Electrospinning and post-drawn processing effects on the molecular organization and mechanical properties of polyacrylonitrile (PAN) nanofibers

Brennan, David; Shirvani, Khosro A.; Rhoads, Cailyn D.; Lofland, Samuel; Beachley, Vince

doi:10.1557/mrc.2019.67

Cited by 10 publications

(13 citation statements)

References 21 publications

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“…For the polarization experiments, various collected mats of aligned SF nanofibers were irradiated with a polarized infrared beam parallel (0°) and perpendicular (90°) to the fiber axis. 51 The IR transmission spectra of the two polarization conditions were recorded, where parallel absorption (A ∥ ) was obtained by the electric vector direction of the polarized parallel (0°) IR beam and perpendicular absorption (A ⊥ ) was obtained by the electric vector direction of the polarized parallel (90°) IR beam. When the polarized electric field contacts the material, the peak intensity reaches its maximum when the chemical bonds reside or are oriented in the same direction.…”

Section: Methodsmentioning

confidence: 99%

“…When the polarized electric field contacts the material, the peak intensity reaches its maximum when the chemical bonds reside or are oriented in the same direction. 51 Omnic spectra software (Thermo Fisher Scientific) was used to record the spectra and analyze the peak intensity of absorbance, after baseline correction and normalization, to determine the degree of macromolecular (polymer chain) orientation with the effect of postdrawing treatment at changing draw ratios. To find the degree of molecular orientation, dichroic ratios (R) of each band were calculated according to the following equation 23,52 R A A / = ⊥ (1) where A ∥ and A ⊥ are the integrated absorbance of parallel (0°) and perpendicular (90°) peak intensities, respectively.…”

Section: Methodsmentioning

confidence: 99%

“…The polarized FTIR was operated in transmission mode with 128 scans at a resolution of 4 cm –1 in the wavenumber range between 4000 and 400 cm –1 . For the polarization experiments, various collected mats of aligned SF nanofibers were irradiated with a polarized infrared beam parallel (0°) and perpendicular (90°) to the fiber axis . The IR transmission spectra of the two polarization conditions were recorded, where parallel absorption ( A ∥ ) was obtained by the electric vector direction of the polarized parallel (0°) IR beam and perpendicular absorption ( A ⊥ ) was obtained by the electric vector direction of the polarized parallel (90°) IR beam.…”

Section: Methodsmentioning

confidence: 99%

“…The IR transmission spectra of the two polarization conditions were recorded, where parallel absorption ( A ∥ ) was obtained by the electric vector direction of the polarized parallel (0°) IR beam and perpendicular absorption ( A ⊥ ) was obtained by the electric vector direction of the polarized parallel (90°) IR beam. When the polarized electric field contacts the material, the peak intensity reaches its maximum when the chemical bonds reside or are oriented in the same direction . Omnic spectra software (Thermo Fisher Scientific) was used to record the spectra and analyze the peak intensity of absorbance, after baseline correction and normalization, to determine the degree of macromolecular (polymer chain) orientation with the effect of postdrawing treatment at changing draw ratios.…”

Section: Methodsmentioning

confidence: 99%

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Bioinspired Silk Fiber Spinning System via Automated Track-Drawing

Jao

Beachley

2021

ACS Appl. Bio Mater.

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Regenerated silk fibroin (SF) fiber is a multifaceted protein matrix suitable for engineering a wide variety of biological materials. Numerous artificial spinning systems have been developed to mimic the molecular structure and hierarchical properties found in native silks. Here, we show a bioinspired technique that can readily form nanofibers and induce both orientation and structure formation of crystalline β-sheet assemblies seen in natural silk. In this study, electrospun postdrawn SF nanofibers were fabricated using an automated track-drawing (TD) approach for the continuous production of highly aligned protein nanofibers. This one-step postdrawing process simulates the dominant pulling force seen in natural spinning. The mechanical performance of the postdrawn SF nanofibers with a draw ratio of 2 (DR2) via TD exhibited a 115% increase in Young's modulus and an 80% increase in ultimate tensile strength, compared with the undrawn SF fibers after water treatment. It was also determined that the intermolecular β-sheet content in DR2 nanofibers increased by 75%. This contribution led to higher glass-transition and degradation temperatures. These biomimetic fibers with structural hierarchy and mechanical properties may be used to build high-performance load-bearing and directionally propagating structures relevant in biomaterial and sustainable material applications.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

Bioinspired Silk Fiber Spinning System via Automated Track-Drawing

Jao

Beachley

2021

ACS Appl. Bio Mater.

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“…After being collected with a draw ratio of 4, the strength and stiffness of the aligned polycaprolactone nanofiber bundles were enhanced by 7 and 15 times respectively. Then they also applied this method on PAN nanofibers, whose strength and modulus were increased by about 100% and 500% respectively [144].…”

Section: Stretchingmentioning

confidence: 99%

Strategies in Precursors and Post Treatments to Strengthen Carbon Nanofibers

Zhang

Liu

et al. 2020

Adv. Fiber Mater.

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The limited mechanical properties of carbon nanofibers (CNFs) have become a severe problem hindering their wide range applications. The restricting issues are found in the whole fabrication process, including the precursor design, spinning and collection techniques, post treatments like stretching and aligning, and complicated thermal treatments involving stabilization and carbonization. Here we access the CNF development by focusing on the mechanical properties, and systematically discuss the strengthening strategies during the different fabrication stages.

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Novel Use of Laser Zone‐Drawing on Nanofibers Enables Ultra‐Fast Thermal Kinetics and Precise Diameter Control

Flamini,

Keblawi,

Lima

et al. 2024

Adv Materials Technologies

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Laser zone‐drawing is shown to significantly enhance control over nanofiber properties. This study investigates the dynamics of nanofiber laser zone‐drawing. It is hypothesized that the equilibrium between heating and cooling guides fiber temperature. The high heating rate of laser irradiation and the high convective cooling rate of nanofibers facilitate fast heating and cooling kinetics. Results showed fiber thinning in the presence of laser irradiation until reaching a steady‐state diameter. Final fiber diameter is correlated to laser power independent of initial fiber diameter. The relationship between final fiber diameter and laser power is used to estimate the heat transfer coefficient, which is used to create a computational model of the thermodynamic system. These simulations predict rapid heating and cooling up to 36 000 K min−1 for the lowest fiber diameters tested experimentally. While laser‐induced softening of polymer nanofibers is described in detail, the forces driving fiber drawing, particularly under different thermal kinetics, remain unexplored. This research showcases the capabilities of laser zone‐drawing in nanofiber manufacturing and facilitates future investigations aimed at enhancing fiber processing by producing highly aligned molecular structures via rapid cooling. This work signifies a pivotal methodological leap, promising transformative nanofiber materials useful across multiple industries including aerospace, electronics, and biomedicine.

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Electrospinning and post-drawn processing effects on the molecular organization and mechanical properties of polyacrylonitrile (PAN) nanofibers

Abstract: Abstract

Cited by 10 publications

References 21 publications

Bioinspired Silk Fiber Spinning System via Automated Track-Drawing

Bioinspired Silk Fiber Spinning System via Automated Track-Drawing

Strategies in Precursors and Post Treatments to Strengthen Carbon Nanofibers

Novel Use of Laser Zone‐Drawing on Nanofibers Enables Ultra‐Fast Thermal Kinetics and Precise Diameter Control

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