Youngho Jin

Aramid-fiber-reinforced epoxy composites are widely utilized in lightweight structural and protective applications; however, their performance is often limited by intrinsically weak and chemically inert fiber–matrix interfaces. Recent advances have shifted attention from conventional surface activation to deliberate interphase engineering, in which chemical functionality, hierarchical structure, and nanoscale reinforcement are integrated to regulate stress transfer and damage evolution. This review provides a comprehensive overview of interfacial design strategies for aramid/epoxy systems, including reactive surface activation, additive interphase construction, bioinspired polydopamine (PDA)-based coatings, and PDA/poly(ethyleneimine)-mediated hierarchical interphases. Particular emphasis is placed on the role of carbon nanotubes and hybrid nanofillers as interphase-active components rather than simple matrix additives, highlighting the importance of their localization, functionalization, and structural integration. This review further examines how interphase architecture influences mechanical responses under multiple loading conditions, including interlaminar shear, impact, tribological wear, viscoelastic behavior, and ballistic loading. Optimal composite performance depends on achieving an appropriate balance between strong interfacial bonding and damage-tolerant deformation mechanisms. By integrating recent experimental and conceptual developments, this review highlights the transition from “surface modification” to “interphase programming” and provides design guidelines for next-generation aramid fiber composites with improved strength, toughness, and multifunctionality.

Accurate molecular identification from mass spectra is essential in analytical workflows, yet conventional library search typically returns the closest match even when the true compound is absent, leading to overconfident false positives. We propose a probabilistic framework that supports both reliable identification of compounds represented in a reference library and model‐based flagging of spectra that may not be adequately represented in the reference library. Spectra are modeled within a Bayesian nonparametric method that does not predefine the number of clusters; instead, the model can allocate new clusters when incoming spectra are insufficiently explained by existing references. This property provides a statistical mechanism for flagging potentially unseen compounds while maintaining coherent grouping of known ones. Experiments on large‐scale electron ionization libraries demonstrate stable performance under diverse noise conditions, consistent grouping of replicate spectra, and the tendency of spectra absent from the reference database to form new clusters. The framework supports reliable identification while reducing forced matches for spectra that are poorly represented in the reference data.

UiO-66-NH2 is an effective material for detoxifying chemical warfare agents (CWAs) due to its high stability and porous structure. In this study, the effects of synthesis parameters on the structural and functional properties of UiO-66-NH2 were systematically investigated using a microwave-assisted approach, which enables rapid crystallization but requires precise control of synthesis parameters within a narrow processing window. Key variables, including reaction time, temperature, modulator concentration, and postsynthetic drying conditions, were controlled to evaluate their effects on the morphology, crystallinity, and porosity of UiO-66-NH2. Comprehensive characterization revealed that modulator-assisted synthesis and optimized activation conditions significantly improved particle size, structural ordering, and accessible microporosity. The optimized sample exhibited well-defined polyhedral crystals and a high Brunauer–Emmett–Teller surface area of 859 m2 g–1. These results highlight that microwave-assisted synthesis operates within a narrow processing window, where precise control of conditions is essential. The detoxification performance was evaluated using a nerve agent simulant under solvent-free (dry) conditions. The optimized sample exhibited excellent performance, achieving approximately 85% degradation of a nerve-agent simulant within 30 min. In contrast, the sample with the largest measured surface area exhibited negligible detoxification activity, suggesting that surface area alone does not reliably predict performance under dry conditions. Instead, the detoxification efficiency appears to be influenced by the accessibility of intrinsic micropores and active sites, as well as the structural integrity of the framework. These findings highlight the importance of controlling the synthesis and activation conditions within microwave-assisted processes and provide a fundamental design principle for metal–organic framework-based detoxification materials in practical solvent-free environments.

Conventional decontamination methods used in urban warfare or terrorist scenarios typically rely on liquid solvents because of their high decontamination efficiency. Nevertheless, gravity causes the liquids to rapidly run off vertical surfaces and ceilings, resulting in short residence times and reduced decontamination efficacy. To address this limitation, viscosity modifiers have been used to improve the retention of decontamination agents. However, highly viscous formulations typically suffer from poor sprayability and are difficult to rinse off, complicating both application and postuse cleanup. Herein, we present a gravity-resistant, fast-acting biofoam enhanced with hydroxyl-rich depolymerized lignin (HDL) derivatives, a sustainable and biodegradable material. HDL was synthesized via hydrothermal treatment, which yielded an 11-fold increase in hydroxyl group content relative to that of native lignin. This increase significantly improved water retention and foam stability. The resulting hydroxyl-rich depolymerized lignin foam (HDLF) adhered to vertical urban surfaces for over 10 min, allowing sufficient contact time for detoxification despite its low viscosity. Foam stability was further enhanced by hydrogen bonding among the hydroxyl groups in HDL. Specifically, HDLF achieved over 90% detoxification efficiency through the hydrolytic degradation of chemical warfare agents and exhibited an environmentally safe end-of-life. Furthermore, it was easily removed from the wall surface, demonstrating that it can overcome the limitations of conventional viscosity-modifier-based decontaminants. This study introduces a high-performance, ecologically compatible formulation for urban detoxification.

Human breathing generates continuous low‐frequency airflow in daily life, which can serve as a naturally available mechanical energy source for wearable energy harvesting without requiring additional user action. Breathing‐driven airflow has attracted attention as an input source for mask‐integrated self‐powered wearable systems. However, breathing‐induced airflow is typically low in intensity (3–6 m/s) and frequency (12–20 breaths/min). Even small structural additions to mask‐based wearables can increase their weight and volume, thereby reducing their wearability. To address these challenges, we developed a mask‐integrated ultralight triboelectric nanogenerator with silver‐coated balls and a discharge‐based power‐generation structure. By coating the expanded polystyrene balls with silver paste, the device maintained metal‐to‐metal contact while minimizing weight. Under breathing‐driven operation, the optimized device produced 22.4 V and 12.8 mA and remained electrically stable over 1 million operating cycles. These results indicate its potential as a compact, lightweight, and comfortable energy harvester for breathing‐based wearable devices.

Chemical warfare agents (CWAs) pose severe threats to human health and the environment because of their extreme toxicity. Conventional liquid-phase decontamination processes can present limitations, including potential equipment corrosion, generation of secondary liquid waste, and increased operational complexity. To overcome these challenges, we report a solar-assisted process intensification strategy for solvent-free decontamination of toxic organophosphorus compounds using UiO-66-NH₂@carbon nanotube (CNT) hybrid platforms. Incorporation of CNTs (optimized at 5 wt%) enables efficient solar-to-thermal conversion, resulting in rapid photothermal self-heating to 85 °C under simulated solar irradiation (1000 W m⁻²). This localized thermal effect contributes to accelerated DMMP removal within the MOF-based hybrid structure, thereby partially alleviating the kinetic limitations typically associated with solvent-free reactions. Consequently, the optimized hybrid achieves 94% removal of dimethyl methylphosphonate (DMMP), a representative sarin simulant, within 10 min under humidity-conditioned, solvent-free conditions, representing a 27% improvement compared with pristine UiO-66-NH₂. This decontamination platform eliminates the need for chemical solvents and external energy input, thereby mitigating secondary contamination and reducing the environmental footprint. By integrating the catalytic framework of Zr-based MOFs with the photothermal capability of CNTs, this study presents a sustainable engineering strategy for advanced defense and environmental protection.

Balancing interfacial shear transfer and damage-tolerant energy dissipation remains a key challenge in high-performance aramid/epoxy composites. In this study, a multiscale interphase engineering strategy was developed by combining polydopamine (PDA)- or polydopamine/poly(ethyleneimine) (PDA–PEI)-modified aramid fibers with carbon nanotube/graphene oxide hybrid fillers in an epoxy matrix. Surface characterization, impact testing, interlaminar shear evaluation, dynamic mechanical analysis, and fracture observations were employed to elucidate how the interphase chemistry and hybrid filler architecture govern the load transfer and failure behavior. The incorporation of hybrid fillers into the neat epoxy matrix alone resulted in a limited performance improvement, whereas their integration within the fiber/interphase architecture led to significantly enhanced composite properties. The PDA-based hybrid system exhibited the most balanced combination of impact resistance, viscoelastic stiffness, and fracture energy dissipation, indicating the formation of an optimized interphase that enabled both efficient load transfer and controlled energy dissipation. In contrast, the PDA–PEI-based interphase exhibited reduced interlaminar shear strength and impact performance despite the increased density of the interfacial functional groups, suggesting the formation of a relatively dense and constrained interphase that limited effective stress transfer and damage tolerance. These results demonstrate that the composite performance is governed by not only increasing interfacial functionalization but also controlling the interplay among interfacial rigidity, molecular mobility, and damage evolution. This study provides a practical interphase design strategy for tailoring the balance between the impact resistance and shear performance in advanced aramid/epoxy composites.

Manganese dioxide (MnO2) is a promising cathode material for aqueous zinc-ion batteries (AZIBs) owing to its low cost and high theoretical capacity. However, its practical application is hindered by sluggish reaction kinetics and structural instability arising from Mn dissolution and irreversible phase transitions during repeated cycling. In this study, an amorphous–crystalline MnO2 (AMC-MnO2) heterostructure is constructed to address these limitations, in which amorphous MnO2 (AM-MnO2) provides abundant active sites and structural flexibility, while crystalline MnO2 (C-MnO2) offers continuous ion diffusion pathways and structural robustness. The heterointerface promotes interfacial charge redistribution, thereby improving the charge-transfer kinetics and structural stability through a buffering effect. Electrochemical analyses revealed that AMC-MnO2 exhibited faster H+ diffusion kinetics than AM-MnO2 and C-MnO2 while maintaining comparable Zn2+ diffusion behavior. Consequently, the AMC-MnO2 electrode delivered enhanced rate capability and superior cycling stability compared with AM-MnO2 and C-MnO2. These findings demonstrate that amorphous–crystalline heterostructure engineering effectively regulates Zn2+/H+ storage behavior and provides a rational strategy for developing high-performance MnO2 cathodes for aqueous zinc-ion batteries.

Breathable membranes that reject chemical warfare agents (CWAs) are required for next‐generation protective apparel. A dual‐function graphene oxide (GO)‐polyamine architecture is introduced that addresses the long‐standing tradeoff between vapor transmission and CWA selectivity. GO‐polymer composite membranes were fabricated on polytetrafluoroethylene (PTFE) supports by pressure‐assisted filtration using ethylenediamine (EDA) to reinforce interlayer cohesion and a branched polyethyleneimine (BPEI) overlayer to introduce additional hydrogen‐bonding sites and charge‐rich domains. Various analytical techniques were used to verify crosslink formation and continuous multilayer architecture. The membranes sustain high water‐vapor transmission (WVTR >7000 g m ^{− 2} day ^{− 1} ) while strongly suppressing dimethyl methylphosphonate (DMMP) permeation; in the GO‐EDA‐PEI configuration no detectable breakthrough is observed. Tests with a live‐GD nerve agent yielded >95% blocking efficiency across all designs and >99% for GO‐EDA‐PEI, supporting effective protection across both vapor‐ and condensed‐phase exposure regimes. Under hydration and sonication stresses, EDA crosslinking together with the BPEI capping layer maintains high vapor permeability with strong CWA suppression, without the formation of dense polymer skins that typically compromise breathability. These results demonstrate that GO‐polymer composites can couple selective CWA resistance with high vapor transport and operational robustness, meeting practical requirements for protective garments and offering a scalable route to breathable barriers.