Solution Blow Spinning Method Research Articles

Influence of the preparation method on selected properties of PLA nanofibers modified with lavender oil

PLA nanofibers containing 30 wt% lavender essential oil (LEO) was obtained by electrospinning (ES) and solution blow spinning (SBS) methods. The structure was assessed by scanning electron microscopy (SEM), and thermal properties were determined by thermogravimetric analysis (TGA). The ES method produced thinner nanofibers than the SBS method. The method of obtaining nanofibers did not affect their thermal properties.

PVDF piezoelectric sensor based on solution blow spinning fibers for structural stress/strain health monitoring

Strain monitoring is of great significance to the maintenance and safe operation of engineering structures. To address the shortcomings of piezoelectric ceramics such as high inflexibility and brittleness, in this study, polyvinylidene fluoride (PVDF) fibrous films were prepared by a safe and efficient solution blow spinning technique. In the case of similar β-phase content, the preparing efficiency of PVDF fibers by the solution blow spinning method increased by about 8–10 times compared to that of electrospinning method in our previous work. The fibers with average diameter of 0.79 μm had the highest β-phase content, around 83%. A flexible piezoelectric fiber sensor with simple design for structural strain monitoring was prepared based on the PVDF fibers. The sensor responded well to strains as low as 23 μϵ, better than commercial strain gauges, with a high response accuracy of 1.11 mV/μϵ. And the piezoelectric properties of the sensors could charge a 4.7 μF capacitor to 3 V in 40 s, offering the potential for low-cost, self-powered structural health monitoring.

Solution blow spun flexible zirconia nanofibers toward high-performance 2D and 3D nanostructures

Polymer templates are critical in the preparation of ceramic fibers from precursor solutions, but the available options are limited. Here, ZrO2 nanofiber films and aerogels are developed by solution blow spinning method using hydroxypropyl methylcellulose (HPMC) and polyvinylpyrrolidone (PVP) as templates. The effects of HPMC ratio, polymer concentration, and calcination temperature on the morphology and structure of the ZrO2 nanofibers are investigated. The nanofiber films with an areal density of 20 mg cm−2 exhibit excellent filtration property, achieving a filtration efficiency of 94.94% and a pressure drop of 136 Pa at an airflow velocity of 32 L min−1. The nanofiber aerogels display low density of 50 mg cm−3, low thermal conductivity of 0.039 W m−1 K−1, as well as superior compressibility, demonstrating significant potential for thermal protection applications. This work expands the formation template option of ceramic fibers, offering significant guidance in the development of flexible, high-temperature-resistant ceramic fiber materials.

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.

Processing Nomex Nanofibers by Ionic Solution Blow-Spinning for Efficient High-Temperature Exhausts Treatment.

Hard-to-dissolve nanofibers provide alternatives for high-efficiency and low-resistant air filtration but are limited by the universality and economics of fabrication methods. A scalable and efficient ionic solution blow-spinning strategy has herein been proposed in preparing hard-to-dissolve nanofibrous filters. The online version contains supplementary material available at 10.1007/s42765-022-00231-x.

Protease Immobilization in Solution-Blown Poly(ethylene oxide) Nanofibrous Nonwoven Webs

Enzyme-functionalized solution-blown nonwoven (EFSBN) fibers were produced by a single-step solution blow spinning method that utilizes high-velocity gas to simultaneously extrude the codissolved polymer–solvent–enzyme spinning solution and evaporate solvent at mild conditions to form a nanofibrous web with preserved enzyme activity. A broad concentration range of 0.6–7.4 wt % protein of subtilisin A protease from Bacillus licheniformis was successfully entrapped by poly(ethylene oxide) (PEO) during solution blow spinning nonwoven web production. The presence of enzyme protein in the solid nanofibers was detected by Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. Time of flight-secondary ion mass spectroscopy and laser confocal microscopy revealed the immobilized enzymes were mainly positioned inside the fibers and homogeneously distributed throughout the webs. Scanning electron microscopy showed that the fiber shape and diameter of PEO nanofibers containing enzymes were irregular compared to PEO-only nanofibers. Residual enzyme activity in the webs was measured by redissolving fibers in buffer and comparing the released enzyme activity to nonimmobilized free enzyme using a casein substrate-based assay. Immobilized protease (1.3% (w/w) protein in solid dry nanofiber webs) retained more than 90% of the free enzyme activity. Protease immobilized in solid nanofiber webs exhibited long storage stability at ambient (∼22 °C) and 4 °C temperature storage conditions, with more than 60% remaining catalytic activity after 300 days compared to the initial activity. Immobilized protease had equally good thermal stability as a stabilized liquid commercial protease, both retaining above 95% of their initial activity after treatment for 12 h at 65 °C. In contrast, the same liquid protease diluted in buffer lost activity within 2 h at that temperature. The nondusting, readily aqueous-soluble EFSBN solid materials are easy to handle and have good storage stability compared to liquid products.

Low-cost and temperature-resistant mullite fiber sponges with superior thermal insulation and high-temperature PM filtration

Fibrous ceramic sponge materials which have compressibility and temperature resistance are pressingly desired in high temperature environment as thermal insulator, energy absorber and high temperature air filter. However, due to the complex preparation process, poor flexibility and mechanical strength, the application of ceramic sponge materials faces many obstacles. Here, elastic layered mullite fiber sponge with high compressibility and temperature-resistance ranging from liquid nitrogen to 1300℃ obtained by solution blow spinning method is reported. It has admirable thermal insulation performance with the thermal conductivity only of 0.0265 W m−1K−1, and has good air filtration performance for inhalable particulate matter (PM) at high temperature. Under 800 ℃, the average filtration efficiency of sponge with basis weight of 36 mg cm−2 for PM0.3-2.5 and PM2.5-10 produced by burning incense are 99.23 % and 99.78 %, and the pressure drop is 49 Pa under the airflow velocity of 4 cm s−1. In the actual filtration test for automotive exhaust gas of mullite fiber filter, the filtration efficiencies of particles with sizes ranging from 0.3 to 10 μm are all higher than 98 %. The mullite fiber sponge emerges as a prospective substitute of extant thermal insulation and high temperature air filter.

Antimicrobial Activity of Blow Spun PLA/Gelatin Nanofibers Containing Green Synthesized Silver Nanoparticles against Wound Infection-Causing Bacteria.

One of the main challenges in wound healing is the wound infection due to various causes, of which moisture is the most important reason. Owing to this fact, wound dressings that can collect wound moisture in addition to showing antibacterial properties have provided an important basis for wound healing research. In this study, gelatin and poly lactic acid (PLA) polymers were used in a wound dressing textile to provide gelation and structure strength properties, respectively. Meanwhile, silver nanoparticles (SNPs) synthesized through the green method were integrated into these fibers to provide the formed textile with antibacterial properties. Nanoparticles were made using donkey dung extract, and nanofibers were produced by the solution blow spinning method which has high production efficiency and low energy consumption among spinning methods. The produced nanoparticles were characterized and evaluated by UV-Vis, DLS, XRD, and FTIR methods, and the production of silver nanoparticles that were coated with metabolites in the extract was proven. In addition, the morphology and diameter of the resulted fibers and presence of nanoparticles were confirmed by the SEM method. The size and size distribution of the synthesized fibers were determined through analyzing SEM results. Gelatin nanofibers demonstrated a mean size of 743 nm before and 773 nm after nanoparticle coating. PLA nanofibers demonstrated a mean size of 57 nm before and 182 nm after nanoparticle coating. Finally, 335 nm was the mean diameter size of gelatin/PLA/SNPs nanofibers. Also, the textiles synthesized by PLA and gelatin which contained silver nanoparticles showed higher antibacterial activity against both gram-positive and gram-negative species compared to PLA and gelatin tissues without nanoparticles. Cytotoxicity test on L929 cells showed that silver nanoparticles incorporated textiles of PLA and gelatin show a very low level and non-significant toxicity compared to the free particles.

Antifungal and antiocratoxigenic potential of Alpinia speciosa and Cymbopogon flexuosus essential oils encapsulated in poly(lactic acid) nanofibres against Aspergillus fungi.

Essential oils encapsulated in a polymeric matrix can be used as an alternative method to control fungi and mycotoxins. The essential oils were extracted by hydrodistillation and characterized by gas chromatography. The nanofibres were produced from poly (acid lactic) (PLA) containing essential oils by the Solution Blow Spinning method. The antifungal and antimicotoxygenic properties were evaluated against Aspergillus ochraceus and Aspergillus westerdijkiae by the fumigation method. Terpinen-4-ol (20·23%), sabinene (20·18%), 1·8-cineole (16·69%) and γ-terpinene (11·03%) were the principal compounds present in the essential oil from Alpinia speciosa, whereas citral (97·67%) was dominant from Cymbopogon flexuosus. Microscopy images showed that the addition of essential oils caused an increase in the diameter of the nanofibres. The infrared spectroscopy results indicated the presence of essential oils in the PLA nanofibres. Differential scanning calorimetry curves also indicated the existence of interactions between the essential oils and polymeric macromolecules through their plasticizing action. The hydrophobic character of nanofibres was revealed by the contact angle technique. An antifungal effect was observed, the mycelial growths (3·25-100%) and the synthesis of ochratoxin A (25·94-100%) were inhibited by the presence of the nanofibres. The results suggest that bioactive nanofibres hold promise for application to control toxigenic fungi.

Bile Duct Regeneration with an Artificial Bile Duct Made of Gelatin Hydrogel Nonwoven Fabrics.

Although choledochojejunostomy is the standard technique for biliary reconstruction, there are various associated problems that need to be solved such as reflux cholangitis. Interposition with an artificial bile duct (ABD) to replace the resected bile duct maintains a physiological conduit for bile and may solve this problem. This study investigated the usefulness of an ABD made of gelatin hydrogel nonwoven fabric (GHNF). GHNF was prepared by the solution blow spinning method. The migration and activity of murine fibroblast L929 cells were examined in GHNF sheets. L929 cells migrated into GHNF sheets, where they proliferated and synthesized collagen, suggesting GHNF is a promising scaffold for bile duct regeneration. ABDs made of GHNF were implanted in place of resected bile duct segments in rats. The rats were killed at 2, 6, and 12 weeks postimplantation. The implantation site was histologically evaluated for bile duct regeneration. At postoperative 2 weeks, migrating cells were observed in the ABD pores. The implanted ABD was mostly degraded and replaced by collagen fibers at 6 weeks. Ki67-positive bile duct epithelial cells appeared within the implanted ABD. These were most abundant within the central part of the ABD after 6 weeks. The percentages of Ki67-positive cells were 31.7 ± 9.1% in the experimental group and 0.8 ± 0.6% in the sham operation group at 6 weeks (p < 0.05), indicating that mature biliary epithelial cells at the stump proliferated to regenerate the biliary epithelium. Biliary epithelial cells had almost completely covered the bile duct lumen at 12 weeks (epithelialization ratios: 10.4 ± 6.9% at 2 weeks, 93.1 ± 5.1% at 6 weeks, 99.2 ± 1.6% at 12 weeks). The regenerated epithelium was positive for the bile duct epithelium marker cytokeratin 19. Bile duct regeneration was accompanied by angiogenesis, as evidenced by the appearance of CD31-positive vascular structures. Capillaries were induced 2 weeks after implantation. The number of capillaries reached a maximum at 6 weeks and decreased to the same level as that of normal bile ducts at 12 weeks. These results showed that an ABD of GHNF contributed to successful bile duct regeneration in rats by facilitating the cell migration required for extracellular matrix synthesis, angiogenesis, and epithelialization. Impact Statement Development of an artificial bile duct (ABD) enables physiological biliary reconstruction and may solve clinical problems associated with choledochojejunostomy. In this study, we created ABDs with gelatin hydrogel nonwoven fabric and implanted them in place of resected bile duct in rats. We evaluated the process of bile duct regeneration as well as decomposition of the ABD and demonstrated successful regeneration of resected bile duct, highlighting the possibility of this novel biliary reconstruction method to replace choledochojejunostomy.

Antifungal and physicochemical properties of Ocimum essential oil loaded in poly(lactic acid) nanofibers.

Poly(lactic acid) (PLA) nanofibres containing different proportions of the essential oils from Ocimum basilicum L. and Ocimum gratissimum L. were prepared by solution blow spinning method. The essential oils were extracted by hydrodistillation and characterized by gas chromatography. MEV, contact angle, DSC and FTIR were used to characterize the nanofibres. The effect of bioative nanofibres on the growth of the fungus and on the production of ochratoxin A were evaluated using the fumigation test. Linalool, 1·8-cineole and camphor were the principal components of the essential oil from O. basilicum, and eugenol was the principal constituent in the oil from O. gratissimum. An increase in the average diameter of the nanofibres was observed with the addition of the essential oils. The essential oils acted as a plasticizer, resulting in a reduction in the crystallinity of the PLA. The encapsulation of essential oils in PLA nanofibres was verified by FTIR. An effective antifungal and antimicotoxygenic activity against Aspergillus ochraceus and Aspergillus westerdjikiae was observed for the bioative nanofibres. These results confirm the potential of PLA nanofibres containing the essential oils for the control of toxigenic fungi that cause the deterioration of food and are harmful to human health.

An engineering-oriented approach to construct rough micro/nano-structures for anticorrosion and antifouling application

Slippery liquid-infused porous surfaces (SLIPS) have attracted considerable attention because of their multiple beneficial applications. In this report, styrene-butadiene-styrene triblock copolymer (SBS) and SBS-SiO2 films with 3D interconnected net-like structures were constructed via a simple solution blow spinning method. The original films exhibited excellent hydrophobicity with a contact angle of 145°, after infiltration with the lubricant, the contact angle of SLIPS was reduced to 110°. The antifouling and anticorrosion performance of the hydrophobic surfaces and SLIPS were also studied. The hydrophobic surfaces showed inferior antifouling and anticorrosion performance because of the large pores in the films, significantly, the lubricant-infused surface demonstrated dramatically improved antifouling and anticorrosion performance. More interestingly, compared with a silicone oil-infused surface, the perfluoropolyether oil-infused surface displayed durable anticorrosion properties over increased immersion durations. The failure mechanism of lubricants was explored. The combined anticorrosion and antifouling capability of the constructed microstructure has excellent potential application in marine environments.

Solution blow spinning (SBS) and SBS-spun nanofibers: Materials, methods, and applications

Solution blow spinning (SBS) is a maturing nanofiber fabrication technology. Over the past decade, there has been a growing interest in employing and developing this facile method of fabricating nanofibers, sourced from different materials to suit varied applications. For the first time, this review will provide a comprehensive overview of solution blow spinning, including the principles, materials, methods, and applications. We start with the principles of the SBS method, followed by a detailed account of the different precursor polymers (i.e., synthetic, biocompatible, and bio-based materials) and composites that have been used in the SBS of nanofibers. The proceeding section presents the known applications of nanofibers obtained through SBS which are discussed primarily in the areas of energy and electronics, biomedical, environmental, membrane separation, and, textile and smart material applications. We highlight the most important and recent advances related to SBS over the last ten years. Lastly, we give perspectives, challenges, opportunities, and new directions of the SBS technology.

A Foldable All-Ceramic Air Filter Paper with High Efficiency and High-Temperature Resistance

Advanced filter materials with high efficiency, low-pressure drop, and high-temperature resistance are urgently needed in the field of high-temperature gas filtration. Here, an Al2O3-stabilized ZrO2 (ASZ) submicron fiber air filter paper with excellent flexibility and thermal stability (up to 1100 °C) is developed using a cost-effective, scalable solution blow spinning method and subsequent calcination. The ASZ papers demonstrate excellent flexibility and foldability, which can be attributed to the tetragonal phase and small crystallite size of the ASZ fibers due to the presence of Al2O3. In addition, the ASZ papers with an areal density of 56 mg cm-2 show a high filtration efficiency (99.56%) and a low-pressure drop (108 Pa) for 15-615 nm NaCl particles at an airflow velocity of 5.4 cm s-1. We envision that the foldable all-ceramic air filter material will provide a solution for the removal of particulate matter from the high-temperature exhaust gases.

Large-scale blow spinning of heat-resistant nanofibrous air filters

Particulate matter (PM) pollution has become a serious problem worldwide and various kinds of nanofibrous filters aiming to solve the problem have been developed. It is urgent to remove PM from high-temperature pollution sources, such as industrial emissions, coal furnaces, and automobile exhaust gases. However, filtration at pollution sources remains challenging because most existing air filters are not resistant to high temperature. Herein, heat-resistant polyimide (PI) nanofibrous air filters are fabricated via a simple and scalable solution blow-spinning method. These air filters show excellent thermal stability at high temperature up to 420 °C. They exhibit a filtration efficiency as high as 99.73% at ambient temperature and over 97% at 300 °C. In addition, a field test shows that the filters remove > 97% of PM from the car exhaust fumes. Hence, the blow-spun PI nanofibrous membranes combined with the facile preparation strategy have great potential in high temperature air filtration fields and other similar applications such as water purification and protein separation.

Well-aligned BaTiO3 nanofibers via solution blow spinning and their application in lithium composite solid-state electrolyte

In this work, an efficient and simple solution blow spinning method for preparing well-aligned nanofibers was proposed. Compared with common electrospinning, this method is more promising for scalable fabrication because of fewer process requirements. Through this method, well aligned BaTiO3 nanofibers were fabricated, and their average diameter was about 300 nm. When introducing PEO and LiTFSI ionic conductive polymer composites into the aligned BaTiO3 nanofibers membrane, a composite solid-state polymer electrolyte was obtained. The excellent structure for the electrolyte was also analyzed and its electrochemical performance was tested. Results showed that the lithium ionic conductivity at 30 °C increased from 5.74 × 10–6 S · cm–1 to 5.83 × 10–5 S · cm –1 with addition of aligned BaTiO3 nanofibers, and its thermal and electrochemical stability were all significantly improved.

Preparation of Nanofibrous PVDF Membrane by Solution Blow Spinning for Mechanical Energy Harvesting.

Self-powered nanogenerators composed of poly(vinylidene fluoride) (PVDF) have received much attention. Solution blow spinning (SBS) is a neoteric process for preparing nanofiber mats with high efficiency and safely, and SBS is a mature fiber-forming technology that offers many advantages over conventional electrospinning methods. Herein, we adopted the SBS method to prepare independent PVDF nanofiber membranes (NFMs), and successfully employed them as nanogenerators. Finally, we tested the change in the output current caused by mechanical compression and stretching, and studied its durability and robustness by charging the capacitor, which can drive tiny electronic devices. The results show that the PVDF nanogenerators by using this SBS equipment can not only be used in wearable electronic textiles, but are also suitable for potential applications in micro-energy harvesting equipment.

Mechanical, thermal, and morphological properties of natural rubber/45S5 Bioglass® fibrous mat with ribbon-like morphology produced by solution blow spinning

Natural rubber (NR)/45S5 Bioglass® (BG) based fibrous mat biocomposite were fabricated using a solution blow spinning (SBS) method. NG/BG fibrous mat with ribbon-like morphology were obtained with different amounts of 45S5 BG to NR. Biocomposites exhibited uniform diameter distribution of fibers in the 40–60 µm range. The preparation method and dispersion of particles in the NR matrix had significant influence on the final mechanical properties of the biocomposite, i.e., the tensile strength of membrane samples increased, while the elongation decreased compared to those of neat NR films. The glass transition temperature (Tg) value of the biocomposite samples shifted toward higher temperatures due to the movement restriction of the NR chains caused by the BG particles. For the biocomposite samples Tg was in the range of −30 to −28 °C, whereas for the NR film and NR fibrous mat Tg was −46.7 and −40.5 °C respectively. The Cole-Cole plot was an imperfect semicircle indicating the heterogeneity of the system as well as the adequate interaction between BG and NR. The production of membrane biocomposites with good thermal and mechanical properties employing the SBS method could be promising and potential for biomedical applications.

Evaluation of Processing Parameters in the Synthesis of Silica Nanofibers Doped with Silver by the Solution Blow Spinning Method

The ceramic fibers can be obtained from different techniques. Due to the technological development, searches are performed to improve the existing fibers. Thus, recent studies have enabled the development of an unprecedented synthesis route for the production of nanofibers, the Solution Blow Spinning (SBS). In this context, the present work proposes to develop silica nanofibers doped with silver by the SBS method, evaluating parameters such as: silver content and acidification of solutions. The fibers were characterized by X-ray Diffraction (XRD) and Scanning Electron Microscopy (SEM). The results of XRD showed that the samples with 4% silver that were not acidified showed the most defined and intense characteristic peaks. The SEM showed the formation of fibers with diameters in the nanometer range independent of acidification or not of the solutions, with reduction of the agglomerates in the samples with 2% silver.

Fabrication and Characterisation of Stimuli Responsive Piezoelectric PVDF and Hydroxyapatite-Filled PVDF Fibrous Membranes.

Poly(vinylidene fluoride) has attracted interest from the biomaterials community owing to its stimuli responsive piezoelectric property and promising results for application in the field of tissue engineering. Here, solution blow spinning and electrospinning were employed to fabricate PVDF fibres and the variation in resultant fibre properties assessed. The proportion of piezoelectric β-phase in the solution blow spun fibres was higher than electrospun fibres. Fibre production rate was circa three times higher for solution blow spinning compared to electrospinning for the conditions explored. However, the solution blow spinning method resulted in higher fibre variability between fabricated batches. Fibrous membranes are capable of generating different cellular response depending on fibre diameter. For this reason, electrospun fibres with micron and sub-micron diameters were fabricated, along with successful inclusion of hydroxyapatite particles to fabricate stimuli responsive bioactive fibres.