Polyvinyl Alcohol Nanofibers Research Articles

Polyvinyl alcohol nanofiber based three phase wound dressings for sustained wound healing applications

Herein we present our research on a novel three phase antibacterial wound dressing prepared from carbon nanotubes, silver nanoparticles (AgNPs) and polyvinyl alcohol nanofibers. The AgNPs were generated on carbon nanotubes surfaces to synthesize carbon nanotubes-AgNP nanoparticles which were added into the polyvinyl alcohol nanofibers prior to electrospinning to prepare PVA/carbon nanotubes-AgNP composite nanofibers. All characterizations confirmed the three phase nanofiber architecture. Owing to growth of AgNPs on carbon nanotubes surfaces and embedding into PVA nanofibers the wound dressings are proposed for sustained and safer wound healing applications. The antibacterial test results confirmed excellent bactericidal and prolonged bacterial growth inhibition properties of the nanocomposites which suggest their suitability as sustained antibacterial wound dressing biomaterial.

Adhesion strength and viscoelastic properties of polydimethylsiloxane (PDMS) based elastomeric nanocomposites with embedded electrospun nanofibers.

In the present study, the adhesive and viscoelastic properties of polydimethylsiloxane (PDMS) based nanocomposite pressure sensitive adhesives (PSAs) with embedded electrospun polyacrylonitrile (PAN) and polyvinyl alcohol (PVA) nanofibers as fillers were investigated. PDMS nanocomposite adhesive films using PAN and PVA nanofibers were synthesized by dispersing fillers in the matrix by a solvent mixing process. The adhesion strength and reusability of the prepared nanocomposite PSA films were measured using peel tests as the fraction of nanofibers in the polymer matrix is increased. The variations of the adhesive properties of the PSAs as function of the type and loading of filler were related to their rheological properties in terms of shear and elastic moduli. Although 3-fold enhancement of the adhesion strength was achieved with 0.5 wt% loading for both types (PAN and PVA) of nanocomposites as compared to elastic PDMS, the composite adhesive with PAN nanofibers can provide a superior balance of rheological properties, resulting in improved reusability over other PSAs. The differences in the adhesion and viscoelastic properties of the composite PSAs are attributed to the polymer chemistry, processability, and architecture of the electrospun nanofibers in the soft PDMS matrix.

Drug-Loaded Poly-Vinyl Alcohol Electrospun Nanofibers for Transdermal Drug Delivery: Review on Factors Affecting the Drug Release

Transdermal drug delivery system (TDDS) was designed to be applied onto the skin surface and deliver the active drug across the skin into the systemic circulation. Thus, this mini-review is focusing on the factors affecting the drug release through the Poly-vinyl Alcohol (PVA) electrospun nanofiber mats into skin epidermis. Several types of non-steroidal anti-inflammatory drug (NSAID) with different molecular weight were reviewed. Electrospinning method was used to fabricate the PVA electrospun nanofiber mats that act as carriers of drugs for TDDS due to its excellent ability to produce ultrafine fibers with average diameters in the sub-micrometer to nanometer range, while Franz-Diffusion Cell was used for drugs release assessment. The molecular weight and the concentration of the drugs, as well as the surface area of the PVA electrospun nanofibers, played an important role in the drug release rate. Overall, mini review on factors that affecting the rate of the drugs release through electrospun PVA nanofibers shows good correlations between drugs and PVA electrospun nanofibers and have a great potential promising deliverable drugs that one day could be one of the best transdermal drug delivery system.

Flexible photoluminescent humidity sensing material based on electrospun PVA nanofibers comprising surface-carboxylated QDs

Flexible humidity-sensitive materials have drawn increasing attention due to their vital function in monitoring ambient humidity for tactile sensors, allowing them to approach the functionality of human skin. In this work, an electrospun polyvinyl alcohol (PVA)-based nanofiber film comprising surface-carboxylated CdSe/CdxZn1-xS quantum dots (QDs) is fabricated as a high-performance flexible humidity sensing material, based on the relationship between its photoluminescence (PL) and the humidity. The as-prepared film shows excellent PL-humidity linearity, a wide sensing range from 10% to 90% relative humidity, a relatively fast response time, good recoverability, and flexibility. The humidity sensing mechanism can be attributed to the breaking and reforming of hydrogen bonds and proton transfer occurring at the PVA-QD interfaces. This flexible humidity-sensitive material is believed to be a good candidate for humidity-sensitive components in electronic skin.

Multifunctional boron nitride nanosheet/polymer composite nanofiber membranes

In this work, we successfully prepared multifunctional boron nitride nanosheets (BNNS)/polyvinyl alcohol (PVA) nanofiber membranes. Using sulfanilic acid (SA) as a medium, hexagonal boron nitride (h-BN) were exfoliated into SA-functionalized BNNS through dry ball-milling process followed with liquid-phase exfoliation based on Lewis acid-base interaction. The f-BNNS/PVA composite nanofiber membranes with different loading amounts of f-BNNS were prepared through electrospinning. The results demonstrated the electrospun f-BNNS/PVA composite nanofiber membranes show high mechanical properties and thermal conductivities. The yield and ultimate tensile strengths of f-BNNS/PVA composite nanofiber membrane at 5 wt% loading amount can reach ∼8.56 and ∼11.37 MPa. Meantime, the thermal conductivity of f-BNNS/PVA composite nanofiber membrane with 10 wt% loading amounts of f-BNNS is ∼0.7328 W/(m•K), almost 6.47 times higher than that of neat PVA membrane. Besides, the f-BNNS/PVA composite nanofiber membrane can also be used as a filtration membrane for fast malachite green (MG) absorption and separation of MG and rhodamine B dyes.

Pt nanoparticles supported on a novel electrospun polyvinyl alcohol-CuO[sbnd]Co3O4/chitosan based on Sesbania sesban plant as an electrocatalyst for direct methanol fuel cells

Here, novel polyvinyl alcohol (PVA) nanofibers with incorporated CuO and Co3O4 nanoparticles (PVA-CuOCo3O4) were synthesized through a conventional single-nozzle electrospinning technique and characterized by atomic force microscopy (AFM), energy dispersive X-ray analysis (EDX), fourier-transform infrared spectroscopy (FT-IR), elemental analysis, transmission electron microscopy (TEM), differential thermal analysis (DTA), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Novel Pt/polyvinyl alcohol-CuOCo3O4/chitosan (Pt/PVA-CuOCo3O4/CH) catalyst was successfully prepared. EDX, TEM, and FT-IR spectroscopy techniques were used to characterize the prepared catalysts. The electrocatalytic activity of Pt/PVA-CuOCo3O4/CH catalyst was investigated for methanol electrooxidation through cyclic voltammetry, chronoamperometry, CO stripping voltammetry, and electrochemical impedance spectroscopy techniques. The effects of some experimental factors for methanol electrooxidation were studied on the prepared catalysts and the optimum conditions were determined. Pt/PVA-CuOCo3O4/CH catalyst had extraordinary electrocatalytic activity for methanol electrooxidation. It exhibited better stability, higher electrochemically active surface area, and better antipoisoning effect than Pt/PVA-CuOCo3O4 and Pt/PVA/CH catalysts indicating that Pt/PVA-CuOCo3O4/CH could be a promising catalyst for direct methanol fuel cell (DMFC) applications. A real DMFC was designed, assembled and tested with Pt/PVA-CuOCo3O4/CH as anodic catalyst.

Evaluation of aloe vera extract loaded polyvinyl alcohol nanofiber webs obtained via needleless electrospinning

In this study aloe vera liquid extract was added to PVA to obtain nanofiber mats with integrated bioactive compounds. Nanofibers are effective in drug release process and the most cost and time effective way to produce them is through roller electrospinning method. Several concentrations of PVA and aloe vera extract have been prepared, as well as pure 10 wt% polyvinyl alcohol solution to compare their properties. Viscosity and electroconductivity of solutions were measured, atomic force microscopy was used for evaluation of nanofiber mats morphology and diameter measurements, samples were analysed and compared by Fourier transform infrared spectroscopy and mechanical properties of the nanofiber mats were tested.

Eumelanin Nanoparticle-Incorporated Polyvinyl Alcohol Nanofibrous Composite as an Electroconductive Scaffold for Skeletal Muscle Tissue Engineering.

Eumelanins are melanocyte-derived natural pigments with inherent electrical cues and outstanding physicochemical properties, which enhance the electroconductivity of the synthetic polymeric scaffold, upon incorporation as nanoparticles. Electrospun nanofibrous meshes generated from such composite polymers are of great interest for muscle tissue engineering applications. In this study, we investigated the feasibility of fabricating nanofibrous scaffolds of polyvinyl alcohol (PVA) incorporated with eumelanin nanoparticles (EUNp) by electrospinning and further assessed their impact on myogenic differentiation of skeletal myoblasts. Morphological and physicochemical analysis of EUNp-PVA nanofibrous mesh showed uniform, bead-free, thermally stable, and randomly oriented nanofibers (450 ± 10 nm) with effective retention of the incorporated EUNp, without any chemical cross-reactivity. Voltammetric measurements of EUNp-PVA mesh exhibits stable electrical conductivity (∼4.0 S cm-1), which was undetectable in plain PVA meshes. In vitrocytocompatibility studies showed a significant increase in viability, proliferation, and metabolic activity of the seeded C2C12 myoblast on EUNp-PVA mesh compared to controls. Interestingly, EUNp-PVA nanofibers supported reorganization of the C2C12 myoblast, with comparatively longer and wider myotube-like structures formed. Our results suggest that an EUNp-PVA composite nanofibrous scaffold with inherent electroconductive properties of incorporated EUNp and topographical cues of PVA nanofibers could be an excellent biomaterial scaffold for skeletal muscle tissue engineering applications.

Fabrication of antibacterial polyvinylalcohol nanocomposite mats with soluble starch coated silver nanoparticles

In this study silver nanoparticles were synthesized by microwave irradiation method using soluble starch as a green capping and reducing agent. The as-prepared soluble starch coated silver nanoparticles (S-Ag NPs) were incorporated in polyvinyl alcohol (PVA) matrix to fabricate nanofibers through electrospinning process. Two different types of crosslinking treatments were used to make the nanofiber mats insoluble in physiological environments. Experimental studies revealed that the choice of the crosslinking treatment led to affect the silver ion release. The nanofiber mats crosslinked with glutaraldehyde have superior silver ion release and stability in simulated body fluid (SBF). The released amounts of silver ions were lower than the toxic level of silver ions for HaCat keratinocytes and human epidermal keratinocytes. After proving antibacterial properties of the glutaraldehyde crosslinked S-Ag NPs loaded PVA nanofiber mats against E. coli and S. aureus it was thought that the nanofibrous mats fabricated in this study can be good candidates as antibacterial scaffolds for wound dressing applications.

Electrospun polyvinyl alcohol membranes incorporated with green synthesized silver nanoparticles for wound dressing applications.

Electrospun membranes have the potential to act as an effective barrier for wounds from the external environment to prevent pathogens. In addition, materials with good antibacterial properties can effectively fight off the invading pathogens. In this paper, we report the development of a novel electrospun polyvinyl alcohol (PVA) membrane containing biosynthesized silver nanoparticle (bAg) for wound dressing applications. Plant extract from a medicinal plant Mimosa pudica was utilized for the synthesis of bAg. Synthesized bAg were characterized by Ultraviolet-Visible (UV) Spectroscopy and Fourier Transform Infrared Spectroscopy (FTIR). The morphology of bAg was obtained from Transmission Electron Microscopy (TEM) and found that they were spherical in morphology with average particle size 7.63 ± 1.2 nm. bAg nanoparticles incorporated PVA membranes were characterized using several physicochemical techniques such as Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray Spectroscopy (EDS) and X-Ray Diffraction (XRD) analysis. Experimental results confirmed the successful incorporation of bAg in PVA fibers. PVA nanofiber membranes incorporated with bAg showed good mechanical strength, excellent exudate uptake capacity, antibacterial activity, blood compatibility and cytocompatibility.

Enhancing Multiple Jets in Electrospinning: The Role of Auxiliary Electrode.

An auxiliary electrode introduced in traditional spinneret electrospinning is an effective and powerful technique to improve the production rate of nanofibers. In this work, the effects of the arrangement of auxiliary electrode, applied voltage, injection speed, and the distance between the electrode tip and the spinneret tip (ESD) on the jet number and the morphology of polyvinyl alcohol (PVA) nanofibers were investigated systematically. The results showed that the number of jets firstly increased and then decreased with the increase of applied voltage and ESD, respectively, while increasing with the injection speed in both the auxiliary electrode in the vertical position and parallel position. The average nanofiber diameter decreased with increasing of applied voltage and injection speed, but decreasing in ESD in these two positions. The numerical simulation results revealed that the auxiliary electrode primarily influenced the electric field intensity in the spinning area. This work provides a deep understanding of multiple jets in electrospinning.

The combined effects of three-dimensional cell culture and natural tissue extract on neural differentiation of P19 embryonal carcinoma stem cells.

Tissue engineering, as a novel transplantation therapy, aims to create biomaterial scaffolds resembling the extracellular matrix in order to regenerate the damaged tissues. Adding bioactive factors to the scaffold would improve cell-tissue interactions. In this study, the effect of chitosan polyvinyl alcohol nanofibres containing carbon nanotube scaffold with or without active bioglass (BG+ /BG- ), in combination with neonatal rat brain extract on cell viability, proliferation, and neural differentiation of P19 embryonic carcinoma stem cells was investigated. To induce differentiation, the cells were cultured in α-MEM supplemented with neonatal rat brain extract on the scaffolds. The expression of undifferentiated stem cell markers as well as neuroepithelial and neural-specific markers was evaluated and confirmed by real-time Reverse transcription polymerase chain reaction (RT-PCR) and immunofluorescence procedures. Finally, the three-dimensional (3D) cultured cells were implanted into the damaged neural tubes of chick embryos, and their fates were followed in ovo. Based on the histological and immunofluorescence observations, the transplanted cells were able to survive, migrate, and penetrate into the host embryonic tissues. Gene network analysis suggested the possible involvement of neurotransmitters as a downstream target of synaptophysin and tyrosine hydroxylase. Overall, the results of this study indicated that combining the effects of 3D cell culture and natural brain tissue extract can accelerate the differentiation of P19 embryonic carcinoma cells into neuronal phenotype cells.

Effect of nanofibrous porosity on the X-ray attenuation properties of electrospun n-Bi2O3/epoxy–polyvinyl alcohol (PVA) nanofiber mats

In this study, the X-ray attenuation properties of electrospun nanoparticles (n)-Bi2O3/epoxy–polyvinyl alcohol (PVA) nanofiber mats with different filler loadings of n-Bi2O3 were compared as a function of X-ray tube voltages (40–100 kV) using a general radiography unit. It was found that the X-ray attenuation by the electrospun n-Bi2O3/epoxy–PVA nanofiber mats increased with the increment of filler loading except for the nanofiber mat with 12 wt% of n-Bi2O3 filler. This indicated that the nanofiber mat presents the lowest X-ray attenuation properties compared to the others with another filler loading. The result was explained by cross-sectional scanning electron microscopy (SEM) image, which revealed that the 12 wt% of electrospun n-Bi2O3/epoxy–PVA nanofiber mat has the highest amount of porosity compared to the other samples.

Characterization and Microstructure of Linear Electrode-Electrospun Graphene-Filled Polyvinyl Alcohol Nanofiber Films.

With the aim of achieving controllable mass production of electrospun nanofiber films, this study proposes and investigates the feasibility of using a custom-made linear electrode- electrospun device to produce conductive graphene (GR)-filled polyvinyl alcohol (PVA) nanofibers. The film morphology and diameter of nanofibers are observed and measured to examine the effects of viscosity and conductivity of the PVA/GR mixtures. Likewise, the influence of the content of graphene on the hydrophilicity, electrical conductivity, electromagnetic interference shielding effectiveness (EMSE), and thermal stability of the PVA/GR nanofiber films is investigated. The test results show that the PVA/GR mixture has greater viscosity and electric conductivity than pure PVA solution and can be electrospun into PVA/GR nanofiber films that have good morphology and diameter distribution. The diameter of the nanofibers is 100 nm and the yield is 2.24 g/h, suggesting that the process qualifies for use in large-scale production. Increasing the content of graphene yields finer nanofibers, a smaller surface contact angle, and higher hydrophilicity of the nanofiber films. The presence of graphene is proven to improve the thermal stability and strengthens the EMSE by 20 dB at 150–1500 MHz. Mass production is proven to be feasible by the test results showing that PVA/GR nanofiber films can be used in the medical hygiene field.

Fabrication and characterization of the magnetic ferrite nanofibers by electrospinning process

Since the magnetic properties of materials are greatly affected by their microstructure, nanostructuring of magnetic materials is attempted in various directions. Various processes have been used to synthesis one dimensional nanomaterials: template, hydrothermal, anodizing, and electrospinning. Among these processes, nanofibers fabricated by the electrospinning method are excellent for reproducibility and have a large aspect ratio. In addition, there have been many attempts to fabricate ceramic nanofibers with a more intricate shape using a sol-gel reaction. In this study, the electrospinning conditions for synthesizing ferrite (α-Fe2O3) nanofiber were optimized by the preliminary results of polyvinyl alcohol (PVA) nanofiber. As-spun composite nanofibers of PVA/Fe(NO3)3·9H2O were transformed to an α-Fe2O3 phase by heat treatment at 550 °C. After heat treatment, the diameters ranged from 105 nm to 124 nm in as-spun composite nanofibers, and with a decrease in PVA content after heat treatment, the diameters ranged from 59 nm to 96 nm. We investigated the magnetization properties with the microstructure of α-Fe2O3 nanofiber by a vibrating sample magnetometer. The saturation magnetization increased with an increasing diameter of the α-Fe2O3 nanofiber, and highest value of 26.2 A·m2/kg was measured in the α-Fe2O3 nanofibers with the largest diameter with a PVA content of 0.12 g/ml. The microstructure and magnetic properties of the α-Fe2O3 nanofibers were controlled by an electrospinning process, and we were able to optimize the α-Fe2O3 nanofibers for various application fields, such as electromagnetic interference and electromagnetic pulse absorbers.

Rapid Determination of Ethyl Alcohol in Alcoholic Beverages Using a Fluorescent Nanofiber Film

Electrospinning has been recognized as a simple, versatile, and viable technique to fabricate ultrathin nanofibers from various materials, e.g., polymers and composites, in aqueous solutions. In this study, we used polyvinyl alcohol (PVA) as a substrate to synthesize nanofibers by using an electric field between the syringe needle and PVA. The nanofibers demonstrate an immense potential for developing fluorescent detection system of ethyl alcohol from several types of beverages due to their special characteristics of a simple, albeit useful, and effective top-down fabrication process. The development of nanofibers, a fundamental understanding of electrospinning, and properties of the nanofibers, as well as their applications to determine the alcohol content in beverages by direct injection into the fiber surface, were described. This method was accomplished using a PVA nanofiber scaffold as the immobilized sensing film in samples of wine, beer, or some alcohol beverages. Various beverages were tested, which were found to contain low alcohol concentrations. The optical properties of nanofibers in an aqueous PVA solution were observed by fluorescence spectra. The PVA nanofiber films could be useful for detecting the alcohol upto 1.0vol% in a real sample within several seconds. Details of the type of electrospun fibers, and their characteristics were also explained. This study should serve as a guiding tool for nanoscience researchers in fibers, textiles, food validations, and polymer fields.

Thiol-yne photo-clickable electrospun phase change materials for thermal energy storage

Fatty acids, fatty acid esters and fatty acid composites have been widely accepted materials as PCMs. In the present work, nanosilica reinforced nanofiber composite was prepared as PCMs. First, polyvinyl alcohol (PVA) and nanosilica was modified with mercaptopropionic acid and 3-(mercaptopropyl)trimethoxysilane respectively and thiolated-PVA-nanosilica nanofibers were prepared by using electrospinning. Stearic acid was used for long chain fatty acid. Then stearic acid was functionalized with propargyl groups to introduce thiol-yne clickable sites. Finally, various amounts of stearic propargyl ester were reacted with thiolated-PVA-nanosilica nanofibers, following to UV-induced thiol-yne click reaction by UV-irradiation at 365 nm between thiol groups of nanofiber and propargyl groups of stearic propargyl ester. The structural characterization was performed by ATR-FTIR spectroscopy. The morphologies of nanofibers after and before modification were investigated by scanning electron microscopy (SEM). It is said that nanofibers have uniform diameter size. Thermal and phase change behaviors of the electrospun nanofibers were investigated. Thiolated-PVA nanofiber showed no phase change behavior. With the addition of stearic propargyl ester increased phase change enthalpy of the PVA nanofibers from 0 J/g to 37 J/g. The freezing cycle phase change enthalpy was also observed and was found between −13 and − 47 J/g.

Solvent vapor treatment improves mechanical strength of electrospun polyvinyl alcohol nanofibers

Electrospun nanofibers of polyvinyl alcohol (PVA) have poor mechanical strength. As such their use has often been avoided, particularly in applications that require high mechanical properties. The objective of this study is to increase the mechanical properties of PVA nanofiber mats via physical crosslinking with solvent vapor treatment using organic solvents, dimethyl sulfoxide (DMSO), N, N-dimethyl formamide (DMF), and methanol. The effect of solvent vapor treatment on PVA nanofibers is clearly observed by scanning electron microscope (SEM). The tensile strength increased by over 60%, 90%, and 115% after solvent vapor treatment with DMF at a temperature of 40 °C for 2 h, 4 h, and 8 h, respectively, compared to untreated PVA nanofibers. In addition, Young's modulus of PVA nanofiber mats also increased after DMF treatment. As a comparison, DMSO and methanol were also used in solvent vapor treatment because of differences in their polymer-solvent affinity. Results showed that the highest improvement (100%) in mechanical strength was obtained using DMF. This study shows that solvent vapor treatment offers a simple and inexpensive method that provides excellent results and is a promising alternative treatment for use in increasing the mechanical properties of electrospun nanofibers.

Fabrication and characterization of electrospun nanofibers using flaxseed (Linum usitatissimum) mucilage

The spin ability of flaxseed mucilage (FM) as a new source was evaluated through electrospinning. At various experimental conditions and different solution properties, it was impossible to fabricate FM nanofiber. Thus, polyvinyl alcohol (PVA) was applied as co-polymer to facilitate nanofiber formation. In terms of morphology, FM:polyvinyl alcohol (PVA) nanofiber using a mixture of 3% FM solution and 12% (PVA) solution at ratio of 60:40 was selected as the best sample. The physicochemical properties of the nanofiber was evaluated by scanning electron microscopy (SEM), fourier transform infrared (FTIR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and X-ray diffraction (XRD). SEM images showed beadless, uniform and smooth nanofibers with an average diameter of 230nm. Based on DSC and TGA results, the thermal stability of the nanofiber was improved by adding PVA. FTIR data revealed that there was no chemical interaction between functional groups of FM and PVA in the nanofiber.

Adsorption of Silver Ions from Aqueous Solution onto Thiol Modified Polyvinyl Alcohol Nanofibers

Adsorption of Silver Ions from Aqueous Solution onto Thiol Modified Polyvinyl Alcohol Nanofibers