Crystal polymorphism in polydiacetylene-embedded electrospun polyvinylidene fluoride nanofibers

Abstract

In this study, polydiacetylene (PDA) is embedded in electrospun polyvinylidene fluoride (PVDF) nanofibers for the preparation of mats with dual colorimetric and piezoelectric responses. The diacetylene monomers are self-assembled during the electrospinning process. The PDA-embedded PVDF nanofibers in the blue phase are obtained via photo-polymerization upon UV-light irradiation. The colorimetric transition of the nanofibers is studied as a function of temperature using a spectrophotometer. The morphology and crystal polymorphism of the nanofibers are investigated. The results show that the addition of PDA increases the diameter of the nanofibers due to the increase in the electrospinning solution viscosity. The results of Fourier transform infrared and wide angle X-ray diffraction demonstrate that PDA has the effect of inhibiting the growth of non-polar α-phase crystals, while promoting the growth of the polar β-phase. However, the red phase of PDA-embedded PVDF exhibits a lower intensity of the β-phase in comparison to that of the blue phase. In fact, the blue-to-red color transition of the PDA-embedded electrospun PVDF nanofibers is accompanied by the variation of piezoelectric signaling caused by variations in the β-phase. This phenomenon creates great potential in commercial detection sensors in addition to their colorimetric detection properties.

Conjugated Copolymers through Electrospinning Synthetic Strategies and Their Versatile Applications in Sensing Environmental Toxicants, pH, Temperature, and Humidity

“…Under annealing conditions, the PCDA-conjugated backbone might disrupt the aligned molecular structures, ultimately leading to inferior beta phase. Blue phase enriched PDA ES nanofiber displayed greater sensitivity than red phase PDA because of the presence of higher beta-phase fractions [75].…”

“…Under annealing conditions, the PCDA-conjugated backbone might disrupt the aligned molecular structures, ultimately leading to inferior beta phase. Blue phase enriched PDA ES nanofiber displayed greater sensitivity than red phase PDA because of the presence of higher beta-phase fractions [75]. [75] with permission from Royal Society of Chemistry and (c) polyaniline (PANI) blended onto polyamide (PA)-6 matrices producing the colorimetric sensory fibers.…”

“…Blue phase enriched PDA ES nanofiber displayed greater sensitivity than red phase PDA because of the presence of higher beta-phase fractions [75]. [75] with permission from Royal Society of Chemistry and (c) polyaniline (PANI) blended onto polyamide (PA)-6 matrices producing the colorimetric sensory fibers. Adapted from work in [76] with permission from Royal Society of Chemistry.…”

“…The synergistic role of polydiarylfluorenes side chain length and ES stretching effect deliberately facilitates the polydiarylfluorene β-phase formation demonstrating the elevated sensitivity [78]. Poly((9,9-bis(3′-(N,N-dimethylamino)propyl)-2,7fluorene)-alt-2,7-(9,9-dioctyl-fluorene))-containing tertiary amine group physically interacts with [75] with permission from Royal Society of Chemistry and (c) polyaniline (PANI) blended onto polyamide (PA)-6 matrices producing the colorimetric sensory fibers. Adapted from work in [76] with permission from Royal Society of Chemistry.…”

“…(b) Demonstration of established electrospun nanofiber with hydrogen bonding b/w polyvinylidene fluoride (PVDF) and PDA. Adapted from in[75] with permission from Royal Society of Chemistry and (c) polyaniline (PANI) blended onto polyamide (PA)-6 matrices producing the colorimetric sensory fibers. Adapted from work in[76] with permission from Royal Society of Chemistry.…”