Seongkyun Kim , Taeyeop Kim , Jaehyun Sung , Yongjun Kim , Dongwoo Lee and Seunghyun BaikMaterials 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 …
C. MUHAMMED AJMAL, SEOKJAE CHA, WONJOON KIM, K. P. FASEELA, HEEJUN YANG, AND SEUNGHYUN BAIKScience 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…
K. P. Faseela, C. Muhammed Ajmal, Seokjae Cha, Seunghyun BaikAdvanced Functional Materials
Copper (Cu) is an attractive low-cost alternative to silver or gold. However, it is susceptible to oxidation in air. Here, facile in situ regeneration of oxidized Cu flakes (CuFLs) for the synthesis of highly conductive non-oxidized nanocomposites is reported. The oxidized CuFLs are regenerated into non-oxidized CuFLs and Cu nanosatellite (CuNS) particles by formic acid-aided in situ etching and r…
Shabas Ahammed Abdul Jaleel, Taehun Kim, Seunghyun BaikAdvanced Materials
Phase-change materials (PCMs) have received considerable attention to take advantage of both pad-type and grease-type thermal interface materials (TIMs). However, the critical drawbacks of leaking, non-recyclability, and low thermal conductivity (κ) hinder industrial applications of PCM TIMs. Here, leakage-free healable PCM TIMs with extraordinarily high κ and low total thermal resistance (Rt) are…
The detection of dissociated gas species, generated either by plasma or partial discharge, is of great interest because the dissociated species can alter inherent potential of a gas: for example, the insulating characteristics of SF6. Here we report that the sensitivity of carbon nanotubes (CNTs) about dissociated species of SF6 substantially increases by functionalizing with benzene. The sensors were prepared by the dielectrophoretic deposion of CNTs on microelectrodes. The target analytes were chemisorbed on the benzene-functionalized CNTs, and the sensors also could be regenerated by annealing at around 400 °C. The sensor response was analytically described by the modified Langmuir isotherm model. Through the density functional theory calculations, we identified that SOF3 was particularly influential on the electronic structure of the benzene-functionalized CNTs whereas SOF1, SOF2, SO2F2, and HF showed negligible effects. The proposed functionalization methodology provides insight into how to increase sensitivity of carbon nanotube sensors for the detection of dissociated SF6 species.
