Poly Vinyl Alcohol Nanofibrous Membranes Research Articles

Polyvinyl alcohol nanofibrous membrane by high-curvature solid-needle electrospinning: Numerical simulation and experimental verification

Herein, polyvinyl alcohol nanofibrous membrane was fabricated firstly by the high-curvature solid-needle electrospinning. The influence of electrode curvature (needle angle), spinning voltage, solution concentration and collector distance on nanofiber morphology was systematically investigated numerically and experimentally. Numerical simulation shows that the electrical field increases with the increase of spinning voltage, while decreases with the increase of needle angle and collector distance. The experimental results are consistent with the numerical results. Furthermore, the solution concentration can be used to adjust the diameter of polyvinyl alcohol nanofibers. The possible applications of the nanofiber membrane to energy generation, water treatment, and separation are also discussed.

Fully nano/micro-fibrous triboelectric on-skin patch with high breathability and hydrophobicity for physiological status monitoring

Recent advancements in flexible electronics have imposed the challenge on developing multifunctional devices for long-term on-skin wearing comfort. Here, a self-powered fully nano/micro-fibrous triboelectric on-skin patch is developed. The all-polymer-based poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)/polyvinyl alcohol nanofibrous membrane is used as the electrode for the first time, and polyimide/thermoplastic polyurethane (1:1) nanofibrous membrane along with thermoplastic polyurethane nano/micro-fibrous membrane work for contact electrification pairs. The patch exhibits excellent breathability with the water vapor transmittance rate of 8 kg m−2 day−1, and hydrophobicity with the water contact angle of 113°. The capability of the patch for physiological status monitoring is further demonstrated through applications of fingertip interaction force detection, pronunciation sensing, human motion monitoring, and finger gesture recognition, representing the promising potential in interactive on-skin devices and health monitoring.

Water-stable zirconium-based metal-organic frameworks armed polyvinyl alcohol nanofibrous membrane with enhanced antibacterial therapy for wound healing

Inadequate water-stability and antibacterial activity limit the biomedical application of polyvinyl alcohol (PVA)-based membranes in moist environments. In this work, we propose a strategy to improve the water-stability of PVA membranes via metal complexation and heat treatment. We report a simple routine where the zirconium-based UiO-66-NH2 metal-organic frameworks (MOFs) are nucleated as a layer on the surface of PVA nanofibrous membranes (UiO-66-NH2@PVA NFMs). We find that the chemical modification of membranes increases their hydrophilicity and adds on mechanical support for the brittle UiO-66-NH2 MOFs. Additionally, we demonstrate the application of UiO-66-NH2 MOFs as drug carriers for antibacterial drug, levofloxacin (LV). The active drug component is preloaded during the one-step nucleation process. The obtained LV loaded UiO-66-NH2@PVA NFMs (LV@UiO-66-NH2@PVA) are shown to be bactericidal with the efficiency > 99.9% at 100 μg/mL against two bacterial species, Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Compared with the commercially available gauzes, the UiO-66-NH2@PVA and LV@UiO-66-NH2@PVA treatments will significantly improve the wound healing process. Animal studies show that the LV@UiO-66-NH2@PVA will effectively offer a safe alternative solution for the patients to protect against bacterial infections, demonstrating the potential application of MOF-based NFMs as wound dressing agents.

Electrospun PVA Nanofibrous Membranes Reinforced with Silver Nanoparticles Impregnated Cellulosic Fibers: Morphology and Antibacterial Property

To enhance the mechanical and antibacterial properties of silver nanoparticle impregnated cellulosic fibers, carboxy-cellulose nanocrystals(CCNs) were grafted with chitooligosaccharide(COS), which was used as a stabilizer for silver nanoparticles (AgNPs). Nanofibrous membranes reinforced with silver nanoparticle impregnated cellulosic fibers(CCN-COS-AgNP) were prepared via electrospinning using polyvinyl alcohol(PVA) as a matrix. The effects of CCN-COS-AgNP contents on the morphology, surface composition, mechanical properties, and antibacterial performances of the prepared CCN-COS-AgNP/PVA membranes were examined. The addition of CCN-COS-AgNP certainly improved the mechanical properties and antibacterial performances of the PVA nanofibers. The tensile strength was significantly increased from 4.40 MPa to 8.60 MPa when 8% CCN-COS-AgNP(mass ratio) was introduced. When 10%(mass ratio) CCN-COS-AgNP was added, the nanofibers showed an excellent antibacterial activity for S. aureus(Staphylococcus aureus) and E. coli(Escherichia coli), with the maximum inhibition zones of 2.30 and 1.60 cm, respectively. Moreover, the 2%(mass ratio) CCN-COS-AgNP/PVA fibrous membrane showed 126% cell viability for mg63 human osteoblasts. The electrospun PVA membrane has great potential application in biomedical field.

The Removal of Reactive Red 141 From Wastewater: A Study of Dye Adsorption Capability of Water-Stable Electrospun Polyvinyl Alcohol Nanofibers

Abstract The dye production and its use in textile and related industries resulted in discharge of dye to wastewater. Adsorption for color removal is known as equilibrium separation process, and the resultant decolorization is influenced by physicochemical factors such as adsorbent surface area. The nanofiber membranes prepared by the electrospinning method have controllable nanofiber diameter and pore size distribution (PSD) with a high surface area to volume or mass ratio. In this study, polyvinyl alcohol (PVA) nanofibrous membranes were prepared by the electrospinning method at different collection times such as 3, 5 and 10 h and heat fixated at 130, 150 and 170°C for 10 min, and then, the adsorption capability of PVA nanofiber membranes for Reactive Red 141 from aqueous solution was investigated. In order to make PVA nanofibers stable to water, the nanofibrous membranes were chemically cross-linked by a polycarboxylic acid (1,2,3,4 butanetetracarboxylic acid (BTCA)). PVA nanofibrous membranes were characterized by scanning electron microscopy, thermogravimetric analysis, swelling tests and pore size analysis. The results indicated that BTCA crosslinking improved the thermal and water stability of the nanofibrous structure but has no significant effect on the pore sizes of the membranes. Adsorption of Reactive Red 141 was studied by the batch technique, and it was observed that PVA nanofibers removed approximately >80% of the dye.

Novel quaternarized N-halamine chitosan and polyvinyl alcohol nanofibrous membranes as hemostatic materials with excellent antibacterial properties

The aim of this study was to develop novel nanofibrous membranes based on the quaternary ammonium N-halamine chitosan (CSENDMH) and polyvinyl alcohol (PVA) for antibacterial and hemostasis wound dressing. To improve the antimicrobial properties of nanofibrous membranes, a new chitosan-quaternary ammonium N-halamine derivative was successfully synthesized, and the structure was analyzed by 1H NMR and 13C NMR, fourier transform infrared (FTIR) spectroscopy, and elemental analysis. The morphological and water absorption ability studies showed that the membrane had a uniform bead-free network and high porosity structure like natural extracellular matrix as well as high hydrophilicity. For in vitro evaluation of the hemostatic effect, the membranes showed excellent blood clotting capacity, especially the PVA/CSENDMH membranes. The antimicrobial assay demonstrated excellent antibacterial activity of nanofibrous membranes against both gram-negative and gram-positive bacteria. Furthermore, the cytocompatibility assay results indicated that human fibroblasts could adhere and proliferate on the membranes, thus corroborating their biocompatibility.

Lappaconitine trifluoroacetate contained polyvinyl alcohol nanofibrous membranes: Characterization, biological activities and transdermal application.

Lappaconitine (LA), a potent analgesic drug extracted from the root of natural aconitum species, has been clinically used for years because of its effectiveness and non-addictive properties. However, it is mainly limited in oral and intravenous administration in the form of Lappaconitine Hydrobromide (LAH). In this work, Lappaconitine trifluoroacetate (LAF), a new derivative of LA, was successfully obtained by introducing organofluorine group to LA. This new compound had a lower toxicity (LD50 of 21.14mg·kg-1), improved analgesic effect and longer half-life (T1/2 of 2.24h) when compared with LAH. Moreover, in vitro transdermal permeation (Jss of 206.82μg·cm-2·h-1) of LAF was 30.54% higher than that of LAH, means that LAF can be conveniently used for transdermal drug delivery (TDD). Therefore, drug membranes with PVA solution (10wt%) containing LAF in various amounts were fabricated by electrospinning. The in vitro release tests confirmed that up to 81.43% of LAF in the PVA/LAF nanofibrous membranes could be released in 72h, accompanied by significant analgesic effect when compared with the blank control group. In conclusion, the prepared LAF-loaded membrane is a novel formulation for the treatment of chronic and long-term pain.

Sorption and regeneration performance of novel solid desiccant based on PVA-LiCl electrospun nanofibrous membrane

Electrospun PVA (polyvinyl alcohol)-LiCl composite membranes were prepared as novel solid desiccants. Experimental results show that nanofibrous membranes (NFMs) exhibit notable advantages in sorption capacity, sorption rate and low-temperature desorption rate, as compared with the solution-cast PVA-LiCl membranes (SCMs). The PVA NFM with 15 wt% LiCl can sorb 1.04 g g−1 water at 25 °C and 90% relative humidity (RH), which is more than twice of the reported capacity of silica gel. Due to the nano-structure and small diffusion distance, the desiccant membranes have fast sorption and desorption rates. The desorption isobars show that about 90% of the sorbed moisture can be removed at temperatures between 40 °C and 60 °C, which makes it promising to utilize solar energy or exhaust heat for air dehumidification. The composite desiccant membranes can also be recycled without the degradation of sorption and desorption performance.

Different Structures of PVA Nanofibrous Membrane for Sound Absorption Application

The thin nanofibrous layer has different properties in the field of sound absorption in comparison with porous fibrous material which works on a principle of friction of air particles in contact with walls of pores. In case of the thin nanofibrous layer, which represents a sound absorber here, the energy of sonic waves is absorbed by the principle of membrane resonance. The structure of the membrane can play an important role in the process of converting the sonic energy to a different energy type. The vibration system acts differently depending on the presence of smooth fibers in the structure, amount of partly merged fibers, or structure of polymer foil as extreme. Polyvinyl alcohol (PVA) was used as a polymer because of its good water solubility. It is possible to influence the structure of nanofibrous layer during the production process thanks to this property of polyvinyl alcohol.

A Novel Photoactive Nano-Filtration Module Composed of a TiO<SUB>2</SUB> Loaded PVA Nano-Fibrous Membrane on Sponge Al<SUB>2</SUB>O<SUB>3</SUB> Scaffolds and Al<SUB>2</SUB>O<SUB>3</SUB>-(m-ZrO<SUB>2</SUB>)/t-ZrO<SUB>2</SUB> Composites

Novel photoactive nano-filtration modules composed of a nano-particle TiO2 loaded polyvinyl alcohol (PVA) nano-fibrous membrane on sponge Al2O3 scaffolds and concentric multi-layered Al2O3-(m-ZrO2)/t-ZrO2 composites were successfully prepared using the electro-spinning method, which was also used to load TiO2 into the PVA nano-fiber. The diameter of the PVA-TiO2 nano-fibers was approximately 200 nm. Nano-particle TiO2 with a highly crystalline structure at a ratio of 50% were well-dispersed in the PVA nano-fibrous material. In addition, the PVA-TiO2 membrane was found in the crystallize structure. Methyl Orange (MO) was degraded and became discolored after 5 h of oxidation by the nano-filtration membranes under UV irradiation. Sponge Al2O3 scaffolds and Al2O3-(m-ZrO2)/t-ZrO2 composites were successfully coated with PVA-50%TiO2 fibers with the goal of fabricating a novel nano-filtration membrane.