Flexible AIE fibrous films and their stimulation response properties

Purpose Stimuli-responsive flexible fibrous films have broad application prospects in biomedicine, energy storage and smart devices, but they currently face challenges such as poor scalability, stimulus crosstalk and high production costs. Design/methodology/approach Composite fibrous films were prepared via the electrospinning method using polyurethane (PU) and two tetraphenylethylene (TPE) derivatives as raw materials. The prepared films were characterized using Fourier-transform infrared spectroscopy (FTIR), UV-vis absorption spectroscopy, scanning electron microscopy (SEM), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), a universal tensile testing machine and an Edinburgh FLS1000 fluorescence spectrometer to analyze their chemical structure, morphology, thermal stability, mechanical properties and photophysical properties. Findings The fiber diameters of PU-TPE-2OH-F and PU-TPE-4OH-F films were in the micron-scale range. Thermal analysis revealed that the glass transition temperature (Tg) of PU-TPE-2OH-F and PU-TPE-4OH-F films was higher than that of pure PU, attributed to hydrogen bonding between TPE hydroxyl groups and PU amide groups. Mechanical tests indicated that the maximum tensile strength of PU-TPE-4OH-F films was 6.72 MPa (with a fracture elongation of 188%), while PU-TPE-2OH-F films showed a lower tensile strength (4.58 MPa) but higher fracture elongation (246%). Photophysical characterization showed that aggregation-induced emission (AIE) effect was retained in the PU-TPE-nOH-F (n =2, 4) films. PU-TPE-4OH-F films exhibited dual-stimuli-responsive properties to mechanical force and light. Research limitations/implications The electrospinning method restricts the large-scale production of the films, which needs to be optimized for scalability in subsequent research. Practical implications PU-TPE composite fibrous films exhibit dual-stimuli responsiveness to mechanical force and light, making them potential candidates for self-reporting materials and adaptive optical devices. Social implications The fibrous films will be used for the multidimensional stimulation response devices. Originality/value This study integrates TPE derivatives with different hydroxyl group contents into the PU matrix via electrospinning, realizing the combination of AIE properties and PU’s films flexibility.