(64g) Highly Stretchable P3HT Containing Core-Shell Composite Fibers from Coaxial Electrospinning

Conjugated polymers have potential applications in many areas including in wearable electronics, healthcare devices, electronic skin, and flexible displays. For these applications, it is important that the polymer maintain electronic properties with mechanical deformation. Achieving such is a significant challenge, as the performance of many systems deteriorates under stretched conditions. Here, we report the fabrication of highly stretchable composite fibers consisting of semiconducting poly(3-hexylthiophene) (P3HT) and butyl rubber (BR) obtained using a coaxial electrospinning technique. BR, an elastomer, was used in the core, whereas P3HT was used in the shell to obtain coaxial stretchable fiber. The polarized optical microscopy analysis captures the ordered structure present in the fibers. Photoluminescence spectroscopic analysis of the fiber mat captured as high as 12 nm redshift for 0-0 aggregation peak in the stretched fibers. This red shift signifies the change of ordered structure in fiber due to the application of tensile load along the strain direction. The fibers were highly stretchable, as the rupture strain of the electrospun fiber was approximately 1000%. The electrical conductivity values at different strain conditions were recorded. Electrical conductivity did not change significantly up to 400% strain. Further, the conductivity is maintained for this applied strain under cyclic loading, showing excellent mechanical and electrical durability of the fibers. Our results demonstrate that the electrospun fibers obtained here can have applications in wearable and deformable electronic devices where high stretchability is required.