Juran Noh - Academia.edu (original) (raw)

Papers by Juran Noh

Nature communications, Mar 29, 2024

Solubility of redox-active molecules is an important determining factor of the energy density in ... more Solubility of redox-active molecules is an important determining factor of the energy density in redox flow batteries. However, the advancement of electrolyte materials discovery has been constrained by the absence of extensive experimental solubility datasets, which are crucial for leveraging data-driven methodologies. In this study, we design and investigate a highly automated workflow that synergizes a high-throughput experimentation platform with a state-of-the-art active learning algorithm to significantly enhance the solubility of redox-active molecules in organic solvents. Our platform identifies multiple solvents that achieve a remarkable solubility threshold exceeding 6.20 M for the archetype redox-active molecule, 2,1,3-benzothiadiazole, from a comprehensive library of more than 2000 potential solvents. Significantly, our integrated strategy necessitates solubility assessments for fewer than 10% of these candidates, underscoring the efficiency of our approach. Our results also show that binary solvent mixtures, particularly those incorporating 1,4-dioxane, are instrumental in boosting the solubility of 2,1,3-benzothiadiazole. Beyond designing an efficient workflow for developing high-performance redox flow batteries, our machine learning-guided high-throughput robotic platform presents a robust and general approach for expedited discovery of functional materials. The ability to design materials with targeted functional properties is critical for developing clean energy technology applications and to achieve deep decarbonization of electricity 1,2. However, the conventional trial-and-error methods are costly and time consuming, and realizing new materials-based technologies typically requires 10-20 years of fundamental and applied research 3,4. While data-driven methods based on machine learning (ML) have shown the potential to significantly accelerate the design of new materials for clean-energy technologies 5-9 , their practical applications in materials research are still limited due to the scarcity of large and high-fidelity experimental databases 7,10. Redox flow batteries (RFBs) have been shown as a leading technology to address the intermittent nature of renewable energy sources

Cell Reports Physical Science

Energy storage, Jun 14, 2022

Energy storage, Nov 6, 2022

The primary challenge of salt hydrates as phase change materials (PCMs) is their high degree of s... more The primary challenge of salt hydrates as phase change materials (PCMs) is their high degree of supercooling (∆TSup). Past studies have attempted to alleviate ∆TSup by incorporating nucleators possessing similar lattice structure, without a thorough analysis of the nucleator/PCM interactions. This work presents a novel in‐operando study to visually observe the crystallization process of zinc nitrate hexahydrate (ZNH) in real‐time using suitable nucleators and a thickener. We have introduced a new dataset where zinc acetate dihydrate (ZnAc.2H) has been employed as an additive to ZNH for thermal energy storage (TES). According to our in‐operando study, ZnAc.2H underwent hydrolysis in molten ZNH to precipitate needle‐like ZnO particles, which acted as nucleators for the PCM. In the absence of a thickener, the crystal propagation of ZNH exhibited a preferential directional tendency, whereas incorporation of thickener made the phase change process uniform along all directions. Self‐hydrolysis of ZnAc.2H generated excess water which caused the undesirable effect of broadening the endothermic peak. The addition of carboxymethyl cellulose (CMC) thickener could restrict the activity of excess water and reduce the broadening of the endothermic peak. Differential scanning calorimetry (DSC) revealed that 5 wt% ZnAc.2H additive and 2 wt% CMC thickener added to ZNH can considerably improve the TES properties of ZNH PCM (∆HFusion 125.9 J·g−1, ∆TSup 3.0°C, melting point [M.P.] 29.0°C). Our in‐operando studies can unveil real‐time phase change behaviors to better design PCM systems with desired characteristics.

Journal of energy storage, Aug 1, 2022

Energy Storage

Journal of Energy Storage

한국방사광이용자협회 & 한국고분자학회, Sep 7, 2018

Conjugated polymers, which have a band gap between their valence and conduction bands, can absorb... more Conjugated polymers, which have a band gap between their valence and conduction bands, can absorb energy upon light irradiation with electron excitation from the valence to conduction band. The absorbed energy can be emitted as light or heat, or charge carriers (electrons and holes) can be transferred to surroundings to participate in photocatalytic reactions [1]. When they are in forms of nanomaterials, significantly enhanced luminescence intensity and photostability were expected, in which the conjugated polymer chains can be separated from surrounding continuous, free-flow media as a discontinuous phase, thereby considerably reducing the radiationless decay and photodegradation. The fluorescence quantum yield of conjugated polymer nanoparticles could be 39% in an aqueous medium, which was comparable to that of conjugated polymers dissolved in non-polar solvents (40~50%) but much higher than that of conjugated polymer electrolytes (<5%) [2]. Therefore, the conjugated polymers of nanomaterials forms have attracted significant attention in aqueousbase applications (fluorescence imaging, photoaccoustic imaging, photothermal therapy, and etc.) and photocatalytic reactions (water splitting for hydrogen generation and organic pollutant degradation) [3-7]. In this study, the conjugated polymer nanoparticles made of the conjugated polymer and phospholipids were used to prolong the photostabiliby of the conjugated backbones. The structural studies by the in-situ grazingincidence X-ray diffraction (GIXD) techniques under various temperature and gas conditions will be discussed in detail

RSC Advances, 2022

Assembly films of a phosphocholine-based lipid and a crystalline conjugated polymer had significa... more Assembly films of a phosphocholine-based lipid and a crystalline conjugated polymer had significant CO2 selective adsorption and light absorption due to the attractive interaction of CO2 with exposed polar lipid heads and enhanced morphologies.

Hydrophobic straight pores and super-hydrophilic metal–organic framework (MOF) in the supporting ... more Hydrophobic straight pores and super-hydrophilic metal–organic framework (MOF) in the supporting and active layers reduced flow resistance and improved wettability, raising water permeability with low internal concentration polarization.

ACS Omega, 2021

We present aqueous dispersions of conjugated polymer nanowires (CPNWs) with improved light absorp... more We present aqueous dispersions of conjugated polymer nanowires (CPNWs) with improved light absorption properties aimed at aqueous-based applications. We assembled films of a donor− acceptor-type conjugated polymer and liquid crystalline 4-noctylbenzoic acid by removing a cosolvent of their mixture solutions, followed by annealing of the films, and then formed aqueous-dispersed CPNWs with an aspect ratio >1000 by dispersing the films under ultrasonication at a basic pH. X-ray and spectroscopy studies showed that the polymer and liquid crystal molecules form independent domains in film assemblies and highly organized layer structures in CPNWs. Our ordered molecular assemblies in films and aqueous dispersions of CPNWs open up a new route to fabricate nanowires of low-band-gap linear conjugated polymers with the absorption maximum at 794 nm remarkably red-shifted from 666 nm of CPNWs prepared by an emulsion process. Our results suggest the presence of semicrystalline polymorphs β 1 and β 2 phases in CPNWs due to long-range π−π stacking of conjugated backbones in compactly organized lamellar structures. The resulting delocalization with a reduced energy bang gap should be beneficial for enhancing charge transfer and energy-conversion efficiencies in aqueous-based applications such as photocatalysis.

Journal of Materials Chemistry, 2021

Graphitic carbon materials are commonly used for storing Li ions owing to their outstanding elect... more Graphitic carbon materials are commonly used for storing Li ions owing to their outstanding electrochemical stability and electrical conductivity, and their 3D porous structures are promising for achieving high capacity anodes by depositing Li metal beyond lithiation. However, lithiophobicity and high conductivity of the graphitic surface engender dendrite formation on the outer surface of the electrode rather than inserting Li metal into the pores. Here, we grafted mossy MnO2 uniformly on the entire surface of carbon nanotubes (CNTs), concurrently providing lithiophilic and dendrite-less surfaces. Our MnO2-decorated CNTs can deliver an outstanding performance parameter, which considers both areal capacity and lifetime, over 10 000 mA h2 cm−2, which is the highest to the best of our knowledge, due to a super-long lifetime over 1800 hours for repeated Li plating/stripping at a high areal capacity of 6 mA h cm−2. The striking improvement can be attributed to low overpotential due to s...