ABSRACT:
Immobilization of quantum dots (QDs) on fiber surfaces has emerged as a
robust approach for preserving their functional characteristics while
mitigating aggregation and instability issues. Despite the advancement,
understanding the impacts of QDs on jet-fiber evolution during
electrospinning, QDs-fiber interface, and composites functional behavior
remains a knowledge gap. The study adopts a high-speed imaging
methodology to capture the immobilization effects on the QDs-fiber matrix. In
situ observations reveal irregular triangular branches within the QDs-fiber
matrix, exhibiting distinctive rotations within a rapid timeframe of 0.00667 ms.
The influence of FeQDs on Taylor cone dynamics and subsequent fiber
branching velocities is elucidated. Synthesis phenomena are correlated with
QD-fiber’s morphology, crystallinity, and functional properties. PAN-FeQDs
composite fibers substantially reduced (50–70%) nano-fibrillar length and
width while their diameter expanded by 17%. A 30% enhancement in elastic
modulus and reduction in adhesion force for PAN-FeQDs fibers is observed.
These changes are attributed to chemical and physical intertwining between
the FeQDs and the polymer matrix, bolstered by the shifts in the position of
C≡N and C═C bonds. This study provides valuable insights into the quantum
dot-fiber composites by comprehensively integrating and bridging jet-fiber
transformation, fiber structure, nanomechanics, and surface chemistry.
"High-Speed Imaging: The jet formation and fiber electrospinning process
was captured using the i-Speed 727 camera from iX Cameras
(Woburn, Massachusetts). For the experiment, two distinct lens systems
were employed. The first system involved a 60 mm AF micron Nikkor
lens with three spacers: a 36, a 20, and a 12 mm VELLOTM AF extension
tube. The 3S system captures both the jet formation and electrospinning
stages, encompassing the linear, linear-nonlinear transition, and
nonlinear phases."
