Name: an inverse analysis approach to the characterization of chemical transport in paints
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作者感谢韦斯·戈登博士（ECBC），用于支持在仪器设计。这项工作是由埃里克·温斯坦和迈克尔·罗伯茨（国防威胁降低局）根据计划CA08MSB317资助的两个研究项目的累积结果。本文引用的技术报告可在以下<a href="http://www.dtic.mil">http://www.dtic.mil</a> 。

1，条件涂料底物的所期望的环境<ol><li>预设的环境室的基板调节到规定的温度和相对湿度（20℃，50％）。确保基板的条件一直保持，因为两者的温度和水含量可以吸收率显著影响到材料。 </li><li>外套0.32厘米厚，5.08厘米半径不锈钢圆片与20.25 平方厘米，表面积有一层涂料（MIL-DTL-53039，溶剂分散性（标准差）的脂肪族聚氨酯涂料系统6）总涂层厚度（大约为100微米的底漆和面漆）。放置在基板（具有重复的期望的数量）在不锈钢托盘与试验表面被暴露在朝上的化学试剂。 </li><li>盖上培养皿的底物。含有试验衬底的托盘放入环境腔室至少60英里n，而是理想的O / N，如果可能的话。 </li></ol> 2，污染预处理基底的<ol><li>唐的个人防护装备，如实验室外套，护目镜和手套。 </li><li>注意:获取从冷库中的化学污染物，并允许初级容器小瓶中平衡至室温。在这个协议中使用的化学品化学战剂的分析标准参考物质（CASARM，98.0％纯度）级高清和CASARM（89.0％高纯度）级VX（包括液相）。从任一核磁共振或气相色谱法/质谱法分析得到的纯度的信息和对文件的维护。 注:警告:化学战剂的处理只能由经过培训的人员在经批准的设施使用相关的安全，保安和担保注意事项执行。 </li><li>注意:安装代理递送工具用枪头和配置提供代理液滴（ 如 1微升）的工具。摘帽了污染物小瓶，然后将引擎盖上表面的帽，螺纹朝上。拿起吸管，慢慢放下尖端插入污染物的解决方案。加载剂递送工具代理按照制造商的指示。轻轻将吸管装上遮光罩的工作表面，并盖上污染物小瓶。 </li><li>注意:污染测试基板。 <ol><li>删除包含从环境试验箱试验基板的托盘。 </li><li>从测试基板取出培养皿，并在罩的表面上。数字拍摄各试验基体，记录每个基片的污染前的外观。 </li><li>拿起装吸管，并提供一个单一的液滴（ 如 1微升）的代理到第一测试基板。覆盖污染的材料有聚苯乙烯培养皿中，以减少蒸发，同时污染额外的底物。重复每个基片;重装枪头（STEP 2.3）是必要的。 注:前，通过色谱分析底物给药后收集吸管确认样品，以确认污染物的质量交付。 </li><li>从测试基板取出培养皿和引擎盖上表面设置。数字拍摄各试验基体，记录初始污染物的材料的相互作用。 </li><li>覆盖测试基板的培养皿。 </li><li>放置衬底的托盘放回环境室。 </li></ol></li></ol> 3，污染物物质相互作用老化期<ol><li>之前老化的样品中，放空不锈钢高真空实验室向它的第4制备的使用。 </li><li>使被污染的基底与年龄的环境室，用于在指定的持续时间，其可以基于所述化学物质与环境相互作用动力学（ 例如 ，60分钟）而变化的。 </li><li>从环境功能移除基板威威廉斯室和地方机罩的工作表面上。从测试基板取出培养皿和数字拍摄的每个基片记录后老化污染物质的相互作用。 </li><li>双包含测试样品（ 例如 ，多个气密容器）和转移到工作机罩具有高真空腔室中。 </li></ol> 4，高真空蒸发排放测试室在高真空室抽用涡轮分子拖动泵和膜片的前级泵（ 图2）的小体积容器。一种四极质谱仪上安装有端口直接面对温度控制的衬底保持器和用于测量从高真空条件下，受污染的基材实时放出气体上。是在真空腔室的规格和材料的全部细节包括在参考文献4。 <ol><li>确保室内适当通风。 </li><li>小心:解包在第3节中制备的样品，并且从测试基板取出培养皿。放置一测试衬底送入用不锈钢镊子每个温度控制的衬底保持器。 </li><li>密封在真空室，并开始抽空序列。执行这个步骤，使得所述腔室是真空中于指定年龄时的密封（ 例如 ，60分钟），就当衬底被污染。 </li><li>开始录制选择的质量碎片频道作为时间确定每单位电荷的值特定的质量（m / z）的一个函数（直接测量质量流量的）。测量特定背景气体物种除了从感兴趣的分子的主要质量碎片:;:实时（VX M / Z = 114的HD M / Z = 109），在&lt;0.25赫兹，直到污染物的分压降至低于检测限的质谱仪（10 - 8帕）。 </li><li>收集用于发射曲线污染物从衬底发射的持续时间。 </li><li>停止录制与质谱仪发射曲线一旦污染物质量通量减小到腔室压力基线。 </li><li>泄的高真空室中的大气压力。 </li></ol> 5，治疗后评价总剩余污染物<ol><li>开启高真空蒸气排放室（HVVEC）仪器和除去从使用不锈钢镊子腔室中的衬底。 </li><li>将底物转化为玻璃萃取罐和添加20毫升萃取溶剂的罐子（ 例如 ，异丙醇:VX:氯仿:HD）。盖上罐子，摇动瓶子三次。留在萃取溶剂中的底物60分钟。 </li><li>再次摇动瓶子三次，然后开盖的罐子。使用干净的，一次性的，玻璃吸管，通过气体或液体转移约1〜2毫升的萃取溶剂的成分析小瓶中以供分析色谱7测量污染物质量的衬底保留。 </li></ol> 6，数据分析和建模<ol><li>原始质谱数据（从测量离子电流的偏压力）转换为质量流量从衬底。使用赫兹 - 克努森式的组合，用于将检测到的气体物种的分压与入射蒸汽熔剂在检测器和包括该占从原始污染事件在衬底上的污染区域的缩放因子。 </li><li>利用反演方法（ 例如 ，Levenberg-Marquardt算法）来确定通过油漆涂料的污染物运移的饱和浓度和扩散常数的值（关键质量传输参数）。比较试验确定水汽通量预测水汽通量（施加适当的边界条件下的解析解菲克第二定律（见式（4）从参考文献4））。 </li&gt; <li>使用质量传递的参数来预测对污染物的材料体系中的浓度分布。 </li></ol>

<ol>
	<li>Willis, M. P., Mantooth, B. A., Lalain, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Novel+Methodology+for+the+Estimation+of+Chemical+Warfare+Agent+Mass+Transport+Dynamics,+Part+II:+Absorption.">Novel Methodology for the Estimation of Chemical Warfare Agent Mass Transport Dynamics, Part II: Absorption.</a> J. Phys. Chem. C. 116, 546-554 (2011).</li><li>Felder, R. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Estimation+of+Gas+Transport-Coefficients+from+Differential+Permeation,+Integral+Permeation,+and+Sorption+Rate+Data.">Estimation of Gas Transport-Coefficients from Differential Permeation, Integral Permeation, and Sorption Rate Data.</a> J. Membr. Sci. 3, 15-27 (1978).</li><li>Taviera, P., Mendes, A., Costa, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+Determination+of+Diffusivity+and+Sorption+Coefficients+Using+Different+Time-lag+Models.">On the Determination of Diffusivity and Sorption Coefficients Using Different Time-lag Models.</a> J. Membr. Sci. 221, 123-133 (2003).</li><li>Willis, M. P., Gordon, W. O., Lalain, T. A., Mantooth, B. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+Chemical+Agent+Transport+in+Paints.">Characterization of Chemical Agent Transport in Paints.</a> J. Hazard Mater. 260, 907-913 (2013).</li><li>Lalain, T., Mantooth, B., Shue, M., Pusey, S., Wylie, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Chemical Contaminant and Decontaminant Test Methodology Source Document. Second Edition. Report No. ECBC-TR-980. , (2011).</li><li>. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> MIL-DTL-53039B: Coating Aliphatic Polyurethane, Single Component, Chemical Agent Resistant. , (2005).</li><li>Shue, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Low-Level Analytical Methodology Updates to Support Decontaminant Performance Evaluations. Report No. ECBC-TR-883. , (2011).</li><li>Schwope, A. D., Klein, J. M., Sidman, K. R., Reid, R. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Sorption-Desorption+Phenomena+of+Chemicals+from+Polymer+(Paint)+Films.">Sorption-Desorption Phenomena of Chemicals from Polymer (Paint) Films.</a> J. Hazard. Mater. 13, 353-367 (1986).</li><li>Li, F., Niu, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Control+of+Volatile+Organic+Compounds+Indoors+-+Development+of+an+Integrated+Mass-Transfer-Based+Model+and+Its+Application.">Control of Volatile Organic Compounds Indoors - Development of an Integrated Mass-Transfer-Based Model and Its Application.</a> Atmos. Environ. 41, 2344-2354 (2007).</li><li>Li, F., Niu, J., Zhang, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Physically-Based+Model+for+Prediction+of+VOCs+Emissions+from+Paint+Applied+to+an+Absorptive+Substrate.">A Physically-Based Model for Prediction of VOCs Emissions from Paint Applied to an Absorptive Substrate.</a> Build. Environ. 41, 1317-1325 (2006).</li><li>Li, F., Niu, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Simultaneous+Estimation+of+VOCs+Diffusion+and+Partition+Coefficients+in+Building+Materials+via+Inverse+Analysis.">Simultaneous Estimation of VOCs Diffusion and Partition Coefficients in Building Materials via Inverse Analysis.</a> Build. Environ. 40, 1366-1374 (2005).</li><li>Li, F., Niu, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Inverse+Technique+to+Determine+Volatile+Organic+Compounds+Diffusion+and+Partition+Coefficients+in+Dry+Building+Material.">An Inverse Technique to Determine Volatile Organic Compounds Diffusion and Partition Coefficients in Dry Building Material.</a> Heat and Mass Transfer. 41, 834-842 (2005).</li><li>Li, F., Niu, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+Inverse+Approach+for+Estimating+the+Initial+Distribution+of+Volatile+Organic+Compounds+in+Dry+Building+Material.">An Inverse Approach for Estimating the Initial Distribution of Volatile Organic Compounds in Dry Building Material.</a> Atmos. Environ. 39, 1447-1455 (2005).</li><li>Vesely, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Diffusion+of+Liquids+in+Polymers.">Diffusion of Liquids in Polymers.</a> Int. Mater. Rev. 53, 299-315 (2008).</li><li>Goossens, E. L. J., van der Zanden, A. J. J., Wijen, H. L. M., van der Spoel, W. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Measurement+of+the+Diffusion+Coefficient+of+Water+in+Paints+and+Polymers+from+Their+Swelling+by+Using+an+Interferometric+Technique.">The Measurement of the Diffusion Coefficient of Water in Paints and Polymers from Their Swelling by Using an Interferometric Technique.</a> Prog. Org. Coat. 48, 112-117 (2003).</li><li>Arya, R. K., Vinjamur, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Measurement+of+Concentration+Profiles+Using+Confocal+Raman+Spectroscopy+in+Multicomponent+Polymeric+Coatings-Model+Validation.">Measurement of Concentration Profiles Using Confocal Raman Spectroscopy in Multicomponent Polymeric Coatings-Model Validation.</a> J. Appl. Polym. Sci. 128, 3906-3918 (2013).</li></ol>

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用于HD和VX的油漆质量传递的参数是通过蒸气排放数据的数值反演分析确定。与计算出的参数，有可能再产生随时间变化的浓度梯度映射为在油漆涂层的污染物分布。逆分析结果表明，HD的在SD涂料中的溶解度比VX为高，但扩散度为约5倍以下。该结果表明，HD污染是高度浓缩在涂层的表面上，而对VX污染信息通过SD漆涂层穿透。因此，对于标清喷漆净化需求将有所不同根据化学污染物。这种方法的应?...

用的材料污染的化学战剂相关联的质量传递机构是由各种卷积处理，其中包括物理状态转换，移动物种之间的化学相互作用，与材料界面驱动。开发有效的净化技术，优化的净化程序，以及预测模式，这一点是至关重要的污染过程是众所周知的，包括污染物的运输成材料通过吸收和随后的化学排放回环境中。因此，当务之急是方法被开发，可用于评估污染物质对由于环境条件的地下浓度分布。甲连续尺度，基于物理学的模型的开发是为了预测在被污染的基底吸收剂的浓度分布。实验得出的质量传递参数使T的预测他蒸气的污染物质净化后排放。的预测中的材料的浓度分布的能力可以促进潜在蒸气危害的评估，并反过来，使毒性危险1的准确的诊断。这种方法允许对污染物的材料对特定质量传输参数，如扩散和饱和浓度的估算，这反过来允许建模的其他方案和条件。在这项研究中，我们已经处理过的溶剂分散，聚氨酯漆涂料液相污染的化学战剂双（2 -氯乙基）硫醚（蒸芥菜，疱剂HD）和O -乙基南- [2 - （异丙基氨基）乙基] methylphosphonothioate（VX），有机磷神经毒剂。 所开发的方法，从污染的材料，包括像HD和VX化学战剂的特征气体解吸曲线，无许多妨碍其他限制接近2,3。时间分辨质谱污染物演变测量受污染的基材允许与反分析扩散输运模型来计算污染物的材料，包括从原来的渗透活动启动污染物的吸收浓度分布质量传输参数。与建立在材料的环境条件的划定污染物浓度分布的预测能力来评估毒性危险，并最终制定有效去污路线的能力。 在本文中，与样品制备相关的细节被提出，包括化学战剂污染的工作，以及从污染的材料的实验数据的收集和随后的模型4。实验中同样进行递减进项税的化学污染物和去污剂源文献5中，并在接下来的部分将讨论。在包括在图1的流程图，用于样品制备和分析步骤。

<table><tbody><tr><td>Stainless Steel Tray</td><td>McMaster Carr</td><td>4189T1</td><td>13-5/8&quot; L x 9-3/4&quot; W, http://www.mcmaster.com/#stainless-steel-trays/=p8dcgp</td></tr><tr><td>MIL-DTL-53039 solvent-dispersible aliphatic polyurethane coating system</td><td></td><td></td><td>Substrates supplied by internal source</td></tr><tr><td>Environmental Chamber</td><td></td><td></td><td>Custom Design. Full details on vacuum chamber specifications and materials included in reference 4.</td></tr><tr><td>bis(2-chloroethyl) sulfide</td><td>CASARM</td><td></td><td>TOXIC</td></tr><tr><td>&lt;em&gt;O&lt;/em&gt;-ethyl &lt;em&gt;S&lt;/em&gt;-[2-(diisopropylamino)ethyl] methylphosphonothioate</td><td>CASARM</td><td></td><td>TOXIC</td></tr><tr><td>Pipetter</td><td>Fisher Scientific</td><td>22260201</td><td>Range of 1.0 &amp;micro;l to 10 ml</td></tr><tr><td>Pipetter Tips</td><td>Fisher Scientific</td><td>13-683-709</td><td>0.1 ml Volume</td></tr><tr><td>Stainless Steel High Vacuum Experimental Chamber</td><td></td><td></td><td>Custom Design</td></tr><tr><td>Quadrupole Mass Spectrometer</td><td>ExTorr</td><td>RGA300</td><td></td></tr><tr><td>Stainless Steel Tweezers</td><td>McMaster Carr</td><td>5516A15</td><td>Any stainless steel tweezers are appropriate.</td></tr><tr><td>Glass Extraction Jar</td><td>Scientific Specialties</td><td>170808</td><td>Jar fits a ~5 cm diameter substrate. Different glass jars with teflon lined lids are appropriate for different sized substrates.</td></tr><tr><td>Chloroform</td><td>Sigma-Aldrich</td><td>650498</td><td>HARMFUL. The extraction solvent for HD may change depending on the analytical method.</td></tr><tr><td>Isopropanol</td><td>Sigma-Aldrich</td><td>650447</td><td>HARMFUL. The extraction solvent for VX may change depending on the analytical method.</td></tr><tr><td>Pasteur Pipette</td><td>VWR</td><td>14673-010</td><td>size = 5 3/4&quot;</td></tr></tbody></table>

an inverse analysis approach to the characterization of chemical transport in paints

直接表征材料中发生的化学品运输和互动的能力（ 即地下动态）是了解污染物大众运输及净化材料的能力的重要组成部分。如果材料被污染，随着时间的推移，高毒性的化学物质（如化学战剂的种类）出来的材料的运输可导致蒸汽暴露或转移到皮肤上，这可能会导致经皮暴露于谁与交互人员材料。由于化学战剂的高毒性，微量化学量的释放是显著关注。吸收剂测绘地下浓度分布和迁移特征使暴露的危险在未经测试的情况进行评估。此外，这些工具可以用来表征地表下的反应动力学，最终设计出更好的去污剂或净化程序。牛逼ö实现这一目标，逆分析质量传递模型方法的开发，利用蒸气排放的从被污染的油漆涂料作为用于对地下浓度分布计算的输入参数的时间分辨质谱法测量。提供了样品制备的详细信息，包括污染物和材料处理，质谱仪的应用程序发出的污染气体的测量，以及反分析使用基于物理学的扩散模型，以确定现场化学战剂的输运性质的实施，包括蒸馏水芥菜（HD）和VX神经毒剂。

图3显示基于时间分辨质谱为VX和HD（主要质量碎片VX所计算的质量流量和HD从SD涂底物的例子在顶板质量电荷比，m / z = 114和109，分别）。四极杆质谱仪，主要有三个组成部分:离子发生器，质量分析器或过滤器，以及充电检测器。气体物质通过电子轰击电离（热丝式电子源）电离，而所产生的离子被注入到四极质量过滤器的途中到达法拉第杯或电子倍增检测器，用于测量离子电?...

Watch this Scientific Journal Video about An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints at JoVE.com

An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

在本文中，用于量化在各种材料的化学品的质量传输参数的过程被呈现。这个过程涉及采用一逆分析基于扩散模型为蒸气所记录的实时，质谱法在高真空中发射分布。

一个反分析方法化工运输的油漆表征

The ability to directly characterize chemical transport and interactions that occur within a material (i.e., subsurface dynamics) is a vital component in ...

an-inverse-analysis-approach-to-characterization-chemical-transport

Universidad San Sebastian

Research

JoVE Journal

Chemistry

8.4K 次观看.  U.S. Army Edgewood Chemical Biological Center. 在本文中，用于量化在各种材料的化学品的质量传输参数的过程被呈现。这个过程涉及采用一逆分析基于扩散模型为蒸气所记录的实时，质谱法在高真空中发射分布。 

视频: An Inverse Analysis Approach to the Characterization of Chemical Transport in Paints

A Whole Cell Bioreporter Approach to Assess Transport and Bioavailability of Organic Contaminants in Water Unsaturated Systems

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is not an appropriate measure for its availability; bioavailability rather depends on the dynamic interplay of potential mass transfer (flux) of a compound to a microbial cell and the capacity of the latter to degrade the compound. In water-unsaturated parts of the soil, mycelia have been shown to overcome bioavailability limitations by actively transporting and mobilizing organic compounds over the range of centimeters. Whereas the extent of mycelia-based transport can be quantified easily by chemical means, verification of the contaminant-bioavailability to bacterial cells requires a biological method. Addressing this constraint, we chose the PAH fluorene (FLU) as a model compound and developed a water unsaturated model microcosm linking a spatially separated FLU point source and the FLU degrading bioreporter bacterium Burkholderia sartisoli RP037-mChe by a mycelial network of Pythium ultimum. Since the bioreporter expresses eGFP in response of the PAH flux to the cell, bacterial FLU exposure and degradation could be monitored directly in the microcosms via confocal laser scanning microscopy (CLSM). CLSM and image analyses revealed a significant increase of the eGFP expression in the presence of P. ultimum compared to controls without mycelia or FLU thus indicating FLU bioavailability to bacteria after mycelia-mediated transport. CLSM results were supported by chemical analyses in identical microcosms. The developed microcosm proved suitable to investigate contaminant bioavailability and to concomitantly visualize the involved bacteria-mycelial interactions.

A whole cell bioreporter assay with Burkholderia sartisoli RP037-mChe was developed to detect fractions of an organic contaminant (i.e., fluorene) available for bacterial degradation after active transport by mycelia bridging air-filled pores in a water unsaturated model system.

全细胞Bioreporter方法​​评估交通有机污染物的生物利用度和水饱和系统

Bioavailability of contaminants is a prerequisite for their effective biodegradation in soil. The average bulk concentration of a contaminant, however, is ...

科研

环境科学

Diffuse Reflectance Infrared Spectroscopic Identification of Dispersant/Particle Bonding Mechanisms in Functional Inks

In additive manufacturing, or 3D printing, material is deposited drop by drop, to create micron to macroscale layers. A typical inkjet ink is a colloidal dispersion containing approximately ten components including solvent, the nano to micron scale particles which will comprise the printed layer, polymeric dispersants to stabilize the particles, and polymers to tune layer strength, surface tension and viscosity. To rationally and efficiently formulate such an ink, it is crucial to know how the components interact. Specifically, which polymers bond to the particle surfaces and how are they attached? Answering this question requires an experimental procedure that discriminates between polymer adsorbed on the particles and free polymer. Further, the method must provide details about how the functional groups of the polymer interact with the particle. In this protocol, we show how to employ centrifugation to separate particles with adsorbed polymer from the rest of the ink, prepare the separated samples for spectroscopic measurement, and use Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS) for accurate determination of dispersant/particle bonding mechanisms. A significant advantage of this methodology is that it provides high level mechanistic detail using only simple, commonly available laboratory equipment. This makes crucial data available to almost any formulation laboratory. The method is most useful for inks composed of metal, ceramic, and metal oxide particles in the range of 100 nm or greater. Because of the density and particle size of these inks, they are readily separable with centrifugation. Further, the spectroscopic signatures of such particles are easy to distinguish from absorbed polymer. The primary limitation of this technique is that the spectroscopy is performed ex-situ on the separated and dried particles as opposed to the particles in dispersion. However, results from attenuated total reflectance spectra of the wet separated particles provide evidence for the validity of the DRIFTS measurement.

Formulation of stable, functional inks is critical to expanding the applications of additive manufacturing. In turn, knowledge of the mechanisms of dispersant/particle bonding is required for effective ink formulation. Diffuse Reflectance Fourier Transform Infrared Spectroscopy (DRIFTS) is presented as a simple, inexpensive way to gain insight into these mechanisms.

弥漫分散剂/粒子绑定机制反射红外光谱鉴定功能性油墨

In additive manufacturing, or 3D printing, material is deposited drop by drop, to create micron to macroscale layers.  A typical inkjet ink is a colloidal ...

化学

Analyzing the Photo-oxidation of 2-propanol at Indoor Air Level Concentrations Using Field Asymmetric Ion Mobility Spectrometry

We demonstrate a versatile protocol to be used for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) volatile organic carbons (VOCs), illustrating this with a titanium dioxide based catalyst, and the VOC 2-propanol. The protocol takes advantage of field asymmetric ion mobility spectroscopy (FAIMS), an analysis tool that is capable of continuously identifying and monitoring the concentration of VOCs such as 2-propanol and acetone at the ppb level. The continuous nature of FAIMS allows detailed kinetic analysis, and long-term reactions, offering a significant advantage over gas chromatography, a batch process traditionally used in air purification characterization. The use of FAIMS in photocatalytic air purification has only recently been used for the first time, and with the protocol illustrated here, the flexibility in allowing alternative VOCs and photocatalysts to be tested using comparable protocols offers a unique system to elucidate photocatalytic air purification reactions at low concentrations.

A protocol for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) model volatile organic carbons such as 2-propanol is described.

用场不对称离子迁移光谱法分析 2-丙醇在室内空气浓度中的光氧化作用

We demonstrate a versatile protocol to be used for determining the effectiveness of photocatalysts in degrading indoor air concentration (ppb) volatile ...

Original Experimental Approach for Assessing Transport Fuel Stability

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several technological changes to fulfill environmental and economic requirements. These developments have resulted in increasingly severe operating conditions whose suitability for conventional and alternative fuels needs to be addressed. For example, fatty acid methyl esters (FAMEs) introduced as biodiesel are more prone to oxidation and may lead to deposit formation. Although several methods exist to evaluate fuel stability (induction period, peroxides, acids, and insolubles), no technique allows one to monitor the real-time oxidation mechanism and to measure the formation of oxidation intermediates that may lead to deposit formation. In this article, we developed an advanced oxidation procedure (AOP) based on two existing reactors. This procedure allows the simulation of different oxidation conditions and the monitoring of the oxidation progress by the means of macroscopic parameters, such as total acid number (TAN) and advanced analytical methods like gas chromatography coupled to mass spectrometry (GC-MS) and Fourier Transform Infrared - Attenuated Total Reflection (FTIR-ATR). We successfully applied AOP to gain an in-depth understanding of the oxidation kinetics of a model molecule (methyl oleate) and commercial diesel and biodiesel fuels. These developments represent a key strategy for fuel quality monitoring during logistics and on-board utilization.

Oxidation stability of transport fuels has become a concern for future fuel development. This work presents an original methodology developed by IFP Energies Nouvelles for assessing fuel stability using two different reactors. This methodology was successfully applied to gain an in-depth understanding of the oxidation kinetics and pathways of model molecules and commercial fuels.

评定运输燃料的稳定性原始实验方法

The study of fuel oxidation stability is an important issue for the development of future fuels. Diesel and kerosene fuel systems have undergone several ...

In Situ Visualization of the Phase Behavior of Oil Samples Under Refinery Process Conditions

To help address production issues in refineries caused by the fouling of process units and lines, we have developed a setup as well as a method to visualize the behavior of petroleum samples under process conditions. The experimental setup relies on a custom-built micro-reactor fitted with a sapphire window at the bottom, which is placed over the objective of an inverted microscope equipped with a cross-polarizer module. Using reflection microscopy enables the visualization of opaque samples, such as petroleum vacuum residues, or asphaltenes. The combination of the sapphire window from the micro-reactor with the cross-polarizer module of the microscope on the light path allows high-contrast imaging of isotropic and anisotropic media. While observations are carried out, the micro-reactor can be heated to the temperature range of cracking reactions (up to 450 &#176;C), can be subjected to H2 pressure relevant to hydroconversion reactions (up to 16 MPa), and can stir the sample by magnetic coupling. 
Observations are typically carried out by taking snapshots of the sample under cross-polarized light at regular time intervals. Image analyses may not only provide information on the temperature, pressure, and reactive conditions yielding phase separation, but may also give an estimate of the evolution of the chemical (absorption/reflection spectra) and physical (refractive index) properties of the sample before the onset of phase separation.

In Situ Visualization of the Phase Behavior of Oil Samples Under Refinery Process Conditions

This article describes a setup and method for the in situ visualization of oil samples under a variety of temperature and pressure conditions that aim to emulate refining and upgrading processes. It is primarily used for studying isotropic and anisotropic media involved in the fouling behavior of petroleum feeds.

在油样品的相行为在炼油工艺条件的原位可视化

To help address production issues in refineries caused by the fouling of process units and lines, we have developed a setup as well as a method to ...

工程学

Using Cyclic Voltammetry, UV-Vis-NIR, and EPR Spectroelectrochemistry to Analyze Organic Compounds

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance (EPR) or ultraviolet-visible and near-infrared (UV-Vis-NIR) spectroscopies, we obtain useful information such as electron affinity, ionization potential, band-gap energies, the type of charge carriers, and degradation information that can be used to synthesize stable organic electronic devices. In this study, we present electrochemical and spectroelectrochemical methods to analyze the processes occurring in active layers of an organic device as well as the generated charge carriers.

In this article, we describe electrochemical, electron paramagnetic resonance, and ultraviolet-visible and near-infrared spectroelectrochemical methods to analyze organic compounds for application in organic electronics.

利用循环伏安法、紫外-近红外光谱和 EPR 光谱电化学对有机化合物进行分析

Cyclic voltammetry (CV) is a technique used in the analysis of organic compounds. When this technique is combined with electron paramagnetic resonance ...

The Diffusion of Passive Tracers in Laminar Shear Flow

A simple method to experimentally observe and measure the dispersion of a passive tracer in a laminar fluid flow is described. The method consists of first injecting fluorescent dye directly into a pipe filled with distilled water and allowing it to diffuse across the cross-section of the pipe to obtain a uniformly distributed initial condition. Following this period, the laminar flow is activated with a programmable syringe pump to observe the competition of advection and diffusion of the tracer through the pipe. Asymmetries in the tracer distribution are studied and correlations between the pipe cross-section and the shape of the distribution is shown: thin channels (aspect ratio &#60;&#60; 1) produce tracers arriving with sharp fronts and tapering tails (front-loaded distributions), while thick channels (aspect ratio ~1) present the opposite behavior (back-loaded distributions). The experimental procedure is applied to capillary tubes of various geometries and is particularly relevant to microfluidic applications by dynamical similarity.

A protocol for the study of the diffusion of passive tracers in laminar pressure-driven flow is presented. The procedure is applicable to various capillary pipe geometries.

无源示踪剂在层流剪切流中的扩散

A simple method to experimentally observe and measure the dispersion of a passive tracer in a laminar fluid flow is described. The method consists of ...

Analyzing Mixing Inhomogeneity in a Microfluidic Device by Microscale Schlieren Technique

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren system is constructed from a Hoffman modulation contrast microscope, which provides easy access to the rear focal plane of the objective lens, by removing the slit plate and replacing the modulator with a knife-edge. The working principle of microscale schlieren technique relies on detecting light deflection caused by variation of refractive index1-3. The deflected light either escapes or is obstructed by the knife-edge to produce a bright or a dark band, respectively. If the refractive index of the mixture varies linearly with its composition, the local change in light intensity in the image plane is proportional to the concentration gradient normal to the optical axis. The micro-schlieren image gives a two-dimensional projection of the disturbed light produced by three-dimensional inhomogeneity.
To accomplish quantitative analysis, we describe a calibration procedure that mixes two fluids in a T-microchannel. We carry out a numerical simulation to obtain the concentration gradient in the T-microchannel that correlates closely with the corresponding micro-schlieren image. By comparison, a relationship between the grayscale readouts of the micro-schlieren image and the concentration gradients presented in a microfluidic device is established. Using this relationship, we are able to analyze the mixing inhomogeneity from associate micro-schlieren image and demonstrate the capability of microscale schlieren technique with measurements in a microfluidic oscillator4. For optically transparent fluids, microscale schlieren technique is an attractive diagnostic tool to provide instantaneous full-field information that retains the three-dimensional features of the mixing process.

Herein, we describe a procedure that employs microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. Through calibration, distribution of concentration gradient can be derived from the micro-schlieren image.

由微型条纹分析技术在微流控设备混合不均匀

In this paper, we introduce the use of microscale schlieren technique to measure mixing inhomogeneity in a microfluidic device. The microscale schlieren ...

生物工程

Imaging Corrosion at the Metal-Paint Interface Using Time-of-Flight Secondary Ion Mass Spectrometry

Corrosion developed at the paint and aluminum (Al) metal-paint interface of an aluminum alloy is analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), illustrating that SIMS is a suitable technique to study the chemical distribution at a metal-paint interface. The painted Al alloy coupons are immersed in a salt solution or exposed to air only. SIMS provides chemical mapping and 2D molecular imaging of the interface, allowing direct visualization of the morphology of the corrosion products formed at the metal-paint interface and mapping of the chemical after corrosion occurs. The experimental procedure of this method is presented to provide technical details to facilitate similar research and highlight pitfalls that may be encountered during such experiments.

Time-of-flight secondary ion mass spectrometry is applied to demonstrate the chemical mapping and corrosion morphology at the metal-paint interface of an aluminum alloy after being exposed to a salt solution compared with a specimen exposed to air.

利用飞行时二次离子质谱法成像金属颜料界面的腐蚀

Corrosion developed at the paint and aluminum (Al) metal-paint interface of an aluminum alloy is analyzed using time-of-flight secondary ion mass ...

A Two-Step Pyrolysis-Gas Chromatography Method with Mass Spectrometric Detection for Identification of Tattoo Ink Ingredients and Counterfeit Products

Tattoo inks are complex mixtures of ingredients. Each of them possesses different chemical properties which have to be addressed upon chemical analysis. In this method for two-step pyrolysis online coupled to gas chromatography mass spectrometry (py-GC-MS) volatile compounds are analyzed during a first desorption run. In the second run, the same dried sample is pyrolyzed for analysis of non-volatile compounds such as pigments and polymers. These can be identified by their specific decomposition patterns. Additionally, this method can be used to differentiate original from counterfeit inks. Easy screening methods for data evaluation using the average mass spectra and self-made pyrolysis libraries are applied to speed up substance identification. Using specialized evaluation software for pyrolysis GS-MS data, a fast and reliable comparison of the full chromatogram can be achieved. Since GC-MS is used as separation technique, the method is limited to volatile substances upon desorption and after pyrolysis of the sample. The method can be applied for quick substance screening in market control surveys since it requires no sample preparation steps.

This method for two-step pyrolysis online coupled to gas chromatography with mass spectrometric detection and data evaluation protocol can be used for multi-component analysis of tattoo inks and discrimination of counterfeit products.

一种用于检测纹身油墨成分和假冒产品的两步热解-气相色谱法

Tattoo inks are complex mixtures of ingredients. Each of them possesses different chemical properties which have to be addressed upon chemical analysis. ...

一个反分析方法化工运输的油漆表征

摘要

探索更多视频

此视频中的章节

全细胞Bioreporter方法评估交通有机污染物的生物利用度和水饱和系统

弥漫分散剂/粒子绑定机制反射红外光谱鉴定功能性油墨

用场不对称离子迁移光谱法分析 2-丙醇在室内空气浓度中的光氧化作用

评定运输燃料的稳定性原始实验方法

在油样品的相行为在炼油工艺条件的原位可视化

利用循环伏安法、紫外-近红外光谱和 EPR 光谱电化学对有机化合物进行分析

无源示踪剂在层流剪切流中的扩散

由微型条纹分析技术在微流控设备混合不均匀

利用飞行时二次离子质谱法成像金属颜料界面的腐蚀

一种用于检测纹身油墨成分和假冒产品的两步热解-气相色谱法

一个反分析方法化工运输的油漆表征

摘要

探索更多视频

此视频中的章节

全细胞Bioreporter方法​​评估交通有机污染物的生物利用度和水饱和系统

弥漫分散剂/粒子绑定机制反射红外光谱鉴定功能性油墨

用场不对称离子迁移光谱法分析 2-丙醇在室内空气浓度中的光氧化作用

评定运输燃料的稳定性原始实验方法

在油样品的相行为在炼油工艺条件的原位可视化

利用循环伏安法、紫外-近红外光谱和 EPR 光谱电化学对有机化合物进行分析

无源示踪剂在层流剪切流中的扩散

由微型条纹分析技术在微流控设备混合不均匀

利用飞行时二次离子质谱法成像金属颜料界面的腐蚀

一种用于检测纹身油墨成分和假冒产品的两步热解-气相色谱法

全细胞Bioreporter方法评估交通有机污染物的生物利用度和水饱和系统