TY - JOUR
T1 - Light Scattering of Electrospinning Jet with Internal Structures by Flow-Induced Phase Separation
AU - Chen, Guan Jie
AU - Lai, Hsin Yi
AU - Lu, Pin Hsien
AU - Chang, Yu Chia
AU - Wang, Chi
N1 - Funding Information:
The authors are deeply grateful to Prof. Takeji Hashimoto for valuable discussions. This research has been supported by the Ministry of Science and Technology of Taiwan (MOST 109‐2221‐E‐006‐202‐MY3).
Publisher Copyright:
© 2022 Wiley-VCH GmbH.
PY - 2023/1
Y1 - 2023/1
N2 - Herein, the direct morphological evidence of the extension-induced phase-separated structures in the electrospinning jet observed by high-speed video imaging and by light scattering technique is reported. Model solutions of poly(vinyl alcohol) (PVA)/water are electrospun. Two types of internal structures, that is, long strings and short ellipsoids, are found. A light scattering model is derived for the Vv scattering configuration to account for the scattered intensities contributed from the liquid jet itself and those from the internal structures. For the severely stretching jet of PVA/water, the Vv intensity profile is dominant by the internal structures to mask the scattering contribution from the jet itself. Moreover, the Hv intensity profile reflects the anisotropy of the oriented chains parallel to the jet axis. For the 7 wt% solution, the derived extension rate in the vicinity of the Taylor cone apex is about 3420 s−1, which is higher than the Rouse relaxation rate measured by rheometer. It is concluded that extension-induced phase separation of the single-phase PVA solution is likely to occur in Taylor-cone apex to trigger the self-assembly process for producing strings (and/or bulges) in the flowing jet, which eventually transform to become the nanofibers, after solvent removal, to be collected on the grounded collector.
AB - Herein, the direct morphological evidence of the extension-induced phase-separated structures in the electrospinning jet observed by high-speed video imaging and by light scattering technique is reported. Model solutions of poly(vinyl alcohol) (PVA)/water are electrospun. Two types of internal structures, that is, long strings and short ellipsoids, are found. A light scattering model is derived for the Vv scattering configuration to account for the scattered intensities contributed from the liquid jet itself and those from the internal structures. For the severely stretching jet of PVA/water, the Vv intensity profile is dominant by the internal structures to mask the scattering contribution from the jet itself. Moreover, the Hv intensity profile reflects the anisotropy of the oriented chains parallel to the jet axis. For the 7 wt% solution, the derived extension rate in the vicinity of the Taylor cone apex is about 3420 s−1, which is higher than the Rouse relaxation rate measured by rheometer. It is concluded that extension-induced phase separation of the single-phase PVA solution is likely to occur in Taylor-cone apex to trigger the self-assembly process for producing strings (and/or bulges) in the flowing jet, which eventually transform to become the nanofibers, after solvent removal, to be collected on the grounded collector.
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U2 - 10.1002/marc.202200273
DO - 10.1002/marc.202200273
M3 - Article
C2 - 35583906
AN - SCOPUS:85130736100
SN - 1022-1336
VL - 44
JO - Macromolecular Rapid Communications
JF - Macromolecular Rapid Communications
IS - 1
M1 - 2200273
ER -