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Electrospinning of Chitosan Biopolymer and Polyethylene Oxide Blends

Varnaitė-Žuravliova Sandra, Savest Natalja, Baltušnikaitė-Guzaitienė Julija, Abraitienė Aušra, Krumme Andres

Autex Research Journal

2020

Vol. 20, no. 4

426--440

The objective of this study is to investigate the morphological (scanning electron microscopicy images), thermal (differential scanning calorimetry), and electrical (conductivity) properties and to carry out compositional analysis (Fourier-transform infrared) of produced nonwoven fibrous materials adapted in biomedical applications as scaffolds. The orientation of produced nanofilaments was also investigated because it is considered as one of the essential features of a perfect tissue scaffold. Viscosity and electrical conductivity of solutions, used in the manufacturing process, were also disassembled because these properties highly influence the morphological properties of produced nanofibers. The nanofibrous scaffolds were fabricated via conventional electrospinning technique from biopolymer, synthetic polymer, and their blends. The chitosan (CS) was chosen as biopolymer and polyethylene oxide (PEO) of low molecular weight as synthetic polymer. Solutions from pure CS were unspinnable: beads instead of nanofibers were formed via spinning. The fabrication of pure PEO nanomats from solutions of 10 wt%, 15 wt%, and 20 wt% concentrations (in distilled water) turned out to be successful. The blending of composed CS solutions with PEO ones in ratios of 1:1 optimized the parameters of electrospinning process and provided the opportunity to fabricate CS/PEO blends nanofibers. The concentration of acetic acid (AA) used to dissolve CS finely spuninned the nanofibers from blended solutions and influenced the rate of crystallization of manufactured fiber mats. The concentration of PEO in solutions as well as viscosity of solutions also influenced the diameter and orientation of formed nanofibers. The beadless, highly oriented, and defect-free nanofibers from CS/PEO solutions with the highest concentration of PEO were successfully electrospinned. By varying the concentrations of AA and low molecular weight PEO, it is possible to fabricate beadless and highly oriented nanofiber scaffolds, which freely can found a place in medical applications.

Influence of inorganic additives on morphology of electrospun fibres

Dobrzański L. A., Adamiak M., Karoń M., Nieradka B.

Journal of Achievements in Materials and Manufacturing Engineering

2015

Vol. 68, nr 2

64--71

Purpose: This paper describes the effect of inorganic additives and operating parameters of an electrospinning process on electrospun fiber diameters and morphology. Design/methodology/approach: Application of different solvents and process parameters impact characteristics of the micro and nanofibers made of PEO and also PVA with CuOAc. Findings: The results show that the three parameters (volumetric charge density, distance from nozzle to collector, and viscosity) have the most significant effect on the electrospun fiber morphology. The nano- and microfibers produced were characterized by scanning electron microscopy as well as with use of image analyzing tool DigitalMicrograph. Changes in length of stream and volatility of the solvent influence the shape of the fibres and internal solution load. The resulting fibre shape shows that for shorter distances the process was unstable, and the morphology of the filaments from a longer distance shows the gradual stabilization and indicates optimal process parameters. Practical implications: Based on the research carried out it is clear that micro and nanofiber characteristics vary widely depending on prepared solutions and process parameters. Originality/value: It was confirmed that inorganic additives, solvent type and process parameters have an effect on morphological aspects of produced micro and nanofibres.

Research on adsorptive and electrokinetic properties of SiO2 in the presence of polyethylene oxide of different purities

Patkowski J., Chibowski S.

Physicochemical Problems of Mineral Processing

2011

Vol. 47

275-284

The influence of impurities present in polymer solutions on adsorptive and electrokinetic properties of PEO 100 000 with commercial silica was analysed. Adsorption was measured with a spectrophotometric method and zeta potential with a zetasizer. A XRF method was used to estimate the quality and quantity of impurities in polyethylene oxide solutions. Impurities left after the polymerisation process, present in polymer solutions can adsorb competitively with macromolecules of the polymer. As a result of that, they block active centres on the surface of the adsorbent thus leaving less surface available for polymer molecules. Purification process is conducted in order to improve the quality of analysed polymer material. Polyethylene oxides used in the presented research were purified by filtration process and fractionation on chromatographic column. Overall, three different samples of PEO were used: commercial of high quality, filtrated and fractionated. Results show that adsorption of polyethylene oxide of high purity is independent on pH of the solution. Adsorption isotherms of fractionated and analytical-grade polymer are sharp, which indicates their low polydispersity ratio. An adsorption amount of analysed polymers is dependent only on the amount of impurities present in polymer material. Zeta potential measurements show, that polyethylene oxide always increases zeta potential of silica.

Zbadano wpływ zanieczyszczeń obecnych w materiale polimeru na adsorpcyjne i elektrokinetyczne właściwości PEO 100 000 na komercyjnej krzemionce. Adsorpcję badano przy pomocy metody spektrofotometrycznej, potencjał zeta przy pomocy zetasizera. Metodą XRF ustalono stężenie oraz jakość zanieczyszczeń w badanych roztworach polimerów.Przeprowadzone badania wskazują, że adsorpcja tlenku polietylenu o wysokiej czystości jest niezależna od pH roztworu. Izotermy adsorpcji PEO frakcjonowanego oraz o wysokiej czystości są ostre, co wskazuje na ich niski stopień polidyspersyjności. Ilość zaadsorbowanego polimeru jest zależna tylko od ilości zanieczyszczeń obecnych w materiale polimeru. Pomiary potencjału zeta wskazują, że obecność tlenku polietylenu zawsze zwiększa potencjał zeta krzemionki.