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(a) Design features of spinneret device. Interior view of new device (b) Bottom half (c) Top half (d) Experimental set-up.
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Core-sheath fibres of two polymers were generated using a novel set-up where rotating speed and pressure can be varied at ambient temperature. The specially designed spinneret consists of inner and outer chambers which can accommodate two polymers and other additives. The new methodology was demonstrated using poly(ethylene oxide) and poly(methylme...
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... two halves of the device and the assembled device used at ambient conditions (20 °C, relative humidity 42%) in this study are shown in Fig. 1b, c and d. One end of the vessel was connected to a motor which can generate apparent speeds up to 6000 rpm, while the other end was connected to a nitrogen gas stream, the pressure of which can be varied up to 3 × 10 5 Pa. Speed of the gyration vessel was calibrated by attaching a photo-sensitive tape to face of the vessel and with a ...
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Citations
... This method provides precise control over fiber morphology and the distribution of the active ingredients within the fibers. [34,35] It addresses the scalability limitations of traditional manufacturing techniques such as coaxial electrospinning. ...
... The core-sheath pressurized gyration apparatus used by Mahalingam et al., [34,35] as depicted in (Figure 1A) was utilized to manufacture both core-sheath and singular-sheath fibers for the experiments conducted with PCL, PEO, PEO/Garlic, CS PEO/PCL and CS PEO/Garlic/PCL fibers. The equipment consists of a twin-reservoir pot with a 20 mL capacity and two concentric orifices on the wall of the vessel. ...
This work explores the application of Allium sativum (Garlic) extract, in the creation of novel polymeric core‐sheath fibers for wound therapy applications. The core‐sheath pressurized gyration (CS PG) technology is utilized to mass‐produce fibers with a polycaprolactone (PCL) core and a polyethylene oxide (PEO) sheath, loaded with garlic extract. The produced fibers maintain structural integrity, long‐term stability and provide a cell‐friendly surface with rapid antibacterial activity. The physical properties, morphology, therapeutic delivery, cytotoxicity, thermal and chemical stability of PCL, PEO, PEO/Garlic, Core‐Sheath (CS) PEO/PCL and PEO/Garlic/PCL fibers are analyzed. Findings show that the addition of garlic extract greatly increases the fibers’ thermal durability, while decreasing their diameter, thus improving cell adhesion and proliferation. In‐vitro release tests reveal a rapid release of garlic extract, which has significant antibacterial action against both Gram‐negative Escherichia coli ( E. coli ) and Gram‐positive Staphylococcus aureus ( S. aureus ) bacteria species. Cell viability experiments validate the fiber samples' biocompatibility and nontoxicity, making them appropriate for integrative medicine applications. These core‐sheath structures emphasize the potential of combining natural therapeutic agents with advanced material technologies to develop cost‐effective, sustainable and highly effective wound dressings, offering a promising solution to the growing concerns associated with conventional synthetic antibacterial agents.
... Fabricating the smooth fiber morphologies needs acceptable polymer entanglement, and for a definite molecular weight, the entanglement density rises with the concentration of the polymer. In addition, increasing the polymer concentration will increase the viscosity, thus preventing the evaporation of the solvent, and this results in thicker fibers [63]. The decrease in the diameter of fibers with the addition of DO and B12 supported that 15PF41 was a suitable choice for drug loading. ...
... In addition, vessels with multi-layer reservoirs have been used for the preparation of core-sheath fibers. [40,41] The inner and outer reservoirs are loaded with different polymer solutions to form the core and the sheath structures of the multi-layer fibers, respectively. ...
... Biphasic fibers are produced by the multi-layer design of the spinning vessel in core-sheath pressurized gyration (core-sheath PG). [40,41] As shown in Figure 6A, the spinning vessel of coresheath PG has a dual-layered reservoir. The inner and outer reservoirs are used to load different polymer solutions to form the core structure and sheath structure of fibers, respectively. ...
... Besides uniform solid fibers, PG has been used to produce beaded fibers, core-sheath fibers, and microbubbles instead of one-dimensional materials. [40,44,64,65] Microbubbles are a promising material in diagnosis, therapeutic applications, targeted drug delivery, etc. [66][67][68][69] These successful instances undoubtedly validate the practicability and extensibility of the PG technology in the preparation of micro/nano-materials. Macromol. Mater. ...
As a facile, efficient, and low‐cost fiber manufacturing strategy, pressurized gyration/rotation (PG) is attracting tremendous attention. This review provides a comprehensive introduction to the working setups, fundamental principles, processing parameters, and material feed properties of this technology. The characterizations of products prepared by this technology and their wide application fields are summarized. The development potentials and broader application prospects of PG are discussed. PG holds significant promise for the scale‐up of ultrafine fiber manufacturing.
... Pressurized gyration was developed by Edirisinghe and co-workers in 2013. (Figure 5b) [111][112][113][114] By combining pressure and spinning of a solution enclosed in a perfo-rated aluminum vessel, pressurized gyration offers a novel electric potential-free manufacturing approach for creating polymer fibers from the micro to nanoscale in a single-step process. [115][116][117] It is an uncomplicated and a functional technique to achieve fibers and fibrous structures with a specific fiber size and distribution. ...
... [119] The novel gyratory technique can also be used for the mass production of alloyed polymeric fibers. [113,120] ...
Over the past decade, there have been many interesting studies in the scientific literature about the interaction of graphene‐based polymeric nanocomposites with microorganisms to tackle antimicrobial resistance. These studies have reported variable intensities of biocompatibility and selectivity for the nanocomposites toward a specific strain, but it is widely believed that graphene nanocomposites have antibacterial, antiviral, and antifungal activities. Such antibacterial activity is due to several mechanisms by which graphene nanocomposites can act on cells including stimulating oxidative stress; disrupting membranes due to sharp edges; greatly changing core structure mechanical strength and coarseness. However, the underlying mechanisms of graphene nanocomposites as antiviral and antifungal agents remain relatively scarce. In this review, recent advances in the synthesis, functional tailoring, and antibacterial, antiviral, and antifungal applications of graphene nanocomposites are summarized. The synthesis of graphene materials and graphene‐based polymeric nanocomposites with techniques such as pressurized gyration, electrospinning, chemical vapor deposition, and layer‐by‐layer self‐assembly is first introduced. Then, the antimicrobial mechanisms of graphene membranes are presented and demonstrated typical in vitro and in vivo studies on the use of graphene nanocomposites for antibacterial, antiviral, and antifungal applications. Finally, the review describes the biosafety, current limitations, and potential of antimicrobial graphene‐based nanocomposites.
... Fibrous scaffolds having a PCL core and a shell of PVA loaded with HAp NPs have recently been produced using a new spinning technique [261]. In this case, the corresponding polymer solutions were extruded trough concentric nozzles under the action of rotation and pressure [262]. The lack of limitations on the selection of solvents appears the main advantage over conventional electrospinning. ...
Tissue engineering is nowadays a powerful tool to restore damaged tissues and recover their normal functionality. Advantages over other current methods are well established, although a continuous evolution is still necessary to improve the final performance and the range of applications. Trends are nowadays focused on the development of multifunctional scaffolds with hierarchical structures and the capability to render a sustained delivery of bioactive molecules under an appropriate stimulus. Nanocomposites incorporating hydroxyapatite nanoparticles (HAp NPs) have a predominant role in bone tissue regeneration due to their high capacity to enhance osteoinduction, osteoconduction, and osteointegration, as well as their encapsulation efficiency and protection capability of bioactive agents. Selection of appropriated polymeric matrices is fundamental and consequently great efforts have been invested to increase the range of properties of available materials through copolymerization, blending, or combining structures constituted by different materials. Scaffolds can be obtained from different processes that differ in characteristics, such as texture or porosity. Probably, electrospinning has the greater relevance, since the obtained nanofiber membranes have a great similarity with the extracellular matrix and, in addition, they can easily incorporate functional and bioactive compounds. Coaxial and emulsion electrospinning processes appear ideal to generate complex systems able to incorporate highly different agents. The present review is mainly focused on the recent works performed with Hap-loaded scaffolds having at least one structural layer composed of core/shell nanofibers.
... These applications are further extended by the development of core-sheath nanofibers used for the drug delivery [49] and nozzle pressurized gyration [50] (Fig. 3b) where uniform and aligned nanofibers are able to be layered within each fiber strand [51]. This allows for the development of novel structures and materials for utilization in many biomedical scenarios [52]. Although pressurized gyration has not been specifically used to date to make nanofiber applied biosensors, it offers promising potential as a serious alternative to electrospinning. ...
Biosensors are analytical tools that enable the transmission of different signals produced from the target analyte to a transducer for the production of real-time clinical diagnostic devices by obtaining meaningful results. Recent research demonstrates that the production of structured nanofiber through various methods has come to light as a potential platform for enhancing the functionality of biosensing devices. The general trend is towards the use of nanofibers for electrochemical biosensors. However, optical and mechanical biosensors are being developed by functionalization of nanofibers. Such nanofibers exhibit a high surface area to volume ratio, surface porosity, electroconductivity and variable morphology. In addition, nanosized structures have shown to be effective as membranes for immobilizing bioanalytes, offering physiologically active molecules a favorable microenvironment that improves the efficiency of biosensing. Cost effective, wearable biosensors are crucial for point of care diagnostics. This review aims to examine the electrically conductive materials, potential forming methods, and wide-ranging applications of nanofiber-based biosensing platforms, with an emphasis on transducers incorporating mechanical, electrochemical and optical and bioreceptors involving cancer biomarker, urea, DNA, microorganisms, primarily in the last decade. The appealing properties of nanofibers mats and the attributes of the biorecognition components are also stated and explored. Finally, consideration is given to the difficulties now affecting the design of nanofiber-based biosensing platforms as well as their future potential.
... In addition to electrospinning, centrifugal spinning (CS) is another specific nanofiber technology featuring low cost and high yield (displayed in Figure 1b). [14][15][16][17][18][19][20][21][22][23][24][25] The CS has the same working principle as cotton candy machine. In brief, centrifugal force is generated from high rotation which stretches the polymeric jet to produce fine fibers. ...
Nanofiber‐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. This review article forces on discussing the differences and relationships of three nanofiber technologies—electrospinning, centrifugal spinning, and electro‐centrifugal spinning. It mainly summarizes the existing devices and crucial processing parameters. The electro‐centrifugal spinning combines the strengths of electrospinning and centrifugal spinning, showing potentials in processing elegant nanofibers in large scale.
... A typical electric motor capable of producing enough torque to spin the vessel of the pressurized gyration system up to 10 000 rpm has a power rating of 21.2 W. [75] A 2019 study claims that the method produces a yield of 3.2 kg of fiber an hour (0.89 g per second) when running at full speed. [76] PEO is utilized to produce solutions of multiple weight percentages, where 21% wt was the largest percentage. This would equate to 0.21 g of PEO in 1 mL of solution at 21% concentration. ...
This review focuses on the effects on the environment due to the production of polymer‐solvent solutions and the manufacture of polymeric fibers of thicknesses from a nanometer up to a millimeter using these solutions. The most common polymeric fiber manufacture methods are reviewed based on their effects on the environment, particularly from the use of hazardous materials and energy consumption. Published literature is utilized to analyze and quantify energy consumption of the manufacturing methods electrospinning, phase separation, self‐assembly, template synthesis, drawing and pressurized gyration. The results show that during the manufacturing stage of the lifecycle of polymeric fibers, pressurized gyration is more environmentally efficient primarily due to its mass‐producing features and fast processing of polymeric solutions into fibers, it also works best with water‐based solutions. Further green alternatives are described such as the use of sustainable polymers and solvents to enhance the environmental benefit. Overall, it is shown that the most effective method of curbing the environmental impact of manufacturing polymeric fibers is the use of nontoxic, water‐soluble polymers along with the evasion of toxic solvents. Estimates of the environmental impact from the production of submicrometer polymeric fibers are derived from published literature for some of the most significant methods used to manufacture these materials. The extraction stage, material processing and end of life stages of the life cycle of polymeric fibers are also explored.
... Among the current techniques, pressurized gyration is a novel method to fabricate multicomponent polymer fibers from the raw polymer materials at the micro or macro scales [30]. Mahalingam et al. indicated that coresheath polymer fibers can be made through a pressurized gyration method which can control the fiber size and distribution with high yield [30,31]. On the other hand, for the ready-made fiber material with only one component made by the melt spinning or solution spinning methods can be subsequently fabricated into multifunctional fiber materials by changing the feeding position and the corresponding materials during the subsequent manufacturing process, such as ring spinning for short fibers or wrapping process for long filaments. ...
In this study, wrapping and weaving techniques are used to produce fibrous composites that can block electromagnetic radiation and ultraviolet radiation. Stainless steel filaments are used as the core, and high-strength ultraviolet resistant polyester (PET) filaments are used as the sheath materials to manufacture functional wrapped yarns. The wrapped yarns are made into woven fabric via weaving process. The electromagnetic shielding effectiveness and ultraviolet resistance of woven fabrics are evaluated in order to examine the influence of the number of laminated layer and laminated angles. The test results show that the two-layered woven fabrics that are laminated at 90° have the optimal ultraviolet resistance and electromagnetic shielding effectiveness. Stainless steel/ultraviolet resistance PET woven fabrics are also light weight and can be custom-made into planar protective textile composites based on users’ commands and also can be used in the outdoor domains.
... PG is an encouraging innovation in polymer forming, which has been reported to successfully manufacture homogeneous fibers, core-sheath fibers, drug-loaded fibers, encapsulated nanoparticles and other nanopolymer materials with specific morphology. [1,41,45,[48][49][50][51][52] In this work, we report a novel nozzle-PG setup for the first time. It effectively improves the uniformity and orientation of produced fiber products. ...
... For a given molecular weight, the degree of chain entanglement increases with the increase of polymer concentration. [48] Thus, a high polymer concentration helps the production of smooth and uniform fibers, while a low concentration generally promotes bead formation. [41] The bead formation is also related to centrifugal force. ...
An innovative development of pressurized gyration is presented, incorporating a directional nozzle system. Thus, nozzle‐pressurized gyration is used to prepare polymeric fibers. In this work we compare three different polymeric fibers (polycaprolactone, polyvinylpyrrolidone and polyethylene oxide) manufactured by the original pressurized gyration and nozzle‐pressurized gyration. Under the same processing parameters (working pressure, rotational speed and collection distance), nozzle‐pressurized gyration is proved to be a highly efficient spinning technology for uniform and uniaxially oriented fiber products. The effects of the spinning vessel geometry on the morphology and alignment of gyrospun fibers are elucidated. This work also reveals the relationship between fiber morphology and collection distance in nozzle‐pressurized gyration. Varying the collection distance provides a useful approach to the synthesis of uniform fibers with anisotropic arrangement. This article is protected by copyright. All rights reserved
