Publication

Advanced Multifunctional Nanocomposite Lab

Selected Representative Publications

  • 2023
  • Giant thermal rectification efficiency by geometrically enhanced asymmetric non-linear radiation
  • Seongkyun Kim , Taeyeop Kim , Jaehyun Sung , Yongjun Kim , Dongwoo Lee and Seunghyun Baik Materials Horizons
  • Thermal rectification is an asymmetric heat transport phenomenon where thermal conductance changes depending on the temperature gradient direction. The experimentally reported efficiency of thermal rectification materials and devices, which are applicable for a wide range of temperatures, is relatively low. Here we report a giant thermal rectification efficiency of 218% by maximizing asymmetry in …
  • 2022
  • Invariable resistance of conductive nanocomposite over 30% strain
  • C. MUHAMMED AJMAL, SEOKJAE CHA, WONJOON KIM, K. P. FASEELA, HEEJUN YANG, AND SEUNGHYUN BAIK Science Advances
  • The dependence of the electrical resistance on materials’ geometry determines the performance of conductive nanocomposites. Here, we report the invariable resistance of a conductive nanocomposite over 30% strain. This is enabled by the in situ–generated hierarchically structured silver nanosatellite particles, realizing a short interparticle distance (4.37 nm) in a stretchable silicone rubber matr…
In-situ reduced non-oxidized copper nanoparticles in nanocomposites with extraordinary high electrical and thermal conductivity
Author
C. Muhammed Ajmal, Aby Paul Benny, Wonjae Jeon, Seongkyun Kim, Sung Wng Kim, Seunghyun Baik
Journal
Materials Today
Vol
48
Page
59-71
Year
2021
Copper has received considerable attention for conductive nanocomposites as an alternative to costly silver or gold. However, practical application has been impeded by its susceptibility to oxidation in air. Here we report a novel scalable synthesis method of non-oxidized copper nanoparticles (InSituCuNPs) by pre-mixing and in-situ reducing copper formate-(butylamine-octylamine) complex inside soft epoxy matrix. The solid–liquid phase change of the copper formate complex, during the nanocomposite spark-plasma-sintering process, promotes uniform dispersion. Even the outermost atoms of InSituCuNPs are not oxidized since they are surrounded by the thick matrix polymer as soon as in-situ reduced into metallic copper, resulting in high electrical (15,048 Scm−1) and thermal (28.4 Wm−1K−1) conductivities of the nanocomposite. Furthermore, a small addition of 1-dimensional carbon nanotubes decorated with 0-dimensional copper nanoparticles (<4 nm), together with bi-functionalization, dramatically enhances connectivity between the InSituCuNPs, resulting in air-stable and record-high 31,974 Scm−1 and 74.1 Wm−1K−1 for isotropic copper-based nanocomposites. The nanocomposite also provides a small thermal resistance (2.64 × 10−6 m2KW−1) and excellent heat dissipation performance.