Papers by Keyword: Electrospinning

Abstract: The development of biocomposite nanofiber-based wound dressing materials using Polylactic Acid (PLA), cellulose, and chitosan was carried out through the electrospinning method. The ideal wound dressing should be biocompatible, biodegradable, antibacterial, and able to maintain optimal wound moisture with its water resistance. In this study, various material compositions and electrospinning feed rates were applied to study their effects on water resistance. The solution mixing process was carried out using Dichloromethane and Dimethylformamide solvents, followed by electrospinning at a voltage of 20 kV with a feed rate ranging from 5 ml/hour to 9 ml/hour, characterization included hydrophobicity testing, scanning electron microscope (SEM), and Fourier Transform Infrared (FTIR). The resulting nanofiber-based wound dressing, based on hydrophobicity testing, was found to have the lowest contact angle value at a feed rate of 6 ml/hour with a 100% PLA composition of 77.9096°, and the highest contact angle value at a feed rate of 6 ml/hour with a chitosan and cellulose composition of 89.37°. This indicates that the combination of cellulose and chitosan is able to maintain stable surface properties despite changing process conditions. Overall, the effect of flow rate on surface properties is strongly influenced by material composition, which ultimately determines the contact angle. This contact angle value plays a crucial role in determining water resistance, whether the surface tends to be hydrophilic (readily absorbs water) or hydrophobic (repels water). Keywords: Wound Dressing, Nanofiber, Polylactic Acid, Cellulose, Chitosan, Electrospinning

Abstract: Oral dispersible film (ODF) containing ascorbic acid (AA) was synthesised using the electrospinning process, and its dissolving behaviour was analysed by Ultraviolet-Visible (UV-Vis) spectroscopy. The obtained time, wavelength and absorbance data were applied to train an Artificial Neural Network (ANN) using the Levenberg-Marquardt algorithm. A total of 42 datasets were separated into training (90%), validation (5%) and testing (5%) sections. The ANN model displayed good predictive ability, giving a low mean squared error (MSE) and a regression coefficient (R=1), demonstrating a significant correlation between predicted and experimental dissolution profiles. These results demonstrate that ANN can efficiently predict ODF dissolution profiles, hence lowering experimental burden and boosting efficiency in pharmaceutical formulation research.

Abstract: This work demonstrates the successful preparation of two types of photocatalytically active nanostructured materials from an industrial waste product – Sal Ammonia Skimming – using hydrochloric acid as a leaching medium. The whole production process was developed to prepare valuable ZnO nanomaterials in both fibrous and powdered forms. This involved a sequence of hydrometallurgical processing, needle-less electrospinning, and conventional calcination of recycled environmentally polluting industrial waste. The morphologies and phase composition of the resulting ZnO powder and ZnO fibers were analyzed using SEM, EDS, and XRD analyses. The impact of the morphology of the prepared nanomaterials on the photocatalytic efficiency of the ZnO-based photocatalyst – powder versus ZnO nanofibers – was evaluated through decolorization experiments of the commonly used methylene blue dye in batch mode. Methylene blue was chosen as a model substance for toxic industrial pollutants. A 25 W UVA lamp with an emission maximum at 365 nm was used as a light source. Removal efficiencies were carefully tested and compared for different nanomaterial morphologies and preparation conditions. The most photocatalytically active ZnO-based nanomaterial was the electrospun nanofibrous one calcined at 600 °C for 1 h. This material achieved 100 % removal of a 10⁻⁵ mol/L methylene blue dye from the solution within 700 minutes at an increased catalyst-to-dye ratio of 500 mg/50 ml. Based on the obtained results, it can be stated that the prepared materials exhibit high photocatalytic activity under UV light irradiation and have a potential for photocatalytic water remediation applications.

Abstract: The composite nanofibers of PVDF/BiFeO₃ (PVDF/BF) signify a notable advancement in the domain of piezoelectric nanogenerators (PENGs), providing a high surface area alongside enhanced physicochemical properties for energy harvesting and storage applications. These nanofibers were synthesized through the electrospinning technique, which enables the creation of porous fibers by the dissolution of polymers in volatile solvents. This study investigates the crystalline and chemical structures of PVDF/BF nanofibers with modified formulations. X-ray diffraction (XRD) analysis has confirmed the presence of a rhombohedral (R3c) phase, characteristic of both BiFeO₃ and the PVDF phase. The measured fiber diameters for pure PVDF and PVDF/BF composites varied from approximately 400 nm to 950 nm. Fourier-transform infrared (FTIR) spectroscopy has identified absorption bands at 410–555 cm^-1, which correspond to the functional groups of BiFeO₃, as well as at 612–1430 cm^-1 for PVDF. Moreover, Raman spectroscopy has validated molecular vibrational shifts for BiFeO₃ (4A1+9E) and PVDF within the range of 2973–2977 cm^-1. The incorporation of BiFeO₃ within the PVDF/BF nanofibers enhances the formation of the electroactive β-phase, thereby potentially improving their electrical properties.

Abstract: Controlling nanomaterials' morphology and molecular structures offers many advantages, such as tunable material properties, lightweight, and high surface-to-volume ratio. Studies have focused on electrospinning as one of the most effective methods in fabricating nanofibrous materials and have closely considered various post-fabrication techniques to improve mechanical properties. This work investigates the effect of constrained heating at 100°C, 110°C and 120°C on the morphology, the static and dynamic mechanical properties, and crystallization properties of electrospun Poly(vinyl) alcohol (PVA) nanofibrous membranes. Constrained heating of PVA nanofibrous membranes at 120°C has the best overall improvement. As compared to unheated samples, the Young’s modulus is multiplied by more than 3, the tensile strength increases more than 75%. At the same time, the fiber diameter decreases from 282.4 nm to 222.2 nm, and the degree of crystallinity and crystallite size increases by more than 10% and about 75%, respectively. This change in molecular structure and the increase in mechanical properties suggest that constrained heating should be further explored to diversify load bearing applications.

Abstract: Electrospinning (ES) is a vital technique for producing ultrafine polymer fibers and is widely used in various applications. However, conventional electrospinning setups with some polymer solutions face challenges like bead formation and inconsistent fiber diameters. Integrating airflow into the system helps stretch the fiber and speed up the evaporation of polymer jets, thereby improving fiber morphology. Despite these benefits, incorporating airflow complicates the setup and makes it less user-friendly, as achieving precise laminar airflow toward the jets is difficult. To address these problems, we developed a novel electrospinning attachment featuring easily adjustable slits incorporating controlled airflow with a pressure regulation system. The design allows for convenient adjustment of airflow direction through replaceable slits and blades. Its simplicity allows for easy blade replacement at different angles to control airflow toward the polymer jet. In our experiments, we tested two different slits angles of 30° and 60° (3D printed) to the setup. The results showed that controlled airflow significantly reduced bead formation and produced more uniform fiber diameters. With a 60° slit angle at 0.1 bar, the average fiber diameter was 647.6 nm, decreasing to 526.4 nm at 0.2 bar. Conversely, fibers spun with a 30° slit angle had an average diameter of 712.6 nm at 0.1 bar, with minimal change at 0.2 bar. These findings indicate that controlled laminar airflow with adjustable slit angles substantially improves the properties of electrospun fiber mats.

Abstract: Chitosan (CS), with its non-toxic and antibacterial properties, and Poly(ε-caprolactone) (PCL), known for its biodegradability and biocompatibility, are crucial materials in medical applications. This study proposed a solution utilizing electrospinning to manufacture fibers with nanometer-sized core-shell structures from these materials, with CS serving as the fiber core and PCL forming the shell. The influence of manufacturing technology parameters on fiber size and morphology was thoroughly researched and investigated. The solvent system used, Chloroform/Dimethylformamide (DMF), ensured complete solubility, viscosity control, conductivity, and proper solvent evaporation. Transmission Electron Microscopy (TEM) and Scanning Electron Microscopy (SEM) results clearly demonstrated the morphology and internal structure of the nanofibers. The water contact angle (WCA) measurements of the fiber membrane showed almost no significant change over time, indicating strong hydrophobicity of the nanofibers. Additionally, the FTIR spectrum revealed distinct core-shell layers without any blending between them, while DSC analysis showed the thermal properties of fiber membranes. In summary, the electrospinning of nanofibers proved to be stable, producing thin fibers with an average diameter of approximately 400 nm. These findings are expected to significantly enhance the applicability of CS/PCL nanofibers across various fields, including healthcare and smart agriculture.

Abstract: With the rapid advancement of global industrialization, there is an increasing year-on-year demand for oil in society. The occurrence of oil spills during the processes of development, refining, and transportation has become an urgent issue that needs to be addressed. Electrospun fiber separation using selective oil/water absorption represents a relatively new yet promising technology. However, despite the lipophilic nature of the membrane for oil absorption, the rate of oil absorption is slow. There are still challenges in meeting the needs of developing communities. The plant employs a strategy of multi-branching with narrowed pores, which serves to enhance the efficiency of water and nutrient transfer. Inspired by plant transpiration, we adjusted the parameters of electrospinning and constructed a PVDF biomimetic nanofiber membrane with gradually reduced pore size through a bottom-up layer-by-layer spinning strategy. This PVDF biomimetic nanofiber membrane conforms to Murray's law. The experimental results showed that the oil absorption of carbon tetrachloride by PVDF Murray membrane was 3.06 g/g. Significantly, the PVDF Murray membrane demonstrates rapid adsorption of the oil slick (0.3 mL, n-hexane) in just 13s, as compared to 24s without the Murray structure. Therefore, the one-step preparation of the PVDF Murray membrane indicates a promising potential for its future application as a sustainable and quick oil-absorbent membrane.

Abstract: Electrospun piezoelectric nanofibrous membrane developed from Polyvinylidene fluoride (PVDF) embedded with thermoplastic polyurethane (TPU) composites found to have superior stretchability and piezoactivity. The piezoresponse behavior of different in-situ bended PVDF/TPU, up to 15wt.% of TPU, is examined using various blending ratios of PVDF and TPU. It has been shown that adding TPU with PVDF at certain specific concentration increased the nanofiber's piezo-efficiency.The generated nanomembranes are annealead at different temperatures up to 100°C. An extensive analysis of the effects of annealing is conducted on these nanomats, and it is thought to be a crucial post-treatment method for improving the piezoresponse of the manufactured nanomats. Nanofibers annealed at 100°C showed best effective response compared to all other samples and this revealed the effectiveness of annealing treatment in the enhancement of piezoactivity. The best effective composition of PVDF with 15 wt% TPU after an annealing treatment of 100°C generated a maximum voltage of 3.2 V under the effect of an applied force of 3 N, where unannealed sample of the same PVDF-TPU composition generated only a voltage of 2.2 V. This annealed piezo nanogenerator (PNG), can be considered an optimum option for electromechanical energy harvesting applications that require flexibility and self-power.

Abstract: Traditional biomedical applications in wound dressing and tissue engineering materials frequently lack the appropriate balance of environmental friendliness, antibacterial effectiveness, and mechanical strength. A growing number of medical applications are focusing on electrospun nanofibers because of their special qualities, which include a high surface area-to-volume ratio, tailor-made mechanical strength and more eco-friendly. The goal of this review paper is to thoroughly examine the corpus of research that is currently available about electrospun, nanofibers especially made from aloe vera and pineapple leaf fibers for use in biomedical applications. This review's goals include optimizing electrospinning conditions, assessing biocompatibility, researching antibacterial activity, and its current challenge.