Electrospun microfibers with embedded leuco dye-based thermochromic material for textile applications

Electrospinning is an inexpensive and versatile technique for fabricating micro- and nano- scaled fibers. There have been limited attempts to employ it for the fabrication of thermochromic (TC) fibers, and the fabrication of a three-component (dye, developer, and solvent) TC material has required the use of a more complicated coaxial electrospinning technique. Herein, a simple and novel method for creating thermochromic fibers by electrospinning single strands of poly (methyl methacrylate) (PMMA) with embedded thermochromic powder of a polymer encapsulated three-component system was employed. Unlike past leuco dye-based thermochromic fibers, an unmodified syringe tip can be used for the spinning process and only one flow rate needs to be determined. A solution of solvent (either N-dimethylformamide or chloroform), PMMA, and a commercially available black thermochromic powder was prepared and spun using a custom-made electrospinning apparatus. The spun fibers exhibited a clear color transition from grey to white and had average diameters of 2.53 µm and 1.96 µm for chloroform and N-dimethylformamide based fibers, respectively. The fibers were characterized by scanning electron and optical microscopy to determine their morphology, Fourier transform infrared spectroscopy to determine their chemical composition, and differential scanning calorimetry and thermogravimetric analysis to characterize their thermal properties.