High Piezoelectric Output Voltage from Blue Fluorescent N,N-Dimethyl-4-Nitroaniline Nano Crystals into Poly-L-Lactic Acid Electrospun Fibers

N,N-dimethyl-4-nitroaniline (NNDM4NA, C8H10O2N2), is a superelastic and superplastic charge-transfer molecular crystal with a high molecular dipole moment, µ=7.95 D, which crystal-lizes in the acentric polar point group 2. Highly aligned poly-l-lactic acid (PLLA) polymer micro-fibers with embedded NNDM4NA nanocrystals were fabricated using the electrospinning tech-nique. The composite fibers display an extraordinarily high piezoelectric output response, where for a small stress of 5.0x103 Nm-2, an effective piezoelectric voltage coefficient of geff=3.6 VmN-1 was obtained. The fibers were found to display solid state blue fluorescence with a long (147 ns) life-time decay. Furthermore, the composite fibers exhibit an average increase of 67% on the Young modulus reaching 55 MPa, while the tensile strength reaches 2.8 MPa when compared with solely PLLA fibers. The results show that nanocrystals, from small organic molecules, with elastic and piezoelectric properties form hybrid functional 2-dimensional luminescent array which are me-chanical strong and generate high output voltages making them promising for applications in energy harvesting and as solid-state blue emitters.