Solution Blow Research Articles

Effect of Collector Rotational Speed on the Morphology and Structure of Solution Blow Spun Polylactic Acid (PLA).

Apart from structure and composition, morphology plays a significant role in influencing the performance of materials in terms of both bulk and surface behavior. In this work, polylactic acid (PLA) constituted by submicrometric fibers is prepared. Using a modified electrospinning (ES) device to carry out solution blow spinning (SBS), the fibrillar morphology is modified, with the aim to induce variations in the properties of the material. The modification of the ES device consists of the incorporation of a source of pressurized gas (air) and a 3D-printed nozzle of our own design. For this work, the morphology of the PLA submicrometric fibers is modified by varying the rotational speed of the collector in order to understand its influence on different properties and, consequently, on the performance of the material. The rotational speed of a cylindrical collector (250, 500, 1000 and 2000 rpm) is considered as variable for changing the morphology. Morphological study of the materials was performed using scanning electron microscopy and image analysis carried out with ImageJ 1.54f software. Besides a morphology study, structural characterization by Fourier transformed infrared spectroscopy using attenuated total reflectance of prepared materials is carried out. Finally, the morphology and structure of produced PLA fibrous mats were correlated with the analysis of mechanical properties, wettability behavior and adhesion of DH5-α E. coli bacteria. It is of interest to highlight how small morphological and chemical structure variations can lead to important changes in materials' performance. These changes include, for example, those above 30% in some mechanical parameters and clear variations in bacterial adhesion capacity.

A Perspective on the Supersonic Solution Blowing: Nanofibers at the Forefront of Energy Storage and Conversion, and Environmental Remediation

Nanofibers play a crucial role in energy storage and conversion, catalysis, and environmental remediation applications. These nanomaterials, characterized by their high surface-to-volume ratio and porous structure, exhibit exceptional properties that render them ideal for various energy applications such as in fuel cells, lithium-ion batteries, supercapacitors, catalysis, and hydrogen production. This discussion outlines the historical context of electrospinning (ES), acknowledging its limitations in terms of commercial viability. Introducing the supersonic solution blowing (SSB) technique as a promising alternative, its energy-efficient process holds potential for commercial feasibility. The ES has remarkable advantages in nanofiber fabrication but faces limitations due to high operating costs. Solution blow spinning (SBS) offers speed and versatility; however, fibers have a broad distribution of diameters. SSB therefore overcomes some of the limitations of both ES and SBS techniques to produce defect-free nanofibers with smaller diameters at higher throughput rates. In this concise perspective paper, we emphasize the primary contributions of nanofibers to the development and optimization of materials used in energy applications. Drawing parallels with the prevalent ES and SBS techniques in the literature, we conclude with a discussion on the potential benefits that may arise as researchers increasingly explore this emerging and more efficient technique.

Bioactive TiO2 Fibers Prepared by Solution Blow Spinning: A Promising Approach for Microbial Control

Bioactive TiO2 Fibers Prepared by Solution Blow Spinning: A Promising Approach for Microbial Control

Automatic in situ short-distance deposition of PLGA/PLLA composite nanofibrous membranes for personalized wound dressings.

Improving the mechanical properties of wound dressings and achieving personalized automatic real-time in situ deposition are important for accelerating wound management and repair. In this study, we report a self-designed automatic in situ deposition device based on solution blow spinning (SBS) to prepare poly(lactic-co-glycolic acid) (PLGA) and poly-L-lactic acid (PLLA) composite (PLGA/PLLA) nanofibrous membranes for wound dressing at a short distance. Polymer solution and in situ deposition conditions, including air pressure, spinning distance, solvent extrusion rate, and spinning rate, were optimized using orthogonal experiments and characterized via dynamic mechanical analysis. The microscopic morphology and physical properties of the prepared PLGA/PLLA composite nanofibrous membranes show that their strength, adhesion, water vapor transmission rate (WVTR), water retention, water absorption, degradation, and other properties were sufficient for wound-dressing applications. To investigate the possibility of a biomedical wound-dressing material, tannic acid (TA) was incorporated into the PLGA/PLLA composite nanofibrous membranes. The resultant PLGA/PLLA/TA composite nanofibrous membranes exhibited good biocompatibility and exceptional antibacterial properties against both Escherichia coli and Staphylococcus aureus. A pilot animal study illustrated the potential of this in situ deposition of PLGA/PLLA/TA composite nanofibrous membranes across multiple applications in wound healing/repair by reducing wound scar tissue formation and fibroblast overactivation.

Production of gelatin fibrous mats using different nanofiber production methods for medical applications and comparison of their properties.

In the literature, there are studies on medical applications using different nanofiber production methods with natural polymers. However, each system has different fiber-forming capabilities. For this reason, in this study, we investigated the production of nanofibers from a biodegradable natural polymer, gelatin, using four separate nanofiber production methods, namely electrospinning (ES), electroblowing (EB), solution blowing (SB), and centrifugal spinning (CS). Our aim was to determine the most suitable fibrous web structure for medical applications and contribute to science in this respect. It was observed that the thinnest fibers (386 nm) and the heaviest mats (15.975 g m-2) were produced by the SB method as a result of using 10 wt.% gelatin solution with a total of 10 mL. With the ES and EB methods, tighter fabric structures were obtained than with the others due to the presence of electric fields. In the CS method, more and bead-free fibers were produced due to the increase in viscosity with a 12.5 wt.% gelatin solution. Moreover, with the concentration of 12.5 wt.%, the fiber diameters of SB and CS samples increased about 2-fold.

Effect of static electricity and thickness of solution blow spun polyamide 6/AgNP nanofibrous membrane on nanoparticle filtration and microbiological activity

The efficient filtration of particulate matter smaller than 0.3 µm is crucial for preventing microbial and viral infections. Nanofiber membranes (NFMs) produced by solution blow spinning (SBS) modified with antimicrobial nanoparticles have emerged as a promising technology for filtration technology. In this context, here we developed novel NFMs produced by SBS using Polyamide 6 (PA6) which was surface functionalized with different types of silver nanoparticles (AgNPs) using a simple immersion procedure. The NFMs thickness was customized to evaluate their performance towards the filtration of NP (nanoparticle) from 30 to 300 nm. The incorporation of AgNPs onto the NFMs was also investigated to test their bactericidal activity against E. coli and S. aureus. The NFMs were physically and chemically characterized using distinct techniques. The filtration efficiency of 30–300 nm NP reached around 93.5 %, where the NFMs thickness played a key role in the filtration efficiency and pressure drop. Furthermore, the presence of static electricity in the NFM inherent to the SBS process also contributed to the greater filtration efficiency of smaller particles. Our results demonstrated that NFMs can be produced through SBS in an easy and scalable way, leading to highly efficient filtration systems, with implications for diverse fields such air purification systems and protective clothing.

Chemical recycling of green poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV)-based air filters through hydrolysis

Sustainable alternatives based on biodegradable polymers, such as poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV), can potentially reduce the environmental impact generated by the massive disposal of face masks. However, the destination of this biodegradable material in post-consumer landfills or composting consumes energy and does not necessarily reduce environmental damage. Therefore, it is necessary to find ways to return this material to the chemical chain, such as chemical recycling through hydrolysis. In this context, the present work aimed to produce face masks by solution blow spinning (SBS) from solutions containing 4, 6, and 8 m/v% of PHBV and assess the polymer recyclability through hydrolysis. The filters were subjected to hydrolytic reactions in aqueous solutions with pH values of 4, 7, and 10 at 40, 60, and 80 °C for three weeks based on a standard statistical design of experiments (DoE). The fibers produced with solutions containing 4 m/v% of polymer provided the highest weight loss of 68 wt% after three weeks immersed in an aqueous solution (pH = 4 at 80 °C), exhibiting the lowest environmental impact during the chemical recycling process. The ANOVA analyses showed that the fiber diameter was the most significant factor during the recycling reactions, evidencing that materials should be designed to promote the principles of the circular economy. Based on the obtained results, it can be concluded that PHBV-based face mask filters can promote the principles of the circular economy if polymer fibers are correctly designed. Finally, they can also potentially reduce the environmental damage of face mask disposal as long as the recycling process is in place with a proper collection and sorting system.

Stretchable and ultra‐light non‐woven thermal material with effective photo‐thermal conversion based on solution blow spinning technology

AbstractAn ideal insulation material has long been envisioned as one that not only minimizes heat loss but also provides additional heat. This study presents a non‐woven fabric, comprising ultra‐fine fibers embedded with zirconium carbide nanoparticles (ZrC NPs), prepared via solution blow spinning (SBS) and thermal crosslinking technology. Our results suggest that the fluffily‐structured elastomer, fabricated using rigid polystyrene and flexible polyurethane, exhibits high porosity (96.96%), ultra‐light characteristics (volume density of 47.12 mg cm−3), and effective heat retention (thermal conductivity of 23.1 mW mK−1 at −40°C). Moreover, the fabric demonstrates remarkable fracture strength (206.38 kPa), high elongation at break (34.5%), and superior elasticity even after 100 compression cycles at 40% strain. Despite the fact that introducing 12% ZrC increases the thermal conductivity of the base fabric by 6%, the NPs endow the material with an excellent photothermal conversion function. Following 10 min of exposure to visible light, the surface temperature increases to 71.5°C. Given its impressive performance, this novel non‐woven fabric demonstrates significant potential for applications in the field of cold protection.

Mullite fiber porous ceramic with high quality factor for high-temperature PM filtration

Porous ceramic filters with high porosity and high filtration are in urgent need of high-temperature gas filtration. Here a lightweight and low thermal conductivity mullite fiber porous ceramic filter was prepared through vacuum filtration method using solution blow spun mullite fiber as the matrix material and silica sol as the high-temperature binder. Mullite fiber porous ceramic with a mass ratio of 10:1 has uniform pore structure, low density (0.58 g cm−3), high porosity (78.11%), high compressive strength (1.79 MPa), as well as low thermal conductivity (0.095 W m−1 K−1) at a sintering temperature of 1300 ℃. When the air flow is 6 L min−1, the pressure drop is 180 Pa, the filtration efficiency of PM2.5 and PM10–2.5 is 98.85% and 99.61%, respectively, and the filtration quality factor is 0.025 Pa−1. The mullite fiber porous ceramic filter have outstanding quality factor, which has broad application prospects in high-temperature gas filtration.

PI nanofiber membranes with pH-responsive wettability fabricated through solution blow spinning for efficient on-demand oil-water separation

Nanofiber membranes (NFMs) are widely used in oil-water separation area due to their unique structure and properties. However, achieving efficient and on-demand separation of oil-water mixtures using NFMs remains a challenge. Herein, we prepared polyimide nanofiber membranes (PI-NFMs) with fluffy structures through solution blow spinning (SBS), and the average diameter of the PI nanofibers was 506.1 ± 75.6 nm. The PI-NFMs exhibited excellent pH responsiveness, demonstrating the ability to swiftly convert their wetting properties between highly hydrophobic and superhydrophilic through a simple acid-alkali treatment. Additionally, the conversion between oil removing model and water removing model according to the type of oil-water mixture was realized. The performance of the membranes in separating oil and water was evaluated using five different densities of oil-water mixtures. Only driven by gravity, the membrane exhibits good separation efficiency and extremely high permeate fluxes with the water and oil fluxes to 37,641.84 and 71,083.16 L·m−2·h−1, respectively, which also shows decent reusability. This work presents a promising solution for the intelligent, efficient, and controllable treatment of industrial oil effluents and oil spills.

Freestanding Carbon Nanofibers Derived from Biopolymer (Kraft Lignin) as Ultra-Microporous Electrodes for Supercapacitors

Lignin-derived carbon nanofibers (LCNFs) formed via the solution blowing of a biopolymer are developed here as a promising replacement for polyacrylonitrile (PAN)-derived carbon nanofibers (PCNFs) formed via electrospinning for such applications as supercapacitor (SC) electrodes. Accordingly, it is demonstrated here that a biopolymer (kraft lignin, which is, essentially, a waste material) can substitute a petroleum-derived polymer (PAN). Moreover, this can be achieved using a much faster and safer fiber-forming method. The present work employs the solution blowing of lignin-derived nonwovens and their carbonization to form electrode materials. These materials are characterized and explored as the electrodes in supercapacitor prototypes. Given the porosity importance of carbon fibers in SC applications, N2 gas adsorption tests were performed for characterization. LCNFs revealed the specific surface area (SSA) and capacitance values as high as 1726 m2/g and 11.95 F/g, which are about one-half of those for PCNFs, 3624 m2/g and 25.5 F/g, respectively. The capacitance values of LCNFs are comparable with those reported in the literature, but the SSA observed here is much higher. Moreover, no further post-carbonization activation steps were performed here in comparison with those materials reported in the literature. It was also found here that fiber pre-oxidation in air prior to carbonization and the addition of zinc chloride affect the SSA and capacitance values of both LCNFs and PCNFs. The electrochemical tests of the SCs prototypes were used to evaluate their capacitance at different charging rates, voltage windows, and the number of cycles. The capacitance of PCNFs decreased by about 47% during fast charging, while the capacitance of LCNFs improved during fast charging, bringing them to the level of only 21% below that of PCNFs. These changes were correlated with the packing density of the electrodes. It should be emphasized that LCNFs revealed a much higher mass yield, which was 4–5 times higher than that of PCNFs. LCNFs also possess a higher packing density, a lower price, and cause a significantly lower environmental impact than PCNFs. The best cell supercapacitor delivered a maximum specific energy of 1.77 Wh/kg and a maximum specific power of 156 kW/kg, surpassing conventional electrochemical supercapacitors. Remarkably, it retained 95.2% of its initial capacitance after 10,000 GCD cycles at a current density of 0.25 A/g, indicating robust stability. Accordingly, kraft lignin, a bio-waste material, holds great promise as a raw material for supercapacitor electrodes.

Solution blow spun bilayer chitosan/polylactic acid nanofibrous patch with antibacterial and anti-inflammatory properties for accelerating acne healing

The quercetin (QC) loaded chitosan (CS) nanofibrous patch (CSQC) was designed and fabricated successfully by solution blow spinning (SBS). And it was employed to explore a functional double-layer nanofibrous patch (CSQC/PLA) with polylactic acid (PLA) for overcoming the resistance of acne-causing bacteria to antibiotics and local cutaneous irritation. The nanofibrous patch possessed a fluffy bilayer structure with good air permeability, which may be befitted from the SBS method. The 10 % QC loaded CSQC0.10/PLA had sustained release ability of QC for 24 h. A high free radical clearance rate (91.18 ± 2.26 %) and robust antibacterial activity against P. acnes (94.4 %) were achieved for CSQC0.10/PLA with excellent biocompatibility. Meanwhile, E. coli and S. aureus were also suppressed with 99.4 % and 99.2 %, respectively. Moreover, the expression of pro-inflammatory cytokines (IL-6 and TNF-α) was significantly reduced, conducive to acne healing. Therefore, the CSQC0.10/PLA bilayer nanofibrous patch designed here may shed some light on developing multifunctional materials for treating acne infectious wounds.

Carboxymethyl chitosan and polycaprolactone-based rapid in-situ packaging for fruit preservation by solution blow spinning

Nanofiber packaging has not yet gained practical application in fruit preservation because of some limitations, such as low production rate and utilization, and failure due to poor adhesion to the fruit. Herein, to solve this issue, a novel fruit packaging method based on solution blow spinning (SBS), called in-situ packaging, was pioneered. Specifically, carboxymethyl chitosan (CMCH) and polycaprolactone (PCL) were chosen as substrate materials and cherry tomatoes were selected as demonstration subjects. CMCH/PCL nanofibers were deposited directly onto the surface of cherry tomatoes by SBS, forming a tightly adherent and stable fiber coating in 8 min. Also, this in-situ packaging could be easily peeled off by hand. The in-situ packaging was an excellent carrier for active substances and was effective in inhibiting gray mold on cherry tomatoes. The in-situ packaging film formed a barrier on the surface of cherry tomatoes to limit moisture penetration, resulting in reduced respiration of fruits, which led to reduced weight and firmness loss. In addition, metabolomics and color analysis revealed that the in-situ packaging delayed ripening of cherry tomatoes after harvest. Overall, the in-situ packaging method developed in the present work provides a new solution for post-harvest fruit preservation.

Mass Production of Polymer-Derived Ceramic Nanofibers through Solution Blow Spinning: Implications for Flexible Thermal Insulation and Protection

Mass Production of Polymer-Derived Ceramic Nanofibers through Solution Blow Spinning: Implications for Flexible Thermal Insulation and Protection

Properties of polyurethane fibrous materials produced by solution blow spinning

Properties of polyurethane fibrous materials produced by solution blow spinning

An airflow-driven system for scalable production of nano-microfiber wrapped triboelectric yarns for wearable applications

Nanofibers, with their large aspect ratio, high specific surface area, and high porosity, hold great promise for applications in textile materials, biomedicine, and smart wearables. Currently, the primary method for producing nanofibers is electrospinning. However, this method carries operational risks due to the use of high-voltage electrostatic fields, and it is not suitable for large-scale production due to low efficiency. To address these challenges, we propose an air-driven spinning system that combines solution blow spinning and vortex tubes for the scalable production of polyvinylidene fluoride-trifluoroethylene (PVDF-TrFE) nano-microfiber wrapped conductive yarn. The airbrushing machine allows for high-speed production of PVDF-TrFE nano-microfibers through solution blow spinning, with a maximum production rate of approximately 36 ml/h. The vortex tubes apply rotation and twist to the core yarn using high-speed airflow to bond the nano-microfibers to core yarn. By optimizing the process, we achieve a tight integration between the outer layer of nano-microfibers and the inner layer of conductive core yarn, imparting water repellency, flexibility, washability, air permeability, and a certain level of abrasion resistance to the resulting yarn. We demonstrate the applications of this yarn as triboelectric nanogenerators, including energy harvesting and self-powered sensing. Furthermore, we employ this method to prepare stretchable self-generating triboelectric yarn. This air-driven spinning system overcomes the limitations of electrospinning, providing a scalable and efficient method for the production of nano-microfiber-wrapped yarns with various functional properties.

Photocatalytic and antimicrobial efficacy of PVDF/TiO2 membranes fabricated by solution blow spinning

AbstractWith its ability to purify water and treat wastewater, photocatalytic membranes have become a promising solution. The membrane's unique properties allow for the separation of solid compounds and the degradation of organic materials through photocatalytic and antibacterial means. Poly(vinylidene fluoride)/titanium oxide (PVDF/TiO2) composite remain the materials of choice for making these membranes due to their economy, effectiveness, safety, and durability. In this work a photocatalytic membrane reactor (PMR) system was developed using PVDF/TiO2 membranes fabricated by the solution blow spinning (SBS) process. Obtaining photocatalytic membranes using this method is an efficient and ecological route that overcomes the disadvantage of separating the photocatalyst after the treatment is complete. The results of PMR system showed that the PVDF/TiO2 membrane could effectively remove total coliforms and E. coli from polluted water. After 10 min of contaminated water circulation through the PMR system, the presence of pathogens was not detected, indicating the efficiency of the obtained membranes.

Biocomposite‐based fibrous scaffolds of natural rubber/polyhydroxybutyrate blend reinforced with 45S5 bioglass aiming at biomedical applications

AbstractThe solution blow spinning technique was used to fabricate a new biocomposite fibrous mat consisting of natural rubber (NR) and polyhydroxybutyrate (PHB) bioblend, with various loads of 45S5 bioglass (BG) particles. According to SEM analysis, NR fibers exhibited ribbon‐like morphologies, whereas the addition of PHB resulted in improved fiber formation and a reduction in their diameter. In NR‐PHB/BG biocomposites with varying BG loadings, typical thermal degradation events of PHB (stage i) and NR (stage ii) were observed. In comparison with pure PHB, the TG/DTG curves of NR‐PHB/BG specimens revealed a lower stage i degradation peak. Such an outcome is possibly due to the fact that PHB in the NR‐PHB fibers is located predominantly at the surface, that is, PHB is more susceptible to thermal degradation. The NR‐PHB/BG biocomposite possessed an increased stiffness due to the addition of PHB and BG, resulting in an increased stress and a decreased strain at rupture compared to the pure NR and NR‐PHB mats. DMA analysis revealed two well‐defined regions, above and below the glass transition temperature (Tg), for the storage modulus (E') of the NR‐PHB/BG specimens. The values of E' were in both regions for NR‐PHB/BG specimens increased at higher BG content. The measured tanδ = E″/E' was used to determine the Tg value for all specimens, with Tg found to be in the −49 to −46°C range. Finally, NR‐PHB/BG biocomposite fibrous were proven noncytotoxic by in‐vitro testing on fibroblasts. These biocomposites enhanced cell growth, holding great promise for tissue engineering applications.Highlights Solution blow spinning technique was used to produce three‐phase biocomposite specimens. NR‐PHB/BG fibrous mat specimens with a diameter of 9–10 μm were obtained. Although high BG loads are applied to the NR‐PHB/BG specimens, they remain elastic and flexible. Fibrous biocomposite mats enhance cell growth and possess great potential for tissue engineering.

Bilayer nonwovens using natural rubber, poly(lactic acid) and bactericidal nanoparticles for wound dressings

Wound healing poses a significant challenge in healthcare, impacting not only on patients' quality of life but also placing a substantial financial burden on healthcare systems. Bilayer nonwovens have emerged as a promising solution for wound dressings due to their porous morphology, providing a high surface area for cellular adhesion and growth, and their permeability, allowing proper oxygen and fluid exchange to promote wound healing. When bactericide materials are added to the formulation, they can decrease or prevent infection caused by microorganisms, further aiding the healing process. Solution blow spinning is an appealing technique for creating bilayer nonwovens as it can produce high yields at a low cost. Yet, even though natural rubber boasts a well-established safety record in biomaterials, it remains an underexplored candidate for generating micro-nanofibrous structures. In this study, solution blow spinning was employed to fabricate bilayer composite nonwovens for wound dressing materials. The material architecture consisted of a bottom layer composed of a blend of natural rubber, poly(lactic acid) (PLA), and polyethylene glycol in the respective proportion of 2:1:3 w/w and a top layer composed of PLA and ZnO nanoparticles added in concentrations of 1%, 2.5%, and 5% based on the PLA mass of this layer. The top layer was further functionalized with Ag nanoparticles through spraying. The obtained materials demonstrated satisfactory hydrophobicity for cellular adhesion in the bottom layer, ranging from 51.95° to 92.20° of water sessile drop contact angle, and tunable mechanical strength, which could be controlled by varying the content of ZnO nanoparticles. Additionally, the material showed antimicrobial properties due to the presence of added Ag nanoparticles, able to inhibit E. coli, S. enterica serovar Typhimurium, and S. aureus by direct contact. Besides, the nonwoven prevented the passage of microorganisms due to the pore size of the structure. Overall, the unique properties of the developed material, such as its low cost, ease of production, and remarkable wound-healing properties, make it a promising candidate for wound dressing applications.

Structural, morphological, optical and thermoresistive study of the polyaniline/polylactic acid/ZnO films produced by solution blow spraying for temperature sensors

The present study aimed to obtain polyaniline/polylactic acid/ZnO (PAni/PLA/ZnO) films via Solution Blow Spraying (SBSp) in order to evaluate their structural, morphological, optical and thermoresistive properties in application such as in temperature sensors. The SBSp technique is a variation of Solution Blow Spinning (SBS), allowing film deposition on any surface using pressurized air and a polymeric solution. ZnO was synthesized via combustion reaction, a method known for producing nanosized particles. PLA was incorporated in the proportion of 10 wt%, while ZnO concentrations ranged from 10% to 60 wt %. Structural analyzes were performed by X-ray diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR) for the polymers; the morphology of the films was analyzed by Scanning Electron Microscopy (SEM); Ultraviolet–visible (UV-VIS) spectroscopy was performed to obtain the bandgap of the material; thermal analysis was carried out by thermogravimetry and the thermosensitive properties were evaluated by a multimeter in a muffle. XRD results confirmed that the PANi/PLA/ZnO film was obtained using the SBSp method, with crystalline phases corresponding to ZnO and PANi. SEM showed an agglomerated and porous appearance of the samples. Decomposition temperatures according to thermogravimetric analysis (TG) were in the range of 200–400 °C, showing that under this regime the films can present their thermoresistive properties without decomposing with temperature. The bandgap was in the range of 2.32–3.92 eV, confirming values of a semiconductor, and that the presence of PLA did not affect this property. Thermoresistive tests demonstrated a Negative Temperature Coefficient (NTC) behavior, indicating that the PAni/PLA/ZnO films obtained by SBSp possess thermoresistive properties suitable for low-temperature sensing applications.