https://scholar.dgist.ac.kr/handle/20.500.11750/10154 2026-11-05T05:44:28Z https://scholar.dgist.ac.kr/handle/20.500.11750/61006 Title: Electrodeposited Prussian Blue analogs on carbon nanofiber for electrochemical cesium removal: Transition-metal-dependent intercalation behavior Author(s): Kim, Minsun; Lee, Huisu; Park, Hyunwoong; Kim, Soonhyun Abstract: The development of regenerable electrochemical systems for radioactive cesium removal requires both mechanistic understanding and material optimization. Although Prussian Blue analogs (PBAs) are promising candidates for Cs+ adsorption, the transition-metal-dependent factors governing electrochemical Cs+ intercalation in binder-free electrode architectures remain insufficiently clarified. Herein, binder-free NiFe-, CoFe-, MnFe-, and CuFe-carbon nanofiber (CNF) composites were prepared using metal-specific electrodeposition strategies and subsequently evaluated under the same electrochemical adsorption/desorption conditions to compare their Cs+ uptake and release behavior. Distinct transition-metal-dependent limiting regimes were identified: CoFe-CNF exhibited morphology-limited behavior owing to oversized crystal growth, MnFe-CNF showed a reversibility-limited performance attributed to Jahn-Teller distortion-induced lattice strain, and NiFe-CNF was constrained by achievable deposition loading. CuFe-CNF emerged as a balanced system maintaining controlled morphology, sufficient loading, and stable redox reversibility, delivering maximum Langmuir capacities of 68.6 mu mol center dot cm-2 (electrochemical adsorption, EA) and 85.3 mu mol center dot cm-2 (electrochemical desorption, ED), stable cycling, and favorable separation factors (RL = 0.035-0.423). XPS analysis further revealed an asymmetric redox mechanism, wherein Cu2+/Cu+ reduction drives Cs+ intercalation during adsorption and Fe2+/Fe3+ oxidation governs Cs+ expulsion during desorption, with Fe2+/Fe3+ couple becoming increasingly dominant over repeated cycling. Classification of morphology-, loading-, and reversibility-limited regimes provides a rational design framework, highlighting CuFe-CNF as an optimized platform for sustainable electrochemical cesium remediation. 2026-09-30T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/61005 Title: Motion-Driven Self-Visualizing Soft Robots Enabled by Mechanoluminescent Tubular Fibers Author(s): Lee, Minseok; Song, Seongkyu; Jeong, Soon Moon Abstract: Motion-responsive optical sensing that directly visualizes deformation without external electronics is highly desirable yet remains difficult to implement in pneumatic soft robotic systems. In particular, integrating wired or battery-powered sensors into soft robots composed of low-modulus elastomers is challenging due to the mechanical mismatch between conventional sensors and highly compliant actuators. Here, we present a compliance-matched tubular mechanoluminescent (ML) fiber that enables battery-free visualization of pneumatic soft robot motion through deformation-induced light emission. The ML fiber is fabricated by encapsulating a self-recoverable ZnS:Cu-PDMS composite within an elastic silicone tube, forming a mechanically adaptive architecture that preserves large stretchability while maintaining stable ML responses under repeated deformation. Owing to the intrinsic compliance of the tubular structure, the fiber sustains tensile strains exceeding 200%. When integrated into a pneumatically driven soft robot in a woven network architecture, the ML fibers generate deformation-associated light emission from regions undergoing actuation, enabling qualitative visual monitoring of robotic motion without wiring, signal-processing circuits, or external power sources for sensing. This compliance-engineered ML fiber architecture provides a scalable strategy for embedding self-powered optical sensing into highly deformable soft systems and offers a versatile platform for self-visualizing soft robotics, wearable motion monitoring, and artificial skin interfaces. 2026-08-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60955 Title: K+ for Na+ guest-ion substitution in nickel hexacyanoferrate enables high-rate aqueous sodium-ion storage via thermodynamic defect suppression Author(s): Kang, San Chun; Song, Na Yeong; Kim, Soonhyun; Chung, Chan-Yeup; Chun, Sang-Eun Abstract: Nickel hexacyanoferrate (NiHCF) is a promising cathode material for high-rate aqueous sodium-ion storage, but its rate capability and specific capacity are hindered by water incorporation and ferrocyanide vacancies formed during synthesis. This study demonstrates that these defects can be suppressed by controlling the alkali guest ion (Na+ vs. K+) and chelating agent (citrate) concentration. K+ incorporation under low-citrate conditions reduced water content by 48% compared to Na+, while Fe vacancy remained constant. Under high-citrate conditions, water content and Fe vacancies decreased by 73% and 43%, respectively. The choice of guest ion strongly influences defect suppression when sufficient chelating agent is present. Density functional theory calculations exhibited that water insertion and ferrocyanide vacancy formation are suppressed in K+-substituted NiHCF, consistent with experimental results. NiHCF synthesized with K+ exhibited a rate capability of 82% at current density of 10.0 vs. 0.1 A g(-1), outperforming the 69% of the Na+-intercalated sample. Specific capacity increased from 72 to 80 mAh g(-1) and cycle stability improved from 77% to 83%, reflecting the less water content and reduced ferrocyanide vacancies. These findings underscore that strategic selection of guest ions during synthesis is an effective pathway for improving the high-rate aqueous Na-ion storage behavior of NiHCF cathodes. 2026-07-31T15:00:00Z https://scholar.dgist.ac.kr/handle/20.500.11750/60612 Title: Water-Soluble Self-Assembled Radical Nanoparticles for Deep-Red Fluorescence-Guided Type I/II Photodynamic Therapy Author(s): Li, Zhuo; Dang, Zetao; Cho, Eunkyung; Sun, Qi; Li, Xinru; Li, Yongming; Brédas, Jean-Luc; Coropceanu, Veaceslav; Zhu, Shoujun; Li, Feng Abstract: Organic luminescent radicals with efficient doublet emission can directly transfer electrons and energy to oxygen, enabling fluorescence-guided photodynamic therapy. However, their water insolubility and unclear oxygen interaction mechanisms limit their application. To address these challenges, we synthesized an amphiphilic organic radical (TTM-2PyPh) that forms self-assembled water-soluble nanoparticles (TTM-2PyPh_SA@NPs) with deep-red emission, serving as Type-I/II photosensitizers. Quantum chemistry calculations confirm an efficient electron transfer process between the radicals and oxygen. These nanoparticles self-assemble in vivo, target tumors, and produce reactive oxygen species more effectively than core-shell nanoparticles (TTM-2Py_CS@NPs), chlorin e6, and methylene blue. Additionally, TTM-2PyPh_SA@NPs demonstrate superior tumor eradication in vivo. This work advances the development of novel water-soluble radical-based photosensitizers for enhanced photodynamic therapy. 2026-05-31T15:00:00Z