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Using X-ray computed tomography and micro-Raman spectrometry to measure individual particle surface area, volume, and morphology towards investigating atmospheric heterogeneous reactions

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Journal of Environmental Sciences 2018年第7期30卷 23-32页

作者： Mingjin Wang Nan Zheng Tong Zhu Jing Shang Ting Yu Xiaojuan Song Defeng Zhao Yong Guan Yangchao Tian BIC-ESAT and SKL-ESPCl College of Environmental Sciences and Engineering Peking University Beijing 100871 China National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029 China

Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography（XCT） and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional（3-D） rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy（FE-SEM） to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.

关键词： Heterogeneous reactions Individual CaCO3 particle Micro-Raman spectrometry Synchrotron radiation X-ray computed tomography Morphology surface area Volume

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Investigation of the methane hydrate surface area during depressurization-induced dissociation in hydrate-bearing porous media

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Chinese Journal of Chemical Engineering 2021年第4期34卷 324-334页

作者： Xuke Ruan Xiao-Sen Li Guangzhou Institute of Energy Conversion Chinese Academy of SciencesGuangzhou 510640China CAS Key Laboratory of Gas Hydrate Guangzhou 510640China

The surface area of hydrate during dissociation in porous media is essentially important for the kinetics of hydrate *** this study,the methane hydrate surface area was investigated by the comparison results of experiments and numerical simulations during hydrate decomposition in porous *** experiments of methane hydrate depressurizationinduced dissociation were performed in a 1D high pressure cell filled with glass beads,an improved and valid 1D corescale numerical model was developed to simulate gas *** conceptual models for hydrate dissociation surface area were proposed based on the morphology of hydrate in porous media,which formed the functional form of the hydrate dissociation surface area with porosity,hydrate saturation and the average radius of sand sediment *** the establishment of numerical model for depressurizationinduced hydrate dissociation in porous media,the cumulative gas productions were modeling and compared with the experimental data at the different hydrate *** results indicated that the proposed prediction equations are valid for the hydrate dissociation surface area,and the graincoating surface area model performs well at lower hydrate saturation for hydrate dissociation simulation,whereas at higher hydrate saturation,the hydrate dissociation simulation from the porefilling surface area model is more ***,the sensitivity analysis showed that the hydrate dissociation surface area has a significant impact on the cumulative gas production.

关键词： surface area Methane hydrate Hydrate dissociation Hydrate morphology Depressurization

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Preparation of High-surface area Nano-CeO_2 by Template-Assisted Precipitation Method

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Journal of Rare Earths 2007年第1期25卷 58-62页

作者：王月娟马静萌罗孟飞方萍何迈 Zhejiang Key Laboratory for Reactive Chemistry on Solid surfaces Institute of Physical Chemistry Zhejiang Normal UniversityJinhua 321004 China

The high-surface area nano-CeO2 was prepared by Ce（NO3）3 by precipitation method, with surfactant cetyhrimethyl ammonium bromide （CTAB） as templating agent. The effects of the precipitating agents, reaction temperature, ageing time, and calcination temperature on the surface area, as well as the pore structure and the mean crystallite size of nano-CeO2 were studied. It was found that the reaction of Ce（NO3）3 with NaOH in the presence of CTAB at 90℃ for 12 h yieldsed a cerium oxide/surfaetant mixture, which after calcination at 400℃ resulted in high-surface area nano-CeO2. The mean crystallite size of CeO2 was approximately 6 nm, surface area was in excess of 200 m^2· g ^- 1, pore size was approximately 9 nm, and the pore distribution was concentrative. Moreover, the surface area can still reach 147 m^2·g^- 1 after calcination at 700 ℃, which showed the good thermal stability of the CeO2. The number of oxygen vacancies in the structure of CeO2 corresponded with the surface area of CeO2, and the high surface area was propitious to the formalion of oxygen vacancies.

关键词： nano-ceria CTAB surface area rare earths

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Relationship between surface area and crystal size of pure and doped cerium oxides

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Journal of Rare Earths 2010年第5期28卷 647-653页

作者： C. Bueno-Ferrer S. Parres-Esclapez D. Lozano-Castelló A. Bueno-López Analytical Chemistry Nutrition & Food Sciences Department Inorganic Chemistry Department University of Alicante Ap. 99 E-03080 Alicante Spain

Pure and Zr, La or Pr-doped cerium oxides were characterised by transmission electron microscopy (TEM), N2 adsorption-desorption at –196 oC and X-ray diffraction (XRD). For crystal sizes calculation, the Scherrer and Williamson-Hall equations were compared, and the relationship between surface area and crystal size was critically discussed. It was demonstrated that the Williamson-Hall equation must be used instead of the Scherrer equation to calculate crystal sizes, since the latter equation underestimated ...

关键词： ceria XRD N2 adsorption crystal size surface area rare earths

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Synthesis and Characterization of Large surface area Yttrium Oxide by Precipitation Method

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Journal of Rare Earths 2004年第6期22卷 771-774页

作者：崔大立龙志奇张顺利崔梅生黄小卫 Grirem Advanced Materials Corporation Limited General Research Institute for Non-Ferrous Metals Beijing 100088 China

The method for preparing yttrium oxide with large specific surface area was introduced. By means of BET, SEM, TG and DTA analysis, the effects of precipitant, stirring velocity, non-RE impurity in solution, calcination temperature, on the surface area were studied respectively. The Y_2O_3 sample with specific surface area of more than 60 m^2·g^(-1) and L.O.I less than 1% was prepared in the suitable precipitation condition and calcinations temperature when the ammonia used as precipitant. The SEM shows that the Y_2O_3 prepared with large surface area is the aggregation of about 50 nm particles.

关键词： surface area yttrium oxide morphology precipitation method rare earths

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Modified-EISA synthesis of mesoporous high surface area CeO_2 and catalytic property for CO oxidation

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Journal of Rare Earths 2009年第6期27卷 943-947页

作者：李霞章陈丰陆晓旺倪超英陈志刚 School of Materials Science and Engineering Jiangsu University School of Materials Science and Engineering Jiangsu Polytechnic University Department of Materials Science and Engineering University of Delaware

Mesoporous CeO2 particles with high surface area were synthesized using a modified evaporation-induced self assembly(EISA) method which combined citric acid as complexing ***-prepared powder and further thermal treatment samples were characterized by X-ray diffraction(XRD),transmission electron microscopy(TEM),selected area electron diffraction(SAED),Fourier transform infrared spectrometer(FTIR),thermogravimetry and differential thermal analysis(TG-DTA),Brunauer-Emmett-Teller(BET) and Barrett-Joyner-Ha...

关键词： ceria mesoporous surface area catalytic oxidation rare earths

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BET surface area and Porous Structure of Fullerenes and Fullerene Soots

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Chemical Research in Chinese Universities 1999年第1期15卷 92-95页

作者： CHEN Jian-xin SHENG Guo-ying LIU Shu-ying LIU Zi-yang LIU Zhi-qiang FU Jia-mo ZHANG Xiao-mei Changchun Institute of Applied Chemistry a Chinese Academy of SciencesChangchun130022 State Key Laboratory of Organic Geochemistry Guangzhou Institute of Geochemistry Chinese Academy of ScienoesGuangzhou510640 Institute of Animal Saience Guangdong Acadeny of Agricultural Science510640 Environmental Monitoring Centeral Station off Jilin Province Changchun130011

ＩｎｔｒｏｄｕｃｔｉｏｎＡｆａｓｃｉｎａｔｉｎｇｓｏｌｉｄｂｌａｃｋｃｏｎｄｅｎｓａｔｅ（ｈｅｒｅｃａｌｅｄｆｕｌｅｒｅｎｅｓｏｏｔ）ｉｓｇｅｎｅｒａｔｅｄｉｎｔｈｅｇａｓｐｈａｓｅａｎｄｄｅｐｏｓｉｔｅｄｄｕｒｉｎ... 详细信息

ＩｎｔｒｏｄｕｃｔｉｏｎＡｆａｓｃｉｎａｔｉｎｇｓｏｌｉｄｂｌａｃｋｃｏｎｄｅｎｓａｔｅ（ｈｅｒｅｃａｌｅｄｆｕｌｅｒｅｎｅｓｏｏｔ）ｉｓｇｅｎｅｒａｔｅｄｉｎｔｈｅｇａｓｐｈａｓｅａｎｄｄｅｐｏｓｉｔｅｄｄｕｒｉｎｇｔｈｅｄｉｓｃｈａｒｇｅｉｎａＫ...

关键词： Fullerenes Fullerene soots surface area Pore size distribution Adsorbent

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Improved Cellulose Adsorption Method for the Preparation of Perovskite Oxides with Large Specific surface area at Low Temperature

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Chinese Chemical Letters 2000年第12期11卷 1103-1106页

作者： Zong Ping SHAO Guang Tao LI Guo Xing XIONG Wei Shen YANG State Key Laboratory of Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesP.O.Box 110Dalian 116023

Perovskite-type La1-xSrxMO3-delta (x=0,0.1,0.2, B=Co,Fe,Mn) oxides were prepared by pyrolysis of metal salt-(organic acid)-cellulose compound precursors. Low calcination temperatures, usually lower than 600 degreesC, were needed. The specific surface area of the as-prepared oxides is higher than that prepared by the cellulose adsorption method, and is comparable to that prepared by sol-gel method. The effective organic acid could be EDTA acid, citric acid or DL-hydroxysuccinic acid, among them, EDTA acid is the best one.

关键词： Cellulose Organic acid Perovskite surface area Synthesis

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surface area processing in GIS for different mountain regions

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Forestry Studies in China 2011年第4期13卷 311-314页

作者： ZHANG Yong ZHANG Lei-na YANG Chun-de BAO Wen-dong YUAN Xue-xia Land Surveying and Planning Institute of Shandong Province Jinan 250014 P. R. China Land Consolidation and Rehabilitation Center of the Ministry of Land and Resources Beijing 100035 P. R. China Central Laboratory of Shandong Academy of Agricultural Sciences Key Laboratory of Test Technology on Food Quality and Safety of Shandong Province Jinan 250100 P. R. China

surface area is a fundamental parameter derived from terrain analysis in geographical information systems （GIS） for modeling the real world. Therefore, an evaluation of the techniques implemented by GIS models is important in order to obtain reliable area measurements. The study compares two raster-based methods with a TIN-based （triangulated irregular network） method for surface area approximation using a digital elevation model （DEM） with 25 m × 25 m resolution in six mountain regions of Shandong Province, China. Raster-based method I calculates surface-area grids from DEMs directly. Eight 3-dimensional triangles connecting the center point of each cell with the center points of the eight surrounding cells are generated and then the areas of the portions of each triangle that lay within the cell boundary are calculated and summed. Raster-based method Ⅱ produces the surface area of each cell directly from the pixel size and the slope value for the pixel. The results demonstrate that the surface areas calculated by rasterbased method I are equal to those of the TIN-based method. The results of raster-based method Ⅱ are the lowest but the difference in areas between the two raster-based methods decreases with the decrease in terrain complexity. Compared to the method with TINs, raster-based method II can do better because it has some advantages, such as neighborhood analysis, more consistent output and faster processing speed. The results also demonstrate that the difference between surface and horizontal areas should be considered if more than 30% of the area of a region has slopes steeper than 18.2 degrees.

关键词： DEM surface area mountain region GIS

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Determination of surface area of Red Mud and Beringite Using Methylene Blue Method

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Pedosphere 2002年第2期12卷 189-192页

作者： ZHANG GANGYA, LUO YONGMING and DENG XIHAIInstitute of Soil Science, the Chinese Academy of Sciences, Nanjing 210008 (China) Institute of Soil Science the Chinese Academy of Sciences Nanjing 210008

The adsorption of methylene blue (MB) on three soil amendments,red mud from Hungary, rd mud from UK and beringite from Belgium, wasstudied to determine the surface areas of the amendments using a0.005 mol L^-1 NaCl solution and deionised water as backgroundsolutions. The surface areas determined by the methylene blue methodin the 0.005 mol L^-1 NaCl solution were 3.357, 2.340 and 5.576 m^2g^-1 for red mud (Hungary), red mud (UK) and beringite, respectively,slightly lower than those in the deionised water system.

关键词： beringite methylene blue red surface area

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