Bio-Inspired Macromolecular Ordering in Elastomer Composites to Achieve Enhanced Contact Electrification
2022 MRS Fall Meeting & Exhibit Abstracts 2022
Andris Šutka, Linards Lapčinskis, Osvalds Verners, Līva Ģērmane, Juris Blūms

Polymer contact electrification (a.k.a. triboelectrification) is crucial for mechanical energy harvesting in triboelectric nanogenerators (TENG), droplet generators, and ferroelectrets [1]. Polymer triboelectrification can be enhanced in several ways, including surface functionalization, adjustment of the electronic and physicochemical properties or by increasing the specific contact area via nanostructuring. Contact electrification can be observed also in nature. Spider ballooning is one of the most exciting natural phenomena. Using electrified strands of silk, spiders can travel in the airstream for distances of hundreds of kilometers [2]. Spider silk is electrified due to contact and friction with airborne particles or during the spinning process. A strong surface charge is required to ensure the electrostatic flight, holding the weight of a spider even in the absence of any air stream. This work presents triboelectric polymer composites with structure inspired by the macromolecule ordering in spider-silk leading to strongly enhanced contact electrification. The ordering in polyether block amide (PEBA) is induced by the addition of inorganic goethite (α-FeOOH) nanowires that form hydrogen bonds with the elastomeric matrix. The addition of as little as 0.1 vol% of α-FeOOH into PEBA increases the surface charge by more than order of magnitude. Hydrogen bonds between α-FeOOH and PEBA promote the formation of inclusions with higher degree of macromolecular ordering, analogous to the structure of spider silk. The formation of these inclusions is proven via nanoindentation hardness measurements, and correlated with H-bond induced changes in structure shown by fourier transform infra-red spectroscopy, and direct scanning calorimetry. Theoretical studies reveal that the irregularity in hardness provides stress accumulation on the polymer surface during contact-separation. Subsequent molecular dynamic studies demonstrate that stress accumulation promotes the mass-transfer during contact electrification. The proposed macromolecular structure design provides a new paradigm for developing materials for applications in mechanical energy harvesting. References [1] B. -Y. Lee, D. H. Kim, J. Park, K. -I. Park, K. J. Lee, C. K. Jeong, Sci. Technol. Adv. Mater. 2019, 20, 758. [2] E. L. Morley, P. W. Gorham, Phys. Rev. E 2020, 102, 012403.


Keywords
Triboelektriskais efekts, polimēri, statiskais lādiņš, enerģijas savākšana

Šutka, A., Lapčinskis, L., Verners, O., Ģērmane, L., Blūms, J. Bio-Inspired Macromolecular Ordering in Elastomer Composites to Achieve Enhanced Contact Electrification. In: 2022 MRS Fall Meeting & Exhibit Abstracts, United States of America, Boston, 27-2 November, 2022. ASV: 2022, pp.1137-1137.

Publication language
English (en)
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