Electrospinning of Colloidal Lignin in Poly(ethylene oxide) N , N -Dimethylformamide Solutions

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The effects of polyethylene oxide (PEO) molecular weight (Mv), and volume fraction ( ϕ) on the morphology of electrospun sulfur free softwood lignin nanofibers were investigated. Small amounts of PEO were used during preparations of the solutions to aid the electrospinning process. It was found that tripling the PEO volume fraction resulted in a transition from semi‐dilute un‐entangled to semi‐dilute entangled solutions. Conversely, the solution remained in the semi‐dilute un‐entangled regime as the molecular weight was increased by five times. The effects of molecular weight and volume fraction of PEO both on entanglement density and fiber morphology were unified by scaling PEO viscosities as a function of ϕ1.3Mvpolymer. We investigated and discussed conditions that would produce smooth fibers and conditions that would produce fibers with beads. In the case of beads‐on‐a‐string formation, bead widths remained constant regardless of the molecular weight and concentration of PEO, but the bead length changed. Additionally, we observed a decrease in the diameter of the fibers and the dimension of beads (length and width of beads) with an increase in the electric field used for electrospinning. The aspect ratio of beads increased with increases to both the electric field and the PEO molecular weight or concentration. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44172.

Section: Methodssupporting

confidence: 82%

“…The values of

ϕ_{P E O} / ϕ^{*}

at volume fraction of 0.0015 for different molecular weights of PEO are less than

ϕ_{P E O} / ϕ^{*} \sim 3.6

. The value of 3.6 was the change of viscosity slope while PEO (Mv = 1,000 kDa) volume fraction was increased . As it was reported in our previous publication for the same system, at

ϕ_{P E O} / ϕ^{*}

= 3.6 both the viscosity slope change and transition from BOAS to smooth fiber occurred.…”

Section: Resultssupporting

confidence: 55%

“…Therefore, we investigated the effects of molecular weight (

{M v}_{P E O}

) and the volume fraction (

ϕ_{P E O}

Section: Resultsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

λ

), and length and width of beads were determined from SEM images by 15 measurements made on each sample that had beads.…”

Section: Methodsmentioning

confidence: 99%

See 3 more Smart Citations

Morphologies of electrospun fibers of lignin in poly(ethylene oxide)/N,N‐dimethylformamide

Aslanzadeh

Ahvazi

Boluk

et al. 2016

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Evaluation of an onset of electrospun beadless poly(ethylene oxide) nanofibres

Filip

Zelenková

Peer

2020

To evaluate the lowest polymer concentration within a solvent from which there appears beadless nanofibres during the process of electrospinning, is rather complicated. A widely used method is based on a determination of so called entanglement concentration c e and the onsets of beadless nanofibres are characterized by multipliers of c e subjected to used materials. However, a determination of c e as an intersection point of two linear segments (in log-log coordinates specific viscosity vs. concentration) in a semi-dilute region is not applicable for all materials as for instance a solution of poly(ethylene oxide) (PEO) in water does not exhibit 'classical' three linear segments within the dilute and semi-dilute regions determining overlap and entanglement concentrations. For such cases a new approach for the evaluation of an initial concentration from which beadless nanofibres are produced is proposed. This method does not use the terms overlap and entanglement concentrations. The procedure is demonstrated using four PEO solutions differing in molecular weight. The relationship expressing initial concentration in dependence on PEO molecular weight containing no adjustable parameters is proposed.

Bio‐cleaned lignin‐based carbon fiber and its application in adsorptive water treatment

Chen

Ghosh

Ayranci

et al. 2021

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Although an agricultural byproduct, lignin can be a felicitous choice serving as a carbon fiber precursor upon bio-cleaning with Pseudomonas fluorescence. In this study, carbon fiber produced from electrospun bio-cleaned lignin (Bio-KLB) was demonstrated to be a novel efficient adsorbent for methylene blue in wastewater treatment. Bio-cleaning effectively changed lignin from unelectrospinnable to easily-electrospinnable by removing impurities. Bio-KLB carbon fiber mats showed average fiber diameter of 278.95 ± 49.89 nm, and randomly dispersed fiber mats showed average elastic modulus of 1532.87 ± 439.63 MPa and tensile strength of 16.72 ± 5.21 MPa. Adsorption of methylene blue on Bio-KLB carbon fibers was analyzed at pH = 9, where optimal adsorption and decent reusability were observed. Kinetic adsorption was fitted well with pseudo-first-order model while adsorption isotherms were fitted to both Langmuir and Freundlich models. The highest adsorption capacity was 548.65 mg/g based on Langmuir model. The results provide clear evidence that electrospun bio-cleaned lignin-based carbon fibers can be a strong alternative material for dye treatment.