Korean Journal of Chemical Engineering最新文献

Furcellaran (FUR) is a polysaccharide extracted from red algae with excellent film forming abilities. Meanwhile, carboxymethyl cellulose (CMC) is a polymer derived from cellulose and possesses desirable characteristics like non-allergen and fracture resistance. Blending these two complementary polymers can contribute to the preparation of sustainable materials with improved properties and meet the pillars of Sustainable Development Goals (SDGs). On the other hand, the absence of antioxidant and antibacterial capabilities shall restrict the potential use of these materials in several fields such as biomedical applications and packaging. Herein, FUR/CMC films incorporated with different amounts of carbon quantum dots synthesized from Cynara Scolymus (artichoke leaves, arti-CQDs) were prepared by solvent casting. The UV shielding properties were highly improved, the hydrophobicity was increased and equilibrium swelling ratio was decreased in FUR/CMC/arti-CQD films depending on the amount of polycrystalline structured arti-CQD. The Young’s modulus decreased, and more flexible films were obtained. The FUR/CMC/arti-CQD films displayed excellent antioxidant properties and antibacterial activity towards Gram-positive (S. aureus and L.monocytogenes) and Gram-negative (E.coli) bacteria depending on arti-CQD amount. The antibacterial FUR/CMC/arti-CQD films were non-toxic towards L 929 mouse fibroblasts. It is concluded that FUR/CMC/arti-CQD films have notable potential as bioactive, sustainable, and renewable materials.

We report a volatile organic compound (VOC) sensing platform based on electrospun nanofibers of a single-component PFO–quinoxaline donor–acceptor copolymer, in which donor and acceptor units are covalently integrated within one conjugated chain. Unlike multicomponent systems governed by intermolecular geometry, this design enables VOC-responsive modulation of intrinsically defined excited-state energy flow and charge-transfer photophysics. By tuning the PFO/QX composition, the copolymer showed systematic changes in emission color and lifetime, reflecting composition-dependent donor-to-acceptor interactions. When processed into nanoporous electrospun nanofibers, these chain-level photophysical responses became strongly amplified by enhanced analyte accessibility and nonequilibrium chain packing. In particular, the 95:5 composition exhibited distinct blue-to-green emission changes, red-shifted photoluminescence, and shortened fluorescence lifetimes upon exposure to chloroform and tetrahydrofuran vapors, whereas spin-coated films showed only minor responses. These results show that VOCs can directly perturb the photophysical balance within a molecularly integrated donor–acceptor copolymer and demonstrate a simple strategy for visually readable optical gas sensing based on single-chain electronic structure and nanofiber morphology.

High water content in sludge has consistently posed a significant challenge in sludge treatment processes. As an effective approach for sludge dewatering, ultrasound treatment induces cavitation effects, mechanical vibration, and thermal effects to rapidly disrupt sludge floc structures and release bound water, with sonication energy density and ultrasonic duration serving as key control parameters that ultimately determine dewatering efficiency. This study identified the optimal sonication energy densities and ultrasonic durations for sludge volumes of 500 ml, 750 ml, 1000 ml, 1250 ml, and 1500 ml as 0.161 W/ml, 0.165 W/ml, 0.171 W/ml, 0.177 W/ml, 0.180 W/ml and 31s, 33s, 34s, 37s, 41s, respectively. Comprehensive analyses including WC, SRF, viscosity, particle size distribution, SEM, FTIR, and NMR were conducted on sludge samples of different volumes under these optimal ultrasonic conditions. The results demonstrated that while ultrasound treatment significantly reduced WC compared to raw sludge across all volumes, the degree of reduction varied with sludge volume. As sludge volume increased, the required ultrasonic intensity and duration increased accordingly, with the improvement in water reduction showing an initial enhancement followed by a gradual decline. The study established optimal sonication energy densities and durations for different sludge volumes, investigated the variations in WC and specific resistance to filtration under optimal ultrasonic conditions, examined the relationship between sonication energy density, ultrasonic duration, and sludge volume, and provided mechanistic insights through microscopic and spectroscopic analyses. These findings offer valuable guidance for industrial-scale sludge treatment by identifying appropriate ultrasonic conditions to enhance sludge reduction efficiency for large-volume applications.

Graphite anodes have limited current density performance, which restricts their application in fast-charging lithium-ion batteries (LIBs). In this study, fluorinated pitch-derived carbon sheets (FPCS) were synthesized from petroleum pitch using a NaCl template followed by NF₃ plasma treatment. The NaCl template process generated thin, two-dimensional (2D) carbon sheets with wide interlayer spacing, shortening the diffusion path for lithium-ions. Subsequent NF₃ plasma treatment introduced fluorine functional groups, forming semi-ionic C–F bonds, which promoted the formation of a LiF-rich solid electrolyte interphase, enhancing interfacial stability and ion transport. As a result, the FPCS exhibited a capacity of 210 mAh/g at 5 A/g, representing a 37% increase over the raw sample. Furthermore, it demonstrated excellent cycling stability, maintaining a capacity of 190 mAh/g, even after 250 cycles at a current density of 1 A/g. These results demonstrate that the synergistic effect of template-assisted 2D structure and plasma fluorination enhances ion transport and interfacial stability, presenting a practical strategy for high-rate LIBs.

A novel adsorptive removal system (ARS) based on a graft copolymer was developed for the efficient elimination of anticancer drugs from aqueous solutions. The copolymer (MGO-g-GMA) was synthesized via free-radical polymerization of glycidyl methacrylate (GMA) onto magnetic graphene oxide (MGO) using 3-(trimethoxysilyl)-1-propanethiol as a chain-transfer agent and 2,2′-azobisisobutyronitrile as the initiator. To enhance the adsorption performance, β-cyclodextrin was covalently immobilized through an epoxy ring-opening reaction, forming a host–guest functional architecture. Gemcitabine was selected as the model drug, and the adsorption process was optimized using response surface methodology based on a Box–Behnken design. Under optimal conditions (adsorbent dosage: 0.0197 g, pH 6.57, temperature: 25.40 °C, contact time: 7.22 min), a maximum adsorption capacity of 844.51 mg g⁻¹ was achieved at an initial concentration of 1000 mg L^− 1. Thermodynamic and isotherm analyses revealed a spontaneous, exothermic, and predominantly monolayer adsorption process governed by physical interactions, whereas mass transfer analysis identified intraparticle diffusion as the main rate-limiting step. The ARS exhibited excellent reusability, retaining approximately 90% and 75% of its initial efficiency after six and ten cycles, respectively. The application of the adsorbent to real hospital wastewater resulted in 94.2% gemcitabine removal and an 87% reduction in total dissolved solids, confirming its effectiveness in complex matrixes. Cytotoxicity assays on L-929 fibroblast cells demonstrated negligible toxicity and high biocompatibility of ARS. Overall, the developed ARS is a highly efficient, magnetically separable, reusable, and biocompatible adsorbent with a strong potential for the removal of anticancer drugs from aqueous solutions.

The accessibility of conventional fire suppression equipment is limited in specialized environments such as high-rise buildings and underground facilities. Although gas-hydrate-based suppressants offer potential advantages through their compact design and effective dispersion, systematic techno-economic and environmental evaluations remain limited. In this study, the techno-economic performances of CO₂, HFC-125, and HFC-23 hydrate-based fire suppression systems were analyzed using an Aspen Plus V14 process simulation. An integrated assessment combining production and environmental costs, as well as specific energy consumption (SEC), was conducted to evaluate their practical viability against conventional suppressants. In particular, CO₂ hydrate-based fire suppression demonstrated the most favorable economics, with production and suppression costs of $0.52/kg and $0.6/m³, respectively, rendering it competitive among conventional suppressants. The HFC-125 hydrate achieved the highest energy efficiency (SEC = 0.008 kWh/kg) and superior fire suppression performance; however, its production cost ($1.36/kg) limits current competitiveness. Moreover, the HFC-23 hydrate showed limited economic viability. This study provides a systematic techno-economic assessment framework that integrates economic viability, energy efficiency, and environmental impact. Consequently, the developed framework establishes comprehensive evaluation criteria for hydrate-based fire suppressants related to conventional suppression systems.

In conventional lithium-ion battery (LIB) manufacturing, N-methyl-2-pyrrolidone (NMP) is commonly used as a solvent for slurry-based cathode fabrication, despite its high cost and environmental burden. To overcome these limitations, NMP-free electrode fabrication strategies have been proposed as practical alternatives. In this study, NMP-free electrodes were fabricated using three different mixing methods and two binder systems, including powder-based processing and a solvent-assisted PTFE fibrillation approach employing low-toxicity volatile solvents. The electrochemical performance of the electrodes was evaluated through galvanostatic charge–discharge testing and differential capacity (dQ/dV) analysis. The solvent-assisted PTFE-based electrode exhibited reduced surface roughness, low irreversible capacity, and stable cycling behavior, whereas powder-based electrodes showed increased irreversible capacity and accelerated degradation. Differential capacity analysis revealed that in NMP-free electrode systems, the electrode morphology is governed by the combined effects of mixing strategy, binder system, and fabrication process, which together influence interfacial stability and electrochemical behavior. These results demonstrated that mixing strategy and binder behavior played critical roles in determining the performance of NMP-free electrodes, providing practical insights for cost-effective and high-areal-capacity LIB fabrication.

Liquid organic hydrogen carriers (LOHCs) have emerged as promising media for hydrogen storage and transport owing to their high hydrogen content and compatibility with existing infrastructure. However, the catalytic efficiency of Ru-based catalysts in LOHC hydrogenation is strongly influenced by the properties of their support materials, which remain insufficiently explored. In this study, Ru nanoparticles were supported on four different metal oxides (Al₂O₃, TiO₂, ZrO₂, and SiO₂) synthesized via a combined sol–gel and ultrasonic spray pyrolysis (USP) process, providing continuous processes amenable to large-scale production. The resulting metal oxide supports exhibited diverse physicochemical characteristics, including variations in surface area, surface hydroxyl group concentration, and metal–support interaction strength. The Ru-supported catalysts were systematically evaluated for the hydrogenation of monobenzyl toluene (MBT), a model LOHC compound. Catalytic activity followed the trend: Ru/Al₂O₃ > Ru/TiO₂ > Ru/SiO₂ > Ru/ZrO₂. The findings reveal that MBT hydrogenation performance is governed by the synergistic interplay of multiple support characteristics rather than any single factor. This work provides an informative direction for the rational design of high-performance LOHC hydrogenation catalysts.

The global water shortage has increased the importance of seawater desalination technologies, with reverse osmosis (RO) emerging as the most widely used process. However, the performance of RO membrane modules is significantly influenced by the trade-off between concentration polarisation and pressure drop, both of which are strongly affected by the geometry and arrangement of spacers. In this study, a computational fluid dynamics (CFD)-based surrogate model was developed to quantitatively capture the influence of spacer geometry on RO performance and subsequently integrated into module- and process-level simulations. Process-level economic optimisation was performed as a demonstration of the proposed framework. Water and salt fluxes at the membrane surface, as well as the pressure drop, were obtained from three-dimensional CFD simulations at the unit-cell level. These results were generalised into regression-based surrogate models and integrated with process models at the module and stage levels. Subsequently, optimal operating conditions were determined to minimise freshwater cost. The analysis showed that freshwater cost converged within a narrow range of approximately 0.62–0.63 $/m³, depending on the spacer geometry, while the resulting process configurations varied significantly (e.g., total module counts ranging from 1,981 to 2,193). Through this framework, spacer effects can be explicitly incorporated into process-level models, where they are typically treated as fixed constants (e.g., mass transfer coefficients and friction factors) in simplified mathematical models.

A radical-scavenging extender is investigated as a novel strategy for improving the chemical stability of anion exchange membranes (AEMs). Unlike typical alkyl chain extenders used in AEMs, the bulky piperidine derivative 2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO), which possesses a redox-active core structure, improved the chemical stability of AEMs by serving as both a radical scavenger and a chain extender. Reactive oxygen species (ROS), such as hydroxyl and superoxide radicals (∙OH and ∙O₂^–), which contribute to AEM degradation, were efficiently scavenged through the reversible TEMPO/TEMPO⁺ redox cycle. Simultaneously, the bulky TEMPO moiety also increased steric hindrance around the quaternary ammonium groups, thereby suppressing hydroxide-induced S_N2 degradation by hindering nucleophilic attack of hydroxide ions on the α-carbon adjacent to the ammonium group. As a result, the QPPO-35-TEMPO membrane exhibited much greater chemical stability than QPPO-25-TMA, QPPO-30-DMHA, and QPPO-35-DATMP, confirming the effectiveness of the radical-scavenging-extender concept. QPPO-35-TEMPO retained its ionic conductivity after 500 h in 1 M KOH at 80 °C and achieved a current density of 3.69 A cm^–2 at 2.0 V in alkaline water electrolysis and a peak power density of 0.49 W cm^–2 in fuel cells. When applied as an anode ionomer, QPPO-35-TEMPO further improved the electrode performance. This work establishes the radical-scavenging-extender concept as a promising molecular design strategy for developing chemically durable and high-performance AEMs for alkaline electrochemical energy technologies.