Thermochromic Fibers via Electrospinning
Journal Article - Open Access
U.S. Army Combat Capabilities Development Command Soldier Center Natick
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Cholesteryl ester liquid crystals exhibit thermochromic properties related to the existence of a twisted nematic phase. We formulate ternary mixtures of cholesteryl benzoate CB, cholesteryl pelargonate CP, and cholesteryl oleyl carbonate COC to achieve thermochromic behavior. We aim to achieve thermochromic fibers by incorporating the liquid crystal formulations into electrospun fibers. Two methods of incorporating the liquid crystal LC are compared 1 blend electrospinning and 2 coaxial electrospinning using the same solvent system for the liquid crystal. For blend electrospinning, intermolecular interactions seem to be important in facilitating fiber formation since addition of LC can suppress bead formation. Coaxial electrospinning produces fibers with higher nominal fiber production rates ghr and with higher nominal LC content in the fiber wt. LCwt. polymer assuming all of the solvent evaporates but larger fiber size distributions as quantified by the coefficient of variation in fiber diameter than blend electrospinning with a single nozzle. Importantly, our proof-of-concept experiments demonstrate that coaxially electrospinning with LC and solvent in the core preserves the thermochromic properties of the LC so that thermochromic fibers are achieved.
- Refractory Fibers