고체수소저장용 나노튜브 소재의 분자동역학 해석 기반 성능 평가

박진우,박형범 한국복합재료학회 2024 Composites research Vol.37 No.1

Solid-state hydrogen storage is gaining prominence as a crucial subject in advancing the hydrogen-based economy and innovating energy storage technology. This storage method shows superior characteristics in terms of safety, storage, and operational efficiency compared to existing methods such as compression and liquefied hydrogen storage. In this study, we aim to evaluate the solid hydrogen storage performance on the nanotube surface by various structural design factors. This is accomplished through molecular dynamics simulations (MD) with the aim of uncovering the underlying ism. The simulation incorporates diverse carbon nanotubes (CNTs) – encompassing various diameters, multi-walled structures (MWNT), single-walled structures (SWNT), and boron-nitrogen nanotubes (BNNT). Analyzing the storage and effective release of hydrogen under different conditions via the radial density function (RDF) revealed that a reduction in radius and the implementation of a double-wall configuration contribute to heightened solid hydrogen storage. While the hydrogen storage capacity of boron-nitrogen nanotubes falls short of that of carbon nanotubes, they notably surpass carbon nanotubes in terms of effective hydrogen storage capacity. 고체수소저장은 수소 기반 경제 발전과 에너지 저장 기술 혁신의 핵심 주제로 부각되고 있다. 이러한 저장 방식은 압축 및 액화수소 저장 등 기존 방식에 비해 안전성과 저장 및 운용 효율성 측면에서 우수한 특성을 보여주고 있다. 본 연구에서는 다양한 구조적 설계 요소 별로 나노튜브 표면에서의 고체수소저장 성능을 평가하고자 한다. 본 연구는 나노튜브의 저장 메커니즘을 밝히고자 분자 역학 시뮬레이션(MD)을 도입하여 수행되었다. 본 연구의 시뮬레이션에는 다양한 직경, 다중벽 구조(MWNT), 단일벽 구조(SWNT)의 탄소나노튜브(CNT) 및 붕소-질소 나노튜브(BNNT)가 도입되어 진행되었다. 방사형 밀도 함수(RDF)를 통해 다양한 조건에서 수소의 저장 및 효과적인 방출을 분석한 결과, 반경 감소와 이중벽 구조가 고체 수소 저장을 높이는 데 기여하는 것으로 나타났다. 또한, 붕소-질소 나노튜브의 수소 저장 용량은 탄소 나노튜브에 비해 낮게 측정되었지만, 유효 수소 저장 측면에서는 탄소 나노튜브를 훨씬 능가하는 것으로 나타났다.

Hydrogen Healing Tour and Beauty

Yoon-Joo Jeong 한국물학회 2020 한국물학회지 Vol.8 No.1

Health is the most important aspect of human life. Recently, there has been a rapid increase in consumer interest in the health-enhancing roles of specific foods and water as it posses’ physiologically active components, so-called as functional foods and functional water. Hydrogen-rich and electrolyzed alkaline waters have been reported as types of functional waters that may ameliorate various oxidative stress–related diseases including various dermatological problems as it has potent anti-oxidant effects. In recent years, molecular hydrogen (H2) has attracted lots of attention in biomedical community such as food and cosmetic industries because of its abilities to modulate signal transduction, protein phosphorylation, and gene expression that enable its anti-inflammatory, anti-allergy, and anti-apoptotic activities. Due to its easy delivery in human body through inhaling H2 gas, drinking H2-dissolved water (H2-water), injecting H2-saline, taking an H2 water bath and H2-spray; popularity of hydrogen business is increasing in many countries including Japan, China and Korea especially in food and cosmetic industries. In Japan, China and Korea, hydrogen-containing beverages and cosmetic items are commercially available in the market. Besides this, new concept of hydrogen-tourism is getting famous in these nations which focuses on the overall holistic approach of human health through introducing various products related with H2 in forms of beverages (coffee, water) and cosmetic products for enhancing beauty and hydrogen spa for relaxation of body and mind and gaining attraction of people.

Hydrogen-rich medium protects mouse embryonic fibroblasts from oxidative stress by activating LKB1-AMPK-FoxO1 signal pathway

Lee, Jihyun,Yang, Goowon,Kim, Young-Joo,Tran, Quynh Hoa,Choe, Wonchae,Kang, Insug,Kim, Sung Soo,Ha, Joohun Elsevier 2017 Biochemical and biophysical research communication Vol.491 No.3

<P><B>Abstract</B></P> <P>Persistent oxidative stress is recognized as a major cause of many pathological conditions as well as ageing. However, most clinical trials of dietary antioxidants have failed to produce successful outcomes in treating oxidative stress-induced diseases. Molecular hydrogen (H<SUB>2</SUB>) has recently received considerable attention as a therapeutic agent owing to its novel antioxidant properties, a selective scavenger of hydroxyl and peroxynitrite radicals. Beyond this, numerous reports support that H<SUB>2</SUB> can modulate the activity of various cellular signal pathways. However, its effect on AMP-activated protein kinase (AMPK) signal pathway, a central regulator of energy hemostasis, has remained almost elusive. Here, we report that hydrogen-rich medium activated LKB1-AMPK signal pathway without ATP depletion, which in turn induced FoxO1-dependent transcription of manganese superoxide dismutase and catalase in mouse embryonic fibroblasts. Moreover, hydrogen-rich media effectively reduced the level of reactive oxygen species in cells treated with hydrogen peroxide and protected these cells from apoptosis in an AMPK-dependent manner. These results suggest that the LKB1-AMPK-FoxO1 signaling pathway is a critical mediator of the antioxidant properties of H<SUB>2</SUB>, further supporting the idea that H<SUB>2</SUB> acts as a signaling molecule to serve various physiological functions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Hydrogen-rich medium exerts anti-oxidant effects through AMPK. </LI> <LI> Hydrogen-rich medium activates LKB1-AMPK signal pathway without ATP depletion. </LI> <LI> AMPK in turn induces FoxO1-dependent expression of antioxidant enzymes. </LI> </UL> </P>

Investigation of hydrogen adsorption behavior of graphene under varied conditions using a novel energy-centered method

Luhadiya Nitin,Kundalwal S. I.,Sahu S. K. 한국탄소학회 2021 Carbon Letters Vol.31 No.4

The adsorption of molecular hydrogen on the monolayer graphene sheet under varied temperature and pressure was studied using molecular dynamics simulations (MDS). A novel method for obtaining potential energy distributions (PEDs) of systems was developed to estimate the gravimetric density or weight percentage of hydrogen. The Tersof and Lennard–Jones (LJ) potentials were used to describe interatomic interactions of carbon–carbon atoms in the graphene sheet and the interactions between graphene and hydrogen molecules, respectively. The results estimated by the use of novel method in conjunction with MDS developed herein were found to be in excellent agreement with the existing experimental results. The efect of pressure and temperature was studied on the adsorption energy and gravimetric density for hydrogen storage. In particular, we focused on hydrogen adsorption on graphene layer considering the respective low temperature and pressure in the range of 77–300 K and 1–10 MPa for gas storage purpose which indicate the combination of optimal extreme conditions. Adsorption isotherms were plotted at 77 K, 100 K, 200 K, and 300 K temperatures and up to 10 MPa pressure. The simulation results indicate that the reduction in temperature and increase in pressure favor the gravimetric density and adsorption energies. At 77 K and 10 MPa, the maximum gravimetric density of 6.71% was observed. Adsorption isotherms were also analyzed using Langmuir, Freundlich, Sips, Toth, and Fritz–Schlunder equations. Error analysis was performed for the determination of isotherm parameters using the sum of the squares of errors (SSE), the hybrid fractional error function (HYBRID), the average relative error (ARE), the Marquardt’s percent standard deviation (MPSD), and the sum of the absolute errors (SAE).

분자 동역학을 이용한 상호 관통된 Metal Organic Framework의 수소 흡착에 관한 연구

이태범(Lee, Tae-Bum),김대진(Kim, Dae-Jin),정동현(Jung, Dong-Hyun),김자헌(Kim, Ja-Heon),최승훈(Choi, Seung-Hoon) 한국신재생에너지학회 2006 한국신재생에너지학회 학술대회논문집 Vol.2006 No.06

We performed molecular dynamics simulations on the conventional MOF, IRMOF-14 and the catenated MOF with two MOF chains, IRMOF13, to find out rational design and synthetic strategies toward efficient hydrogen storage materials. The molecular dynamics calculations were done using Universal force fields and the analysis of result was performed during the NVE dynamics after preliminary NVT dynamics at 77K. The results showed the density of adsorbed hydrogen molecules was increased in the various pores created by catenation of MOFs while the large amount of volume in conventional MOF was not effectively utilized to store hydrogen. Those calculation results commonly showed the proper control of pore si Be for hydrogen storage into MOF by catenation would be one of the efficient ways to increase hydrogen capacity of MOFs.

탄소 나노 구조체에 대한 수소 분자의 분자동역학 시뮬레이션

임의순 한국물리학회 2009 새물리 Vol.58 No.6

The properties of carbon nanostructures as a hydrogen storage medium have been investigated. We have calculated the probabilities of adsorption of hydrogen molecules incident upon a single-walled carbon nanotube (SWCNT) by using a molecular-dynamics simulation. Though interactions with carbon atoms of the nanostructures, the hydrogen molecules dissociated and behave as individual atoms. The calculations were performed over a wide range of incident hydrogen kinetic energies (0.1~100 eV). Over the energy range, we studied the dependences of the adsorption probabilities on the kinetic energies of the incident hydrogen molecule, we showed that the maximum and the minimum probabilities were given by H2 incident `following' and `parallel' to the typical target hexagon in a SWCNT. 탄소 나노 구조체들에의 수소 저장 가능성을 분자 동역학 시뮬레이션으로 조사 하였다. 입사 운동 에너지를 갖고 탄소 나노 구조체 표면으로 입사하는 수소 분자는 탄소 원자와의 상호작용에 의하여 두 원자로 해리된 후 독립 원자와 같이 행동한다. 입사하는 수소 분자의 에너지는 0.1 eV로부터 100 eV까지 넓은 영역에서 계산하였다. 수소 저장 확률은 4 eV로부터 30 eV에서 상당히 큰 값을 갖는다. 또한 표적 육각형 면에 수직으로 입사하는 수소 분자는 최대 저장 확률을 보이는 반면, 면에 나란하게 입사하는 수소 분자는 최저 저장 확률을 보인다.

Simulation of Hydrogen Transport in a Single-walled Carbon Nanotube for Storage Safety

Oh, Kyung-Su,Kim, Dong-Hyun,Park, Seung-Ho,Kim, Jung-Soo The Korean Society of Safety 2007 International Journal of Safety Vol.6 No.1

Carbon nanotubes hold much promise as future materials for safe storage of hydrogen. In this paper, hydrogen transport mechanisms in single-walled carbon nano-tubes (SWNTs) for various temperatures and chiral indices were studied using molecular dynamics simulation method. The SWNT models of zigzag (10,0), chiral (10,5) and armchair (10,10) with hydrogen molecules inside were simulated at temperatures ranging from 253K to 373K. Movements of hydrogen molecules ($H_2$) inside a SWNT were analyzed using mean-square displacements and velocity autocorrelation functions.

Review on hydrogen-enriched slush LNG fuel

Kang-Ki Lee,Rien Hoogerbrugge,Jacques Dam,김희동 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.4

Liquefied natural gas (LNG) is a well-known fuel consisting mainly of methane as main component of natural gas and is produced by liquefying the natural gas from gas fields at a temperature of 111 K. Since LNG has a very low sulfur content it significantly reduces the emission of harmful pollutants compared to other fossil fuels. As it has a high calorific value and is chemically stable under normal usage conditions it is extensively used as fuel for large engines for ships or power plants. However, in recent years methane has been identified as green-house gas which has a high global warming potential. Therefore, it is necessary to reform LNG so it emits less pollution and has a higher combustion efficiency in engines. This can be done by enriching LNG in a slush state with hydrogen molecules during its phase transition. The introduction of the hydrogen enrichment into slush LNG involves various interesting thermo-fluid dynamics phenomena which are not well understood yet. In the current review paper, an innovative method for the production process of hydrogen enriched slush LNG is introduced and the related thermo-fluid dynamics are described in detail with an emphasis on the promising potential as a fuel for LNG engines.

Benzene-, Pyrrole-, and Furan-Containing Diametrically Strapped Calix[4]pyrroles—An Experimental and Theoretical Study of Hydrogen-Bonding Effects in Chloride Anion Recognition

Yoon, Dae-Wi,Gross, Dustin E.,Lynch, Vincent M.,Sessler, Jonathan L.,Hay, Benjamin P.,Lee, Chang-Hee WILEY-VCH Verlag 2008 Angewandte Chemie Vol.47 No.27

<B>Graphic Abstract</B> <P>Weak but important: The chloride anion binding properties of diametrically strapped calixpyrroles bearing benzene (see structure), pyrrole, and furan moieties in the strap have been studied in the solid state, in solution, and through theoretical analyses. The results obtained provide support for the notion that C&n.bond;H⋅⋅⋅Cl<SUP>−</SUP> hydrogen bonds are significant and contribute substantially to the Cl<SUP>−</SUP> binding energetics. <img src='wiley_img/14337851-2008-47-27-ANIE200801426-content.gif' alt='wiley_img/14337851-2008-47-27-ANIE200801426-content'> </P>

Solvation of a Small Metal-Binding Peptide in Room-Temperature Ionic Liquids

Youngseon Shim,Hyung J. Kim,정연준 대한화학회 2012 Bulletin of the Korean Chemical Society Vol.33 No.11

Structural properties of a small hexapeptide molecule modeled after metal-binding siderochrome immersed in a room-temperature ionic liquid (RTIL) are studied via molecular dynamics simulations. We consider two different RTILs, each of which is made up of the same cationic species, 1-butyl-3-methylimidazolium (BMI+), but different anions, hexafluorophosphate (PF6 −) and chloride (Cl−). We investigate how anionic properties such as hydrophobicity/hydrophilicity or hydrogen bonding capability affect the stabilization of the peptide in RTILs. To examine the effect of peptide-RTIL electrostatic interactions on solvation, we also consider a hypothetical solvent BMI0Cl0, a non-ionic counter-part of BMI+Cl−. For reference, we investigate solvation structures in common polar solvents, water and dimethylsulfoxide (DMSO). Comparison of BMI+Cl− and BMI0Cl0 shows that electrostatic interactions of the peptide and RTIL play a significant role in the conformational fluctuation of the peptide. For example, strong electrostatic interactions between the two favor an extended conformation of the peptide by reducing its structural fluctuations. The hydrophobicity/hydrophilicity of RTIL anions also exerts a notable influence; specifically, structural fluctuations of the peptide become reduced in more hydrophilic BMI+ Cl−, compared with those in more hydrophobic BMI+ PF6 −. This is ascribed to the good hydrogen-bond accepting power of chloride anions, which enables them to bind strongly to hydroxyl groups of the peptide and to stabilize its structure. Transport properties of the peptide are examined briefly. Translations of the peptide significantly slow down in highly viscous RTILs.