Centrifugal Spinning Research Articles

A vertically translating collection system to facilitate roll-to-roll centrifugal spinning of highly aligned polyacrylonitrile nanofibers

Centrifugal spinning is a fiber spinning method capable of producing fibers in the nanoscale diameter range from a multitude of polymers, including polyacrylonitrile (PAN). With a traditional centrifugal spinner, fiber can be rapidly spun and collected on static collection posts. However, the use of posts inevitably forms a dense fiber “ring” that is incompatible with roll-to-roll manufacturing processes. In this work, factors that influence throughput and scalability of highly aligned centrifugally spun PAN fibers are explored. A custom centrifugal setup is used to vertically translate collected fibers during the spinning process to distribute them over a large surface area. In addition, factors that affect PAN fiber diameter during the spinning process are investigated, including spinneret to collector distance, rotational speed, and humidity. Resulting data demonstrates that these factors can be independently optimized to reliably produce quality PAN fiber in the nanoscale diameter range. Furthermore, the fiber mass collection rate can be increased without affecting sample quality when the vertical translation speed is increased. This work demonstrates the potential scalability of centrifugal spinning to quickly produce large amounts of highly aligned nanofiber in a cheap, efficient, and reliable manner, and also lends the ability to be collected in a roll-to-roll fashion.

Optimization Mechanism of Nozzle Parameters and Characterization of Nanofibers in Centrifugal Spinning

Nanofibers are an emerging kind of nano-material, widely used in several application domains such as biomedicine, high-efficiency filtration media, precision electronics, and optical devices. Centrifugal spinning, which is a novel nanofiber production technology, has been widely studied. This paper proposes a structural parameter optimization design method of a bent-tube nozzle. The mathematical model of the spinning solution motion in the nozzle is first developed. The optimization function of the structure parameters of the bent-tube nozzle is then obtained by calculation. Afterwards, these parameters are optimized using a neural network algorithm. The obtained results show that, when the bending angle is 15°, the curvature radius is 10 mm, the outlet radius is 0.205 mm, and the head loss of the solution can be minimized. Finally, centrifugal spinning experiments are conducted and the influence of the centrifugal spinning parameters on the nanofibers is analyzed. In addition, the optimized bent-tube nozzle improves the surface morphology of the nanofibers as their diameter distribution becomes more uniform.

Preparation and performance of nanofibers by centrifugal spinning with multi-field coupling

Nanomaterials are used in a variety of fields. As a novel way to produce nanofibers, high-speed centrifugal spinning has attracted wide attention. Nanofibers are widely used in medical transmission, bio-chips, and environmental protection. In high-speed centrifugal spinning production, the quality of nanofibers will be affected by the coupling effects of gravity field, centrifugal position, flow field, temperature and humidity field. The quality of nanofibers will also be affected by the collection distance, motor speed and nozzle structure size. In this paper, the flow of spinning solution in the nozzle is investigated mathematically. Then the solution flow in the nozzle is simulated. Finally, high-speed centrifugal spinning experiments were carried out and nanofiber membranes were collected. The surface quality of the nanofiber membrane was observed by scanning electron microscope (SEM), and the figure of fiber diameter distribution was obtained. Thermogravimetric (TG) analysis shows that the thermal stability and ablative resistance of nanofiber membranes are improved. The results show that the high-speed centrifugal spinning method has high production efficiency. The nanofibers produced by high-speed centrifugal spinning method have good surface quality, uniform diameter distribution and good thermal stability.

Comparing the performance of WO3 nanoparticles and nanofibers: Photocatalytic dye degradation versus photoelectrochemical water oxidation

Nanostructured WO3 is a widely studied, attractive material for photocatalysis applications, ranging from degradation of organic contaminants to water photooxidation, related to its relatively small bandgap, good stability, and adequate charge transport and charge transfer efficiencies. In catalysis, a large surface-to-volume ratio generally improves activity; however, this is not always the case for photoelectrochemical systems. In this work, we compare the photocatalytic and photoelectrochemical performance of commercial WO3 nanoparticles with that of WO3 nanofibers prepared by centrifugal spinning. The photocatalytic dye degradation kinetics are faster for the nanofibers, related to their larger specific surface area. On the other hand, the photoelectrochemical performance is essentially the same for both materials. This fundamental difference in performance is demonstrated to be due to the influence of trap-limited electron transport on the collection efficiency of photoelectrons, required for the observation of photocurrent in the external circuit, whereas photocatalysis is more surface-driven.

Novel recycled PET/tannin nanofibers for effective removal of lead(II) from water

The pollution of water by hazardous metals such as lead(II) and the growing generation of polymeric wastes such as polyethylene terephthalate (PET) are critical global concerns. Thus, new recycled PET nanofibers functionalized with tannin were applied in the removal of lead(II) from water by adsorption. PET was collected from post-consumer water bottles and obtained as nanofibers by centrifugal spinning. The characterization performed on the nanofibers showed average diameters of 188 nm and functional groups adequate for lead(II) adsorption. Under the adsorption conditions tested, lead(II) adsorption was favored at pH 6 and 328 K, with a maximum adsorption capacity of 350.81 mg g−1. The kinetic data was better represented by the pseudo-first order model. The equilibrium data was better represented by the Sips model. The thermodynamic parameters showed that the process was spontaneous, favorable, and endothermic. The nanofibers kept 45.20 % of their original adsorption capacity after four cycles of adsorption–desorption. The results indicated that the recycled PET/tannin nanofibers are a great alternative as lead(II) adsorbent. They are also an environmentally friendly option for the transformation of an abundant post-consumer polymer into a versatile nanomaterial functionalized with a sustainable biopolymer.

Fabrication of cassava (Manihot esculenta Crantz) starch‐based ultrafine fibers: Investigation of fundamental and antimicrobial properties

AbstractMicro/nano‐based fibrous membranes loaded with antibacterial agents have been widely studied in the medical field. In this research, we describe the development of a new environmentally friendly medical dressing based on centrifugally spun cassava starch‐based ultrafine fibers loaded with nanosilver (Ag). For this purpose, the spinnability of amylopectin‐rich native cassava starch in a centrifugal spinning system was investigated. Polyvinyl alcohol (PVA) was applied to improve the water stability and mechanical properties of the starch‐based fibers, and the water stability of the fibers was further improved by posttreatment with formic acid. The morphology, structure, thermal, and tensile properties were studied. The results indicated that the native cassava starch showed excellent spinnability in the centrifugal spinning system. The tensile strength and water stability of the obtained fibrous membranes were improved by adding PVA and further improved after the posttreatment. The antibacterial properties of fibers loaded with Ag were evaluated through a bacteriostatic zone test, and the results showed that the fibers presented good antibacterial properties against Escherichia coli. Therefore, the obtained fibers have great potential for application in the medical dressing field.

Centrifugally spun magnetic nanofibers for anionic dye removal: Optimization and predictive modeling with RSM and ANN

Response surface methodology (RSM) and artificial neural network (ANN) approach were used for the modeling-optimization of dye removal by adsorption using poly(ethylene terephthalate)/Fe3O4 nanocomposites nanofibers. The nanoparticles of Fe3O4 were synthesized by the chemical co-precipitation method in the presence of linoleic acid as a stabilizer. The polymer matrix was obtained by recycling PET from plastic water bottles. We used a simple homemade centrifugal spinning device to prepare PET/Fe3O4 nanofibers and the resulting material was characterized by XRD, FTIR and SEM. The performance of the nanofiber material as an adsorbent was examined in water treatment to remove Naphthol Green B anionic dye in batch mode. Box–Behnken-RSM and ANN were employed to optimize the effect of pH, contact time, initial dye concentration, and adsorbent mass. The optimized conditions leading to the maximum predicted dye removal were a pH of 2, a contact time of 60 min, an adsorbent mass of 0.125 g/L, and a dye concentration of 20 mg/L, and. The results demonstrated that both methods showed good predictions of dye removal. The pseudo-first-order kinetic and Langmuir isotherm models were found to be best fitted with the experimental data and rePET/Fe3O4 exhibited a maximum NGB dye adsorption capacity up to 155 mg/g. This study also indicates that magnetite nanoparticles combined with recycled PET in the form of nanocomposite nanofibers could be used for the treatment of dye wastewater.

Photocatalytic degradation of methylene blue using PMMA/TiO2 nanoparticles composites fibers obtained through centrifugal spinning

Photocatalytic degradation of methylene blue using PMMA/TiO2 nanoparticles composites fibers obtained through centrifugal spinning

Dual-bioinspired fabrication of Janus Micro/nano PDA-PTFE/TiO2 membrane for efficient oil-water separation

Oily wastewater poses a severe threat to the environment and human health, and its disposition is a worldwide urgency. Rencently, Janus membranes has provided excellent selectivity for oil/water separation due to thin layers of different wettability on opposite sides. However, the fabrication of Janus asymmetric multilayer with simple syntheses and excellent stability has been proved challenging. Herein, a Janus polydopamine-polytetrafluoroethylene/titanium dioxide (PDA-PTFE/TiO2) membranes were inspired by dual-bionic strategy (lotus leaf and mussel) and constructed by centrifugal spinning technology. The membranes showed significant separation efficiency for both water–oil mixtures and emulsions above 99%. Most notably, the separation efficiency of the membranes are still maintained above 98.5% after 24 h immersion in the corrosive solutio. Meanwhile, the nanofiber membrane has outstanding reusability, acid/alkali resistance, and mechanical stability. Therefore, the dual-bioinspired Janus micro/nano PTFE/TiO2 membrane suggests a promising potential application for a sustainable and effective oil–water separation membrane in the future.

Solubility Enhancement of Itraconazole by Centrifugal Melt Spinning Technique

Itraconazole is an antifungal drug with poor water solubility and limited bioavailability, presenting difficulties in achieving effective therapeutic applications. This study aimed to employ centrifugal melt spinning, an innovative method, to improve the solubility of itraconazole. In this process, itraconazole was subjected to centrifugal forces while melting, forming amorphous solid dispersions. Microfibers loaded with 10% w/w itraconazole were prepared through centrifugal melt spinning, employing sucrose as a carrier. ITZ-sucrose microfibers with uniform morphology and an average diameter of 14.27 ± 2.90 μm were successfully fabricated, as evidenced by the scanning electron microscopy results. XRD and DSC measurements confirmed the amorphous nature of the spun microfibers. The solubility of Itraconazole sucrose microfibers was significantly enhanced by 17-fold compared to plain itraconazole. The dissolution experiments demonstrated that sucrose microfibers loaded with ITZ achieved a significant release of 94.96 ± 1.47% within 10 minutes, representing a substantial enhancement compared to plain drugs. The study indicated that utilizing the centrifugal melt spinning technique successfully generated amorphous solid dispersions of itraconazole, leading to a considerable improvement in the drug’s solubility.

Flexible centrifugally spun PVP based SnO2@carbon nanofiber electrodes

Sodium-ion batteries (SIBs) have attracted significant attention because of the abundant resource and low-cost of sodium. Furthermore, flexible and wearable functional electronics have been presented as one of the most important emerging technology. Carbon nanofibers are promising candidates for flexible electrodes due to their high electronic conductivity and high surface area, while it is vital to use non-petroleum-based polymers considering environmental concerns. Developing flexible nanostructured electrodes by using environment friendly polymers with a fast and low-cost technique is critical to develop high performance flexible electronics. Electrochemical properties are influenced by the morphology and average fiber diameters of nanofibers. In this study, poly(vinylpyrrolidone) (PVP) solutions with various concentrations and two different solvent systems (ethanol/water and ethanol/dimethylformamide) were successfully spun into nanofibers by the fast, safe, low-cost, and environment friendly technique of centrifugal spinning. The effect of solvent system and solution concentration was investigated by using scanning electron microscopy images, and the average fiber diameters varied from 436 nm to 3 µm. Moreover, nine different heat treatments were studied, and the effect of time and temperature during stabilization and carbonization on the morphology of carbon nanofibers (CNFs) was investigated. Furthermore, flexible carbon nanofibers were fabricated and used as binder-free anodes in sodium-ion batteries. In order to enhance the electrochemical properties of flexible CNFs, flexible SnO2@CNFs were fabricated by combining centrifugal spinning and heat treatment. The electrochemical performance of the flexible SnO2@carbon nanofiber anodes was evaluated by conducting galvanostatic charge/discharge tests and cycling voltammetry. A high rate of performance was also presented. The high reversible capacity of 400 mA h/g was delivered when flexible centrifugally spun PVP based SnO2@carbon nanofiber electrodes were used in SIBs.

Efficient Gallium Recovery from Aqueous Solutions Using Polyacrylonitrile Nanofibers Loaded with D2EHPA

Centrifugal spinning was utilized in producing polyacrylonitrile (PAN) nanofibers loaded with extractant di-(2-ethylhexyl) phosphoric acid (D2EHPA) for efficient adsorption recovery of gallium from aqueous solutions. The adsorption experimental data were best fitted by a pseudo-second-order kinetic model and the BET equilibrium isotherm model. Optimal adsorption performance by the PAN/D2EHPA nanofibers exhibited an adsorption capacity of 33.13 mg g−1 for the recovery of gallium at pH 2.5 and 55 °C. The thermodynamic parameters demonstrated that adsorption was endothermic, spontaneous, and favorable. The stability and reusability of the nanofibers was assessed, demonstrating retention of structural and functional integrity for the nanofibers over five cycles of an adsorption/desorption process, whilst retaining adsorption efficiency. The results demonstrate that PAN/D2EHPA nanofibers have excellent potential for utilization in an efficient adsorption process for gallium recovery, offering significant positive environmental impact over conventional liquid–liquid extraction methods.

Optimization and Production of Aceclofenac-Loaded Microfiber Solid Dispersion by Centrifugal Spinning.

Aceclofenac-loaded polyvinylpyrrolidone fiber-based amorphous solid dispersion was produced successfully by centrifugal spinning. The solution concentration and rotational speed were optimized to produce the fiber-based drug carrier system, with a determined production rate of 12.7 g/h dry solid fibers. The obtained fibers were bead-free and smooth-surfaced with an average diameter of 7.5 ± 2.5 μm. Gas chromatographic determinations revealed that ethanol, as a residual solvent, was well below the regulatory limit of 0.5%. Differential scanning calorimetric investigation and infrared spectroscopic measurements were used to track the physicochemical changes that intervene during fiber formation in the solid state. The results revealed that the rapid evaporation of the solvent was accompanied by a probable crystalline to amorphous transition of the active substance during centrifugal spinning. In vitro dissolution studies revealed an instantaneous disintegration of the fibrous structure and a rapid release of the active substance, with the microfibrous webs greatly outperforming the crystalline active substance, especially in the early time-points. This implies that centrifugal spinning offers a viable scale-up production process to prepare drug-loaded fiber-based solid dispersions.

Optimization of Oil Sorbent Thermoplastic Elastomer Microfiber Production by Centrifugal Spinning.

Fibrous structures are promising candidates for oil-water separation applications. In this study, we have produced poly(styrene-b-isobutylene-b-styrene) thermoplastic elastomeric fibers with the centrifugal spinning fiber production method. The optimal fiber production conditions were achieved when using a 25% w/w solution concentration in an 80/20 tetrahydrofuran/toluene (w/w) solvent system at 8000 rpm rotational speed. The produced fibers were bead-free and smooth-surfaced with a diameter of 3.68 µm. The produced fibers were highly hydrophobic and oleophilic, suggested by a water contact angle of 129° and the instantaneous absorption of the oil droplet. The oil absorption study showed fast absorption kinetics with 94% relative oil uptake after 1 min and a maximum of 16.5 g sunflower oil/g fiber. The results suggest that polyisobutylene-based thermoplastic elastomers could be promising alternatives in oil absorption applications.

Recent developments in the use of centrifugal spinning and pressurized gyration for biomedical applications.

Centrifugal spinning is a technology used to generate small diameter fibers and has been extensively studied for its vast applications in biomedical engineering. Centrifugal spinning is known for its rapid production rate and has inspired the creation of other technologies which leverage the high-speed rotation, namely Pressurized Gyration. Pressurized gyration incorporates a unique applied gas pressure which serves to provide additional control over the fiber production process. The resulting fibers are uniquely suitable for a range of healthcare-related applications that are thoroughly discussed in this work, which involve scaffolds for tissue engineering, solid dispersions for drug delivery, antimicrobial meshes for filtration and bandage-like fibrous coverings for wound healing. In this review, the notable recent developments in centrifugal spinning and pressurized gyration are presented and how these technologies are being used to further the range of uses of biomaterials engineering, for example the development of core-sheath fabrication techniques for multi-layered fibers and the combination with electrospinning to produce advanced fiber mats. The enormous potential of these technologies and their future advancements highlights how important they are in the biomedical discipline. This article is categorized under: Implantable Materials and Surgical Technologies > Nanotechnology in Tissue Repair and Replacement Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Biology-Inspired Nanomaterials > Lipid-Based Structures.

Development of pullulan/chitosan/salvianolic acid ternary fibrous membranes and their potential for chemotherapeutic applications

This study investigates the feasibility of centrifugal spinning for producing fibrous membranes containing pullulan, chitosan, and danshen extract. The danshen extract is composed of 20 wt% salvianolic acid B (SA). Citric acid was added to the mixture as a crosslinking agent to promote its use in the aqueous medium. The influence of the danshen concentration (25 wt% and 33 wt%) on fiber morphology, thermal behavior, and the biochemical effect was analyzed. Developed fiber-based membranes consist of long, continuous, and uniform fibers with a sparse scattering of beads. Fiber diameter analysis shows values ranging from 384 ± 123 nm to 644 ± 141 nm depending on the concentration of danshen. The nanofibers show adequate aqueous stability after crosslinking. Thermal analysis results prove that SA is loaded into nanofibers without compromising their structural integrity. Cell-based results indicate that the developed nanofiber membranes promote cell growth and are not detrimental to fibroblast cells. Anticancer studies reveal a promising inhibition to the proliferation of HCT116 colon cancer cells. The developed systems show potential as innovative systems to be used as a bioactive chemotherapeutic drug that could be placed on the removed tumor site to prevent development of colon cancer microdeposits.

Alumina Ceramic Nanofibers: An Overview of the Spinning Gel Preparation, Manufacturing Process, and Application.

As an important inorganic material, alumina ceramic nanofibers have attracted more and more attention because of their excellent thermal stability, high melting point, low thermal conductivity, and good chemical stability. In this paper, the preparation conditions for alumina spinning gel, such as the experimental raw materials, spin finish aid, aging time, and so on, are briefly introduced. Then, various methods for preparing the alumina ceramic nanofibers are described, such as electrospinning, solution blow spinning, centrifugal spinning, and some other preparation processes. In addition, the application of alumina ceramic nanofibers in thermal insulation, high-temperature filtration, catalysis, energy storage, water restoration, sound absorption, bioengineering, and other fields are described. The wide application prospect of alumina ceramic nanofibers highlights its potential as an advanced functional material with various applications. This paper aims to provide readers with valuable insights into the design of alumina ceramic nanofibers and to explore their potential applications, contributing to the advancement of various technologies in the fields of energy, environment, and materials science.

Role of Rheology in Morphology Development and Advanced Processing of Thermoplastic Polymer Materials: A Review.

This review presents fundamental knowledge and recent advances pertaining to research on the role of rheology in polymer processing, highlights the knowledge gap between the function of rheology in various processing operations and the importance of rheology in the development, characterization, and assessment of the morphologies of polymeric materials, and offers ideas for enhancing the processabilities of polymeric materials in advanced processing operations. Rheology plays a crucial role in the morphological evolution of polymer blends and composites, influencing the type of morphology in the case of blends and the quality of dispersion in the cases of both blends and composites. The rheological characteristics of multiphase polymeric materials provide valuable information on the morphologies of these materials, thereby rendering rheology an important tool for morphological assessment. Although rheology extensively affects the processabilities of polymeric materials in all processing operations, this review focuses on the roles of rheology in film blowing, electrospinning, centrifugal jet spinning, and the three-dimensional printing of polymeric materials, which are advanced processing operations that have gained significant research interest. This review offers a comprehensive overview of the fundamentals of morphology development and the aforementioned processing techniques; moreover, it covers all vital aspects related to the tailoring of the rheological characteristics of polymeric materials for achieving superior morphologies and high processabilities of these materials in advanced processing operations. Thus, this article provides a direction for future advancements in polymer processing. Furthermore, the superiority of elongational flow over shear flow in enhancing the quality of dispersion in multiphase polymeric materials and the role of extensional rheology in the advanced processing operations of these materials, which have rarely been discussed in previous reviews, have been critically analyzed in this review. In summary, this article offers new insights into the use of rheology in material and product development during advanced polymer-processing operations.

A versatile hot melt centrifugal spinning apparatus for thermoplastic microfibres production

The centrifugal spinning (CS) method could address common issues such as low production rate and high energy consumption in the industry of nonwoven textile fabrication. Similarly to cotton candy production, the high-speed rotating reservoir extrudes melt or solvent-based polymer from orifices to produce fibres. Using polymer melt avoids solvent elimination and toxicity, but the process is more difficult. Thus, a versatile lab-scale hot melt spinneret with the ability to pour pellets inside continuously to expand our knowledge of the CS method and investigating different extrusion geometries such as nozzlefree is developed. Among the controllable parameters are, the spinneret heating temperature (up to 300°C), its two interchangeable 3D printer nozzles. An Arduino code is used to stabilize the temperature. The system performance is investigated with polypropylene and polylactide. The results show that fibres under 15 μm in diameter are produced. This work is licensed under CC BY-NC 4.0. To view a copy of this license, visithttp://creativecommons.org/licenses/by-nc/4.0/.

Centrifugally spun hybrid polyhydroxyalkanoate/dextran nanocapsule fiber matrix for the delivery of hydrophilic payloads

Biopolymeric micro- and nanofibers with active ingredients have gained significant attention for biological applications. However, the incorporation of hydrophilic compounds into hydrophobic matrices via spinning techniques remain rather unexplored. Here we report the incorporation of dextran nanocapsules (Dex-NCs) in centrifugally spun poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) fibers for the release of hydrophilic payloads. Inverse miniemulsion polymerization was employed to synthesize hydrophilic Dex-NCs with an average size of 0.25 µm. The Dex-NCs were embedded into PHBHHx via dual solvent centrifugal spinning at 0–7 wt% loading, resulting in beaded fibers with average fiber diameters of 4–6 µm. The effect of Dex-NC loading on the melting and crystallization behavior of PHBHHx was limited, while the strength and stiffness of the hybrid fibers was retained. The elongation of the hybrid fiber mats is reduced with increasing Dex-NC loading, but remains suitable for biological applications. Further, the in vitro release measurements showed a time dependent release of embedded Dex-NCs and the payload from the hybrid fibers. We anticipate this hybrid fiber matrix to be a starting point for the development of non-woven mats for slow release of hydrophilic payloads for biological applications, especially for medical wound dressings.