, Et, nPr, nBu) from enantiopure 1,1'-bi-2-naphthol (BINOL)-based tetraaldehydes and tetraamine. COF-13-OEt exhibits macroscopic chirality as right-handed and left-handed superhelical fibers, whereas others adopt spherical or non-helical morphologies. Time-tracking shows a self-assembly process from non-helical strands to single-stranded helical fibers and intertwined superhelices. Ethoxyl substituents, being of optimal size, balance solvophobic effects and intermolecular interactions, driving the formation of superhelical nanostructures, with handedness determined by BINOL chirality. The superhelical nature of these materials is evident in their chiral recognition and spin-filter properties, showing significantly improved enantiodiscrimination in carbohydrate binding (up to six times higher enantioselectivity) and a remarkable chiral-induced spin selectivity (CISS) effect with a 48-51% spin polarization ratio, a feature absent in non-helical analogs.

Hydrothermal Synthesis of Fe-Doped Nickel Cobalt Phosphate Nanofibers for High-Stability Electrochemical Overall Water Splitting

Hydrothermal Synthesis of Fe-Doped Nickel Cobalt Phosphate Nanofibers for High-Stability Electrochemical Overall Water Splitting

Novel synthesis method of carbon nanofibers (CNFs) by using Proteus mirabilis bacteria

Carbon nanofiber (CNF) is a cylindrical carbon nanomaterial, with diameter around 100 nm and its length sometimes extends up to a few micrometers. Different types of CNFs are synthesized based on the production method, which differs dramatically in terms of structure, composition, and characteristics. Today, using green chemistry methods and microorganisms has resulted in biocompatible nanoparticles materials. In this work Proteus mirabilis bacteria were used as nanometer template for synthesis of carbon nanofibers. For this propose, two carbon electrodes were put into the solution containing Proteus mirabilis bacteria, sodium chloride, nickel chloride, molybdenum powder. To find optimized conditions for the synthesis of CNFs, the parameters of time, kind of electrodes and amount current were studied. The optimized conditions were found as follows: synthesis time 60 s, the carbon–carbon electrode and the electric current (90 A) with voltage of 24 V. The optimized synthesized carbon nanofibers were characterized with the techniques of FTIR spectroscopy, Raman spectroscopy, X-Ray diffraction, scanning electron microscopy coupled with energy dispersive (SEM-EDX) and BET method.

Ultra-Fast, One-Pot Synthesis of Nanofibers by Lewis Pair Polymerization-Induced Self-Assembly

Ultra-Fast, One-Pot Synthesis of Nanofibers by Lewis Pair Polymerization-Induced Self-Assembly

Turbostratic carbon nanofibers produced from C2HCl3 over self-dispersing Ni-catalyst doped with W and Mo

In this research, a self-dispersing 92Ni-4Mo-4W catalyst showing high productivity towards the H2-assisted synthesis of turbostratic carbon nanofibers was proposed. The effect of reaction temperature on the efficiency of 92Ni-4Mo-4W alloy in the decomposition of trichloroethylene was studied. It was found that in the temperature range of 580–620 °C, the most rapid destruction of the initial alloy followed by the growth of carbon material is realized. This is confirmed by the minimum induction period (9–11 min) and the maximum carbon yield (95–107 g/gcat). As revealed, the catalytically active particles of submicron size contain uniformly distributed Ni, Mo, and W. It is demonstrated that the decomposition of trichloroethylene over the 92Ni-4Mo-4W catalyst results in the formation of a turbostratic carbon material with a segmented structure, containing a minimum quantity of amorphous carbon and possessing high textural characteristics (specific surface area of 330–410 m2/g; pore volume of 0.48–0.58 cm3/g).

Synthesis of carbon nanofibers using bimetallic nickel-palladium nano catalysts and evaluation of charge storage capacity

Metal-nanoparticle (NP) catalysts play a crucial role in the chemical vapor deposition synthesis of various nanomaterials, such as nanotubes, nanofibers, and nanowires. The alloying of different metal elements offers the potential for achieving higher growth rates and improving catalyst performance and longevity. However, the precise synthesis of small and uniform metal NPs with the desired composition remains challenging due to theoretical limitations, notably the Hume-Rothery rule. In this study, nickel (Ni)-palladium (Pd) alloy NPs were successfully synthesized via the reverse micelle method, resulting in NPs characterized by consistent and uniform size and shape, with an average diameter of 2.8 nm. The addition of Pd atoms to Ni to form alloy-NPs shifted the growth mode from surface diffusion to bulk diffusion, such that herringbone carbon nanofibers (CNFs) were grown with reduced diameters using CVD. These alloy catalysts maximize the physicochemical properties of herringbone CNFs for electrochemical applications. The increased number of active sites at the CNF edges considerably enhances charge storage while improving charge and discharge rates. Notably, the versatility of the alloy nanocatalysts introduced in this study extends beyond CNF synthesis, as they can also find application in the synthesis of carbon nanotubes and boron nitride nanotubes.

Design of inherently polarized nanofiber-based membranes for superior filtration performance

As airborne particulate matter (PM) such as pathogens and ultrafine dust threaten the human health, air quality control technologies are becoming increasingly important. Herein, poly(vinylidene fluoride-co-hexafluoropropylene) (PVdF-HFP) nanofibers with various fiber diameters and pore size distributions were prepared using various compositions of volatile (acetone) and less volatile N,N-dimethylformamide (DMF) solvent mixtures to design the optimum filtration media. Morphologies and molecular configurations were examined thoroughly with respect to the filtration performance. Among the various solvent compositions, the specimen prepared with the lowest DMF content (denoted as ePVdF-HFP55) showed the best filtration performance, with a filtration efficiency of 99.95% and a pressure drop of 29.0 mmH2O. The quality factor (QF) of ePVdF-HFP55 (0.0266 Pa−1) is superior to that achieved in electrospun nanofibrous media in previous works. In addition, the QF was further improved to 0.0276 Pa−1, with a remarkably reduced resistance of 14.45 mmH2O achieved by employing the layered nanofiber media with a PVdF-HFP top layer. Our work demonstrates that optimization of the inherently polarized nanofiber synthesis is a fruitful pathway to enhancing the filtration performance of air filter media.