3D Bioplotter Research Papers

Displaying all papers by N. A. Shepelin (3 results)

Direct ink writing of dehydrofluorinated Poly(Vinylidene Difluoride) for microfiltration membrane fabrication

Journal of Membrane Science 2021 Volume 632, Article 119347

Here, a hybrid process for the fabrication of dehydrofluorinated PVDF (dPVDF) microfiltration (MF) membranes is presented. dPVDF was fabricated through the bulk modification of PVDF using ethylenediamine. To produce inks for direct ink writing (DIW), the dPVDF was dissolved in N,N-dimethyacetamide along with a pore-forming agent, poly(vinyl pyrrolidone) (PVP) (5–30 wt%, relative to dPVDF concentration). Membranes were produced by direct ink writing of the inks into continuous films – followed by non-solvent induced phase separation (NIPS). Attenuated total reflectance – Fourier transform infrared (ATR-FTIR) and Raman spectroscopies confirmed alkene moieties within the dPVDF polymer, resulting from the dehydrofluorination process. The…

Interfacial Piezoelectric Polarization Locking in Printable Ti3C2Tx MXene-Fluoropolymer Composites

arXiv 2021 Condensed Matter > Materials Science, Article 2101.12211

Piezoelectric fluoropolymers convert mechanical energy to electricity and are ideal for sustainably providing power to electronic devices. To convert mechanical energy, a net polarization must be induced in the fluoropolymer, which is currently achieved via an energy intensive electrical poling process. Eliminating this process will enable the low-energy production of efficient energy harvesters. Here, by combining molecular dynamics simulations, piezoresponse force microscopy, and electrodynamic measurements, we reveal a hitherto unseen polarization locking phenomena of poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE) perpendicular to the basal plane of two-dimensional (2D) Ti3C2Tx MXene nanosheets. This polarization locking, driven by strong electrostatic interactions enabled exceptional energy harvesting…

3D printing of poly(vinylidene fluoride-trifluoroethylene): a poling-free technique to manufacture flexible and transparent piezoelectric generators

MRS Communications 2019 Volume 9, Issue 1, Pages 159-164

Flexible piezoelectric generators (PEGs) present a unique opportunity for renewable and sustainable energy harvesting. Here, we present a low-temperature and low-energy deposition method using solvent evaporation-assisted three-dimensional printing to deposit electroactive poly(vinylidene fluoride) (PVDF)-trifluoroethylene (TrFE) up to 19 structured layers. Visible-wavelength transmittance was above 92%, while ATR-FTIR spectroscopy showed little change in the electroactive phase fraction between layer depositions. Electroactivity from the fabricated PVDF-TrFE PEGs showed that a single structured layer gave the greatest output at 289.3 mV peak-to-peak voltage. This was proposed to be due to shear-induced polarization affording the alignment of the fluoropolymer dipoles without an electric field…