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

Abstract

N,N-dimethyl-4-nitroaniline is a piezoelectric organic superplastic and superelastic charge transfer molecular crystal that crystallizes in an acentric structure. Organic mechanical flexible crystals are of great importance as they stand between soft matter and inorganic crystals. Highly aligned poly-l-lactic acid polymer microfibers with embedded N,N-dimethyl-4-nitroaniline nanocrystals are fabricated using the electrospinning technique, and their piezoelectric and optical properties are explored as hybrid systems. The composite fibers display an extraordinarily high piezoelectric output response, where for a small stress of 5.0 × 103 Nm−2, an effective piezoelectric voltage coefficient of geff = 4.1 VmN−1 is obtained, which is one of the highest among piezoelectric polymers and organic lead perovskites. Mechanically, they exhibit an average increase of 67% in the Young modulus compared to polymer microfibers alone, reaching 55 MPa, while the tensile strength reaches 2.8 MPa. Furthermore, the fibers show solid-state blue fluorescence, important for emission applications, with a long lifetime decay (147 ns) lifetime decay. The present results show that nanocrystals from small organic molecules with luminescent, elastic and piezoelectric properties form a mechanically strong hybrid functional 2-dimensional array, promising for applications in energy harvesting through the piezoelectric effect and as solid-state blue emitters.

Bioinspired Cyclic Dipeptide Functionalized Nanofibers for Thermal Sensing and Energy Harvesting

“…In our case, the direction of stretching is the same as the fiber longitudinal axis orientation [ 28 ]. In our previous work, we have demonstrated that the incorporation of lead-free organic ferroelectric perovskite N-methyl-N′-diazabicyclo [2.2.2]octonium)-ammonium triiodide (MDABCO-NH 4 I 3 ) nanocrystals embedded in polyvinyl chloride microfibers [ 29 ] and N,N -dimethyl-4-nitroaniline embedded in PLLA microfibers [ 30 ] improve the Young’s modulus compared to polymer microfibers alone. In this work we demonstrate that not only does the Young modulus increase, but all the mechanical properties measured for Cyclo (L-Trp-L-Trp)@PCL are improved as well.…”

Nanostructured Electrospun Fibers with Self-assembled Cyclo-L-Tryptophan-L-Tyrosine Dipeptide as Piezoelectric Materials and Optical Second Harmonic Generators

“…On average, the elastic modulus (Young's modulus) increased by 445% (from 6.9 to 37.6 MPa) and the tensile strength by 72% (from 1.5 to 2.6 MPa), while the elongation at break was reduced by 35% (from 121 to 79%). Additionally, in previous studies, a notable improvement in the mechanical characteristics of the polymers was observed with the integration of organic crystals, specifically involving polyvinyl chloride (PVC) and PLLA [16,30,31].…”

Bioinspired Cyclic Dipeptide Functionalized Nanofibers for Thermal Sensing and Energy Harvesting

“…[25]. In our previous work, we have demonstrated that the incorporation of lead-free organic ferroelectric perovskite N-methyl-N′-diazabicyclo[2.2.2]octonium)-ammonium triiodide (MDABCO-NH4I3) nanocrystals embedded in polyvinyl chloride microfibers [26] and N,N-dimethyl-4-nitroaniline embedded in PLLA microfibers [27] improve the Young's modulus compared to polymer microfibers alone. In this work we demonstrate that not only the Young modulus increases, as well all the mechanical properties measured for Cyclo(L-Trp-L-Trp)@PCL are improved.…”