Centrifugal Spinning Research Articles

Preparation and characterization of SA/AKP composite fibers by centrifugal wet continuous spinning

In wet spinning, balancing the conflict between fiber densities and diffusion resistance is essential to obtain fibers with low differences in radial structure, high densities, and excellent properties. Different from the conventional centrifugal spinning, this paper utilizes the combined effect of friction and winding tension of the rotating coagulation bath to obtain continuous sodium alginate/Antarctic krill protein composite fibers by stretching the polymer ejected from the spinneret. The curing rate constant (Sr =0.1543 mm/s1/2) and the fiber solidification model were first obtained by monitoring the draft solidification process. Then the principle of the effect of rotational speed on the internal radial structure of the fibers was analyzed using SEM, AFM, FTIR, XRD, orientation, and mechanical property tests. Continuous sodium alginate/ Antarctic krill protein composite fibers with small differences in radial structure, high orientation (0.94266) and high modulus (44.14 cN/dtex), and high strength (2.0 cN/dtex) were obtained at 300 rpm. Finally, thermodynamic studies also find that the increase in rotational speed improves the fibers' thermal stability. The process provides reference parameters for obtaining composite fibers with balanced radial structure differences, high orientation, high modulus, and high strength.

Power law liquid jets’ trajectories and instability during centrifugal spinning

Nanofibers are produced using a revolutionary technique called centrifugal jet spinning. This technique is known as an industrial prilling process, where small droplets are performed from breaking up of a thread liquid jet. Therefore, It has been used the curved jet to control the size of these small droplets and the break-up length. In this study, the linear instability of a power law liquid jet is investigated in the presence of centrifugal forces, gravity and surface tension. Furthermore, an asymptotic method has been applied to simplify the system of governing equations into a set of one-dimensional equations. Therefore, the trajectory of the power law liquid jet during the centrifugal spinning has been determined using the Roung-Kutta method. Further investigation has been done into wavenumber and the growth rate of the most unstable mode for various flow index numbers. From the linear instability results, it can be observed that when the rotation rate and gravitational force are high, shear thickening is more stable than shear thinning jets. We have also found that more viscous becomes longer jets and it produces larger droplet which is a crucial finding.

Innovative and efficient preparation of high-performance polyacrylonitrile-based carbon fiber paper by centrifugal spinning

Polyacrylonitrile (PAN) carbon fibers are often used to prepare high-performance paper-based materials owing to their high strength, good electrical and thermal conductivity, and superior comprehensive properties. In this study, a novel method for preparing PAN-based carbon fibers by centrifugal spinning was developed, and a stable and homogeneous PAN carbon fiber paper was successfully obtained. Subsequently, the formation process, microscopic morphology, electrical conductivity, electrochemical performance and hydrophobicity of the PAN carbon fiber paper were studied and evaluated. The results showed that the electrical conductivity of the PAN carbon fiber paper prepared via this method reached 43.250 s·cm−1, resistivity was as low as 0.023–0.033 Ω·cm, and contact angle exceeded 140°. This study adopted a new method to prepare PAN carbon fiber paper, which provided another method for the preparation of high-performance fiber paper.

Preparation of a Janus-polyvinylidene fluoride micro/nano fiber membrane by centrifugal spinning and investigation into its unidirectional water transfer and oil–water separation functions

Traditional oil–water separation membranes have a high energy consumption and complicated operation. To solve this problem, an asymmetric wetting polyvinylidene fluoride (PVDF) fiber membrane with a hydrophobic side and a hydrophilic side was prepared. Octamethylcyclotetrasiloxane was grafted onto one side of a centrifugal spun PVDF fiber membrane by plasma initiation, and dopamine was sprayed on the other side of the fiber membrane. The Janus-PVDF fiber membrane prepared can separate a mixture of water and dibromoethane, a toluene–water emulsion and a mixture of n-hexane and water. The initial interception rates were 98.53% ± 1.31%, 98.52% ± 1.12% and 98.61% ± 1.23%, respectively. After five cycles of separation, the separation rates remained at 96.15% ± 1.25%, 95.02% ± 1.21% and 96.91% ± 1.42%, respectively. The Janus-PVDF fiber membrane has excellent unidirectional water transfer capability and possesses well-repeated separability. The preparation of its unique Janus structure also provides a new direction for the field of oil–water separation.

N-Doped carbon nanoparticles on highly porous carbon nanofiber electrodes for sodium ion batteries.

Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber electrodes were successfully synthesized via combining centrifugal spinning, chemical polymerization of pyrrole and a two-step heat treatment. Nanoparticle-on-nanofiber morphology with highly porous carbon nanotube like channels were observed from SEM and TEM images. Nitrogen doped carbon nanoparticles on highly porous carbon nanofiber (N-PCNF) electrodes exhibited excellent cycling and C-rate performance with a high reversible capacity of around 280 mA h g-1 in sodium ion batteries. Moreover, at 1000 mA g-1, a high reversible capacity of 172 mA h g-1 was observed after 300 cycles. The superior electrochemical properties were attributed to a highly porous structure with enlarged d-spacings, enriched defects and active sites due to nitrogen doping. The electrochemical results prove that N-PCNF electrodes are promising electrode materials for high performance sodium ion batteries.

Evaluation of Lapatinib-Loaded Microfibers Prepared by Centrifugal Spinning.

Lapatinib (Lap) is a lypophilic drug frequently used in cancer treatment; however, due to its limited solubility and permeability, achieving therapeutic dose through oral administration proves to be a challenge. There are various methods for enhancing the solubility of Lap and other similar drugs, one being the preparation of amorphous solid dispersions (ASD). In this study, a Lap-loaded polyvinylpyrrolidone (PVP) fiber mat was created with centrifugal spinning from a PVP/Lap solution in dimethyl formamide and ethanol. The production rate was 12.2 g/h dry fibers, and the fibers had an average thickness of 2.55 ± 0.92 μm. In the differential scanning calorimetry (DSC) thermogram of the fiber mat, the melting peak of the crystalline Lap was not visible, suggesting that Lap was in an amorphous state. A dissolution study was carried out in 0.2 M phosphate buffer saline solution at 37 °C. UV spectrophotometry data indicated that in the sample containing the fiber mat, the Lap concentration was 332 μg/mL (66%) in 10 min, decreasing to 227 μg/mL by 45 min. Meanwhile the crystalline Lap formed a 30-40 μg/mL (6-8%) solution in 5 min, maintaining that concentration. We conclude that centrifugal spinning can be an effective and easy method to produce ASDs.

Centrifugally Spun PVA/PVP Based B, N, F Doped Carbon Nanofiber Electrodes for Sodium Ion Batteries.

Owing to their high electrical conductivity, high surface area, low density, high thermal stability, and chemical stability, carbon nanofibers have been used in many fields, including energy storage, electromagnetic shielding, filtering, composites, sensors, and tissue engineering. Considering the environmental impact of petroleum-based polymers, it is vital to fabricate carbon nanofibers from environmentally-friendly materials using fast and safe techniques. PVA/PVP nanofibers were fabricated via centrifugal spinning and the effects of variations in the PVP content on the morphology and thermal properties of PVA/PVP-blend nanofibers were studied using SEM and DSC analyses. Moreover, the effects of carbonization conditions, including stabilization time, stabilization temperature, carbonization time, and carbonization temperature on the morphology and carbon yield, were investigated. Centrifugally spun PVA/PVP-based carbon nanofiber electrodes with an average fiber diameter around 300 nm are reported here for the first time. Furthermore, centrifugally spun PVA/PVP-based B, N, F-doped carbon nanofibers were fabricated by combining centrifugal spinning and heat treatment. Through B, N, F doping, CNFs demonstrated a high reversible capacity of more than 150 mAh/g in 200 cycles with stable cycling performance.

Preparation of Copper Ion Adsorbed Modified Montmorillonite/Cellulose Acetate Porous Composite Fiber Membrane by Centrifugal Spinning.

The natural adsorption material montmorillonite (MMT) was selected, and cellulose acetate (CA) was used as the loading substrate to design and prepare a kind of green and environment-friendly recyclable porous composite fiber membrane with good heavy metal ion adsorption performance. Acetic acid modified montmorillonite (HCl-MMT), sodium dodecyl sulfonate modified montmorillonite (SDS-MMT), and chitosan modified montmorillonite (CTS-MMT) were prepared by inorganic modification and organic modification, and the porous MMT/CA composite fiber membrane was constructed by centrifugal spinning equipment. The morphological and structural changes of MMT before and after modification and their effects on porous composite fiber membranes were investigated. The morphology, structure, and adsorption properties of the composite fibers were characterized by scanning electron microscopy (SEM) and atomic absorption spectrometry (ASS). The experimental results showed that the maximum adsorption capacity of Cu2+ on the prepared 5 wt% CTS-MMT composite fiber membrane was 60.272 mg/g after 10 h static adsorption. The adsorption of Cu2+ by a porous composite fiber membrane conforms to the quasi-second-order kinetic model and Langmuir isothermal adsorption model. The main factor of the Cu2+ adsorption rate is chemical adsorption, and the adsorption mechanism is mainly monolayer adsorption.

Recent advances in ZrO2 nanofibers: From structural design to emerging applications

One-dimensional (1D) zirconium dioxide nanofibers (ZrO2 NFs), as an important inorganic material, have attracted significant attention because of their unique structural characteristics, outstanding chemical/thermal stability, and excellent optical/electronic properties. The biotemplate method, phase inversion method, centrifugal spinning, and electrospinning are facile and highly versatile approaches for the synthesis of ZrO2 NFs, which have great potential in many emerging applications, such as thermal insulation, air filtration, water purification, catalyst supports, dye-sensitized solar batteries, and lithium-ion batteries. In this review, strategies for synthesizing ZrO2 NFs with various structures, such as porous, hollow, layered, and even 3D self-assembled structures, are described and analyzed in detail. Recent revolutionary progress in mitigating the brittle nature of ceramics and constructing flexible ZrO2 NFs, as well as their deformation mechanisms, is also discussed. Then, achievements concerning the application fields of ZrO2 NFs in thermal insulation, environmental remediation, catalysis, and batteries are presented. Finally, we provide a comprehensive summary of the critical challenges and future perspectives on ZrO2 NFs. This review is envisioned to guide future research on novel ZrO2 NFs for emerging applications.

Centrifugally spun lignin fibers with high Cr(Ⅵ) adsorption capacity

Due to its structural cohesiveness, lignin is unable to construct an efficient adsorption structure and exhibits poor adsorption capacity of heavy metal ions. Most of the current studies have been conducted to improve the adsorption performance of lignin by functionalization or construction of spatial network structure to change the aggregation state of lignin. However, this did not develop the adsorption capacity of lignin itself and the enhancement is quite dependent on the introduced materials. In this study, lignin fibers were prepared by facile centrifugal spinning method to expose more effective adsorption sites, and the corresponding Cr(VI) adsorption capacity was improved. The further enhancement of the Cr(VI) adsorption capacity of lignin fibers can be achieved by the formation of porous structure via adding sodium dodecyl sulfate and then dissolving it in aqueous solution during adsorption. The obtained lignin fibers exhibited maximum Cr(VI) adsorption capacity of 339.0 mg/g, which is quite higher than that of modified lignin in previous studies. As-prepared lignin fibers showed monolayer adsorption and chemical adsorption which mainly included reduction, electrostatic attraction, complexation, π-cation interaction, and pore filling. These results are useful for the application of lignin adsorbent materials in wastewater treatment.

Flow field in micro-triangle of centrifugal composite spinning and the effect of slippage on PA composite nanofibers

Composite nanofibers have been widely investigated in aerospace, new energy, and biomedical fields, and the preparation method of them has become a hot research topic. Centrifugal spinning to prepare composite nanofibers is a neoteric pattern. In high-speed centrifugal composite spinning, the slippage theory of the two polymer solutions in the micro-triangle area has been analyzed, and the flow of the polymer solution in the micro-triangle area can further verify the occurrence of the slip motion in the micro-triangle area. It can be found that the rotational speed has the greatest effect on the preparation of composite nanofibers. When the rotational speed continues to increase, the slippage in the micro-triangle region occurs first with liquid-wall slippage, then with liquid–liquid interface slippage and finally with gas–liquid interface slippage. At the same rotational speed, the higher the concentration, the more concentrated the velocity distribution, and the better the prepared composite nanofiber structure. Finally, the optimal parameters for the preparation of PA composite nanofibers were obtained through the centrifugal composite spinning test. It provides theoretical and data support for centrifugal composite spinning micro-triangle slip and composite nanofibers preparation.

Sol–Gel Routes toward Ceramic Nanofibers for High-Performance Thermal Management

Ceramic-based nanofiber materials for high-performance thermal management have drawn increasing attention owing to their high-temperature resistance, efficient thermal insulation, superior mechanical flexibility, as well as excellent physical–chemical stability. We present an overview of the ceramic-based nanofiber obtained by sol–gel routes for high-performance thermal management, including the materials, the fabrication methods of the sol–gel route, and their application for thermal management. We first provide a brief introduction to the ceramic-based nanofibers. The materials and fabrication methods of the sol–gel route are further discussed in the second part, including the kinds of nanofibers such as oxide, carbide, and nitride, and the methods such as centrifugal spinning, electrospinning, solution blow spinning, and self-assembly. Finally, their application for thermal management is further illustrated. This review will provide some necessary suggestions to researchers for the investigation of ceramic-based nanofibers produced with the sol–gel route for thermal management.

A Review on Current Nanofiber Technologies: Electrospinning, Centrifugal Spinning, and Electro‐Centrifugal Spinning

AbstractNanofiber‐based products are widely used in the fields of public health, air/water filtration, energy storage, etc. The demand for nonwoven products is rapidly increasing especially after COVID‐19 pandemic. Electrospinning is the most popular technology to produce nanofiber‐based products from various kinds of materials in bench and commercial scales. While centrifugal spinning and electro‐centrifugal spinning are considered to be the other two well‐known technologies to fabricate nanofibers. However, their developments are restricted mainly due to the unnormalized spinning devices and spinning principles. High solution concentration and high production efficiency are the two main strengths of centrifugal spinning, but beaded fibers can be formed easily due to air perturbation or device vibration. Electro‐centrifugal spinning is formed by introducing a high voltage electrostatic field into the centrifugal spinning system, which suppresses the formation of beaded fibers and results in producing elegant nanofibers. It is believed that electrospinning can be replaced by electro‐centrifugal spinning in some specific application areas. This article gives an overview on the existing devices and the crucial processing parameters of these nanofiber technologies, also constructive suggestions are proposed to facilitate the development of centrifugal and electro‐centrifugal spinning.

Highly Aligned Centrifugal Spun Polyacrylonitrile Nanofibers Collected and Processed with Automated Tracks

AbstractA parallel automated track collector is integrated with a rationally designed centrifugal spinning head to collect aligned polyacrylonitrile (PAN) nanofibers. Centrifugal spinning is an extremely promising nanofiber fabrication technology due to high production rates. However, continuous oriented fiber collection and processing presents challenges. Engineering solutions to these two challenges are explored in this study. A 3D‐printed head design, optimized through a computational fluid dynamics simulation approach, is utilized to limit unwanted air currents that disturb deposited nanofibers. An automated track collecting device has pulled deposited nanofibers away from the collecting area. This results in a continuous supply of individual aligned nanofibers as opposed to the densely packed nanofiber mesh ring that is deposited on conventional static post collectors. The automated track collector allows for simple integration of the postdraw processing step that is critical to polymer fiber manufacturing for enhancing macromolecular orientation and mechanical properties. Postdrawing has enhanced the mechanical properties of centrifugal spun PAN nanofibers, which have different crystalline properties compared with conventional PAN microfiber. These technological developments address key limitations of centrifugal spinning that can facilitate high production rate commercial fabrication of highly aligned, high‐performance polymer nanofibers.

Efficient centrifugal spinning of soda lignin for the production of activated carbon nanofibers with highly porous structure

In this study, centrifugally spun soda lignin (SL) nanofibers were prepared as precursors to produce lignin-based carbon nanofibers (LCNF) and activated carbon nanofibers (LACNF). The impact of concentration of spinning solution and rational speed on the spinnability and fiber diameters were systematically examined by scanning electron microscopy (SEM). The result showed that the produced fibers diameter was in the range of 0.47–2.36 μm. The effect of SL nanofiber diameter on its morphology and thermal properties during carbonization was obtained by SEM, thermogravimetric (TGA) and differential calorimetric scanning (DSC) analyses. Subsequently, the SL nanofibers were ease to transform into LCNF and further LACNF with highest specific surface area of approximately 1900 m2/g, which is superior to those of LACNF in previously prepared by electrospinning. It can be concluded that centrifugal spinning method is a facile and efficient technique to develop large scale production of lignin-based nanofibers and in particular LACNF with high specific surface area.

Novel active food packaging based on centrifugally spun nanofibers containing lavender essential oil: Rapid fabrication, characterization, and application to preserve of minced lamb meat

This study aimed to develop novel nano fibers loaded with lavender essential oil (LEO) for food packaging via centrifugal spinning technique. LEO was extracted from dried lavender flowers by hydrodistillation. The dominant two of the 16 components of the extract identified by GS-MS were linalool (34.37 %) and linalyl acetate (28.82 %). PVP nanofiber mats loaded with three different concentrations of LEO were fabricated with centrifugal spinning and subsequently crosslinked. Nanofibers were characterized in encapsulation efficiency, morphological, mechanical, chemical, thermal, hydrophobicity and bioactivity aspects. The in-vitro antioxidant effect of nanofiber mats, which increased with the loaded LEO concentration, were determined by DPPH and ABTS methods. This effect was also consistent with the in-situ assessment where nanofibers were applied to minced lamb meat. Moreover, LEO-loaded PVP centrifugal spun positively affected the shelf life by suppressing the growth of aerobic mesophilic bacteria, psychotropic bacteria and, yeast molds that cause spoilage in meat.

Centrifugal spinning of polyvinyl alcohol/sodium alginate-di -aldehyde-gelatin based antibacterial nanofibers intended for skin tissue engineering

In this study, three types of nanofibers, i.e. polyvinyl alcohol (PVA), alginate di-aldehyde (ADA)/PVA, and ADA-gelatin (GEL)/PVA, were fabricated via centrifugal spinning. The spinability of ADA was improved by mixing with PVA. Furthermore, GEL and sesame oil were added in the ADA solution to control the degradation kinetics and to improve the viscosity of the solution, respectively. Later, the solution was fed to a rotating spinneret (3000 rpm at 250 °C) which led to the fabrication of nanofibers. The developed nanofibers were loaded with copper-silver (Cu-Ag) doped mesoporous bioactive glass nanoparticles (MBGNs) to provide therapeutic effects (antibacterial effect). Scanning electron microscopy images showed that the nanofiber diameters were 139 ± 62 nm, 258 ± 42 nm, and 281 ± 34 nm, for PVA, ADA/PVA, and ADA-GEL/PVA respectively, with web-like morphology. Fourier transform infrared spectroscopy confirmed the presence of chemical bonds attributed to the ADA, GEL, and PVA components. The results of the inhibition halo test confirmed that the nanofibers (ADA-GEL/PVA & ADA/PVA) exhibit potent antibacterial effect against Staphylococcus aureus and Escherichia coli.

Recent Advances in Designing Fibrous Biomaterials for the Domain of Biomedical, Clinical, and Environmental Applications.

Unique properties and potential applications of nanofibers have emerged as innovative approaches and opportunities in the biomedical, healthcare, environmental, and biosensor fields. Electrospinning and centrifugal spinning strategies have gained considerable attention among all kinds of strategies to produce nanofibers. These techniques produce nanofibers with high porosity and surface area, adequate pore architecture, and diverse chemical compositions. The extraordinary characteristics of nanofibers have unveiled new gates in nanomedicine to establish innovative fiber-based formulations for biomedical use, healthcare, and a wide range of other applications. The present review aims to provide a comprehensive overview of nanofibers and their broad range of applications, including drug delivery, biomedical scaffolds, tissue/bone-tissue engineering, dental applications, and environmental remediation in a single place. The review begins with a brief introduction followed by potential applications of nanofibers. Finally, the future perspectives and current challenges of nanofibers are demonstrated. This review will help researchers to engineer more efficient multifunctional nanofibers with improved characteristics for their effective use in broad areas. We strongly believe this review is a reader's delight and will help in dealing with the fundamental principles and applications of nanofiber-based scaffolds. This review will assist students and a broad range of scientific communities to understand the significance of nanofibers in several domains of nanotechnology, nanomedicine, biotechnology, and environmental remediation, which will set a benchmark for further research.

Research on the Mechanism of Multi-Domain Coupling Centrifugal Electrostatic Blowing Flying Deposition.

The centrifugal electrostatic blowing process proposed in this paper solves the difficult continuous and stable deposition problem in the traditional centrifugal electrostatic spinning process. By establishing a flight deposition model of the centrifugal electrostatic spraying process, CFD is used to simulate and analyze the electrohydrodynamic effect of centrifugal jets, and the driving mechanism is explored. Subsequently, MATLAB is used to obtain the optimal solution conditions, and finally, the establishment of a two-dimensional flight trajectory model is completed and experimentally verified. In addition, the deposition model of the jet is established to clarify the flight trajectory under the multi-field coupling, the stable draft area of the jet is found according to this, and the optimal drafting station is clarified. This research provides new ideas and references for the exploration of the deposition mechanism of the centrifugal electrostatic blowing and electrostatic spinning process.

Centrifugally spun alginate-poly(lactic acid) microbeads: A promising carrier for drug delivery and tissue engineering

A facile and high yield centrifugal spinning technique known as Forcespinning® (FS) was used to develop unique microstructures consisting of PLA microbeads along alginate fibers. Morphological variation and structural features appeared in the field-emission scanning electron micrographs for the PLA-alginate composites and dried PLA-alginate films from precursor emulsions at constant PLA and varied alginate contents. Shrunk and deflated microbeads were observed for composites whilst spherical beads were evident for the PLA control. Furthermore, PLA was found surrounding the alginate when the alginate was present at 0.24 wt% or lower, while alginate (mushroom-like structures), were seen protruding through the PLA layer at ≥0.34 wt% alginate. Rheological characterization of the composite emulsions revealed that the filler (alginate) provided shear thinning properties including pseudoplasticity, desirable for printing and other related applications in contrast to the Newtonian flow shown by the PLA control. Along with infra-red spectroscopy, the nanocomposites were further characterized using thermal gravimetry and differential scanning calorimetry featuring reversible events influenced by heat capacity and irreversible kinetic/thermodynamic counterparts. The work provides a comprehensive investigation of biocompatible networks of PLA-alginate microbeads embedded in nano-sized fibers and the prospective application of these microbeads as a drug delivery system.