Name: x-ray powder diffraction in conservation science: towards routine crystal structure determination of corrosion products on heritage art objects
Uploaded: 2016-06-08T14:00:00.000+00:00
Duration: 9 min 16 s
Description: Watch this Scientific Journal Video about X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects at JoVE.com

作者非常感谢克里斯蒂娜·史蒂芬尼女士进行XRPD测量。玛丽安·舒赫和雷秸卡Kuiter（艺术与设计斯图加特州立学院）被确认为瓷砖（ 图7）的图片。

1.样品制备<ol><li> 材料收集 <ol><li>使用从不透明的蓝绿色凸圆形设置手术刀和镊子上的一个历史性扣仔细挑选样品1少量的（小于1毫克）的数字显微镜下，属于Rosgartenmuseum康斯坦茨（RMK-1964.79）（收集图6）。 </li><li>小心划伤样品2几毫克与釉面瓷砖表面的手术刀，在近代早期，在德国南部生产的约会，与41 X 29×3.5厘米大小，和国家博物馆符腾堡州的集合的一部分（没有的E 3004）（ 图7）。 注:瓷砖储存从20世纪80年代至2004年的木碗柜。背侧很大程度上受到存在作为相纯品（ 图7b）thecotrichite风化。 </li></ol></li><li> 样品保持器的制备 <ol><li>研为s在一个小玛瑙研杵仔细amples。 </li><li>分发样品1，它由几个附聚颗粒（&lt;1毫克），两个薄的X射线透明的聚酰亚胺箔片之间，并与直径为8毫米的中心开口它们安装在透射样品架。固定在衍射的θ-圆的发送样本保持器。 </li><li>在0.5mm直径的硼硅玻璃毛细管填充样品2（约5毫克）。 <ol><li>这样做，将粉末少量成使用刮刀毛细管的漏斗。然后将粉末向下到有电振动器的帮助毛细管的尖端。通过将毛细管厚壁玻璃管小巧的粉和人工挖掘它放在桌子上。 </li><li>继续，直到达到3厘米左右的填充高度。小心切开玻璃毛细管在使用薄刚玉叶片的大约为4厘米的高度，并用打火机密封的开口端。 </li><li>放置少量蜂蜡的黄铜销的开口和熔融使用烙铁它。然后将在熔化的蜡毛细管，并保持直立，直到凝固。安装在测角仪头上的铜针和衍射仪的θ-圈固定测角仪头。 </li><li>最后，通过叠加一个十字数码相机投影支持的扳手手动中心通过反复对准四度的测角头自由的（使用XY使用翻译阶段弯曲滑梯和两个译本2转）安装的毛细血管。 </li></ol></li></ol></li></ol> 2，数据收集<ol><li>为（α1 -辐射与主光束约翰型Ge（111）单色器为了铜K），在室温下使用一个高分辨率粉末衍射仪的样品1（ 图8）和图2（ 图9）的实验室XRPD图谱其中配备有线性位置敏感SI力诚条探测器大约12°2θ的开口。 <ol><li>测量样品1的范围与传输模式0.015°2θ一个步长20小时，从5-85°2θ（扫描模式:传输;扫描类型:2ThetaOmega;欧米茄方式:移动，PSD模式:移动）。为了达到更好的颗粒统计圈旋转上。 </li><li>为期6小时的覆盖在2θ范围5-60°，在德拜 - 谢乐模式0.015°的步长记录的样品2（扫描模式:德拜谢乐;扫描类型:2Theta;欧米茄模式:固定; PSD模式:移动）。为了达到更好的颗粒统计圈旋转上。 </li></ol></li></ol> 3.晶体结构测定和细化注意:对于样品1和2的晶体结构的测定和细化，一个复杂的计算机程序用于11。它用图形用户界面或通过基于文本的输入文件运行秒。后者化妆用一个复杂的脚本语言。使用样品1的结构分析的不同阶段的样品输入文件列在表S1，S2，S4-S8。的一般方法是对样品2相同。 <ol><li> 峰值搜索 <ol><li>使用根据低阶（ 图10）的Savitzky-格雷polynoms的第一和第二导数，以制造商的协议通过在布拉格反射的半最大值设定1-1.5倍全宽的数量级上的回旋范围执行自动峰值搜索（0.12°2θ为样品1），调整噪声阈值，以1.5-2倍的估计的标准偏差（1.74样品1）和限制性的粉末型态其显示清楚区分的峰的部分的检索（5-66° 2θ为背景上面的示例1）。 <ol><li>启动通过双击该图标的程序。点击加载扫描文件 。拉下拉菜单中选择XY数据文件（* .xy）。双击1-GNM-4145-P4-Kapton.xy。 </li><li>扩大范围1-GNM-4145-P4-Kapton.xy。点击发射简介 | 负荷排放简介 | CuK1sharp.lam。 </li><li>点击按钮自动插入峰 。取消选中删除K-2阿尔法峰 。用滑杆设置峰宽为0.12。设置有滑动条噪声阈值 1.74。按下按钮添加峰 。按关闭 。 </li></ol></li><li>手动使用人的眼睛和正确的整合特性，删去非布拉格峰这显然是由于计数统计和添加峰它们是可辨认但隐藏在其它峰的尾部的自动检测到的峰。建立索引文件，套30至40为反射使用S每个样品TANDARD设置，但允许所有晶系（ 表S1）。 <ol><li>鼠标放大模式，使用鼠标滚轮滚动。按F3开峰详细信息窗口。通过按鼠标左键设置峰。按F9删除峰。关闭峰详细信息窗口。 </li><li>点击高峰期 。马克所有峰通过点击位置的黄色。在黄左击标柱。单击全部复制/选择 | 创建索引范围 。取消范围1-GNM-4145-P4-Kapton.xy。选择范围索引 。选择所有布拉维点阵（点击使用突出显示列表中，并设置了刻度线）。 </li></ol></li></ol></li><li> 索引 <ol><li>索引应用"重复使用奇异值分解"算法12（ <stro纳克&gt;表S2），直到发现样品1原始四方单元电池和用于样品2（参见晶胞参数见表1）一个简单单斜晶格。 <ol><li>按运行按钮（F6）。按是保持索引的解决方案。按下按钮解决方案 。通过突出显示左点击按钮1第一个解决方案。右键单击选中的（黄色）解决方案。单击全部复制/选择 。取消选择范围索引 。选择范围1-GNM-4145-P4-Kapton.xy。 注:其他的单元电池示出优点的所有的一个高的数字相比，在表1中列出的具有多个卷但是未观察到的反射的高数量的程序自动建议基于所观察到的反射灭绝的最可能的空间群是P 4。 2 / N（86）样品1和P 2 1 / 一 </em&gt;对于样品2（ 图11）。 </li></ol></li><li>通过搜索使用晶体A卷13（ 表S3）的国际表灭绝手动确认这些发现。公式个单位晶胞从平均体积增量的数量估算Z = 8样品1和Z = 4样品2。 </li></ol></li><li> 全粉谱拟合 <ol><li>装修根据波利14为粉模式进行全粉格局。为的峰轮廓的描述中，使用基本参数（FP）方法15（ 图12）。由高阶正交切比雪夫多项式（一般为8），并描述了在低衍射角散射空气额外的1 / X项模型的背景。洛伦茨-极化因子设置为使用Cu-Kα1拉迪27.3这是布拉格角为戈（111）单色器通货膨胀表S4包含了所有相关的输入参数。 <ol><li>按添加HKL阶段 。扩大范围1-GNM-4145-P4-Kapton.xy。展开hkl_Phase。点击索引详细 | 粘贴索引的详细信息 。单击背景 。改变以 8（精炼）。勾选1 / X BKG（精炼）。 </li><li>点击仪器 。 主半径（mm）设置为217.5。 二级半径（mm）设置为217.5。勾选点探测器 。勾选接收狭缝宽度 ，0.1（固定）的价值。勾选全部轴向模型 。设置源长度（mm）到6（固定）。设置样品长度（mm）到6（固定）。集RS长度（mm）到6（固定）。 </li><li>点击更正 。勾选零误差值为0（精炼）。蜱LP因素 ，价值27.3（修正）。点击杂项 。设置转换次数。步骤 2。勾选启动X，值8。蜱完成 X，值75.点击高峰期 | 删除高峰期 | 是的 。 </li><li>点击hkl_Phase | 微观结构 。勾选惊魂尺寸长 ，价值为200（精炼）。勾选惊魂尺寸克 ，价值为200（精炼）。蜱应变L，值0.1（精炼）。蜱应变G，价值0.1（精炼）。按运行按钮（F6）。 </li></ol></li><li>创建布拉格列表峰适于充电翻转6。点击hkl_Phase。点击电荷翻转输出 。打钩A为CF，价值CF.A 文件 。勾选为CF HKL文件 ，值CF.hkl。按运行按钮（F6）。菜单File下拉| 导出到INP ​​文件 。文件名 ​​，价值Pawley.INP。按保存 。 注:对于连续结构测定，保持所有的仪器，峰形和晶格参数固定的。 </li></ol></li><li> 晶体结构测定 注意:三种方法（以迭代的方式使用）的组合被用来确定试样1和2的晶体结构。 <ol><li>首先，使用充电翻转6通过包含切线式16（ 图13）所支持的方法找到的最较重原子的位置。删除观察REF与门经一个d-间距小于1.28（样品1）和所计算的范围扩大到0.9的d间距。所有必要的参数列于表S5中 。挑从结果列表中识别的电子密度，正确的错误分配原子类型相似的散射力碳，氧，氮手动的原子。 <ol><li>拉下文件文件 | 关闭全部 -点击确认是 。拉下启动启动 | 启动内核 。 </li><li>拉下启动启动 | 设置INP文件 。选择CF.INP（制备输入文本文件，在表S5中列出）。通过单击打开进行确认。按R键取消（F6）。按STOP按钮（F8）约了。 20000次。确认充电翻转按完成是。 </li><li>按临时输出窗口显示在Z矩阵格式按钮来选择原子。按云的选项对话框按 ​​钮。 N设置为挑到45。蜱对称 。 媒体报道按钮。复制临时输出，并将其保存到一个名为FirstGuess.str一个文本文件中。关闭充电翻转图形窗口。 </li></ol></li><li>其次，应用模拟退火7,17（ 图14）的全局最优化方法，找到所有缺失的非氢原子（主要是甲酸盐/乙酸酯基团的碳原子）的位置。使用该软件提供的自动退火方案。仅须的比例因子和位置和/或所选的原子模拟退火的职业参数。对于样品1，合并1.1埃的半径范围内的钠原子和氧原子以检测特殊的位置（ 表S6）。 <ol><li>拉下启动启动 </str翁&gt; | 设为INP文件 。选择SA.INP（制备输入文本文件，在表S6所列）。通过单击打开进行确认。按运行按钮（F6）。几千个周期后按停止按钮（F8）。按确认是以 更新输入文件 。 </li></ol></li><li>第三，关闭模拟退火和注释掉命令Auto_T（0.1）切换到特维德细化5模式。修复所有确定位置参数。包括差异傅立叶图（F OBS -F 计算 ）的计算（ 图15， 表S7）来检查下落不明电子密度。包括在原子列表中还发现了原子和细化原子的位置和占有率。 <ol><li>拉下启动启动 | 设置INP文件 。选择Fourier_search_for_C.INP（准备输入的文本文件，在表S7中列出）。通过单击打开进行确认。按运行按钮（F6）。检查两个图形输出窗口显示几乎完全晶体结构和差异傅立叶地图。 注:循环三种结构求解方法迭代地在故障的情况下。如果需要的话，应用抗凸点约束轻原子（碳原子和氧原子）（ 参见表S7）。 </li></ol></li></ol></li><li> Rietveld精修 <ol><li>对于样品1和2的最终晶体结构精炼中，使用的Rietveld全图案精制方法5（ 图16）。为了避免原子的无意义原子转移在样品2的乙酸和硝酸基，采用所谓的软约束（也称为约束）的基础上理想化的键长和角度。使用标准的软件计算丢失的氢原子的理想化位置是18（ 表S8）。 </li><li>缩小为每个晶体结构的非氢原子的各向同性原子位移参数。在样品二，模型的情况下，引起的微观的布拉格反射通过包括对称的宽度的视各向异性适于二阶球谐。 </li><li>最后创建样品1（ 图17）和样品2的晶体结构（ 图18），并且从现在起，可用于充分定量相分析两个晶体学信息文件（CIFS）的突起的图。这种全定量分析的一个例子是使用样品1的晶体结构在图19中给出。 </li></ol></li></ol>

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The authors have nothing to disclose.

XRPD is a suitable technique for conservation research as it is non-destructive, fast and easy-to-use. XRPD data can be used in routine qualitative analysis, owing to the fact that the powder pattern is a fingerprint signature to the corresponding crystal structure. The biggest advantage of XRPD over other analytic techniques is the ability of performing simultaneous qualitative and quantitative analysis of crystalline constituents in mixtures by using the Rietveld refinement method5. Moreover, the presence of...

保护科学应用于文物的保护科学（通常化学）方法。这包括制作器物的调查（"技术艺术史"？这怎么在那个时候做的），它们的衰变途径为前提，以发展适当的保护治疗。通常情况下，这些研究处理像碳酸盐，甲和乙酸盐金属有机盐。其中一些已用合适的化合物（ 例如，醋）被故意制造的，他人与大气（二氧化碳或从室内空气污染的羰基化合物）劣化反应得到1。作为事实上，许多这些腐蚀材料的晶体结构仍不清楚。这是不幸的事实，因为几何结构的知识有助于保护科学，以便更好地了解生产和衰变反应并允许在混合物的情况下充分定量分析。 根据所关注的材料形成足够的尺寸和质量的单晶的情况下，单晶衍射是选择用于晶体结构的测定方法。如果这些边界条件不满足，粉末衍射是最接近的替代产品。粉末衍射相比单晶衍射作为最大的缺点在于的倒数ð -矢量D *（散射矢量）的取向的信息丢失。换句话说，一个单一的衍射斑点强度被涂污的球体的表面上。这可被认为是三维衍射（=倒数）空间上的投影的粉末图案的一维2θ轴。因此，散射方向不同，但相同或相似的长度载体，系统地重叠或意外使得它很难甚至不可能对这些反射2个独立的 （Figure 1）。这也是最主要的原因，粉末衍射，尽管仅仅四年后的第一单晶实验3,4，主要用于相位识别和量化超过半世纪早期的发明。尽管如此，一个粉末图案的信息内容是巨大的，如从图2中可以很容易地推导出来。真正的挑战，但是，是揭示尽可能多的信息有可能在一个常规的方法。 实现这一目标的一个关键步骤，毫无疑问，来自特维德雨果于1969年5想法是谁发明从粉末衍射数据的晶体结构的细化局部优化技术。该方法不修改单强度而是针对日益复杂，因此采取的高峰重叠本质兼顾的典范整个粉末格局。从那个时候起，用粉末衍射技术，科学家们不再局限于数据分析bŸ方法单晶调查开发。 Rietveld方法的发明几年后，为从头计算结构测定粉末衍射法的功率被识别。如今，自然科学和工程用粉末衍射的几乎所有的分支，以确定更多，更复杂的晶体结构，尽管该方法仍不能视为常规。在过去的十年中，在实验室的新一代粉末衍射仪的设计提供高分辨率，高能量和高强度。更高的分辨率立即带来更好的峰的分离，而更高的能量吸收战斗。基于基本的物理参数更好的峰形说明（ 图3），这样做的好处是布拉格反射从而提供更详细的结构调查更准确的强度。拥有现代化的设备和软件，甚至微观结构参数，如域的大小和microstra在例行的粉末衍射数据推断。 从粉末衍射数据为晶体结构测定所有算法使用单峰强度，整个粉末图案或两者的组合。传统的单晶倒易空间技术往往不能由于可用的观察和结构参数之间的不利比例。这种情况下，与引进的"充电翻转"技术6（ 图4）和全局优化方法中的直接空间，其中模拟退火技术7（ 图5）是最突出的代表发展的显着改变。特别是，引入化学知识到结构确定处理使用刚体或关于键长分子化合物的已知的连接和角度强烈减少必要的参数的数量。换言之，在为每一个原子三个位置参数代替，只有外部（和一些内部）度的原子团的自由的需要来确定。它是该还原结构复杂，这使得该粉末方法的真正替代单晶分析。 作者8,9的两个开创性案例研究证明，它可以解决使用粉末衍射数据的复杂的腐蚀产物复杂的晶体结构。相比于其它方法的晶体学研究的优越性是由以下事实，在这两种情况下，所报告的公式有考虑到解决晶体结构后待校正等等证明。 这两种材料的受调查在博物馆的发生有关，其存储在木制橱柜或暴露于羰基其它形式的污染源。被调查的第一材料是铜甲酸钠氢氧化物九头蛇德，铜4娜4 O（HCOO）8（OH）2∙4H 2 O（样品1），形成于博物馆藏品苏打玻璃/铜合金复合历史性的对象（ 例如，搪瓷），暴露于甲醛和甲酸从木制的储存柜，胶粘剂等 。这种退化现象最近被定性为"玻璃引起的金属腐蚀"10。对于第二个案例，thecotrichite，CA 3（CH 3 COO）3 CL（NO 3）2∙6H 2 O（示例2），被选中。 Thecotrichite是一个经常出现风化形成盐瓷砖和石灰石博物馆的对象，它们存储在橡木柜和陈列柜针状结晶。在这种情况下，木充当源为乙酸与来自工件可溶性氯化物和硝酸盐的盐反应。 在文本中，结构D的各个步骤的以下部分从保护科学应用到腐蚀产物确定过程采用粉末衍射数据进行了详细的介绍。

<table><tbody><tr><td>Stadi-P&amp;nbsp;</td><td>Stoe &amp;amp; Cie GmbH</td><td></td><td>Powder Diffractometer</td></tr><tr><td>Mythen 1-K (450 &amp;mu;m)</td><td>Dectris Ltd.</td><td></td><td>Position Sensitive Detector</td></tr><tr><td>Mark tube borosilicate glass No. 50, 0.5 mm diameter</td><td>Hilgenberg GmbH</td><td>4007605</td><td>Low absorbing capillaries</td></tr><tr><td>Topas 5.0</td><td>Bruker AXS Advanced X-ray Solutions GmbH</td><td></td><td>Powder Diffraction Evaluation Software</td></tr></tbody></table>

x-ray powder diffraction in conservation science: towards routine crystal structure determination of corrosion products on heritage art objects

该晶体结构测定和使用实验室的高分辨率X射线粉末衍射（XRPD）历史悠久的艺术对象的腐蚀产物细化过程是通过两个案例呈现的细节。 被调查的第一材料是铜甲酸钠氢氧化物水合物，铜4娜4 O（HCOO）8（OH）2∙4H 2 O（样品1）构成的钠钙玻璃/铜合金复合历史性的对象（ 例如 ，搪瓷）在博物馆藏品，暴露于甲醛和从木制储藏柜，粘合剂等这种退化现象最近被定性为"玻璃诱导金属腐蚀"发射甲酸。 对于第二个案例，thecotrichite，CA 3（CH 3 COO）3 CL（NO 3）2∙6H 2 O（示例2），被选中，这是一种风化盐形成在其上存储在木制橱柜和陈列柜瓷砖和石灰石对象针状微晶。在这种情况下，木充当源为乙酸与来自工件或其环境可溶性氯化物和硝酸盐的盐反应。 几何结构的知识有助于保护科学，以便更好地了解生产和衰变反应并允许以混合物的常见的情况充分定量分析。

高分辨率XRPD来测定的具有历史意义的对象的两个长知腐蚀产物先前未知的晶体结构。将样品从两个博物馆对象采取的，并仔细研磨它们在传输和毛细管样品架进行密封前（ 图6,7）。用的传输和使用单色X射线德拜-谢乐几何本领域实验室高分辨率粉末衍射仪的状态测量标准进行（ 图8）。 从粉末衍射数?...

Watch this Scientific Journal Video about X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects at JoVE.com

X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects

Modern high resolution X-ray powder diffraction (XRPD) in the laboratory is used as an efficient tool to determine crystal structures of long-known corrosion products on historic objects.

X射线粉末衍射在保护科学:迈向文物艺术品腐蚀产物的常规晶体结构测定

The crystal structure determination and refinement process of corrosion products on historic art objects using laboratory high-resolution X-ray powder ...

x-ray-powder-diffraction-conservation-science-towards-routine-crystal

Research

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Chemistry

15.8K 次观看.  Max-Planck-Institute for Solid State Research. Modern high resolution X-ray powder diffraction (XRPD) in the laboratory is used as an efficient tool to determine crystal structures of long-known corrosion products on historic objects.

视频: X-ray Powder Diffraction in Conservation Science: Towards Routine Crystal Structure Determination of Corrosion Products on Heritage Art Objects

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary interiors, design materials with novel properties, understand the mechanical behavior of materials exposed to very high stresses as in explosions or impacts. Synthesis and structural analysis of materials at extreme conditions of pressure and temperature entails remarkable technical challenges. In the laser heated diamond anvil cell (LH-DAC), very high pressure is generated between the tips of two opposing diamond anvils forced against each other; focused infrared laser beams, shined through the diamonds, allow to reach very high temperatures on samples absorbing the laser radiation. When the LH-DAC is installed in a synchrotron beamline that provides extremely brilliant x-ray radiation, the structure of materials under extreme conditions can be probed in situ. LH-DAC samples, although very small, can show highly variable grain size, phase and chemical composition. In order to obtain the high resolution structural analysis and the most comprehensive characterization of a sample, we collect diffraction data in 2D grids and combine powder, single crystal and multigrain diffraction techniques. Representative results obtained in the synthesis of a new iron oxide, Fe4O5 1 will be shown.

The laser heated diamond anvil cell combined with synchrotron micro-diffraction techniques allows researchers to explore the nature and properties of new phases of matter at extreme pressure and temperature (PT) conditions. Heterogeneous samples can be characterized in situ under high pressure by 2D mapping and combined powder, single-crystal and multigrain diffraction approaches.

在极端的压力和温度的合成和Microdiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

科研

工程学

High Pressure Single Crystal Diffraction at PX^2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the GSECARS 13-BM-C beamline at the Advanced Photon Source. The DAC program at 13-BM-C is part of the Partnership for Extreme Xtallography (PX^2) project. BX-90 type DACs with conical-type diamond anvils and backing plates are recommended for these experiments. The sample chamber should be loaded with noble gas to maintain a hydrostatic pressure environment. The sample is aligned to the rotation center of the diffraction goniometer. The MARCCD area detector is calibrated with a powder diffraction pattern from LaB6. The sample diffraction peaks are analyzed with the ATREX software program, and are then indexed with the RSV software program. RSV is used to refine the UB matrix of the single crystal, and with this information and the peak prediction function, more diffraction peaks can be located. Representative single crystal diffraction data from an omphacite (Ca0.51Na0.48)(Mg0.44Al0.44Fe2+0.14Fe3+0.02)Si2O6 sample were collected. Analysis of the data gave a monoclinic lattice with P2/n space group at 0.35 GPa, and the lattice parameters were found to be: a = 9.496 &#177;0.006 &#197;, b = 8.761 &#177;0.004 &#197;, c = 5.248 &#177;0.001 &#197;, &#946; = 105.06 &#177;0.03&#186;, &#945; = &#947; = 90&#186;.

In this report, we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell at the GSECARS 13-BM-C beamline at the Advanced Photon Source. ATREX and RSV programs are used to analyze the data.

高压单晶衍射PX ^ 2

In this report we describe detailed procedures for carrying out single crystal X-ray diffraction experiments with a diamond anvil cell (DAC) at the ...

化学

Reliable Mechanochemistry: Protocols for Reproducible Outcomes of Neat and Liquid Assisted Ball-mill Grinding Experiments

The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the presence of very small amounts of added solvent. To reproducibly and accurately capture this sensitivity, the experimentalist needs to carefully consider every single factor that can affect the ball mill grinding reaction under investigation, from ensuring the grinding jars are clean and dry before use, to accurately adding the stoichiometry of the starting materials, to validating that the delivery of solvent volume is accurate, to ensuring that the interaction between the solvent and the powder is well understood and, if necessary, a specific soaking time is added to the procedure. Preliminary kinetic studies are essential to determine the necessary milling time to achieve equilibrium. Only then can exquisite phase composition curves be obtained as a function of the solvent concentration under ball mill liquid assisted grinding (LAG). By using strict and careful procedures analogous to the ones here presented, such milling equilibrium curves can be obtained for virtually all milling systems. The system we use to demonstrate these procedures is a disulfide exchange reaction starting from the equimolar mixture of two homodimers to obtain at equilibrium quantitative heterodimer. The latter is formed by ball mill grinding as two different polymorphs, Form A and Form B. The ratio R = [Form B] / ([Form A] + [Form B]) at milling equilibrium depends on the nature and concentration of the solvent in the milling jar.

We present detailed procedures to produce experimental equilibrium curves of the phase composition as a function of solvent concentration in a solid state system under milling conditions.

可靠的化学: 整洁和液体辅助球磨机研磨试验的可再生结果协议

The equilibrium outcomes of ball mill grinding can dramatically change as a function of even tiny variations in the experimental conditions such as the ...

Synchrotron X-ray Microdiffraction and Fluorescence Imaging of Mineral and Rock Samples

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder microdiffraction two-dimensional (2D) maps at beamline 12.3.2 of the Advanced Light Source (ALS), Lawrence Berkeley National Laboratory. Measurements can be performed on any sample that is less than 10 cm x 10 cm x 5 cm, with a flat exposed surface. The experimental geometry is calibrated using standard materials (elemental standards for XRF, and crystalline samples such as Si, quartz, or Al2O3 for diffraction). Samples are aligned to the focal point of the x-ray microbeam, and raster scans are performed, where each pixel of a map corresponds to one measurement, e.g., one XRF spectrum or one diffraction pattern. The data are then processed using the in-house developed software XMAS, which outputs text files, where each row corresponds to a pixel position. Representative data from moissanite and an olive snail shell are presented to demonstrate data quality, collection, and analysis strategies.

We describe a beamline setup meant to carry out rapid two-dimensional x-ray fluorescence and x-ray microdiffraction mapping of single crystal or powder samples using either Laue (polychromatic radiation) or powder (monochromatic radiation) diffraction. The resulting maps give information about strain, orientation, phase distribution, and plastic deformation.

矿物和岩石样品的同步辐射 x 射线 Microdiffraction 和荧光成像

In this report, we describe a detailed procedure for acquiring and processing&#160;x-ray microfluorescence (&#956;XRF), and Laue and powder ...

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 ...

基于膦酸盐的 MOF 的合成和发现：一种溶热方法

Discovery and Synthesis Optimization of Isoreticular Al(III) Phosphonate-Based Metal-Organic Framework Compounds Using High-Throughput Methods

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This manuscript describes the synthesis of metal-organic frameworks (MOFs) from solution using an HT reactor system, resulting in the discovery of various phosphonate-based MOFs of the composition [Al2H12-x(PMP)3]Clx&#8729;6H2O (H4PMP = N,N &#39;-piperazine bis(methylenephosphonic acid)) for x = 4, 6, denoted as Al-CAU-60-xHCl, containing trivalent aluminum ions. This was accomplished under solvothermal reaction conditions by systematically screening the impact of the molar ratio of the linker to the metal and the pH of the reaction mixture on the product formation. The protocol for the HT investigation includes six steps: a) synthesis planning (DOE = design of&#160;experiment) within the HT methodology, b) dosing and working with in-house developed HT reactors, c) solvothermal synthesis, d) synthesis workup using in-house developed filtration blocks, e) characterization by HT powder X-ray diffraction, and f) evaluation of the data. The HT methodology was first used to study the influence of acidity on the product formation, leading to the discovery of Al-CAU-60&#8729;xHCl (x = 4 or 6).

作者聚焦：加速微孔材料化学的发现 

The targeted synthesis of new metal-organic frameworks (MOFs) is difficult, and their discovery depends on the knowledge and creativity of the chemist. High-throughput methods allow complex synthetic parameter fields to be explored quickly and efficiently, accelerating the process of finding crystalline compounds and identifying synthetic and structural trends.

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

High-throughput (HT) methods are an important tool for the fast and efficient screening of synthesis parameters and the discovery of new materials. This ...

X-ray Diffraction

Source: Faisal Alamgir, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA
X-ray diffraction (XRD) is a technique used in materials science for determining the atomic and molecular structure of a material. This is done by irradiating a sample of the material with incident X-rays and then measuring the intensities and scattering angles of the X-rays that are scattered by the material. The intensity of the scattered X-rays are plotted as a function of the scattering angle, and the structure of the material is determined from the analysis of the location, in angle, and the intensities of scattered intensity peaks. Beyond being able to measure the average positions of the atoms in the crystal, information on how the actual structure deviates from the ideal one, resulting for example from internal stress or from defects, can be determined.
The diffraction of the X-rays, that is central to the XRD method, is a subset of the general X-ray scattering phenomena. XRD, which is generally used to mean can wide-angle X-ray diffraction (WAXD), falls under several methods that use the elastically scattered X-ray waves. Other elastic scattering based X-ray techniques include small angle X-ray scattering (SAXS), where the X-rays are incident on the sample over the small angular range of 0.1-100 typically). SAXS measures structural correlations of the scale of several nanometers or larger (such as crystal superstructures), and X-ray reflectivity that measures the thickness, roughness, and density of thin films. WAXD covers an angular range beyond 100.

X-Ray Diffraction for Determining Atomic and Molecular Structure

X 射线衍射

Source: Faisal Alamgir, School of Materials Science and Engineering, Georgia Institute of Technology, Atlanta, GA
X-ray diffraction (XRD) is a technique ...

教育

JoVE Science Education

材料工程

X-ray Fluorescence (XRF)

Source: Laboratory of Dr. Lydia Finney &#8212; Argonne National Laboratory
X-ray fluorescence is an induced, emitted radiation that can be used to generate spectroscopic information. X-ray fluorescence microscopy is a non-destructive imaging technique that uses the induced fluorescence emission of metals to identify and quantify their spatial distribution.

X射线粉末衍射在保护科学:迈向文物艺术品腐蚀产物的常规晶体结构测定

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在极端的压力和温度的合成和Microdiffraction

高压单晶衍射PX ^ 2

可靠的化学: 整洁和液体辅助球磨机研磨试验的可再生结果协议

矿物和岩石样品的同步辐射 x 射线 Microdiffraction 和荧光成像

利用飞行时二次离子质谱法成像金属颜料界面的腐蚀

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

基于高通量方法的等网状Al（III）膦酸盐基金属有机骨架化合物的发现与合成优化

X 射线衍射

X 射线荧光光谱 (XRF)