Name: an atmospheric pressure plasma setup to investigate the reactive species formation
Uploaded: 2016-11-03T14:00:00.000+00:00
Duration: 8 min 36 s
Description: Watch this Scientific Journal Video about An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation at JoVE.com

The authors thank Chris Mortimer, Chris Rhodes (Department of Chemistry workshops) and Kari Niemi (York Plasma Institute) for their help with the equipment. The work was supported by the Leverhulme Trust (grant No. RPG-2013-079) and EPSRC (EP/H003797/1 &amp; EP/K018388/1).

1.屏蔽等离子设置<ol><li>放置在笼子里面的电环境的所有部分:电源，电压/电流仪，电源线，等离子电极，等离子体射流等 </li><li>确保轿厢内有足够的空间，使得活电极，接地电极和各电缆不与彼此或金属网接触。 </li><li>装备笼与连接到等离子体电源，以避免从高电压电极电击的等离子体操作期间的风险的联锁。 </li><li>放置保持器的外表面上的电压和频率控制，以允许参数的变化不中断等离子体操作。 </li><li>地面全金属支持的网笼，并通过他们向布线接地插头粘接笼自身内部。 </li></ol> 2.放电参数<ol><li>接地电极下方Ø现场电极位置n中的玻璃管（ 即 ，更接近于管喷嘴）。 </li><li>电压探头连接到等离子体电源来测量的工作电压，并通过圆形电流探头通过接地电极来监测返回电流。 </li><li>两者的电压和电流探头连接到示波器，监测电流，电压和等离子体操作频率（通过电流或电压探针测定）。 </li><li>设置气体通过玻璃管2 SLM使用质量流量控制器（流量控制器）的流动。 </li><li>点燃等离子体中与进料气体氦穿过它通过打开的等离子体电源的玻璃管。从探针使用的读数，分别放电的电压和频率设置为18千伏和25千赫。 注意:参数变化被进行，以确定的最小电压和频率在该放电与所有实验中的最高分子含量存在。钍e增分子内容需要更高的电压为等离子体被点燃。注意，升高的电压可导致等离子体的显著气体温度增加，从而导致增加的液体试样的蒸发。 </li><li>保持电压在所有实验不变。 </li></ol> 3.引入外加剂原料气<ol><li>第二MFC连接到使用一个T形连接器的主要进料气体管线。 </li><li>添加的水蒸汽的原料气体，通过网笼的Drechsel烧瓶充满水和位于外侧（上顶或上侧）指示氦气的MFC调节流动。 </li><li>通过分割进料气体的流动获得饱和的期望水平。气流（200sccm的）通过Drechsel烧瓶用水（H 2 16 O）的直接的10％，实现了进料气体的10％的饱和度。 </li><li>使用T形连接器，结合这充分水蒸气饱和气体与的90％（1800 sccm）的干气流。 </li></ol> 4.反应堆<ol><li>制备由两部分组成，上和下的玻璃反应器中。装备的与排气管的下部。 </li><li>该玻璃反应器在等离子体射流的喷嘴的位置。 </li><li>插入等离子体喷嘴入在反应器的上部的开口内的橡胶索环。 </li><li>准备在支架上的顶部由一般的良好贮存器的容器中。使两个支架和由电介质材料（ 例如 ，玻璃，石英玻璃）的井。 </li><li>放置样品容器的反应器内，以便它暴露于从喷射的喷嘴的等离子体产生的废水。 </li><li>把液体H 2 17 O样品的样品容器内。用于检测羟基自由基，使用5,5-二甲基-1- pyrroline- N-氧化物（DMPO）自旋阱中的溶液（见5.1）。 注:自旋阱的选择以及液体样品的选择玉米ponents取决于研究的具体种类。例如，•OH自由基的源使用H 2 16 O / H 2 17 O和DMPO自旋陷阱的研究。 •H基的源需要使用的H 2 O / D 2 O中（气体和液体）。1.叔丁基-α苯基硝酮（PBN）的应用于检测的•H基的。在他的情况下，用H 2 O蒸气等离子体，它被证明主要捕集氢基，而DMPO形成大多DMPO-OH的加合物15。 </li><li>通过毛玻璃表面接触连接两个反应器部分。 </li></ol> 5.自旋自由基捕获的<ol><li>用所需浓度制备所选择的自旋捕集器的解决方案。对于水溶液，使用去离子水。对于硝酮自旋陷阱（如DMPO），使用100毫米的浓度。 </li><li>预冲洗与原料气（2 SLM）的反应器中持续30秒。 </li><li> IGN伊特等离子体（见2.5）和暴露的液体试样向等离子体流出物的时间设定的时间（ 例如 ，60秒）。 </li><li>所需的曝光时间后，关闭等离子体电源并打开反应器。从反应器中取出样品容器。 </li><li>收集样品，并使用电子顺磁共振光谱法（EPR）15进行分析。 </li></ol>

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The authors have nothing to disclose.

在这里，我们演示了如何使用一个内部的内置常压等离子体设置的。金属网笼有助于实现与从外场最小化干扰通过任何等离子体诱导字段保护附近的敏感设备从可能的干扰和/或损坏可再现等离子体的条件下，在同一时间。设置的屏蔽（隔离罩）取决于操作等离子体和其电气特性的类型。这样做的目的是为了确保不存在在等离子体操作外部干扰，避免等离子体字段与周围设备的干扰。在这种情况下，网目尺寸为22毫米，然而，可能需要使用不同的等离子体减小目尺寸。使用电压和连接到示波器电流探测器的等离子体操作参数进行控制。引入高压探头的显著改变电环境，因此探针必须成为电气系统的一部分，并且被断定ioned贯穿所有实验中以同样的方式。 利用玻璃反应器中包封样品和等离子流的允许从反应体系经常未知组合物的环境气氛的排斥。于所呈现的结果（见上文），它被用来确定等离子体诱导的活性氧的暴露于等离子体流出物中的水样中的源。这种调查是可能的，如果液体水的分子，并在进料气体（蒸气）的水可以区别。以确定是否形成在气相或从液体水分子的羟基自由基，同位素标记的水被引入:H 2 17 O作为液体介质中，进料气体中的 H 2 16 O蒸汽。如果假设实验在一个开放的气氛中进行，这两个阶段之间进行区分会受到阻碍水蒸汽在周围空气中存在。一个减少周围大气的影响的替代方法被证明在文献中，在其使用的保护气体17防止从大气到等离子体流出物中的物质的扩散。保护气体（N 2 O 2）创建与已知成分18气帘。在这个手稿提出的反应器是一个简单的方法，以消除环境空气组分（如水蒸气）的影响，并且可以与不同的等离子体射流而不引入附加的气体流被使用。类似于•OH自由基的•水平的根本源可以通过使用D 2 O / H 2 O系统来确定。如上所述的廉价的D 2 O中，也可引入到进料气作为蒸气。 的气体用H 2 O蒸气饱和是由前称量Drechsel烧瓶中并鼓泡气流THROU之后确定GH它。的气体的相对湿度（ 即 ，饱和度）被蒸发的水的量和气体通过通过量计算出来。 需要注意的是在延长的试验中，在Drechsel烧瓶中的液体的温度可能会降低由于蒸发。相对湿度被计算为一个特定的温度。计算出的值与文献19进一步比较，以确定进料气体的相对湿度。我们已经凭经验发现通过一个充满水的Drechsel高达2 SLM氦的流烧瓶中完全用水蒸气饱和的气体。然而，升高的流速可能不允许气体的足够的停留时间在液体为完全饱和。其它饱和技术可能需要。 另一个挑战性的任务是确保没有周围的空气中存在的系统。与进料气体的反应器中的预冲洗以除去残留的空气。预冲洗所需的时间将取决于反应器的体积和进料气体的流动上。诸如氦进料气体等离子体系统没有外部环境空气的扩散和夹带到系统的可使用•NO自由基捕获反应进行测试。由选自N 2等离子体和O的空气的2分子生成的一氧化氮可通过EPR作为（MGD）2 Fe的自由基加合物2+络合物20（MGD = N-甲基-D-葡糖胺二硫代氨基甲酸）来检测。在完全不存在空气的情况下，加合物的EPR信号没有观察到。由于没有在反应器外部的水分子可以通过以下实验证明。 D 2 O中的液体样品暴露于干燥的进料气体等离子体。曝光后样品的NMR分析揭示了在曝光期间带入液体中氧化氢量。这允许估计在tubin残留的 H 2 O含量克用于在实验中的进料气体15。 样本容器的设计是在实验工作的关键。最初，我们用塑料和玻璃离心管未遂。具有相对高的等离子体的进料气体流一起，开口的小直径不让周围空气穿透离心管中。然而，这有许多缺点。等离子体显示拱和微量离心管的边缘附近大的温度上升。从气相到液体的种类的输送也显著效率较低由于不同的气相动力学和液体试样的低表面积（和体积大）。因此，液体样品的表面积是为反应性物质的递送从气相到液体样品是至关重要的。这是短命的基团特别重要。液体试样容器，因此必须设计成允许暴露液体具有用于高效的扩散的高表面积。样品也应具有低的深度，以减少液体试样的对流相关的限制。它必须考虑到该高架气体流量，特别是与点燃的等离子体在液体样品21的表面创建显著扰动帐户。因此，该样本容器具有直径和深度的具体实验所需要的井状形状。在其上以及位于支架的高度可以进行调整，以实验的需要。通过该等离子体射流插入反应器中的橡胶索环使得有可能改变与液体流出物的接触角。 所提出的方法允许反应性物质（•OH，•H 等 ）由一千赫频率并行字段等离子体喷射在液体诱导的源的调查。采用周围射流的玻璃反应器中的方法并不限定于图示ribed条件，也可以与其他大气压等离子体一起使用。该方法允许引入任何外加剂到进料气:水蒸气，O 2，N 2 等。在它的另一优点是导电里面光学测量的可能性，虽然在这种情况下，光学质量石英玻璃，必须使用作为反应器材料。在反应器的下部的排气管允许使用几乎任何实验室的等离子流:排气可通过塑料管被连接到一个远程抽油烟机。在反应器的概念是通用的，并且可以在需要控制的气氛不同等离子体的研究中使用。例如苯乙烯的聚合是由氧22抑制，但所用的反应器中可以观察到，当液体苯乙烯暴露于氦进料气体等离子体。

低温常压等离子体（LTPS）已经吸引了近几年越来越多的关注，由于其生物医学应用1-3的巨大潜力。当与周围大气接触，LTP与空气的分子含量反应（N 2，O 2，H 2 O蒸汽），产生各种活性氧和氮物种（RONS）2,4。在这些是相对稳定的物质（例如过氧化氢，臭氧，亚硝酸盐和硝酸盐阴离子）和高度反应性的自由基（•OH，•OOH / O 2• - ，•H，•NO 等 ）。这些物种中，在气相中最初生成，进一步通过等离子体递送至生物基板5。 RONS与底物相互作用，从而定义了抗菌，抗癌和LTP 6-8的抗病毒效果。 LTP疗法的发展要求的反应复杂的造型RONS 9。水是生物环境的一个重要组成部分，并在水相中的反应增加了系统的复杂性显着。通过使用各种分析技术，包括光学发射光谱学，激光诱导的荧光，红外光谱，质谱（MS）， 等等 10-12被广泛进行气相等离子体的调查。同时，在液相检测的物种的详细调查仍然很少。可用的报告描述了使用的各种分析方法，如紫外线和电子顺磁共振（EPR）波谱法，流式细胞仪等 ，为在水溶液13,14的检测RONS的。 EPR是用于在液体中自由基检测的最直接的方法之一。然而，许多自由基种不能由EPR由于其寿命短的时间进行检测。在这些情况下，自旋捕获经常被使用。自旋捕捉涉及化合物（旋转陷阱）的技术WHICH迅速且有选择地与自由基反应以产生更持久自由基的加合物（ 例如 ，DMPO与羟基自由基反应，形成DMPO-OH的加合物）。 在等离子液体相互作用研究的共同挑战是不能控制围绕等离子体流出物周围气氛及其它干扰因素（外场，环境敏感性电源部件等 ）。在这里，我们演示了如何使用由含有血浆工作和周围的等离子体射流喷嘴的内部建反应堆的金属网状的容器的安装程序。金属网作为法拉第笼，使显著改善再现性和等离子体喷射的一般的可操作性。在玻璃反应器中同时封装的等离子流和液体试样，不包括从系统周围大气中。 可用于与液体溶液接触的任何大气压等离子体喷射此方法。例如，我们最近提出暴露于等离子体的水溶液样品中检测到的活性氧源的调查。同位素被用来标记水形成在液体和在等离子体喷射液体溶液系统15的气相物种之间进行区分。

<table><tbody><tr><td>Plasma Resonant and Dielectric Barrier Corona Driver power supply&amp;nbsp;</td><td>Information Unlimited</td><td></td><td>PVM500&amp;nbsp;</td></tr><tr><td>Mass flow controller (MFC)</td><td>Brooks Instruments&amp;nbsp;</td><td></td><td>2 slm (He calib.)</td></tr><tr><td>MFC</td><td>Brooks Instruments&amp;nbsp;</td><td></td><td>5 slm (He calib.)</td></tr><tr><td>Microcomputer controller for MFCs</td><td>Brooks Instruments&amp;nbsp;</td><td></td><td>0254</td></tr><tr><td>H&lt;sub&gt;2&lt;/sub&gt;&lt;sup&gt;17&lt;/sup&gt;O</td><td>Icon Isotopes</td><td>IO 6245</td><td></td></tr><tr><td>5,5-dimethyl-1-pyrroline &lt;em&gt;N&lt;/em&gt;-oxide</td><td>Dojindo Molecular Technologies, Inc.&amp;nbsp;</td><td>D048-10</td><td>&amp;ge;99%</td></tr><tr><td>2,2,6,6-tetramethylpiperidine 1-oxyl&amp;nbsp;</td><td>Sigma-Aldrich</td><td>214000</td><td>98%</td></tr><tr><td>Helium</td><td>BOC UK</td><td>110745-V</td><td>99.996%</td></tr><tr><td>High voltage probe</td><td>Tektronix&amp;nbsp;</td><td></td><td>P6015A</td></tr><tr><td>Current probe</td><td>Ion Physics Corporation&amp;nbsp;</td><td></td><td>CM-100-L</td></tr><tr><td>Oscilloscope</td><td>Teledyne LeCroy</td><td></td><td>WaveJet 354A&amp;nbsp;</td></tr></tbody></table>

an atmospheric pressure plasma setup to investigate the reactive species formation

非热大气压力（"冷"）等离子体已收到近几年越来越多的关注，由于其显著生物医学的潜力。冷等离子体与周围气氛的反应产生各种反应性物质，其可以定义其有效性。虽然冷等离子体疗法的高效发展要求的动力学模型，模型的基准需要的经验数据。在暴露于等离子体的水溶液检测反应性物质源的实验研究仍然很少。生物医学等离子体经常与他或Ar原料气操作，并且一个特定的兴趣在于通过与各种气体外加剂等离子体产生的反应性物种的调查（O 2，N 2，空气，H 2 O蒸气等 ）这样的调查是非常复杂的，由于在与等离子体流出物接触控制环境气氛的困难。在这项工作中，我们讨论&#39;高&#39;电压的共同问题kHz的频率驱动的等离子体射流实验研究。反应器被开发从而允许环境气氛的从等离子体 - 液系统的排除。因此，系统包括与外加剂和液体试样的组分的进料气体。这种受控气氛允许通过氦 - 水蒸气等离子体在水溶液中引起的活性氧源的调查。使用同位素标记水的允许起源于气相和物种的那些形成在液体之间进行区分。等离子体设备载法拉第笼子里，以消除任何外场的可能影响。安装程序是通用的，可以进一步了解冷等离子体液体相互作用的化学帮助。

使用上述的方法和设备，我们已经调查了LTP系统中的活性氧的原点在与水接触。等离子体工作频率和电压分别为25千赫和18千伏（峰-峰），分别为（ 图1）。 例如，使用同位素标记的水，测定羟基自由基的来源。这使得从那些液体试样中的进料气中的水分子之间进行区分。对于这一点，H 2 16 O原料气（如蒸汽）的引入。的H 2 17 O与溶解的自旋陷阱DMPO的液体样品置于样品容器。将反应器的预冲洗用于与进料气体30秒。重要的是，在这种情况下，较长的预冲水的时间，可能会导致输送到H液的H 2 16 O大量<sUB&gt; 2 17 O样本。然后，等离子体被点燃并将样品暴露于流出物60秒。曝光后的溶液通过EPR进行分析。两DMPO-OH自由基加合物（DMPO- 17 OH和DMPO- 16 OH）进行检测（ 图2）。所形成的加合物的比率通过EPR数据的进一步分析确定。液相组合物的质谱分析显示的H 2 16 O（扩散到从气相的液体）的比例的 H 2 17 O（ 表1）。两者的比较表明，在液体检测出的羟自由基，事实上，原产于气相中，而不是在液体中。 类似的研究可以使用其他系统，诸如D 2 O / H 2 O系统来检测•H（•D）的基15的源极来进行。 用于活性氧源的调查 图1 安装程序。在石英玻璃管（4-内径1毫米壁厚）与氦进料气体产生的等离子体。进料气流量为2的SLM。进料气体含H 2Ø蒸汽引入如上所述。 <a href="https://www.jove.com/files/ftp_upload/54765/54765fig1large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="图2" src="/files/ftp_upload/54765/54765fig2.jpg" /> DMPO-H，DMPO- 16 OH和DMPO- 17 OH自由基加成物中的 H 2 17 DMPO的溶液引起 的混合物的图 2. EPR谱图 </SUP&gt; 0照射等离子体。使用光谱模拟软件使用文献16提供的超精细值进行分析。 <a href="https://www.jove.com/files/ftp_upload/54765/54765fig2large.jpg" target="_blank">请点击此处查看该图的放大版本。</a> <img alt="表格1" src="/files/ftp_upload/54765/54765tbl1.jpg" /> 使用EPR校正，得到表 1 DMPO- 16 OH 浓度 和DMPO- 17 OH自由基加成和H 2 16 O 2 17 O血浆曝光后样品 H液 量 。绝对数量加合物的浓度与稳定的自由基2，2,6,6-四甲基-1-氧基（TEMPO）。在不添加水蒸汽（条目1）的情况下，残留湿度为存在于原料气中使用的肉桂酰氯，得到的混合物在与等离子体曝光后溶液反应16 O-和17 O -肉桂酸的水解反应进行测定的H 2 17 O和H 2 16 O的液体样品中的相对量。如别处15中描述的所得混合物通过高分辨率质谱分析。

Watch this Scientific Journal Video about An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation at JoVE.com

An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

An experimental setup was created for the helium-operated kHz frequency plasma jet. The setup includes a cage for the plasma power supply and jet and an in-house built reactor to monitor plasma-induced reactive species without the interference of the ambient atmosphere.

大气压等离子体设置调查活性物种形成

Non-thermal atmospheric pressure (&#39;cold&#39;) plasmas have received increased attention in recent years due to their significant biomedical potential. ...

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9.9K 次观看.  University of York. An experimental setup was created for the helium-operated kHz frequency plasma jet. The setup includes a cage for the plasma power supply and jet and an in-house built reactor to monitor plasma-induced reactive species without the interference of the ambient atmosphere. 

视频: An Atmospheric Pressure Plasma Setup to Investigate the Reactive Species Formation

Encapsulation and Permeability Characteristics of Plasma Polymerized Hollow Particles

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma polymerization of isopropanol on various solid substrates, including silica and potassium chloride. This versatile technique is used to treat nanoparticles and nanopowders with sizes ranging from 37 nm to 1 micron, by depositing films whose thickness can be anywhere from 1 nm to upwards of 100 nm. Dissolution of the core allows us to study the rate of permeation through the film. In these experiments, we determine the diffusion coefficient of KCl through the barrier film by coating KCL nanocrystals and subsequently monitoring the ionic conductivity of the coated particles suspended in water. The primary interest in this process is the encapsulation and delayed release of solutes. The thickness of the shell is one of the independent variables by which we control the rate of release. It has a strong effect on the rate of release, which increases from a six-hour release (shell thickness is 20 nm) to a long-term release over 30 days (shell thickness is 95 nm). The release profile shows a characteristic behavior: a fast release (35% of the final materials) during the first five minutes after the beginning of the dissolution, and a slower release till all of the core materials come out.

We have used plasma enhanced chemical vapor deposition to deposit thin films ranging from a few nm to several 100 nm on nano-sized particles of various materials. We subsequently etch the core material to produce hollow nanoshells whose permeability is controlled by the thickness of the shell. We characterize the permeability of these coatings to small solutes and demonstrate that these barriers can provide sustained release of the core material over several days.

等离子体聚合空心颗粒的封装和渗透特征

In this protocol, core-shell nanostructures are synthesized by plasma enhanced chemical vapor deposition. We produce an amorphous barrier by plasma ...

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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 ...

How to Ignite an Atmospheric Pressure Microwave Plasma Torch without Any Additional Igniters

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a stable and continuous operation of the plasma is possible and the plasma torch can be used for many different applications. On one hand, the hot (3,600 K gas temperature) plasma can be used for chemical processes and on the other hand the cold afterglow (temperatures down to almost RT) can be applied for surface processes. For example chemical syntheses are interesting volume processes. Here the microwave plasma torch can be used for the decomposition of waste gases which are harmful and contribute to the global warming but are needed as etching gases in growing industry sectors like the semiconductor branch. Another application is the dissociation of CO2. Surplus electrical energy from renewable energy sources can be used to dissociate CO2 to CO and O2. The CO can be further processed to gaseous or liquid higher hydrocarbons thereby providing chemical storage of the energy, synthetic fuels or platform chemicals for the chemical industry. Applications of the afterglow of the plasma torch are the treatment of surfaces to increase the adhesion of lacquer, glue or paint, and the sterilization or decontamination of different kind of surfaces. The movie will explain how to ignite the plasma solely by microwave power without any additional igniters, e.g., electric sparks. The microwave plasma torch is based on a combination of two resonators &#8212; a coaxial one which provides the ignition of the plasma and a cylindrical one which guarantees a continuous and stable operation of the plasma after ignition. The plasma can be operated in a long microwave transparent tube for volume processes or shaped by orifices for surface treatment purposes.

This movie shows how an atmospheric plasma torch can be ignited by microwaves with no additional igniters and provides a stable and continuous plasma operation suitable for plenty of applications.

如何点燃常压微波等离子体炬没有任何额外的点火器

This movie shows how an atmospheric pressure plasma torch can be ignited by microwave power with no additional igniters. After ignition of the plasma, a ...

Basic Research in Plasma Medicine - A Throughput Approach from Liquids to Cells

In plasma medicine, ionized gases with temperatures close to that of vertebrate systems are applied to cells and tissues. Cold plasmas generate reactive species known to redox regulate biological processes in health and disease. Pre-clinical and clinical evidence points to beneficial effects of plasma treatment in the healing of chronic ulcer of the skin. Other emerging topics, such as plasma cancer treatment, are receiving increasing attention. Plasma medical research requires interdisciplinary expertise in physics, chemistry, and biomedicine. One goal of plasma research is to characterize plasma-treated cells in a variety of specific applications. This includes, for example, cell count and viability, cellular oxidation, mitochondrial activity, cytotoxicity and mode of cell death, cell cycle analysis, cell surface marker expression, and cytokine release. This study describes the essential equipment and workflows required for such research in plasma biomedicine. It describes the proper operation of an atmospheric pressure argon plasma jet, specifically monitoring its basic emission spectra and feed gas settings to modulate reactive species output. Using a high-precision xyz-table and computer software, the jet is hovered in millisecond-precision over the cavities of 96-well plates in micrometer-precision for maximal reproducibility. Downstream assays for liquid analysis of redox-active molecules are shown, and target cells are plasma-treated. Specifically, melanoma cells are analyzed in an efficient sequence of different consecutive assays but using the same cells: measurement of metabolic activity, total cell area, and surface marker expression of calreticulin, a molecule important for the immunogenic cell death of cancer cells. These assays retrieve content-rich biological information about plasma effects from a single plate. Altogether, this study describes the essential steps and protocols for plasma medical research.

A high-throughput cold physical plasma treatment protocol of liquids and cells is shown. It involves setting up different feed gas compositions for plasma ignition, measuring the plasma&#39;s emission spectra, and the subsequent analysis of liquids and cellular activity after plasma treatment.

等离子体医学基础研究--从液体到细胞的吞吐量方法

In plasma medicine, ionized gases with temperatures close to that of vertebrate systems are applied to cells and tissues. Cold plasmas generate reactive ...

环境科学

Experimental Methods of Dust Charging and Mobilization on Surfaces with Exposure to Ultraviolet Radiation or Plasmas

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using three recently developed experiments in which dust particles are exposed to thermal plasma with beam electrons, beam electrons only, or ultraviolet (UV) radiation only. The UV light source has a narrow bandwidth in wavelength centered at 172 nm. The beam electrons with the energy of 120 eV are created with a negatively biased hot filament. When the vacuum chamber is filled with the argon gas, a thermal plasma is created in addition to the electron beam. Insulating dust particles of a few tens of microns in diameter are used in the experiments. Dust particles are recorded to be lofted to a height up to a few centimeters with a launch speed up to 1 m/s. These experiments demonstrate that photo and/or secondary electron emission from a dusty surface changes the charging mechanism of dust particles. According to the recently developed &#34;patched charge model&#34;, the emitted electrons can be re-absorbed inside microcavities between neighboring dust particles below the surface, causing the accumulation of enhanced negative charges on the surrounding dust particles. The repulsive forces between these negatively charged particles may be large enough to mobilize and lift them off the surface. These experiments present the advanced understanding of dust charging and transport on dusty surfaces, and laid a foundation for future investigations of its role in the surface evolution of airless planetary bodies.

Dust charging and mobilization is demonstrated in three experiments with exposure to thermal plasma with beam electrons, beam electrons only, or ultraviolet (UV) radiation only. These experiments present the advanced understanding of electrostatic dust transport and its role in shaping the surfaces of airless planetary bodies.

紫外辐射或等离子体照射表面的粉尘充电和动员实验方法

Electrostatic dust transport has been hypothesized to explain a number of observations of unusual planetary phenomena. Here, it is demonstrated using ...

Emission Spectroscopic Boundary Layer Investigation during Ablative Material Testing in Plasmatron

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution for future high-speed reentry missions. But despite the advancements made since Apollo, heat flux prediction remains an imperfect science and engineers resort to safety factors to determine the TPS thickness. This goes at the expense of embarked payload, hampering, for example, sample return missions. 
Ground testing in plasma wind-tunnels is currently the only affordable possibility for both material qualification and validation of material response codes. The subsonic 1.2MW Inductively Coupled Plasmatron facility at the von Karman Institute for Fluid Dynamics is able to reproduce a wide range of reentry environments. This protocol describes a procedure for the study of the gas/surface interaction on ablative materials in high enthalpy flows and presents sample results of a non-pyrolyzing, ablating carbon fiber precursor. With this publication, the authors envisage the definition of a standard procedure, facilitating comparison with other laboratories and contributing to ongoing efforts to improve heat shield reliability and reduce design uncertainties.
The described core techniques are non-intrusive methods to track the material recession with a high-speed camera along with the chemistry in the reactive boundary layer, probed by emission spectroscopy. Although optical emission spectroscopy is limited to line-of-sight measurements and is further constrained to electronically excited atoms and molecules, its simplicity and broad applicability still make it the technique of choice for analysis of the reactive boundary layer. Recession of the ablating sample further requires that the distance of the measurement location with respect to the surface is known at all times during the experiment. Calibration of the optical system of the applied three spectrometers allowed quantitative comparison. At the fiber scale, results from a post-test microscopy analysis are presented.

Development of new ablative materials and their numerical modeling requires extensive experimental investigation. This protocol describes procedures for material response characterization in plasma flows with the core techniques being non-intrusive methods to track the material recession along with the chemistry in the reactive boundary layer by emission spectroscopy.

烧蚀材料在试验过程中等离子体发生器发射光谱边界层研究

Ablative Thermal Protection Systems (TPS) allowed the first humans to safely return to Earth from the moon and are still considered as the only solution ...

Non-equilibrium Microwave Plasma for Efficient High Temperature Chemistry

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose of efficiently driving non-equilibrium chemistry is discussed. The advantage of a flowing plasma reactor is that continuous chemical processes can be driven with the flexibility of startup times in the seconds timescale. The plasma approach is generically suitable for conversion/activation of stable molecules such as CO2, N2 and CH4. Here the reduction of CO2 to CO is used as a model system: the complementary diagnostics illustrate how a baseline thermodynamic equilibrium conversion can be exceeded by the intrinsic non-equilibrium from high vibrational excitation. Laser (Rayleigh) scattering is used to measure the reactor temperature and Fourier Transform Infrared Spectroscopy (FTIR) to characterize in situ internal (vibrational) excitation as well as the effluent composition to monitor conversion and selectivity.

This article describes a flowing microwave reactor that is used to drive efficient non-equilibrium chemistry for the application of conversion/activation of stable molecules such as CO2, N2 and CH4. The goal of the procedure described here is to measure the in situ gas temperature and gas conversion.

用于高效高温化学的非平衡微波等离子体

A flowing microwave plasma based methodology for converting electric energy into internal and/or translational modes of stable molecules with the purpose ...

化学

Total Internal Reflection Absorption Spectroscopy (TIRAS) for the Detection of Solvated Electrons at a Plasma-liquid Interface

The total internal reflection absorption spectroscopy (TIRAS) method presented in this article uses an inexpensive diode laser to detect solvated electrons produced by a low-temperature plasma in contact with an aqueous solution. Solvated electrons are powerful reducing agents, and it has been postulated that they play an important role in the interfacial chemistry between a gaseous plasma or discharge and a conductive liquid. However, due to the high local concentrations of reactive species at the interface, they have a short average lifetime (~1 &#181;s), which makes them extremely difficult to detect. The TIRAS technique uses a unique total internal reflection geometry combined with amplitude-modulated lock-in amplification to distinguish solvated electrons&#39; absorbance signal from other spurious noise sources. This enables the in situ detection of short-lived intermediates in the interfacial region, as opposed to the bulk measurement of stable products in the solution. This approach is especially attractive for the field of plasma electrochemistry, where much of the important chemistry is driven by short-lived free radicals. This experimental method has been used to analyze the reduction of nitrite (NO2-(aq)), nitrate (NO3-(aq)), hydrogen peroxide (H2O2(aq)), and dissolved carbon dioxide (CO2(aq)) by plasma-solvated electrons and deduce effective rate constants. Limitations of the method may arise in the presence of unintended parallel reactions, such as air contamination in the plasma, and absorbance measurements may also be hindered by the precipitation of reduced electrochemical products. Overall, the TIRAS method can be a powerful tool for studying the plasma-liquid interface, but its effectiveness depends on the particular system and reaction chemistry under study.

Total Internal Reflection Absorption Spectroscopy TIRAS for the Detection of Solvated Electrons at a Plasma-liquid Interface

This article presents a total internal reflection absorption spectroscopy (TIRAS) method for measuring short-lived free radicals at a plasma-liquid interface. In particular, TIRAS is used to identify solvated electrons based on their optical absorbance of red light near 700 nm.

全内反射吸收光谱法 (拉斯) 在等离子体-液体界面上检测溶剂电子

The total internal reflection absorption spectroscopy (TIRAS) method presented in this article uses an inexpensive diode laser to detect solvated ...

Treating Surfaces with a Cold Atmospheric Pressure Plasma using the COST-Jet

In recent years, non-thermal atmospheric pressure plasmas have been used extensively for surface treatments, in particular, due to their potential in biological applications. However, the scientific results often suffer from reproducibility problems due to unreliable plasma conditions as well as complex treatment procedures. To address this issue and provide a stable and reproducible plasma source, the COST-Jet reference source was developed.
In this work, we propose a detailed protocol to perform reliable and reproducible surface treatments using the COST reference microplasma jet (COST-Jet). Common issues and pitfalls are discussed, as well as the peculiarities of the COST-Jet compared to other devices and its advantageous remote character. A detailed description of both solid and liquid surface treatment is provided. The described methods are versatile and can be adapted for other types of atmospheric pressure plasma devices.

This protocol is presented to characterize the setup, handling, and application of the COST-Jet for the treatment of diverse surfaces such as solids and liquids.

使用成本喷气机用冷大气压力等离子体处理表面

In recent years, non-thermal atmospheric pressure plasmas have been used extensively for surface treatments, in particular, due to their potential in ...

Building Langmuir Probes and Emissive Probes for Plasma Potential Measurements in Low Pressure, Low Temperature Plasmas

Langmuir probes have long been used in experimental plasma physics research as the primary diagnostic for particle fluxes (i.e., electron and ion fluxes) and their local spatial concentrations, for electron temperatures, and for electrostatic plasma potential measurements, since its invention by Langmuir in the early 1920s. Emissive probes are used for measuring plasma potentials. The protocols exhibited in this work serve to demonstrate how these probes may be built for use in a vacuum chamber in which a plasma discharge may be confined and sustained. This involves vacuum techniques for building what is essentially an electrical feedthrough, one that is rotatable and translatable. Certainly, complete Langmuir probe systems may be purchased, but they can also be built by the user at considerable cost savings, and at the same time be more directly adapted to their use in a particular experiment. We describe the use of Langmuir probes and emissive probes in mapping the electrostatic plasma potential from the body of the plasma up to the sheath region of a plasma boundary, which in these experiments&#160;is created by a negatively biased electrode immersed within the plasma, in order to compare the two diagnostic techniques and assess their relative advantages and weaknesses. Although Langmuir probes have the advantage of measuring the plasma density and electron temperature most accurately, emissive probes can measure electrostatic plasma potentials more accurately throughout the plasma, up to and including the sheath region.

The main goal of this work is to make it easier for research groups unfamiliar with Langmuir probes and emissive probes to use them as plasma diagnostics, especially near plasma boundaries. We do this by demonstrating how to build the probes from readily available materials and supplies.

构建朗缪尔探头和发射探头，用于低压、低温等离子体中的等离子体电位测量

Langmuir probes have long been used in experimental plasma physics research as the primary diagnostic for particle fluxes (i.e., electron and ion fluxes) ...