Quantum Dots on a String: In Situ Observation of Branching and Reinforcement Mechanism of Electrospun Fibers

Abstract 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.