Spider Silk Inspired PEBA/Goethite Nanocomposite for Stronger Triboelectrification
2022 International Symposium on Polymer Nanocomposites (ISPN2022) 2022
Andris Šutka, Linards Lapčinskis, Līva Ģērmane, Osvalds Verners, Juris Blūms

Polymer triboelectric charging takes a critical role in mechanical energy harvesting by triboelectric nanogenerator (TENG) devices [1]. In order to boost the performance of TENG devices, the researchers aim to magnify the triboelectric charge on polymer surface. To enhance the polymer triboelectrification, several approaches have been used, such as surface functionalization [2], choosing the proper polymer couple by taking the triboelectric series as guidance [3], or increasing the specific contacting area via nanostructuring [4, 5]. However, these approaches have their limits such as low durability, limited enhancement or high cost and low scalability. In nature, strong triboelectrification in streams of air dusts is presented by spider silk [6]. The electrification of threads provides spider ballooning at distances measurable in thousands of kilometers [7]. The spider silk structure is composed from highly ordered macromolecular inclusions enclosed within a soft elastomeric matrix [8]. Herein we are mimicking the spider silk structure by adding nanoparticles to thermoplastic poly(ether-block-amide) (PEBA) elastomer. It is well known that the interphase, a region surrounding the inclusions where the properties differ from the bulk, is forming in nanoparticle-reinforced polymers [9]. The interphase show higher degree of macromolecular ordering and hardness. In the present study we observe more than order of magnitude increase of surface contact charge for PEBA composites with small addition (0.1 vol%) of goethite α-FeOOH nanowires. The surface of goethite is densely covered by hydroxyl groups (–OH), thus ensuring sites for hydrogen bonding [10]. Nanoindentation measurements reveal the differentiation in hardness, but theoretical studies show that the increase in surface triboelectrification is due to this irregularity which enhances the stress accumulation and reduce the potential energy for heterolytic covalent bond break and material transfer. Magnified material transfer was also confirmed by AFM studies.


Keywords
Triboelectric, mechanical energy harvesting

Šutka, A., Lapčinskis, L., Ģērmane, L., Verners, O., Blūms, J. Spider Silk Inspired PEBA/Goethite Nanocomposite for Stronger Triboelectrification. In: 2022 International Symposium on Polymer Nanocomposites (ISPN2022), France, Lorient, 28-30 September, 2022. Lorient: 2022, pp.1-2.

Publication language
English (en)
The Scientific Library of the Riga Technical University.
E-mail: uzzinas@rtu.lv; Phone: +371 28399196