Crystal polymorphism in polydiacetylene-embedded electrospun polyvinylidene fluoride nanofibers

Area of Science:

• Materials Science
• Nanotechnology
• Polymer Science

Background:

• Polydiacetylene (PDA) and polyvinylidene fluoride (PVDF) are known for their unique optical and piezoelectric properties, respectively.
• Combining these materials in nanofiber form offers potential for novel sensor applications.

Purpose of the Study:

• To embed polydiacetylene (PDA) within electrospun polyvinylidene fluoride (PVDF) nanofibers.
• To investigate the resulting dual colorimetric and piezoelectric responses of the composite nanofibers.
• To explore the material's potential for advanced detection sensors.

Main Methods:

• Electrospinning of PVDF nanofibers with embedded PDA monomers.
• Photo-polymerization of PDA using UV light to form blue-phase nanofibers.
• Spectrophotometry to study temperature-dependent colorimetric transitions.
• Fourier Transform Infrared (FTIR) and Wide Angle X-ray Diffraction (WAXD) for material characterization.

Main Results:

• PDA addition increased nanofiber diameter due to higher solution viscosity.
• PDA inhibited non-polar α-phase crystal growth while promoting polar β-phase in PVDF.
• The blue-to-red color transition of PDA-embedded PVDF nanofibers correlated with variations in piezoelectric signaling.
• A decrease in β-phase intensity was observed in the red phase compared to the blue phase.

Conclusions:

• PDA-embedded PVDF nanofibers possess dual colorimetric and piezoelectric properties.
• The observed color change is linked to alterations in the PVDF crystal phase, affecting piezoelectric output.
• These composite nanofibers demonstrate significant potential for use in commercial detection sensors.