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…
We presented a feasible framework of studying dynamics of macromolecules by applying elastic network model (ENM) and vibration spectroscopy. We first identified the precise force constants of covalent bonds commonly observed in macromolecules by matching their reported Raman shifts data with predicted wavenumbers determined by normal mode analysis (NMA). Assigning the obtained spring constants to other small chemical compounds such as ethynyl isocyanide (C3HN) and diacetylene (C4H2), we not only predicted their vibration wavenumbers precisely but also identified their individual mode shapes from NMA. We extensively tested this chemical information based ENM with one of amino acids, cysteine. Subsequent comparison of frequencies and modeshapes also yields a strong agreement between computed and experimental data. Consequently, the proposed method enables us to identify low frequency modeshapes that are in general functionally important collective motions of macromolecules but have hardly been revealed experimentally even using terahertz spectroscopy.
