作者希望承认托莱多大学开办的资金, 以及美国化学学会赫尔曼 Frasch 基金会的资金, 部分支持这项工作。托马斯爱上先生得到了他的帮助, 他开发了一个合适的压力表来测量反应压力。史蒂夫. Modar 先生对有用的讨论表示感谢。

警告: 1) 通过反复试验, 下列议定书被认为是安全的。然而, 当密封瓶, 在整个反应, 特别是当打开反应时应谨慎, 因为反应瓶的不均匀性可能导致设备故障。在使用前, 应检查瓶子的物理缺陷。瓶子应该被放置在某种形式的爆炸盾或罩窗扇后, 立即密封, 以防止事故, 如果瓶子失败。2) 虽然几乎没有机会窒息由于少量 CO2使用, 反应应该被设置并且打开在一个通风良好的区域或在通风罩。3) 干冰是一种制冷剂, 会引起严重的组织损伤。因此, 在操作时应谨慎, 以避免冻伤, 例如限制直接接触或使用低温手套。4) 干冰将凝结水蒸气, 即在使用前, 干冰应机械脱落, 以确保质量仅为 CO2 (s) 。这可以通过简单地摩擦手指之间的干冰, 或者更安全地, 在手指之间用一个防护层 (如手套或毛巾) 摩擦它来实现。
1. 7.5 毫升瓶中的反应 (空气不被排除)
<ol><li>在干燥的7.5 毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (99.9 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (92.3 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (26.3 毫克, 0.30 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (21.7 ul, 12.1 毫摩尔) 的瓶子。</li>
	<li>称干冰 (26.3 毫克, 0.60 毫摩尔), 并立即加入干冰的瓶子, 同时确保也立即密封瓶聚四氟乙烯衬里帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (6 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (4 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>2. 7.5 毫升瓶中的反应 (净化条件–排除空气)
<ol><li>在干燥的7.5 毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (99.9 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (92.3 毫克, 0.45 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (26.3 毫克, 0.30 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (21.7 ul, 12.1 毫摩尔) 的瓶子。</li>
	<li>把瓶子的平衡, 添加约98毫克干冰, 然后允许 CO2升华, 直到最终质量约26毫克达到, 然后立即密封瓶与聚四氟乙烯衬里帽。 注: 如果可取, 这一步骤可以执行与更多的干冰, 进一步排除空气从瓶子。值得注意的是, 这可能会引入水, 因此可能不是最有效的水敏感反应策略。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (6 毫升) 的反应混合物, 并搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (4 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>3. 40 毫升瓶中的反应 (空气不被排除)
<ol><li>在干燥的40毫升瓶中加入搅拌条。</li>
	<li>将醋酸钯 (33.5 毫克, 0.15 毫摩尔) 加入瓶中。</li>
	<li>将三氟乙酸银 (499.5 毫克, 2.25 毫摩尔) 加入瓶子。</li>
	<li>将苯基碘化物 (461.5 毫克, 2.25 毫摩尔) 加入瓶子。</li>
	<li>将叔戊胺 (131.5 毫克, 1.5 毫摩尔) 加入瓶中。</li>
	<li>将醋酸 (5.0 毫升) 添加到瓶子里。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>加入去离子水 (108.5 ul, 6.02 毫摩尔) 的瓶子。</li>
	<li>称干冰 (131.5 毫克, 3.0 毫摩尔), 并立即加入干冰的瓶子, 同时确保也立即密封瓶聚四氟乙烯衬里帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应瓶搅拌15分钟。</li>
	<li>将反应容器转移到预热板110摄氏度, 搅拌14小时, 然后才允许冷却。</li>
	<li>冷却后, 小心打开小瓶, 以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在小瓶中执行, 也可以将溶液转移到较大的圆底烧瓶中。</li>
	<li>加入1.2 米 HCl (蒽醌) (30 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (20 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 20 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基4苯基丁胺) 作为黄油。</li>
</ol>4. 35 毫升压力管中的反应 (空气不排除)
<ol><li>在干35毫升压力管中加入搅拌条。</li>
	<li>将醋酸钯 (6.7 毫克, 0.03 毫摩尔) 添加到压力管上。</li>
	<li>将三氟乙酸银 (132.5 毫克, 0.6 毫摩尔) 添加到压力管上。</li>
	<li>将苯基碘化物 (183.6 毫克, 0.9 毫摩尔) 添加到压力管上。</li>
	<li>添加 2-甲基n-(3-甲基苄基) 氨基正丁2胺 (57.4 毫克, 0.3 毫摩尔) 到压力管。</li>
	<li>将醋酸 (1.0 毫升) 添加到瓶子, 后跟 11, 13, 33,-hexafluoroisopropanol (1.0 毫升)。 注: 溶液体积与瓶体尺寸的比值是很重要的, 因为 CO2在加入干冰后的立即升华, 如果相对于反应容器的尺寸使用过多, 可以机械地取代溶剂。</li>
	<li>添加去离子水 (21.7 ul, 1.2 毫摩尔) 到压力管。</li>
	<li>称干冰 (1.32 克, 30 毫摩尔), 并立即加入干冰到压力管, 同时确保也立即密封的压力管与适当的聚四氟乙烯螺钉帽。 注: 整个操作应在大约5秒内进行, 以防止在少量 CO2添加的升华和逃逸 (这是缓慢的形成冷冻醋酸周围的干冰)。增加 CO2的数量将是一个近似价值, 并且在我们的手少量镁的偏差是可允许的。</li>
	<li>在室温下将密封反应釜搅拌15分钟。</li>
	<li>将反应容器转移到预热板90摄氏度, 搅拌24小时, 然后才允许冷却。</li>
	<li>冷却后, 在瓶盖上放一条毛巾或软垫手套, 并小心地打开压力管以发泄 CO2。</li>
	<li>除去真空中的所有挥发物。 注: 此操作可以在压力管中使用适当的适配器, 或者解决方案可以转移到更大的圆底烧瓶。</li>
	<li>加入1.2 米 HCl (蒽醌) (12 毫升) 的反应混合物和搅拌开放到空气中15分钟。</li>
	<li>将水的分数转移到一个部位漏斗, 用额外的1.2 米 HCl (8 毫升) 洗涤, 并提取与1:1 二乙基醚/hexanes 混合物 (3 x 8 毫升)。 注: 本有机洗涤含有过量的苯基碘化物和其他中性副产品, 可以处理。</li>
	<li>加入饱和 NH4OH(蒽醌) (10 毫升是一个良好的出发点), 中和并使基本的水溶液。</li>
	<li>用二氯甲烷 (2 x 10 毫升) 提取水层。</li>
	<li>干燥的组合有机馏分在 Na2所以4, 然后过滤成一个 tared 样品瓶。</li>
	<li>在真空中蒸发溶剂, 将该产品 (2-甲基-n-(3-苄基)-4-丁醇2胺) 作为黄油。</li>
</ol>

使用 CO2作为一个指挥小组为 C H 活化刘易斯基本的基体是当前美国临时专利 #62 的焦点608074。

利用范德华状态方程, 可以计算出这些系统的近似压强45 。
情商 1:<img alt="Equation" src="/files/ftp_upload/58281/58281eq1.jpg">
在协议1的条件下, 我们可以假设26.3 毫克的 CO2给n = 5.98 x 10-4 mols
<img alt="Equation 1b" src="/files/ftp_upload/58281/58281eq2.jpg">
粗略估计, 这表明在1号议定书中, 反?...

气体化合物在化学反应中的使用通常需要专门的设备和程序1,2。在工作台刻度上, 某些气体可以直接从油箱中添加, 使用高压调节器3。另一种方法是在低温条件下冷凝气体4,5。虽然有用, 这些战略需要使用专门的压力反应堆与阀门, 这可能是成本高昂的运行许多反应并行。因此, 这可以大大减慢反应筛查的速度。因此, 化学家们发现使用其他方法来介绍这些化合物是可取的。氨可以添加到反应使用不同的羧酸铵盐, 利用弱平衡, 这些盐和自由氨6。转移氢化是烯烃、羰基和硝基基团还原反应的重要策略, 它绕过了以甲酸铵或肼等化合物为 H27的载体的易燃氢气的使用。另一种对这一地区感兴趣的气体是一氧化碳8 -co 可以通过从金属羰基络合物9,10的解放原位产生, 也可以由脱羰产生。来源如合成和芳基11,12,13或氯仿14,15。
在这方面没有取得重大进展的一种气体是二氧化碳16。其中一个原因是, 涉及 CO2的许多转换也需要高温和压力, 因此自动降级到专门的反应堆17,18。然而, 最近开发更多反应性催化剂的努力促进了在 CO219、20、21、22的大气压下运行许多这些反应。我们最近发现了一种反应, 其中二氧化碳可以用来调解γ C (sp3) –H arylation 脂肪胺23。这一战略预计将结合静态指导组方法的好处, 包括酰胺24,25,26,27,28, 磺胺类药物29,30,31,32, thiocarbonyl33,34, 或腙35基指挥小组 (化学鲁棒性), 以容易瞬变指挥小组(减少的步经济)36, 37,38,39。
尽管反应可能发生在 CO2的大气压下, 但对筛查反应的 Schlenk 的需要却是缓慢的。此外, 增加的压力轻微导致改善反应的收益率, 但不能轻易实现使用 Schlenk 线。因此, 我们寻求一种替代战略, 随后确定干冰可以很容易地用作 CO2的固体来源, 可以添加到各种反应容器中, 引入必要量的二氧化碳, 以达到适度压力 (图 1)。虽然在合成中未充分利用, 类似的策略是相当常见的一种方法来生成液体 CO2用于色谱和萃取应用40,41,42,43, 44。利用这一策略, 我们的小组能够快速地筛查大量的反应, 而在2-20 大气压之间获得适度 CO2压力的能力对于提高反应的产量至关重要。在这些条件下, 主要 (1°) 和二次 (2°) 胺可以 arylated 与电子丰富和电子可怜的芳卤化物。

<table><tbody><tr><td>7.5 mL Sample Vial with Screw Cap (Thermoset)</td><td>Qorpak</td><td>GLC-00984</td><td>Can be reused.</td></tr><tr><td>40 mL Sample Vial with Screw Cap (Thermoset)</td><td>Qorpak</td><td>GLC-01039</td><td>Can be reused.</td></tr><tr><td>Pressure Tube, #15 Thread, 7&quot; Long, 25.4 mm O.D.</td><td>Ace Glass</td><td>8648-06</td><td>Can be reused.</td></tr><tr><td>Pie-Block for 2 Dram Vials</td><td>ChemGlass</td><td>CG-1991-P14</td><td>Can be reused.</td></tr><tr><td>Pie-Block for 10 Dram Vials</td><td>ChemGlass</td><td>CG-1991-P12</td><td>Can be reused.</td></tr><tr><td>3.2 mm PTFE Disposable Stir Bars</td><td>Fisher</td><td>14-513-93</td><td>Can be reused.</td></tr><tr><td>C-MAG HS 7 Control Hotplate</td><td>IKA</td><td>20002695</td><td></td></tr><tr><td>Analytical Weighing Balance</td><td>Sartorius</td><td>QUINTIX2241S</td><td></td></tr><tr><td>Double-Ended Micro-Tapered Spatula</td><td>Fisher Scientific</td><td>21-401-10</td><td></td></tr><tr><td>Hei-VAP Advantage - Hand Lift Model with G5 Dry Ice Condenser Rotary Evaporator</td><td>Heidolph</td><td>561-01500-00</td><td></td></tr><tr><td>Bump Trap 14/20 Joint</td><td>ChemGlass</td><td>CG-1322-01</td><td></td></tr><tr><td>&lt;em&gt;tert&lt;/em&gt;-Amyl amine</td><td>Alfa Aesar</td><td>B24639-14</td><td>Used as received.</td></tr><tr><td>2-Methyl-N-(3-methylbenzyl)butan-2-amine</td><td>N/A</td><td>N/A</td><td>Prepared from reductive amination of &lt;em&gt;tert&lt;/em&gt;-amyl amine and 3-tolualdehyde in the presence of sodium borohydride in methanol.</td></tr><tr><td>Palladium Acetate</td><td>Chem-Impex International, Inc.</td><td>4898</td><td>Used as received.</td></tr><tr><td>Silver Trifluoroacetate</td><td>Oakwood Chemicals</td><td>007271</td><td>Used as received.</td></tr><tr><td>Phenyl Iodide</td><td>Oakwood Chemicals</td><td>003461</td><td>Used as received.</td></tr><tr><td>Acetic Acid</td><td>Fisher Chemical</td><td>A38</td><td>Used as received.</td></tr><tr><td>1,1,1,3,3,3-Hexafluoroisopropanol</td><td>Oakwood Chemicals</td><td>003409</td><td>Used as received.</td></tr><tr><td>Deionized Water</td><td></td><td></td><td>Obtained from &lt;em&gt;in-house&lt;/em&gt; deionized water system.</td></tr><tr><td>Dry Ice</td><td>Carbonic Enterprises Dry Ice Inc.</td><td></td><td>&lt;em&gt;Non-food grade&lt;/em&gt; dry ice.</td></tr><tr><td>Concentrated Hydrochloric Acid</td><td>Fisher Chemical</td><td>A144SI</td><td>Diluted to a 1.2 M solution prior to use.</td></tr><tr><td>Diethyl Ether, Certified</td><td>Fisher Chemical</td><td>E138</td><td>Used as received.</td></tr><tr><td>Hexanes, Certified ACS</td><td>Fisher Chemical</td><td>H292</td><td>Used as received.</td></tr><tr><td>Saturated Ammonium Hydroxide</td><td>Fisher Chemical</td><td>A669</td><td>Used as received.</td></tr><tr><td>Dichloromethane</td><td>Fisher Chemical</td><td>D37</td><td>Used as received.</td></tr><tr><td>Sodium Sulfate, Anhydrous</td><td>Oakwood Chemicals</td><td>044702</td><td>Used as received.</td></tr><tr><td>250 mL Separatory Funnel</td><td></td><td></td><td>Prepared &lt;em&gt;in-house&lt;/em&gt; by staff glassblower.</td></tr><tr><td>100 mL Round Bottom Flask</td><td></td><td></td><td>Prepared &lt;em&gt;in-house&lt;/em&gt; by staff glassblower.</td></tr><tr><td>Scientific Disposable Funnel</td><td>Caplugs</td><td>2085136030</td><td></td></tr><tr><td>Borosilicate Glass Scintillation Vials, 20 mL</td><td>Fisher Scientific</td><td>03-337-15</td><td></td></tr><tr><td>5 mm O.D. Thin Walled Precision NMR Tubes</td><td>Wilmad</td><td>666000575</td><td></td></tr><tr><td>Chloroform-&lt;em&gt;d&lt;/em&gt;</td><td>Cambridge Isotope Laboratories, Inc.</td><td>DLM-7</td><td>Used as received.</td></tr></tbody></table>

achieving moderate pressures in sealed vessels using dry ice as a solid co2 source

本文提出了在轻度至中度 CO2压力下, 用干冰进行反应的一般策略。这种技术省却了需要专门的设备来达到适度的压力, 甚至可以用来在更专业的设备和更坚固的反应容器中获得更高的压力。在反应结束时, 瓶子可以很容易地减压在室温下打开。在本例子 CO2担当两个假定的指挥的小组并且方式到钝化胺基体, 从而防止氧化在有机金属反应期间。除了容易添加, 指导组也被排除在真空下, 不需要广泛的净化, 以消除指导组。这一策略允许简便的γ C (sp3) H arylation 脂肪胺, 并有可能被应用于各种其他胺基反应。

遵循这些协议, 有可能向反应瓶收取适量的二氧化碳, 以实现化学反应, 需要 CO2大气。在步骤1中实现的压力计算为大约3大气压 (参见讨论确定这个值), 虽然由于部分溶剂化, 观察到的压力在室温附近2大气压, 应大约2.6 大气在反应条件之下。因此, 在步骤1中的条件下, 2-甲基-4-苯基丁胺可以获得69% 的产量 (图 2)。通过升华 CO2 (步骤 2) 首?...

Watch this Scientific Journal Video about Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source at JoVE.com

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

在这里, 我们提出了一个协议, 以执行反应的简单反应容器在低到中等压力的 CO2。这种反应可以通过在各种容器中进行, 只需以干冰的形式管理二氧化碳, 而不需要昂贵的或精密的设备或装置。

用干冰作为固体 CO2源实现密封容器中的适度压力

Herein is presented a general strategy to perform reactions under mild to moderate CO2 pressures with dry ice. This technique obviates the need for ...

achieving-moderate-pressures-sealed-vessels-using-dry-ice-as-solid

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

9.9K 次观看.  University of Toledo. 在这里, 我们提出了一个协议, 以执行反应的简单反应容器在低到中等压力的 CO2。这种反应可以通过在各种容器中进行, 只需以干冰的形式管理二氧化碳, 而不需要昂贵的或精密的设备或装置。

视频: Achieving Moderate Pressures in Sealed Vessels Using Dry Ice As a Solid CO2 Source

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. Specifically, the sapphire cell enables visual data collection from multiple loadings to solve a set of material balances to precisely determine phase composition. Ternary phase diagrams can then be established to determine the proportion of each component in each phase at a given condition. In principle, any ternary system can be studied although ternary systems (gas-liquid-liquid) are the specific examples discussed herein. For instance, the ternary THF-Water-CO2 system was studied at 25 and 40&#160;&#176;C and is described herein. Of key importance, this technique does not require sampling. Circumventing the possible disturbance of the system equilibrium upon sampling, inherent measurement errors, and technical difficulties of physically sampling under pressure is a significant benefit of this technique. Perhaps as important, the sapphire cell also enables the direct visual observation of the phase behavior. In fact, as the CO2 pressure is increased, the homogeneous THF-Water solution phase splits at about 2 MPa. With this technique, it was possible to easily and clearly observe the cloud point and determine the composition of the newly formed phases as a function of pressure.
The data acquired with the sapphire cell technique can be used for many applications. In our case, we measured swelling and composition for tunable solvents, like gas-expanded liquids, gas-expanded ionic liquids and Organic Aqueous Tunable Systems (OATS)1-4. For the latest system, OATS, the high-pressure sapphire cell enabled the study of (1) phase behavior as a function of pressure and temperature, (2) composition of each phase (gas-liquid-liquid) as a function of pressure and temperature and (3) catalyst partitioning in the two liquid phases as a function of pressure and composition. Finally, the sapphire cell is an especially effective tool to gather accurate and reproducible measurements in a timely fashion.

High-pressure Sapphire Cell for Phase Equilibria Measurements of CO2/Organic/Water Systems

The high pressure sapphire cell apparatus is a unique tool to study, without sampling, phase behavior under a wide range of pressures. Using a cathetometer, very precise volume measurements can be recorded to measure liquid expansion and phase composition. Thus, this synthetic method enables the study of (1) phase equilibria of multi-component mixtures and (2) the partition behavior of catalyst or model compounds as a function of pressure.

高压蓝宝石细胞对CO的相平衡测量<sub&gt; 2</sub&gt; /有机/水系统

The high pressure sapphire cell apparatus was constructed to visually determine the composition of multiphase systems without physical sampling. ...

科研

化学

Biofilm Removal Using Carbon Dioxide Aerosols without Nitrogen Purge

Biofilms can cause serious concerns in many applications. Not only can they cause economic losses, but they can also present a public health hazard. Therefore, it is highly desirable to remove biofilms from surfaces. Many studies on CO2 aerosol cleaning have employed nitrogen purges to increase biofilm removal efficiency by reducing the moisture condensation generated during the cleaning. However, in this study, periodic jets of CO2 aerosols without nitrogen purges were used to remove Pseudomonas putida biofilms from polished stainless steel surfaces. CO2 aerosols are mixtures of solid and gaseous CO2 and are generated when high-pressure CO2 gas is adiabatically expanded through a nozzle. These high-speed aerosols were applied to a biofilm that had been grown for 24 hr. The removal efficiency ranged from 90.36% to 98.29% and was evaluated by measuring the fluorescence intensity of the biofilm as the treatment time was varied from 16 sec to 88 sec. We also performed experiments to compare the removal efficiencies with and without nitrogen purges; the measured biofilm removal efficiencies were not significantly different from each other (t-test, p &gt; 0.55). Therefore, this technique can be used to clean various bio-contaminated surfaces within one minute.

Biofilms on surfaces can be effectively and rapidly removed by using a periodic jet of carbon dioxide aerosols without a nitrogen purge.

去除生物膜使用二氧化碳气溶胶没有氮气吹扫

Biofilms can cause serious concerns in many applications. Not only can they cause economic losses, but they can also present a public health hazard. ...

环境科学

Fizzy Extraction of Volatile Organic Compounds Combined with Atmospheric Pressure Chemical Ionization Quadrupole Mass Spectrometry

Chemical analysis of volatile and semivolatile compounds dissolved in liquid samples can be challenging. The dissolved components need to be brought to the gas phase, and efficiently transferred to a detection system. Fizzy extraction takes advantage of the effervescence phenomenon. First, a carrier gas (here, carbon dioxide) is dissolved in the sample by applying overpressure and stirring the sample. Second, the sample chamber is decompressed abruptly. Decompression leads to the formation of numerous carrier gas bubbles in the sample liquid. These bubbles assist the release of the dissolved analyte species from the liquid to the gas phase. The released analytes are immediately transferred to the atmospheric pressure chemical ionization interface of a triple quadrupole mass spectrometer. The ionizable analyte species give rise to mass spectrometric signals in the time domain. Because the release of the analyte species occurs over short periods of time (a few seconds), the temporal signals have high amplitudes and high signal-to-noise ratios. The amplitudes and areas of the temporal peaks can then be correlated with concentrations of the analytes in the liquid samples subjected to fizzy extraction, which enables quantitative analysis. The advantages of fizzy extraction include: simplicity, speed, and limited use of chemicals (solvents).

Fizzy extraction is a new laboratory technique for analysis of volatile and semivolatile compounds. A carrier gas is dissolved in the liquid sample by applying overpressure and stirring the sample. The sample chamber is then decompressed. The analyte species are liberated to the gas phase due to effervescence.

挥发性有机化合物与大气压化学电离四极杆质谱联用

Chemical analysis of volatile and semivolatile compounds dissolved in liquid samples can be challenging. The dissolved components need to be brought to ...

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and increasing the recovery of coalbed methane. A visualized and constant-volume gas-solid coupling system is introduced here to investigate the influence of CO2 sorption on the physical and mechanical properties of coal. Being able to keep a constant volume and monitor the sample using a camera, this system offers the potential to improve instrument accuracy and analyze fracture evolution with a fractal geometry method. This paper provides all steps to perform a uniaxial compression experiment with a briquette sample in different CO2 pressures with the gas-solid coupling test system. A briquette, cold-pressed by raw coal and sodium humate cement, is loaded in high-pressure CO2, and its surface is monitored in real-time using a camera. However, the similarity between the briquette and the raw coal still needs improvement, and a flammable gas such as methane (CH4) cannot be injected for the test. The results show that CO2 sorption leads to peak strength and elastic modulus reduction of the briquette, and the fracture evolution of the briquette in a failure state indicates fractal characteristics. The strength, elastic modulus, and fractal dimension are all correlated with CO2 pressure but not with a linear correlation. The visualized and constant-volume gas-solid coupling test system can serve as a platform for experimental research about rock mechanics considering the multifield coupling effect.

A Uniaxial Compression Experiment with CO2-Bearing Coal Using a Visualized and Constant-Volume Gas-Solid Coupling Test System

This protocol demonstrates how to prepare a briquette sample and conduct a uniaxial compression experiment with a briquette in different CO2 pressures using a visualized and constant-volume gas-solid coupling test system. It also aims to investigate changes in terms of coal&#8217;s physical and mechanical properties induced by CO2 adsorption.

使用可视化和恒定体积气体-固体耦合测试系统使用 CO2轴承煤的单轴压缩实验

Injecting carbon dioxide (CO2) into a deep coal seam is of great significance for reducing the concentration of greenhouse gases in the atmosphere and ...

Methane Hydrate Crystallization on Sessile Water Droplets

This paper describes a method to form methane hydrate shells on water droplets. In addition, it provides blueprints for a pressure cell rated to 10 MPa working pressure, containing a stage for sessile droplets, a sapphire window for visualization, and temperature and pressure transducers. A pressure pump connected to a methane gas cylinder is used to pressurize the cell to 5 MPa. The cooling system is a 10 gallon (37.85 L) tank containing a 50% ethanol solution cooled via ethylene glycol through copper coils. This setup enables the observation of the temperature change associated with hydrate formation and dissociation during cooling and depressurization, respectively, as well as visualization and photography of the morphologic changes of the droplet. With this method, rapid hydrate shell formation was observed at ~-6 &#176;C to -9 &#176;C. During depressurization, a 0.2 &#176;C to 0.5 &#176;C temperature drop was observed at the pressure/temperature (P/T) stability curve due to exothermic hydrate dissociation, confirmed by visual observation of melting at the start of the temperature drop. The "memory effect" was observed after repressurizing to 5 MPa from 2 MPa. This experimental design allows the monitoring of pressure, temperature, and morphology of the droplet over time, making this a suitable method for testing various additives and substrates on hydrate morphology.

We describe a method to form gas hydrate on sessile water droplets to study the effects of various inhibitors, promoters, and substrates on the hydrate crystal morphology.

甲烷水合物在无柄水滴上的结晶

This paper describes a method to form methane hydrate shells on water droplets. In addition, it provides blueprints for a pressure cell rated to 10 MPa ...

Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures without Metal Nanoparticles while Retaining Gas-phase Bioactivity

Applications such as sensors, batteries, and fuel cells have been improved through the use of highly porous aerogels when functional compounds are encapsulated within the aerogels. However, few reports on encapsulating proteins within sol&#8211;gels that are processed to form aerogels exist. A procedure for encapsulating cytochrome c (cyt. c) in silica (SiO2) sol-gels that are supercritically processed to form bioaerogels with gas-phase activity for nitric oxide (NO) is presented. Cyt. c is added to a mixed silica sol under controlled protein concentration and buffer strength conditions. The sol mixture is then gelled and the liquid filling the gel pores is replaced through a series of solvent exchanges with liquid carbon dioxide. The carbon dioxide is brought to its critical point and vented off to form dry aerogels with cyt. c encapsulated inside. These bioaerogels are characterized with UV-visible spectroscopy and circular dichroism spectroscopy and can be used to detect the presence of gas-phase nitric oxide. The success of this procedure depends on regulating the cyt. c concentration and the buffer concentration and does not require other components such as metal nanoparticles. It may be possible to encapsulate other proteins using a similar approach making this procedure important for potential future bioanalytical device development.

Encapsulating Cytochrome c in Silica Aerogel Nanoarchitectures without Metal Nanoparticles while Retaining Gas-phase Bioactivity

This procedure describes how to encapsulate cytochrome c (cyt. c) in silica (SiO2) sol-gels, process these gels to form bioaerogels, and use these bioaerogels to rapidly recognize nitric oxide (NO) through a gas-phase reaction. This type of protocol may aid in the future development of biosensors or other bioanalytical devices.

细胞色素封装<em&gt;ç</em&gt;在二氧化硅气凝胶Nanoarchitectures没有金属纳米粒子，同时保持气相生物活性

Applications such as sensors, batteries, and fuel cells have been improved through the use of highly porous aerogels when functional compounds are ...

生物工程

Cryogenic Liquid Jets for High Repetition Rate Discovery Science

This protocol presents a detailed procedure for the operation of continuous, micron-sized cryogenic cylindrical and planar liquid jets. When operated as described here, the jet exhibits high laminarity and stability for centimeters. Successful operation of a cryogenic liquid jet in the Rayleigh regime requires a basic understanding of fluid dynamics and thermodynamics at cryogenic temperatures. Theoretical calculations and typical empirical values are provided as a guide to design a comparable system. This report identifies the importance of both cleanliness during cryogenic source assembly and stability of the cryogenic source temperature once liquefied. The system can be used for high repetition rate laser-driven proton acceleration, with an envisioned application in proton therapy. Other applications include laboratory astrophysics, materials science, and next-generation particle accelerators.

This protocol presents the operation and principles of micron-scale cylindrical and planar cryogenic liquid jets. Until now, this system has been used as a high repetition rate target in laser-plasma experiments. Anticipated cross-disciplinary applications range from laboratory astrophysics to material science, and eventually next-generation particle accelerators.

用于高重复率发现科学的低温液体射流

This protocol presents a detailed procedure for the operation of continuous, micron-sized cryogenic cylindrical and planar liquid jets. When operated as ...

工程学

Microfluidic Fabrication Techniques for High-Pressure Testing of Microscale Supercritical CO2 Foam Transport in Fractured Unconventional Reservoirs

Pressure limitations of many microfluidic platforms have been a significant challenge in microfluidic experimental studies of fractured media. As a result, these platforms have not been fully exploited for direct observation of high-pressure transport in fractures. This work introduces microfluidic platforms that enable direct observation of multiphase flow in devices featuring surrogate permeable media and fractured systems. Such platforms provide a pathway to address important and timely questions such as those related to CO2 capture, utilization and storage. This work provides a detailed description of the fabrication techniques and an experimental setup that may serve to analyze the behavior of supercritical CO2 (scCO2) foam, its structure and stability. Such studies provide important insights regarding enhanced oil recovery processes and the role of hydraulic fractures in resource recovery from unconventional reservoirs. This work presents a comparative study of microfluidic devices developed using two different techniques: photolithography/wet-etching/thermal-bonding versus Selective Laser-induced Etching. Both techniques result in devices that are chemically and physically resistant and tolerant of high pressure and temperature conditions that correspond to subsurface systems of interest. Both techniques provide pathways to high-precision etched microchannels and capable lab-on-chip devices. Photolithography/wet-etching, however, enables fabrication of complex channel networks with complex geometries, which would be a challenging task for laser etching techniques. This work summarizes a step-by-step photolithography, wet-etching and glass thermal-bonding protocol and, presents representative observations of foam transport with relevance to oil recovery from unconventional tight and shale formations. Finally, this work describes the use of a high-resolution monochromatic sensor to observe scCO2 foam behavior where the entirety of the permeable medium is observed simultaneously while preserving the resolution needed to resolve features as small as 10 &#181;m.

Microfluidic Fabrication Techniques for High-Pressure Testing of Microscale Supercritical CO2 Foam Transport in Fractured Unconventional Reservoirs

This paper describes a protocol along with a comparative study of two microfluidic fabrication techniques, namely photolithography/wet-etching/thermal-bonding and Selective Laser-induced Etching (SLE), that are suitable for high-pressure conditions. These techniques constitute enabling platforms for direct observation of fluid flow in surrogate permeable media and fractured systems under reservoir conditions.

破碎非常规储层微尺度超临界CO泡沫运输的高压 试验微流体制造技术

Pressure limitations of many microfluidic platforms have been a significant challenge in microfluidic experimental studies of fractured media. As a ...

Working with Hot and Cold Sources

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Working with extreme temperatures, both high and low, is an integral part of many laboratory operations. For many, mentioning a laboratory instantly evokes the mental picture of a Bunsen burner. Bunsen burners and hot plates are used extensively in small and large operations in research laboratories and industries, thus making it necessary for all users to be aware of their safe handling procedures. Hot plates and Bunsen burners are high temperature heat sources, while low temperatures are obtained using dry ice and cryogenic liquids, such as liquid nitrogen. Both dry ice and liquid nitrogen can pose significant hazards to the user if not handled carefully.

Working with Extreme Temperatures: Hot and Cold Sources

使用冷热源

Source: Robert M. Rioux &amp; Suprita Jharimune, Pennsylvania State University, University Park, PA
Working with extreme temperatures, both high and low, ...

教育

JoVE Science Education

基础生物学

实验室安全

Degassing Liquids with Freeze-Pump-Thaw Cycling

Source: Laboratory of Dr. Neil Branda &#8212;&#160;Simon Fraser University
Degassing refers to the process by which dissolved gases are removed from a liquid. The presence of dissolved gases such as oxygen or carbon dioxide can impede chemical reactions that utilize sensitive reagents, interfere with spectroscopic measurements, or can induce unwanted bubble formation.

A number of different techniques are available for degassing liquids; some of these include heating, ultrasonic agitation, chemical removal of gases, substitution with inert gas by bubbling and freeze-pump-thaw cycling. Freeze-pump-thaw cycling is a common and effective method for small scale degassing, and will be demonstrated here in more detail.

随着冻融泵循环脱气液体

Source: Laboratory of Dr. Neil Branda &#8212;&#160;Simon Fraser University
Degassing refers to the process by which dissolved gases are removed from a ...

用干冰作为固体 CO₂源实现密封容器中的适度压力

摘要

探索更多视频

此视频中的章节

高压蓝宝石细胞对CO的相平衡测量

去除生物膜使用二氧化碳气溶胶没有氮气吹扫

挥发性有机化合物与大气压化学电离四极杆质谱联用

使用可视化和恒定体积气体-固体耦合测试系统使用 CO₂轴承煤的单轴压缩实验

甲烷水合物在无柄水滴上的结晶

细胞色素封装

用于高重复率发现科学的低温液体射流

破碎非常规储层微尺度超临界CO泡沫运输的_高压试验微流体制造技术

使用冷热源

随着冻融泵循环脱气液体

用干冰作为固体 CO2源实现密封容器中的适度压力

摘要

探索更多视频

此视频中的章节

高压蓝宝石细胞对CO的相平衡测量

去除生物膜使用二氧化碳气溶胶没有氮气吹扫

挥发性有机化合物与大气压化学电离四极杆质谱联用

使用可视化和恒定体积气体-固体耦合测试系统使用 CO2轴承煤的单轴压缩实验

甲烷水合物在无柄水滴上的结晶

细胞色素封装

用于高重复率发现科学的低温液体射流

破碎非常规储层微尺度超临界CO泡沫运输的高压 试验微流体制造技术

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