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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

The roles of heterogeneous chemical processes in the formation of an air pollution complex and gray haze

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Science China Chemistry 2011年第1期54卷 145-153页

作者： ZHU Tong,SHANG Jing & zhao defeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 1. State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China

Urban and regional air pollutions are characterized by high concentrations of secondary pollutants such as photo-oxidants （mainly ozone） and fine particulate matter, which are formed through chemical reactions of the primary pollutants emitted from various sources. The accumulation of these pollutants under stagnant meteorological conditions results in the formation of gray haze, reducing visibility and causing major impacts on human health and climate. In an air pollution complex, the co- existence of high concentrations of primary and secondary gaseous and particulate pollutants provides a large amount of reac- tants for heterogeneous reactions on the surface of fine particles; these reactions change the oxidizing capacity of the atmos- phere, as well as chemical compositions along with the physicochemical and optical properties of particulate matter, thereby accelerating formation of the air pollution complex and gray haze. Using in situ technologies, such as diffuse reflectance infra- red Fourier-transform spectroscopy and single-particle Raman spectroscopy, we systematically investigated the reaction kinet- ics and mechanisms of gaseous pollutants （i.e., NO2, SO2, 03, and formaldehyde） on the surfaces of the major components of atmospheric particles such as CaCO3, kaolinite, montmorillonite, NaC1, sea salt, A1203, and Tit2. We found that the main re- action products were sulfate, nitrate, or formate, which can change the hygroscopicity and light extinction parameters of those particles significantly. By analyzing the reaction kinetics of these heterogeneous reactions, we identified synergetic mechanisms of the three ternary reaction systems, ,i.e., NOE-particles-H2O, SO2-particles-O3, and organics/SO2-particles-UV illumination. These synergetic mechanisms can provide experimental and theoretical bases for understanding the feedback mechanisms and nonlinear processes in the formation of an air pollution complex and gray haze.

关键词： fine particles secondary pollutants oxidizing capacity ternary reaction nonlinear processes

Raman micro-spectrometry as a technique for investigating heterogeneous reactions on individual atmospheric particles

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Science China Chemistry 2011年第1期54卷 154-160页

作者： zhao defeng,ZHU Tong,CHEN Qi,LIU YingJun & ZHANG ZeFeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 1. State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering Peking University Beijing 100871 China

Investigating the heterogeneous reaction on individual atmospheric particles is important because it approximates actual atmospheric conditions and can aid in reducing artifacts in elucidating real mechanisms and processes,and determining real kinetic parameters of the atmosphere *** study developed a Raman microspectrometry method to investigate heterogeneous reactions on individual *** method was applied to the reaction of NO2 with individual CaCO3 *** was demonstrated that Raman microspectrometry can obtain information on both chemical composition and microscopic morphology at the same time,as well as information on chemical characteristics,such as the phase,which is useful for studying reaction *** spectra of individual particles deposited on a substrate showed no interference by morphological resonance,which is helpful for obtaining high-quality ***,Raman microspectrometry was compared with other methods for investigating heterogeneous reactions on individual particles and was found to have several advantageous characteristics.

关键词： Raman microspectrometry individual atmospheric particle heterogeneous reaction

In Vitro Study of Carbamate-Linked Cationic Lipid for Gene Delivery Against Cervical Cancer Cells

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Advances in Materials Physics and Chemistry 2012年第4期2卷 229-232页

作者： Defu Zhi Shuibao Zhang Yinan zhao Shaohui Cui Bing Wang Huiying Chen Defu Zhi defeng zhao SEAC-ME Key Laboratory of Biochemistry Engineering Dalian Nationalities University Dalian China State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian China tate Key Laboratory of Fine Chemicals Dalian University of Technology Dalian China

Design and synthesis of a carbamate-linked cationic lipid DDCTMA (N-[1-(2,3-didodecylcarbamoyloxy)propyl]-N,N,N-trimethylammonium iodide)? as gene delivery carriers was described in this work. The transfection efficiency of cationic liposome increased dramatically with the increase in the content of DOPE. In addition, the transfection efficiency of some of cationic lipoplexes was superior or parallel to that of two commercial transfection agents, Lipofectamine2000 and DOTAP. The carbamate-linked cationic lipid DDCTMA/DOPE may be a promising gene carrier that has high transfection efficiency as well as low cytotoxicity.

关键词： Cationic Lipids DNA Condensation Gene Delivery Transfection Efficiency

Synthesis and In Vitro Study of Carbamate-Linked Cationic Lipid for Gene Delivery

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Synthesis and In Vitro Study of Carbamate-Linked Cationic Li...

Al-MCM-41介孔分子筛在辛醇乙氧基化反应中的催化性能

第八届全国化学生物学学术会议

作者： Defu Zhi Shuibao Zhang Yinan zhao Shaohui Cui Huiying Chen defeng zhao SEAC-ME Key Laboratory of Biochemistry Engineering Dalian Nationalities University

＜正＞As an important non-viral gene vector,cationic lipids have attracted increasing attention because they have many potential advantages compared with other non-viral vectors,including significant simplicity and ea... 详细信息

关键词： cationic lipids DNA condensation gene delivery transfection efficiency

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化学反应工程与工艺 2005年第3期21卷 257-262页

作者：宋伟明邓启刚赵德丰大连理工大学国家精细化工重点实验室辽宁大连116000 齐齐哈尔大学化学化工学院黑龙江齐齐哈尔161000

以乙胺为碱性介质合成了硅铝摩尔比为30的 Al-MCM-41介孔分子筛。该分子筛具有典型的六方介孔结构特征,其平均孔径为2.6nm,中强酸度。实验考察了其在正辛醇乙氧基化反应中的催化特性。结果表明,Al-MCM-41介孔分子筛在正辛醇乙氧基化反... 详细信息

以乙胺为碱性介质合成了硅铝摩尔比为30的 Al-MCM-41介孔分子筛。该分子筛具有典型的六方介孔结构特征,其平均孔径为2.6nm,中强酸度。实验考察了其在正辛醇乙氧基化反应中的催化特性。结果表明,Al-MCM-41介孔分子筛在正辛醇乙氧基化反应中具有较高催化活性,而且产物分子量分布较窄。升高反应温度、增加初始压力以及提高催化剂用量,环氧乙烷反应速度增加。当环氧乙烷平均加合度为5.5时,正辛醇聚氧乙烯醚分子量分布选择性系数达到20。当反应温度为130℃时,正辛醇与环氧乙烷的反应速率常数约为0.035min^(-1)。

关键词： Al-MCM-41介孔分子筛催化活性乙氧基化反应辛醇环氧乙烷

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介孔氧化铁对正辛醇乙氧基化反应的催化性能

石油化工 2005年第8期34卷 770-774页

作者：宋伟明邓启刚赵德丰大连理工大学国家精细化工重点实验室辽宁大连116012 齐齐哈尔大学化学化工学院黑龙江齐齐哈尔161006

以十二烷基磺酸钠为模板剂、乙二胺为碱性介质,将水热法合成的氧化铁/十二烷基磺酸钠复合中孔材料在550℃、空气气氛中煅烧10h,除去模板剂,得到介孔氧化铁。通过X射线衍射、氮气吸附-脱附方法对介孔氧化铁的晶体结构和表面物性进行表征... 详细信息

以十二烷基磺酸钠为模板剂、乙二胺为碱性介质,将水热法合成的氧化铁/十二烷基磺酸钠复合中孔材料在550℃、空气气氛中煅烧10h,除去模板剂,得到介孔氧化铁。通过X射线衍射、氮气吸附-脱附方法对介孔氧化铁的晶体结构和表面物性进行表征。表征结果显示,煅烧后的介孔氧化铁具有典型的六方介孔的结构特征,平均孔径为5.4nm。将介孔氧化铁用于催化正辛醇乙氧基化反应,研究结果表明,升高反应温度和初始压力、增加催化剂用量,可加快环氧乙烷的反应速率,同时产物的相对分子质量分布较窄。当平均聚合度为6.5时,正辛醇聚氧乙烯醚相对分子质量分布的选择性系数达到21.1。

关键词：介孔氧化铁催化乙氧基化反应窄分布正辛醇

Ce改性SBA-15分子筛催化合成棕榈酸甲酯

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石油化工 2007年第8期36卷 763-767页

作者：田志茗邓启刚赵德丰大连理工大学国家精细化工重点实验室辽宁大连116012 齐齐哈尔大学化学化工学院黑龙江齐齐哈尔161006

用浸渍法对SBA-15分子筛进行Ce改性，制备了Ce（SO4）2／SBA-15催化剂，采用X射线衍射、红外光谱、N2吸附-脱附、热重-差热分析方法对试样进行了表征。表征结果显示，Ce已进入SBA-15分子筛中，制得的Ce（SO4）2／SBA-15催化剂保持高度... 详细信息

用浸渍法对SBA-15分子筛进行Ce改性，制备了Ce（SO4）2／SBA-15催化剂，采用X射线衍射、红外光谱、N2吸附-脱附、热重-差热分析方法对试样进行了表征。表征结果显示，Ce已进入SBA-15分子筛中，制得的Ce（SO4）2／SBA-15催化剂保持高度有序的介孔二维六角结构。用Hammett指示剂法测得ce（SO4）2／SBA-15催化剂的表面酸强度为0．99—1．80，酸量为0．2344mmol／g。采用Ce（So4）2／SBA-15催化剂催化甲醇和棕榈酸酯化合成棕榈酸甲酯，优化的合成条件为：n（棕榈酸）：n（甲醇）=1：15，催化剂用量为棕榈酸质量的5．0％，反应时间8h。在此条件下，酯化率大于92％。

关键词： SBA-15分子筛铈改性棕榈酸甲醇棕榈酸甲酯酯化反应催化生物柴油

Research on Some Brown Iron Complex Azo Dyes

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Chinese Journal of Chemical Engineering 2003年第1期11卷 68-72页

作者：修景海肖金秋赵德丰 StateKey Laboratory of Fine Chemicals Dalian University of Technology

Some novel 1:1 and 1 ：2 Fe complex azo dyes were synthesized in this *** mass spectrum analysis of 1:1 and 1:2 Fe complex azo dyes is ***,rubbing fastness and washing fastness of these metallized complex dyes were e... 详细信息

关键词： Fe metallized azo dyes synthesis Fe complexes