Tunable Photoluminescent Fibers of a Discotic Columnar Liquid Crystal in Electrospun Mats

High Resolution Image Download MS PowerPoint Slide Electrospun mats typically feature a high surface area, porosity, and flexibility, making them well-suited for use in biotechnology and organic electronics. Incorporating nanofillers or small molecules, such as liquid crystals (LCs), into the polymer solution can tailor the fibers’ optical, mechanical, and morphological properties. Self-organizing materials, such as discotic LCs, which form columnar mesophases, are very attractive for the development of functional nanomaterials, with many applications in organic electronics and photonics. Here, we obtain photoluminescent fibers produced by a single-needle electrospinning technique of the polymer thermoplastic polyurethane (TPU) doped with different concentrations of a perylene-based discotic liquid crystal molecule. The electrospun mats showed photoluminescence (PL) changing from light green to orange depending on the LC concentration (0.01 to 10.00 wt %) and high photoluminescence quantum yield (PLQY), reaching up to 78% at low LC content. The addition of LC led to more homogeneous fibers with reduced diameters, down to 0.77 μm for 10.00 wt% of LC, and preserved mechanical flexibility. Polarizing optical microscopy (POM), X-ray diffraction (XRD), and photophysical measurements confirmed the incorporation of LC into the mats, suggesting the presence of LC-rich regions preferentially confined within the polymeric fiber rather than homogeneously distributed on its surface.