Electrospinning Machine Resources

Production of biohybrid protein/PEO scaffolds by electrospinning 2021-03-18

Electrospun polymeric micro‐ and nanofibers offer the opportunity to reproduce the filamentous structure of the extracellular matrix in native tissues. The ability to electrospin extracellular matrix proteins offers the additional benefit of being able to create a chemical and structural microenvironment for cells in order to influence their behavior during scaffold seeding and tissue formation. This offers significant advantages over unspecific protein adsorption or functionalisation with adhesion promoting peptide sequences. However, producing electrospun fibers from pure protein solutions remains difficult and costly. A more accessible approach is to introduce proteins into electrospun fibers by blending synthetic polymer solutions with selected extracellular matrix proteins. The correct choice of polymer also makes the usage of toxic and denaturing solvents unnecessary. In this study we have investigated the production process for and the suitability of protein/PEO fibers, specifi

Porous Chitin Microbeads for More Sustainable Cosmetics 2021-03-18

The microbead form is a material architecture that is promising for use in biomedical and cosmetic applications; however, the use of petroleum-based microbeads (i.e., plastics) has raised significant environmental concerns in recent years. Microbeads prepared from renewable polymers could represent a sustainable alternative to these synthetic microbeads. This work explores the use of chitin in preparing biodegradable, biocompatible microbeads of low toxicity. Chitin microbeads were synthesized using the ionic liquid (IL) 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]); the IL was used to both extract chitin directly from waste shrimp shell and to prepare the porous microbeads by coagulation in polypropylene glycol (PPG). The effects of biopolymer source and bead-preparation parameters on the formation of beads were investigated, as well as the effects of the drying conditions on the dry bead structure. It was found that IL-extracted chitin could be used to prepare beads of homogeneo

Synthesis and characterization of calcium zirconate nanofibers produced by electrospinning 2021-03-18

Calcium zirconate fibers were produced by electrospinning and characterized in this work. The solution was prepared from zirconium and calcium salts, using polyvinyl-pyrrolidone (PVP) as processing aid. The decomposition of the organic fraction and crystallization of calcium zirconate were followed by thermogravimetry and differential scanning calorimetry (TG/DSC). Raman Spectroscopy was used to measure the vibrational modes in the green as well as in the calcined fibers. The final phase composition was studied by means of X-ray diffraction (XRD). The fiber morphology was investigated by confocal laser scanning microscopy (CLS) and scanning electron microscopy (SEM). The formation reaction of calcium zirconate was observed at about 740 °C. Highly crystalline fibers were obtained already at 800 °C, but the crystallinity and calcium zirconate yield improved when the temperature was increased to 1000 °C.

Palladium/Carbon Nanofibers by Combining Atomic Layer Deposition and Electrospinning for Organic Pollutant Degradation 2021-03-18

As organic dyes are a major source of pollution, it is important to develop novel and efficient heterogeneous catalysts with high activity for their degradation. In this work, two innovative techniques, atomic layer deposition and electrospinning, were used to prepare palladium nanoparticles (Pd NPs) supported on carbon nanofibers (CNFs). The sample morphology was investigated using scanning and transmission electron microscopy. This showed the presence of nanofibers of several micrometers in length and with a mean diameter of 200 nm. Moreover, the size of the highly dispersed Pd NPs was about 7 nm. X-ray photoelectron spectroscopy visually validated the inclusion of metallic Pd. The prepared nano-catalysts were then used to reduce methyl orange (MO) in the presence of sodium borohydride (NaBH4). The Freundlich isotherm model was the most suitable model to explain the adsorption equilibrium for MO onto the Pd/CNF catalysts. Using 5 mL MO dye-solution (0.0305 mM) and 1 mL NaBH4 (0.026 m

Statistical analysis of nanofibers alignment in magnetic‐field‐assisted electrospinning including an alignment percentage formula 2021-03-18

Magnetic‐field‐assisted electrospinning (MFAES) is a simple and effective method to align polymer nanofibers. In this method, further research is needed to identify alignment mechanism. Hence, this article includes statistical analysis of affecting factors to investigate alignment mechanism in MFAES. Tip to target distance, magnets distance, voltage, and collection time, which are recognized as the most effective factors on nanofibers alignment, were applied in design of experiments. Central composite method was applied to get required experiments with designed expert 8 software. A response surface was proposed with regression coefficient of 97%. Then, the common physics concepts and statistical results were used to discuss the affecting mechanism of the electric and magnetic fields on the electrospinnig jet and the nanofibers alignment. Field emission scanning electron microscopy images were used to characterize the nanofibers alignment and calculate overall alignment percentage using

Electrospinning of chitosan/PVA nanofibrous membrane at ultralow solvent concentration 2021-03-18

In this work, chitin flakes were deacetylated with 50% (w/v) sodium hydroxide under nitrogen atmosphere at 120 °C for 80 min to obtain chitosan. The chitosan produced was characterized for degree of deacetylation (DD) and molecular weight. Chitosan with the DD of 78–80% was reproducibly obtained. Molecular weight showed an inverse relationship with concentration of NaOH. Chitosan nanofibrous membrane was prepared via the electrospinning of chitosan/ polyvinyl alcohol (CH/PVA) aqueous solutions with varying blend compositions. The characteristics of CH/PVA nanofibrous membranes were studied as a function of viscosity of solution and applied voltage. A uniform nanofibrous membrane of average fibre diameter of 80–300 nm was obtained with blend of 2% (w/v) chitosan solution in 1% (v/v) acetic acid and 5% (w/v) PVA in distilled water in the electric field of 20–25 kV with varying proportion of CH/PVA. With the CH/PVA mass ratios; 40/60 to 10/90, electrospinning of nanofibres could be done.

Electrospinning of Octenylsuccinylated Starch-Pullulan Nanofibers from Aqueous Dispersions 2021-03-18

We aimed to develop a greener process for dry-electrospinning food-grade modified starch through the elimination of organic solvents. The rheological properties and electrospinnability of aqueous dispersions of commercial octenylsuccinylated (OS) starches with various molecular weight (Mw) were investigated, yet only nanofibers with beads or defects could be obtained from OS starch with the highest Mw, i.e., Purity Gum@ Ultra (PGU). Further improvement in the fiber morphology was achieved by adding pullulan (PUL) as a minor component in the spinning dope. Smooth, continuous, and bead-free nanofibers (147-250 nm) were obtained from the PGU-PUL dispersions. Shown on an electrospinnability map, the successful electrospinning of 12%, 15%, and 20% (w/v) aqueous PGU dispersions required a minimum addition of 6%, 5%, and 3% (w/v) of PUL, respectively. The addition of PUL contributed to establishing sufficient molecular entanglement for electrospinning. This study provides a promising green pr

Photocatalytic properties of Fe2O3-modified rutile TiO2 nanofibers formed by electrospinning technique 2021-03-18

In this study, we aimed to fabricate rutile phase titania nano-catalysts by electrospinning and further doped them with different concentrations of ferric oxide by precipitation technique. The X-Ray Diffraction, Scanning Electron Microcopy and Energy-dispersive X-ray spectroscopy results of 4wt% ferric oxide modified titania nanofibers suggested that the doping of iron with titania nanofibers was highly achievable. It was observed, that ferric oxide is soluble in its lattice matrix, which provided be the rate determining step for degradation model dye i.e., Congo Red. The results confirmed that titania nanofibers incorporated ferric oxide presents the highest dye degradation efficiency and rate constant values, as compared to those of commercially available titanium nanoparticles and pristine nanofibers.

Substitution of petroleum-based polymeric materials used in the electrospinning process with nanocellulose: A review and future outlook 2021-03-18

The most fibrous reinforcing materials for engineered composites (e.g. carbon fiber, glass fiber) are solid fibers or loops, garments, and their preforms. In design and fabrication methods, the fiber orientation and design can therefore be regulated broadly. The continuous fibers from biobased materials such as plants are nevertheless growing interest. Nanocelluloses, which are projected to be cheaper than many other nanomaterials and potentially produce in great quantities, are of particular interest recently. They have an impressive strength to weight ratio and have so far demonstrated no care in their unmodified condition with respect to the climate, health and safety. The efficient and effective use of nanocellulose in continuous fibers is, however, difficult and a range of approaches have been studied where either directly or in combination with the polymers spin nanocellulose dispersions. In this study, a variety of approaches are reviewed and a perspective is provided to better

Randomly oriented and aligned cellulose fibres reinforced with cellulose nanowhiskers, prepared by electrospinning 2021-03-18

The goal of this work was to prepare random and aligned cellulose fibres by electrospinning. Cellulose acetate (CA) was used as a matrix and a mixture of acetic acid and acetone (1∶1) was used as an solvent. Cellulose nanowhiskers (CNWs) with different concentrations (0–5 wt‐%) were used as reinforcement. Microscopy studies showed fibres with smooth surfaces, different morphologies and diameters ranging between 200 and 3300 nm. It was found that the fibre diameters decreased with increased CNW contents. The microscopy studies also indicated well aligned fibres. Results from dynamic mechanical thermal analysis indicated improved mechanical properties with the addition of CNWs. The storage modulus of electrospun CA fibres increased from 81 to 825 MPa for fibres with 1 wt‐% CNW at room temperature. X‐ray analysis showed that the electrospun CA fibres had a crystalline nature and that there was no significant change in crystallinity with the addition of CNWs.

Alumina castable with electrospun fibers 2021-03-18

In this work, cement-free alumina castables with different fiber additives were produced. The effect of commercial polypropylene fibers was compared to that of magnesium borate precursor fibers produced by electrospinning. The drying behavior of different batches was monitored by means of thermogravimetry. Elastic moduli were estimated in dried, sintered and thermally-shocked samples through the impulse excitation technique. The mechanical strength as cold modulus of rupture (CMOR) was measured by three-point bending tests. The open porosity and bulk density after sintering were assessed by water immersion. The thermal shock resistance was evaluated by heating the samples up to 950 ∘C and then quenching with compressed air. After 1 or 5 thermal shock cycles, the residual CMOR was determined. The microstructure of fracture surfaces was analyzed by scanning electron microscopy (SEM). The possible formation of new phases during thermal treatment was also assessed by means of XRD. Finally,

Fabrication of PMMA/zeolite nanofibrous membrane through electrospinning and its adsorption behavior 2021-03-17

The present work investigates the effect of various solution parameters and electrospinning parameters on the characteristics of electrospun nanofibrous membranes. Scanning electron microscopy was used to analyze the surface morphology of the nanofibrous membrane. Adsorption test on methyl orange was also carried out and analyzed using the UV–vis. Results showed that increasing voltage decreased mean nanofiber diameter. Meanwhile, increasing PMMA concentration, feed rate, distance between collector‐and‐needle tip increased mean nanofiber diameter. Zeolite concentration and needle size did not affect the surface morphology significantly. The UV–vis spectra of the adsorption test showed that ∼93%, 85.5%, and 78% of methyl orange were adsorbed for 30, 50, and 100 mg L−1 initial dye concentration, respectively, within 11 min. The maximum adsorption capacity was found to be 95.33 mg g−1. Therefore, PMMA/zeolite nanofibrous membranes possess the adsorption capability toward effective dye rem

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