Seunghyun Baik
Sungkyunkwan University, South Korea
Seminar Information
Electrically and thermally conductive polymer-matrix nanocomposites have received considerable attention especially for flexible and stretchable electronics due to the excellent electrical/thermal conductivity and flexibility. The carbon and metal nanoparticles are typically incorporated into the matrix polymer to impart electrical and thermal conductivity due to the intrinsic insulating nature of the polymer. Here we compare two different percolation network mechanisms: particle coalescence vs. electron tunneling [1-7]. We have investigated carbon nanotubes and metal nanoparticles to increase the conductivity based on the particle coalescence mechanism [1-5]. Multi-walled carbon nanotubes with high aspect ratios constructed effective electrical network between micro-scale metal particles, and the contact was improved by the metal nanoparticles functionalized on the surface of nanotubes. This multi-dimensional carbon nanotube-metal nanoparticle architecture successfully increased electrical [1-2] and thermal conductivity [3-5] of various polymer-matrix nanocomposites and fibers. We also developed flower-shaped silver nanoparticles and in-situ reduction method to increase conductivity based on the coalescence mechanism [2, 4, 5]. In contrast, we recently investigated a new electron-tunneling mechanism of hierarchically structured silver nanosatellite particles, without relying on the physical coalescence [6, 7]. The two different approaches will be comparatively discussed together with the recent advance in my laboratory including thermal rectification study [1-8]. References: [1] Chun et al, Nature Nanotechnology, 5, 853 (2010) [2] Ma et al, ACS Nano, 9, 10876 (2015) [3] Suh et al, Advanced Materials, 28, 7220 (2016) [4] Ajmal et al, Small, 15, 1803255 (2019) [5] Ajmal et al, Materials Today, 48, 59 (2021) [6] Suh et al, Nature Communications, 11, 2252 (2020) [7] K.P. Faseela et al, Small, 18, 2104764 (2022) [8] Lee et al, Materials Horizons, 8, 1998 (2021)
Professor Seunghyun Baik has worked at School of Mechanical Engineering at Sungkyunkwan University (SKKU) since 2004. He is also a director of the Center for Nanotubes and Nanostructured Composites. He received his Ph.D. at Department of Mechanical Engineering at University of Wisconsin-Madison in 2001. He worked at Department of Chemical and Biomolecular Engineering at University of Illinois-Urbana-Champaign as a postdoctoral researcher (2001-2004). His recent research interests include carbon/metal nanoparticles, wearable electronics and electrically/ thermally conductive nanocomposites.