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Phase Stability and Hydroxyl Vibration of Brucite Mg(OH)_(2) at High Pressure and High Temperature

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Chinese Physics Letters 2021年第3期38卷 111-115页

作者：桂维彬赵超帅刘锦 Center for High Pressure Science and Technology Advanced Research(HPSTAR) Beijing 100094China

Brucite Mg(OH)_(2) is an archetypal hydrous mineral and it has attracted a great deal of attention.However,little is known about the evolution of Hydroxyl groups in brucite with respect to subduction fluids.We carried out Raman measurements up to 15.4 GPa and 874 K via an externally heated diamond anvil cell,investigating the stability of brucite under the conditions relevant to subducting slabs.The Hydroxyl vibration mode A_(1g)(I) of brucite is weakened under simultaneous high pressure-temperature conditions.Meanwhile,the presence of carbonated solution can destabilize the Hydroxyl groups of brucite at low pressure.Our results suggest that brucite releases water when reacting with hydrogen carbonate ion to form magnesite MgCO_(3) in subduction zones.This implies that the global water cycle is largely coupled with the deep carbon cycle in Earth’s interior.

关键词： Hydroxyl cycle implies

Facile Synthesis of Dendritic Hydroxyl-terminated Cyanuric Chloride Derivatives and Their Properties

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Chinese Journal of Chemistry 2012年第7期30卷 1485-1489页

作者：林休休周建华徐冬梅 College of Chemistry Chemical Engineering and Materials ScienceNational Engineering Laboratory for Modern SilkKey Laboratory of Organic Synthesis of Jiangsu ProvinceJiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSoochow UniversitySuzhouJiangsu 215123China (Suzhou)Zhongke Nanotech Coating Co.LTD SuzhouJiangsu 215024China

Novel dendritic compounds G1.5（OH）4 and G1.5（OH）8 with peripheral Hydroxyl were synthesized under mild conditions from eyanuric chloride, ethylene diamine, ethanolamine and diethanolamine. The products could be separated and purified through dispersion and precipitation in organic solvents with good yields （over 93.0%） and high purity （above 98.0%, HPLC）. The structures of the products were characterized by 1R, MS, 1H NMR and elementary analysis. G1.5（OH）4 and Gl.5（OH）8 could be dissolved in polar solvents such as methanol, water and dimethylsulfoxide. TGA analysis showed that G1.5（OH）4 and G1.5（OH）8 had good thermo stability. The aqueous solutions ofG1.5（OH）4 and G1.5（OH）8 exhibited low surface tension.

关键词： dendritic cyanuric chloride ethylene diamine Hydroxyl surface activity

Effects of Hydroxyl group on H_2 dissociation on graphene:A density functional theory study

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Journal of Energy Chemistry 2013年第3期22卷 493-497页

作者： Ning Wang Likun Wang Qinggang Tan Yun-Xiang Pan College of Materials Science and Engineering Key Laboratory for Advanced Civil Engineering Materials(Ministry of Education)Tongji University

Graphene-based materials are promising for hydrogen production and storage. In this work, using density functional theory calculations, we explored how a Hydroxyl group influences H2 dissociation on graphene. Presence of the Hydroxyl group makes the binding of H atom with graphene stronger, as the binding energy of H atom with the Hydroxyl-modified graphene is higher than that with the pristine graphene. The para-site is the most favorable site for H2 dissociation on both the pristine and Hydroxyl-modified graphene. The energy barrier of H2 dissociation at para-site on the pristine graphene is 3.10 eV whereas that on the Hydroxyl-modified graphene is 2.46 eV, indicating a more facile H2 dissociation on the Hydroxyl-modified graphene.

关键词： graphene Hydroxyl H2 dissociation hydrogen transfer density functional theory

Bonding of Hydroxyl and Epoxy Groups on Graphene:Insights from Density Functional Calculations

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Chinese Journal of Structural Chemistry 2013年第10期32卷 1475-1484页

作者：贾田田孙宝珍林华香李奕陈文凯 Department of Chemistry Fuzhou University School of Chemistry & Chemical Engineering Guangxi University Fujian Provincial Key Laboratory of Photocatalysis-state Key Laboratory Breeding Base Fuzhou University

Density functional theory and GGA-PW91 exchange correlation function were performed to simulate the bonding behavior of Hydroxyl and epoxy groups on the graphene surface. We compared the different binding energies for two epoxy groups, as well as one Hydroxyl group and one epoxy group on all possible positions within a 6-fold ring, respectively. The calculated results suggest that two oxygen-containing groups always tend to bind with the neighboring carbon atoms at the opposite sides. Moreover, two Hydroxyl groups on the meta position are unstable, and one of the Hydroxyl groups easily migrates to the para position. In contrast to the disperse arrangement, the aggregation of multiply Hydroxyl groups largely enhances the binding energy of every Hydroxyl group. It is worth noting that the binding sites and hydrogen bonds play an important role in stability. Our work further points out the number of oxygen-containing groups and the location of oxide region largely influence the electronic properties of graphene oxide.

关键词： density functional theory graphene Hydroxyl epoxy bonding

Microstructured Hydroxyl environments and Raman spectroscopy in selected basic transition-metal halides

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Chinese Physics B 2011年第8期20卷 435-442页

作者：刘晓东孟冬冬萩原雅人郑旭光 Department of Physics Graduate School of Science and EngineeringSaga University Department of Physics College of ScienceTianjin Polytechnic University Department of Physics Faculty of Science and EngineeringSaga University

Raman vibrational spectra of the selected basic （Hydroxyl OH and deuteroxyl OD） transition-metal halides, geomet- rically frustrated material series α-, β-, γ-Cu2（OH）3Cl, α-Cu2（OH）3Br, β-Ni2（OH）3Cl, β-Co2（OH）3Cl, β-Co2（OH）3Br, γ-Cu2（OD）3Cl, and β-Co2（OD）3Cl are measured at room temperature and analysed to investigate the relationship be- tween the microstructured OH environments and their respective Raman spectra. Among these selected samples, the last two are used to determine the OH stretching vibration region （3600 cm-1-3300 cm-1） and OH bending vibra- tion region （1000 cm-1-600 cm-1） of OH systems in the spectra. Through the comparative analysis of the distances d（metal-O）, d（O-halogen）, and d（OH）, the strong metal-O interaction and trimeric hydrogen bond （Car, C8 or C1 symmetry） are found in every material, but both determine simultaneously an ultimate d（OH）, and therefore an OH stretching vibration frequency. According to the approximately linear relationship between the OH stretching vibration frequency and d（OH）, some unavailable d（OH） are guessed and some doubtful d（OH） are suggested to be corrected. In addition, it is demonstrated in brief that the OH bending vibration frequency is also of importance to check the more detailed crystal microstructure relating to the OH group.

关键词： Hydroxyl trimeric hydrogen bond Raman spectrum basic transition-metal halide

Ammonium Impacts on Vibrations of Hydroxyl and Lattice of Phengite at High Temperature and High Pressure

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Journal of Earth Science 2021年第5期32卷 1278-1286页

作者： Weihua Huang Yan Yang Zeming Qi Wendi Liu Zhongping Wang Yan Liu Qunke Xia School of Earth Sciences Zhejiang UniversityHangzhou 310027China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Department of Physics University of Science and Technology of ChinaHefei 230026China

Dehydration in hydrous phases of the downgoing slab controls water release processes in subduction zones. Interplay between volatiles in hydrous minerals has complicated the previous knowledge of their dehydration. Phengite is an essential mineral carrying both hydrogen and nitrogen to the deep Earth. To further understand the link between nitrogen and dehydration process of phengite at an atomic level, we here carry out high temperature and high pressure vibrational spectroscopic investigations on Hydroxyl and lattice of ammonium-bearing and ammonium-free phengites. The results show that heating to 800 oC hardly influences Hydroxyl bonding strength, whereas pressure induces strengthening of hydrogen bonding until 10 GPa. Moreover, hydrogen transits between the sites with increasing temperature and pressure. The lattice modes soften with increasing temperature and stiffen under compression. Ammonium has no effect on Hydroxyl bonding strength, but hinders hydrogen transition at high temperatures and high pressures. Ammonium does not influence the lattice at high pressures either, but delays softening of the lattice at high temperatures. These data unveil behavior of Hydroxyl and lattice in phengite at high temperature and high pressure, and also evaluate ammonium impacts, shedding new lights on dehydration processes of phengite during subduction.

关键词： Hydroxyl lattice ammonium phengite high temperature high pressure

A Comparative Study of the Hydroxyl and Saponification Values of Polysorbate 60 in International Food Additive Specifications

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American Journal of Analytical Chemistry 2014年第3期5卷 199-204页

作者： Kazuaki Wakita Haruyoshi Kuwabara Noriko Furusho Chiye Tatebe Kyoko Sato Hiroshi Akiyama Division of Food Additives National Institute of Health Sciences Tokyo Japan Oleo & Specialty Chemicals Research Laboratory NOF Corporation Kawasaki-shi Japan Quality Assurance Department Gunma Complex Shin-Etsu Chemical Co. Ltd. Annaka-shi Japan

We investigated the Hydroxyl and saponification values of 27 samples of Polysorbate 60 products that were commercially available worldwide. We observed that the values of most of the studied samples were not within the range established at the Joint FAO/WHO Expert Committee on Food Additives (JECFA), while they did agree with the specifications described in the USA, the EU and Japan. We believe that purities of the new commercial Polysorbate 60 samples are higher than those of the older products which were available when the JECFA specifications were discussed (around 1973). The present study suggests that the Hydroxyl and saponification values of the current JECFA specifications for Polysorbate 60 should be re-evaluated.

关键词： Polysorbate 60 Polyoxyethylene Sorbitan Monostearate Hydroxyl Value Saponification Value Emulsifier Specification

DFT Study on Reaction Mechanism of DNA Base Pair with Hydroxyl Radical

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Journal of Modern Physics 2013年第3期4卷 442-451页

作者： Eisuke Shimizu Ryota Hoshino Kazuya Nomura Victor I. Danilov Noriyuki Kurita Department of Computer Science and Engineering Toyohashi University of Technology Toyohashi Japan Department of Molecular and Quantum Biophysics Institute of Molecular Biology and Genetics National Academy of Sciences of Ukraine Kyiv Ukraine

In order to elucidate the indirect effect by radiation on DNA base pairs, we investigate the mechanism for the attacking reaction of a Hydroxyl radical (·OH-radical) to the G-C and A-T base pairs, by the density functional theory (DFT) calculations. The effect of solvation on the mechanism is also revealed by performing the same DFT calculations under the continuum solvation approximation. We find the stable structures for the dehydrogenated G-C and A-T base pairs, in which the hydrogen atom of NH2 group of G or A base is abstracted by the ·OH-radical. The solvation around the base pairs stabilizes the dehydrogenated structures significantly, indicating the acceleration of the attacking reaction by ·OH-radical to the base pairs in water. Therefore, we conclude that the hydrogen atom of the NH2 group of G or A base in the G-C and A-T base pairs is the most preferably abstracted by the ·OH-radical in living cells.

关键词： Density Functional Theory DNA Hydroxyl Radical Base Pair Reaction Mechanism Dehydrogenation

Hydroxyl in continental deep subduction zone: Evidence from UHP eclogites of the Dabie Mountains

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Chinese Science Bulletin 2001年第7期46卷 592-596页

作者： HarryW.Green The Faculty of Earth Sciences China University of Geosciences Wuhan China Institute of Geophysics & Planetary Physics University of Califonia Riverside USA

Infrared spectra in the region of 3 000 to 4 000 cm-1 have been measured by an FTIR spectrometer on minerals in UHP eclogites from the Bixiling and Shuanghe areas, the Dabie Mountains. It is shown that omphacite is the most important hydrous mineral (100-200 μg/g) in UHP eclogites. Garnet and quartz contain virtually no H2O or OH. Accessory mineral rutile contains a significant amount of OH (>1 000 μg/g). Coesite gives no indication of the presence of OH but apparent H2O bands. The results have considerable implications for existing forms and contents of Hydroxyl in the continental deep subduction zone, the eastern Dabie Mountains.

关键词： UHP eclogite Hydroxyl FTIR quantitative analysis.