https://scholarworks.unist.ac.kr/handle/201301/116 2026-05-12T16:10:40Z https://scholarworks.unist.ac.kr/handle/201301/91670 Title: Mechanochemistry drives the mild activation of stable small molecules Author(s): Guan, Runnan; Zhang, He; Li, Changqing; Baek, Jong-Beom Abstract: Runnan Guan is a postdoctoral research fellow in the School of Energy and Chemical Engineering/Center for rea. He received his PhD degree from the University of Science and Technology of China in 2021. His research interests focus on mechanochemistry-driven small-molecule conversions. He Zhang received her PhD degree from the University of Science and Technology of China in 2025. She is currently working as a postdoctoral research fellow in the School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology, South Korea. Her research interests are energy-related smallChangqing Li received his PhD degree from the School of Energy and Chemical Engineering at the Ulsan National Institute of Science and Technology, South Korea, under the supervision of Prof. Jong-Beom Baek. He subsequently joined the same department as a postdoctoral researcher. His research focuses on the design and development of nanostructured functional materials for sustainable energy and environmental applicaJong-Beom Baek received his PhD degree from the University of Akron (USA, 1998). He is currently a distinguished professor/director of the Department of Energy and Chemical Engineering/Center for Dimension was elected as a member of the Korean Academy of Science and Technology in 2021. His current research interests include the mechanochemical synthesis of materials for sustainable applications. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91669 Title: Subporphyrin Frameworks: A Missing Link Between Porphyrinoids and Porous Aromatic Networks Author(s): Zhao, Liufang; Liu, Panpan; Zhao, Yuling; Li, Zhiyong; Wang, Huiyong; Zhao, Yang; Qiu, Jikuan; Li, Zhongping; Baek, Jong-Beom; Wang, Jianji Abstract: Subporphyrins represent a distinctive class of bowl-shaped, pi-conjugated, and intrinsically electron-deficient macrocycles that exhibit photophysical and coordination behaviors unlike those of planar porphyrins. While current studies have primarily focused on the synthesis of subporphyrins with an increased number of aromatic rings and complex heterostructures, research on polymeric subporphyrin materials has not yet been reported. Herein, we report the first subporphyrin-based porous aromatic networks (PAF-HNU1 and PAF-HNU2) synthesized by coupling meso-functionalized subporphyrins with rigid aromatic linkers under solvothermal conditions. The frameworks exhibit extended pi-delocalization and strong red-shifted absorption covering the UV-vis-NIR region, enabling efficient full-spectrum light harvesting. It was discovered that PAF-HNU2 exhibited high photogenerated charge separation and transport capabilities, as well as outstanding catalytic efficiency for a series of advanced oxidation reactions. Performance was two to three times that of PAF-HNU1 and its porphyrin-based PAF analogues. This work introduces a new family of subporphyrinic porous materials, providing the missing link between porphyrinoid chemistry and extended pi-conjugated frameworks, and highlights their potential as a metal-free platform for next generation full-spectrum photocatalytic transformations. 2026-03-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91657 Title: Analysis of volatile organic compound droplets via wetting and evaporation using inkjet-printed carbon nanotube chemiresistors Author(s): Lim, Seongyeop; Park, Sanghwan; Moon, Seung Min; Lee, Seongwoo; Lee, Chang Young Abstract: Volatile organic compounds (VOCs) are prevalent in food, environmental, and industrial systems, yet their liquid-phase analysis is often limited by bulky instrumentation and operational complexity. Here, inkjet-printed carbon nanotube (CNT) chemiresistors on paper are presented as a simple and accessible platform for analyzing microliter-scale droplets of VOCs and their binary mixtures. Upon droplet deposition, the device exhibits a characteristic resistance peak: an initial increase due to wetting, followed by a decrease as evaporation and desorption from CNTs become dominant. The time from droplet dispensing to the resistance peak, defined as the turnover time, shows strong correlation with the vapor pressure of VOCs, enabling compound differentiation. Analysis of binary mixtures, including ideal (benzene-toluene) and non-ideal (acetone-chloroform, benzene-methanol) systems, reveals information on intermolecular interactions. In addition, time-resolved turnover time measurements during evaporation allow tracking of compositional shifts, exemplified by the gradual enrichment of the less volatile component as the more volatile species evaporates. The method is further demonstrated using alcoholic beverages with varying ethanol concentrations, highlighting its applicability to real liquid samples encountered in practical settings. These results establish turnover time of CNT-based chemiresistors as a valuable metric for probing wetting, evaporation, and molecular interactions in multicomponent liquid systems, with potential applications in chemical sensing, environmental analysis, and quality control. 2026-07-31T15:00:00Z https://scholarworks.unist.ac.kr/handle/201301/91654 Title: Side-Chain Branching Dictates the σ-S Coupling in Conjugated Polymer Thermoelectrics Author(s): Zhang, Yingyao; Kang, So-Huei; Chen, Po; Xie, Huadeng; Zhang, Qinfang; Kim, Seoyoung; Won, Donghoo; Zhang, Zilong; Li, Chi; Liu, Liang; Zhu, Qi; Wu, Feiyan; Chen, Lie; Keshavarzia, Reza; Yang, Changduk; Gao, Peng Abstract: Understanding the intrinsic coupling between electrical conductivity (sigma) and the Seebeck coefficient (S) remains a central challenge in organic thermoelectrics, where energetic disorder and charge transport are highly sensitive to molecular design. Here, we show that precise control over the side-chain branching position provides an effective structural lever to tune the sigma-S relationship in conjugated polymers. Two DPP-selenophene copolymers with identical backbones but branched at distinct positions exhibit markedly different molecular packing, charge-carrier delocalization, and density-of-states (DOS) widths. Polymers with more distant branching points form tighter pi-pi stacks, yielding enhanced carrier mobility and a narrower DOS that collectively boost sigma to 129.3 S cm- 1. In contrast, closer branching induces greater energetic disorder and broader DOS distributions, resulting in a substantially higher S of 160 & micro;V K- 1. Despite their contrasting transport characteristics, both polymers deliver similar peak power factors owing to complementary changes in sigma and S. These results identify side-chain branching as a previously underappreciated design parameter that mechanistically governs the coupling between conductivity and Seebeck coefficient in organic thermoelectric materials. 2026-03-31T15:00:00Z