Article
Multidisciplinary Sciences
Ke-Qing Xiao, Oliver W. Moore, Peyman Babakhani, Lisa Curti, Caroline L. Peacock
Summary: Minerals have been proposed to protect organic carbon from degradation, but the mechanism behind this is not well understood. This study found that clay minerals in marine surface sediment strongly adsorb methylamines, reducing their concentration in the dissolved pool. The presence of clay minerals also slows methane production and reduces the final methane produced. X-ray absorption spectroscopy revealed that reversible adsorption and occlusive protection of methylamines in clay interlayers are responsible for the decrease in methane production. This research highlights the importance of mineral-organic carbon interactions in controlling methane production in marine sediments and provides new insights into the role of adsorption in methane cycling.
NATURE COMMUNICATIONS
(2022)
Article
Geochemistry & Geophysics
Sandra Fernandez-Landero, Juan Carlos Fernandez-Caliani
Summary: Glaucony is a significant green marine facies in the northwestern passive margin of the Guadalquivir Basin, formed on a sediment-starved continental shelf. The mineral composition and chemical maturity of glauconite are remarkably heterogeneous, reflecting a complex interaction of micro-environmental factors, substrate influences, and post-depositional alterations. The glauconitization process starts with the slow precipitation of a Fe-rich smectite phase, evolving into a regularly interstratified glauconite-smectite.
Article
Energy & Fuels
Gustavo A. B. Sandoval, Marcio Couto Ozorio, Monica F. Naccache, Paulo R. de Souza Mendes, Amadeu K. Sum, Leandro Valim, Adriana Teixeira
Summary: This work presents a rheological analysis of cyclopentane hydrates formed in water-in-oil emulsions, investigating the influence of parameters such as pretreatment temperatures and cooling/heating rates. The study shows that the resulting hydrate slurry exhibits elasticity and shear thinning behavior, likely caused by breakdown of hydrate structures and alignment of hydrate agglomerates to the flow.
Article
Energy & Fuels
Zhixue Sun, Yifan Yin, Yuqi Wu, Zhilei Sun, Linqi Zhu, Yuting Zhan, Vahid Niasar, Senyou An
Summary: The formation and dissociation of hydrate at the pore scale can be qualitatively observed using μ-CT X-ray imaging, but a quantitative criterion for hydrate pattern is lacking in the literature. This study fills this research gap by generating numerically-simulated sediments with specific hydrate patterns and accurate saturation levels. A quantitative criterion for microscopic classification of hydrates based on pore and hydrate topology was proposed. The study also analyzed the 3D distribution and dynamic evolution of hydrate, as well as the variation of permeability and tortuosity under different saturation levels.
Article
Chemistry, Multidisciplinary
Ningru Sun, Yanjun Li, Nianxiang Qiu, Shiyu Du
Summary: This article investigates the structural and mechanical properties of some nitride gas hydrates using DFT calculations. The equilibrium lattice structure, complete second-order elastic constants, and polycrystalline elasticity are determined. It is found that NH3, N2O, and NO hydrates exhibit high elastic isotropy but differ in shear characteristics. The study provides a theoretical foundation for understanding the structural evolution of clathrate hydrates under mechanical conditions.
Article
Geosciences, Multidisciplinary
Ahmed Mohamed
Summary: The study found that by treating the clays from the Dakhla Formation with different concentrations of potassium bromide and potassium chloride, their structure can be altered, and the transformation rate is directly proportional to K+ ion concentration. By treating the clays under specific conditions, their ceramic properties can be enhanced, making them more suitable for brickmaking.
JOURNAL OF AFRICAN EARTH SCIENCES
(2021)
Article
Engineering, Mechanical
Lei Hao, Xinrui Zhao, Chengcheng Zhang, Lei Wang, Hong Xu, Jinxiang Dong
Summary: In this study, pure smectite was synthesized and used as a thickener for lubricating grease. Compared to natural smectite, synthetic smectite demonstrated superior rheological and tribological properties. It showed higher energy storage modulus, better thixotropy, and more stable tribological behavior. The convenient synthetic method and promising potential make synthetic smectite a suitable grease thickener for demanding applications in various industries.
TRIBOLOGY INTERNATIONAL
(2023)
Article
Chemistry, Applied
Mihkel Saluri, Kadri-Liis Kaljuvee, Tiina Paalme, Indrek Reile, Rando Tuvikene
Summary: Furcellaran samples extracted from both drifting and attached forms of red algae Furcellaria lumbricalis collected from the Estonian waters were characterised and their properties were examined. Results showed the presence of sulphate ester groups, nearly equimolar amounts of beta- and kappa-carrageenans, and higher molecular weights for samples extracted from attached specimens. The gels formed by furcellaran samples exhibited decreased storage moduli with reduced KCl concentrations, and had a significant degree hysteresis in certain conditions.
FOOD HYDROCOLLOIDS
(2021)
Article
Construction & Building Technology
Ricarda Sposito, Matthias Maier, Nancy Beuntner, Karl-Christian Thienel
Summary: This study investigates the impact of calcined clays on the flow properties of blended cement paste. The demand for superplasticizers increases significantly due to the particle size, water demand, and negative zeta potential of calcined clays. The presence of muscovite in raw clay is critical as it increases water demand, yield stress, and viscosity. The addition of industrial polycarboxylate-based superplasticizers shows good dispersion except for metamuscovite.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Energy & Fuels
Weiguo Liu, Ran Liu, Mengmeng Zhang, Zaixing Liu, Chen Lang, Yanghui Li
Summary: Solid fluidization is a promising method for exploring hydrate resources. The rheological properties of hydrate slurry play a significant role in preventing blockages during pipeline transportation. This study found that the presence of hydrate substantially increases the apparent viscosity of mudflow, with higher water conversion rates leading to significantly increased viscosity of hydrate slurry.
Article
Energy & Fuels
Parisa Naeiji, Mengdi Pan, Manja Luzi-Helbing, Saman Alavi, Judith M. Schicks
Summary: A study was conducted to investigate the dissociation behavior of methane hydrates under different temperature and pressure conditions. Both experimental and simulated data showed that the behavior differed above and below the freezing point of water. At temperatures near or below freezing, CH4 hydrates exhibited self-preservation behaviors due to the formation of a quasi-liquid or amorphous phase at the outer layers of the hydrate crystal. Above the freezing point, dissociation appeared to initiate at the surface of the hydrate phase.
Article
Chemistry, Multidisciplinary
Pinqiang Cao, Jianlong Sheng, Henrik Andersen Sveinsson, Jianyang Wu, Fulong Ning
Summary: This study explores the effects of external static electric fields on the structural instability and mechanical properties of methane hydrates using molecular dynamics simulation methods. The results show that strong electric fields can distort and dissociate local water cages in methane hydrates, weakening their mechanical properties. Instability failure modes are attributed to reorientations of water molecules and molecular diffusions.
CRYSTAL GROWTH & DESIGN
(2022)
Article
Thermodynamics
Lingli Shi, Junhui Li, Yong He, Jingsheng Lu, Zhen Long, Deqing Liang
Summary: Memory effect plays an important role in enhancing the formation rate of hydrates and increasing the efficiency of industrial applications. The strength and mechanism of memory effect were investigated through methane hydrate reformation experiments under different conditions. The results showed that the memory effect was not strengthened with an increase in repeated times, but varied with different initial pressures and gas-water ratios. A mechanism involving residual water lattice or super-saturated gas nano-bubbles was proposed for systems with relatively high or low initial pressures, respectively.
Article
Multidisciplinary Sciences
B. P. Kagonbe, D. Tsozue, A. N. Nzeukou, S. I. I. I. I. I. I. Ngos
Summary: The clayey materials from northern Cameroon show characteristics suitable for the manufacture of earthenware products, with properties such as red color after firing, significant variations in particle size, high plasticity, and gradual increases in linear shrinkage values, weight loss, and bulk density after firing.
Article
Chemistry, Multidisciplinary
Feng Zhang, Hao Ni, Yi Wang, Fujun Xia, Baojun Wei, Xuefeng Liu
Summary: By using classical molecular dynamics simulations, the mechanical stability of CO2-N2 heteroclathrate hydrates (CNHHs) under uniaxial loading was investigated. The ratio of CO2 to N2 in the large and small water cages was found to have a crucial effect on the mechanical properties and fracture behaviors of CNHHs. The occupancy of small cages by CO2 was identified as a decisive factor affecting fracture position, leading to brittle or ductile fracture behavior. These findings provide insights into the deformation and fracture mechanisms of heteroclathrate hydrates and the impact of CO2 sequestration on the stability of gas hydrate reservoirs.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Chemical
Kyunam Kim, Young-Eun Hwang, Young Hum Lee, Seong-Jun Park, Daeok Kim, Dong-Yeun Koh
Summary: This study reports an efficient blend of organic and inorganic materials to form all-nanoporous fiber sorbents for the separation of volatile organic compounds (VOCs). The fiber sorbent exhibits feasible sorption performance capabilities under both dry and humid conditions.
SEPARATION AND PURIFICATION TECHNOLOGY
(2022)
Article
Chemistry, Multidisciplinary
Suk Lee, Yun-Ho Ahn, Dong-Yeun Koh
Summary: In this paper, the CO2 sorption performance of raw p-phenylenediamine (pPD) solid molecule is assessed, which can be coupled with construction materials to meet the design construction standards for sustainable buildings.
KOREAN JOURNAL OF CHEMICAL ENGINEERING
(2022)
Editorial Material
Multidisciplinary Sciences
Hyeokjun Seo, Dong-Yeun Koh
Article
Chemistry, Multidisciplinary
Jiyun Heo, Young-Eun Hwang, Gisu Doo, Jinkwan Jung, Kyungjae Shin, Dong-Yeun Koh, Hee-Tak Kim
Summary: In this study, a polymer of intrinsic microporosity (PIM-1) was used as an ion regulating layer and an interface modulator in zinc ion batteries. The PIM-1 coating significantly improved the cyclability and Coulombic efficiency of the batteries, demonstrating the potential of microporous materials in the design of reversible zinc electrodes.
Article
Biochemistry & Molecular Biology
Hwa-Jin Choi, Dong-Yeun Koh
Summary: Efficient separation of enantiomers is crucial in various industries. Membrane-based processes offer lower energy consumption compared to traditional separation methods. This study demonstrates the successful enantioselective separation of R-1-phenylethanol over S-1-phenylethanol using a mixed-matrix membrane containing a homochiral filler.
Article
Energy & Fuels
Jiwoong Seol
Summary: In this study, novel CH4 hydrates containing nitroalkanes were synthesized and investigated. The results showed that nitroalkanes can significantly decrease the CH4 storage pressures and the hydrates have high energy density and potential for energy-efficient CH4 storage and transport technologies.
Article
Chemistry, Multidisciplinary
Ari Chae, Sehyun Doo, Daesin Kim, Tae Yun Ko, Taegon Oh, Seon Joon Kim, Dong-Yeun Koh, Chong Min Koo
Summary: This study demonstrates the control over lattice structures and domain sizes of MXene-derived TiO2 crystallites by adjusting oxidation conditions, pH, and temperature. The preference for anatase phase over rutile phase is observed in basic and hot oxidizing solutions, while the portion of rutile phase increases at lower pH and temperature.
Article
Multidisciplinary Sciences
Banseok Oh, Hyeokjun Seo, Jihoon Choi, Sunggyu Lee, Dong-Yeun Koh
Summary: This study demonstrates precise selectivity tuning in carbon membranes through controlled electron irradiation. The method enables efficient separation of molecules with extremely small size differences, and the irradiated membranes exhibit higher stability and selectivity compared to pristine membranes.
NATURE COMMUNICATIONS
(2022)
Article
Chemistry, Multidisciplinary
Ari Chae, G. Murali, Seul-Yi Lee, Jeonghwan Gwak, Seon Joon Kim, Yong Jin Jeong, Hansol Kang, Seongmin Park, Albert S. Lee, Dong-Yeun Koh, Insik In, Soo-Jin Park
Summary: Recently, MXene-based wearable hydrogels have become promising candidates for epidermal sensors due to their softness and unique properties. However, it is challenging to achieve reliable sensing performance and prolonged service life due to MXene oxidation in water-containing hydrogels. To address this issue, catechol-functionalized poly(vinyl alcohol) (PVA-CA)-based hydrogels are proposed to inhibit MXene oxidation, resulting in rapid self-healing and superior strain sensing behaviors. The PVA-CA-MXene hydrogel demonstrates potential for real-time motion monitoring and accurate signal classification using deep learning models.
ADVANCED FUNCTIONAL MATERIALS
(2023)
Article
Thermodynamics
Jiwoong Seol
Summary: In this study, the thermodynamic promotion effect of nitroalkane large guest molecules (LGMs) on CH4 hydrates was investigated. The structural analysis confirmed the formation of different hydrate types with different LGMs. All nitroalkanes improved the equilibrium temperatures, with tBuNO2 showing the strongest promotion effect. The structural and thermodynamic results of this study provide valuable information for the development of CH4 storage and transport technologies.
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2023)
Article
Biotechnology & Applied Microbiology
Jimin Park, Young-Eun Hwang, Dong-Yeun Koh
Summary: As the interest in 2D materials grows, various methods to synthesize them have been studied. However, there are still challenges in fabricating 2D membranes, specifically related to scalability and homogeneity. To overcome these challenges, support-mediated interfacial synthesis is suggested as a scalable fabrication method.
CURRENT OPINION IN CHEMICAL ENGINEERING
(2023)
Article
Multidisciplinary Sciences
Chaehoon Kim, Dong-Yeun Koh, Yongjin Lee, Jihoon Choi, Hae Sung Cho, Minkee Choi
Summary: In this study, a zeolite-templated bottom-up synthesis of ordered microporous 2D carbon is reported. The carbon material has an extremely thin polyaromatic backbone and well-defined vertically aligned micropores (0.69 nm in diameter). The resulting carbon has a considerably higher areal pore density (0.70 nm-2) compared to porous graphene prepared using top-down perforation methods. An isoporous membrane fabricated from the exfoliated 2D carbon nanosheets exhibits outstanding permeance and molecular sieving properties in organic solvent nanofiltration.
Article
Engineering, Chemical
Banseok Oh, Kyunam Kim, YongSung Kwon, You-In Park, Hosik Park, Dong-Yeun Koh
Summary: This study utilizes membrane pervaporation to recover ethylene glycol by dehydrating water from a mixture of ethylene glycol and water. Two hydrophilic derivatives from the polymer of intrinsic microporosity (PIM-1) were suggested as feasible membrane materials, which showed increased water sorption capacity and tenfold greater water permeability compared to pure PIM-1. The modified membranes retained a water content of 99.9% in the permeate, demonstrating a simple method for modifying suitable dehydration materials while maintaining the original polymer's structural quality.
JOURNAL OF MEMBRANE SCIENCE
(2023)
Article
Chemistry, Physical
Sunggyu Lee, Ilia Kevlishvili, Heather J. Kulik, Hee-Tak Kim, Yongchul G. Chung, Dong-Yeun Koh
Summary: This study introduces two N-containing porous organic cages for safe capture of bromine molecules. Experimental and computational research reveals their outstanding reversible sorption capacities, which are influenced by the chemical and structural nature of the cages.
JOURNAL OF MATERIALS CHEMISTRY A
(2022)
Article
Chemistry, Multidisciplinary
Ari Chae, Sehyun Doo, Daesin Kim, Tae Yun Ko, Taegon Oh, Seon Joon Kim, Dong-Yeun Koh, Chong Min Koo
Summary: Control of lattice structures and domain sizes of MXene-derived TiO2 crystallites are demonstrated by oxidation conditions, pH, and temperature.
