Name: high-contrast and fast photorheological switching of a twist-bend nematic liquid crystal
Uploaded: 2019-10-31T14:45:00
Description: Watch this Scientific Journal Video about High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal at JoVE.com

这项工作得到了HAS-JSPS双边联合研究项目的支持。NKFIH PD 121019 和 FK 125134 的赠款提供财政支持。

1. 制备摩擦表面，以平面方式对齐LC分子
<ol><li>准备干净的玻璃基板。<ol>
<li>使用金刚石玻璃切割器（材料表）将玻璃基板切割成小方形，平均尺寸为1厘米x1厘米。在碱性洗涤剂（材料表）中，以38 kHz或42 kHz的声波将其洗涤。洗涤剂：水体积比为1：3），用蒸馏水反复冲洗（通常，每次冲洗超过10倍，声波5分钟）。</li>
		<li>使基材接受紫外线臭氧（UV-O3）清洁剂?...

<ol>
	<li>Grindy, S. C., Holten-Andersen, N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bio-inspired+metal-coordinate+hydrogels+with+programmable+viscoelastic+material+functions+controlled+by+longwave+UV+light.">Bio-inspired metal-coordinate hydrogels with programmable viscoelastic material functions controlled by longwave UV light.</a> Soft Matter. 13, 4057-4065 (2017).</li><li>Rosales, A. M., Mabry, K. M., Nehls, E. M., Anseth, K. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoresponsive+elastic+properties+of+azobenzene-containing+poly(ethylene-glycol)-based+hydrogels.">Photoresponsive elastic properties of azobenzene-containing poly(ethylene-glycol)-based hydrogels.</a> Biomacromolecules. 16, 798-806 (2015).</li><li>Chang, D., Yan, W., Yang, Y., Wang, Q., Zou, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+light-controllable+intelligent+gel+based+on+simple+spiropyran-doped+with+biocompatible+lecithin.">Reversible light-controllable intelligent gel based on simple spiropyran-doped with biocompatible lecithin.</a> Dyes and Pigments. 134, 186-189 (2015).</li><li>Irie, M., Hirano, Y., Hashimoto, S., Hayashi, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photoresponsive+Polymers.+2.+Reversible+Solution+Viscosity+Change+of+Polymamides+Having+Azobenzene+Residues+in+the+Main+Chain.">Photoresponsive Polymers. 2. Reversible Solution Viscosity Change of Polymamides Having Azobenzene Residues in the Main Chain.</a> Macromolecules. 14, 262-267 (1981).</li><li>Ito, S., Akiyama, H., Sekizawa, R., Mori, M., Yoshida, M., Kihara, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-Induced+Reworkable+Adhesives+Based+on+ABA-type+Triblock+Copolymers+with+Azopolymer+Termini.">Light-Induced Reworkable Adhesives Based on ABA-type Triblock Copolymers with Azopolymer Termini.</a> ACS Applied Materials and Interfaces. 10, 32649-32658 (2018).</li><li>Yamamoto, T., Norikane, Y., Akiyama, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photochemical+liquefaction+and+softening+in+molecular+materials,+polymers,+and+related+compounds.">Photochemical liquefaction and softening in molecular materials, polymers, and related compounds.</a> Polymer Journal. 50, 551-562 (2018).</li><li>Petr, M., Helgeson, M. E., Soulages, J., McKinley, G. H., Hammond, P. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rapid+Viscoelastic+Switching+of+an+Ambient+Temperature+Range+Photoresponsive+Azobenzene+Side-chain+Liquid+Crystal+Polymer.">Rapid Viscoelastic Switching of an Ambient Temperature Range Photoresponsive Azobenzene Side-chain Liquid Crystal Polymer.</a> Polymer. 54, 2850-2856 (2013).</li><li>Han, G. G. D., Li, H., Grossman, J. 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Y., Lee, S. A., Kim, H., Kim, S. M., Kim, N., Jeong, K. U. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=An+azobenzene-based+photochromic+liquid+crystalline+amphiphile+for+a+remote-controllable+light+shutter.">An azobenzene-based photochromic liquid crystalline amphiphile for a remote-controllable light shutter.</a> Chemical Communications. 51, 11080 (2015).</li><li>Saito, S., 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=Light-melt+adhesive+based+on+dynamic+carbon+frameworks+in+a+columnar+liquid-crystal+phase.">Light-melt adhesive based on dynamic carbon frameworks in a columnar liquid-crystal phase.</a> Nature Communications. 7, 1-7 (2016).</li><li>Peng, S., Guo, Q., Hughes, T. C., Hartley, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+Photorheological+Lyotropic+Liquid+Crystals.">Reversible Photorheological Lyotropic Liquid Crystals.</a> Langmuir. 30, 866-872 (2014).</li><li>Ito, S., Yamashita, A., Akiyama, H., Kihara, H., Yoshida, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Azobenzene-Based+(Meth)acrylates:+Controlled+Radical+Polymerization,+Photoresponsive+Solid&#8211;Liquid+Phase+Transition+Behavior,+and+Application+to+Reworkable+Adhesives.">Azobenzene-Based (Meth)acrylates: Controlled Radical Polymerization, Photoresponsive Solid&#8211;Liquid Phase Transition Behavior, and Application to Reworkable Adhesives.</a> Macromolecules. 51, 3243-3253 (2018).</li><li>Yue, Y., Norikane, Y., Azumi, R., Koyama, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Light-induced+mechanical+response+in+crosslinked+liquid-crystalline+polymers+with+photoswitchable+glass+transition+temperatures.">Light-induced mechanical response in crosslinked liquid-crystalline polymers with photoswitchable glass transition temperatures.</a> Nature Communications. 9, 1-8 (2018).</li><li>Lee, H. Y., Diehn, K. K., Sun, K., Chen, T., Raghavan, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reversible+Photorheological+Fluids+Based+on+Spiropyran-Doped+Reverse+Micelles.">Reversible Photorheological Fluids Based on Spiropyran-Doped Reverse Micelles.</a> Journal of the American Chemical Society. 133, 8461-8463 (2011).</li><li>Su, X., Cunningham, M. F., Jessop, P. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Switchable+viscosity+triggered+by+CO2+using+smart+worm-like+micelles.">Switchable viscosity triggered by CO2 using smart worm-like micelles.</a> Chemical Communications. 49, 2655-2657 (2013).</li><li>Cho, M. Y., Kim, J. S., Choi, H. J., Choi, S. B., Kim, G. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Ultraviolet+light-responsive+photorheological+fluids:+as+a+new+class+of+smart+fluids.">Ultraviolet light-responsive photorheological fluids: as a new class of smart fluids.</a> Smart Materials and Structures. 26, 1-8 (2017).</li><li>Oh, H., 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+simple+route+to+fluids+with+photo-switchable+viscosities+based+on+a+reversible+transition+between+vesicles+and+wormlike+micelles.">A simple route to fluids with photo-switchable viscosities based on a reversible transition between vesicles and wormlike micelles.</a> Soft Matter. 9, 5025-5033 (2013).</li><li>Akamatsu, 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=Photoinduced+viscosity+control+of+lecithin-based+reverse+wormlike+micellar+systems+using+azobenzene+derivatives.">Photoinduced viscosity control of lecithin-based reverse wormlike micellar systems using azobenzene derivatives.</a> RSC Advances. 8, 23742-23747 (2018).</li><li>Song, B., Hu, Y., Zhao, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+single-component+photo-responsive+fluid+based+on+a+gemini+surfactant+with+an+azobenzene+spacer.">A single-component photo-responsive fluid based on a gemini surfactant with an azobenzene spacer.</a> Journal of Colloid and Interface Science. 333, 820-822 (2009).</li><li>Borshch, V., 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=Nematic+twist-bend+phase+with+nanoscale+modulation+of+molecular+orientation.">Nematic twist-bend phase with nanoscale modulation of molecular orientation.</a> Nature Communications. 4, 2635-2643 (2013).</li><li>Panov, V. 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如图1所示，CB6OABOBu是一种光响应材料，冷却时具有I、N、TB和哭相序列。由于这些相的局部顺序差异很大，风变特性的光驱动切换预计将表现出良好的粘弹性对比度。为了定量地调查这一点，进行了光变学测量。
首先，我们考虑在黑暗中测量的流变数据（图2a，红色开放圆圈）。在I-N相变时，有效粘度（αeff?...

能够改变其粘弹性特性以响应环境变化的智能机械材料引起了研究人员的极大兴趣。可切换性被认为是最重要的物质因素，它为生物体中的重复机械反应提供了鲁棒性。迄今为止，利用软质（即光反应水凝胶1、2、3、聚合物4、5、5、）设计了具有多功能功能的人工可切换材料。6，7，8，9，10，11，液晶 [LC]9，10，11， 12，13，14，15，16，17，pH响应型云母18，19，20 ，21，22和表面活性剂23。然而，这些材料存在以下不止一个问题：缺乏可逆性、粘弹性开关对比度低、适应性低和开关速度慢。在传统材料中，粘弹性的开关对比度与开关速度之间存在权衡;因此，设计涵盖所有这些高标准的材料具有挑战性。为了实现具有上述无所不能的材料，选择或设计具有高流动性（粘度）和刚度（弹性特性）的突发性分子至关重要。
液晶是理想的系统，具有潜在的大量液晶和固体相，可以通过分子设计进行调谐。这允许在特定的LC相级的不同长度尺度上进行自组装结构。例如，高对称内形 LC （NLC） 由于其短距离空间顺序而表现出低粘度和弹性，而低对称柱或薄色 LC 则由于一维和二维远程，表现出高粘度和弹性周期性。如果LC材料可以在两相之间切换，其粘弹性性能差异较大，则可实现高性能的粘弹性智能材料。据报有9、10、11、12、13、14、15的例子。
本文演示了光热LC材料的制备，其相序为各向异性（I）-核质（N）-扭弯（TB）24-晶体（在加热时，反之亦然），其表现出快速和可逆粘弹性开关响应光。这里介绍了测量粘弹性的方法，并说明了微观结构与粘弹性的关系。详细信息在代表性结果和讨论部分中介绍。

<table>
	<tbody>
		<tr>
			<td>21-401-10</td>
			<td>AS ONE</td>
			<td></td>
			<td>Microspatula</td>
		</tr>
		<tr>
			<td>AL1254</td>
			<td>JSR</td>
			<td></td>
			<td>Planar alignment agent for liquid crystals</td>
		</tr>
		<tr>
			<td>BX53P</td>
			<td>Olympus</td>
			<td></td>
			<td>Polarising microscope with transmission/epi-illumination units</td>
		</tr>
		<tr>
			<td>Discovery DSC 25P</td>
			<td>TI instruments</td>
			<td></td>
			<td>Photo-DSC equipment</td>
		</tr>
		<tr>
			<td>Glass cutter PRO-1A</td>
			<td>Sankyo</td>
			<td></td>
			<td>A diamond-based glass cutter</td>
		</tr>
		<tr>
			<td>HS82</td>
			<td>Mettler Toledo</td>
			<td></td>
			<td>hot stage</td>
		</tr>
		<tr>
			<td>MCR502</td>
			<td>Anton Paar</td>
			<td></td>
			<td>A commercial rheometer</td>
		</tr>
		<tr>
			<td>MRJ-100S</td>
			<td>EHC</td>
			<td></td>
			<td>Rubbing machine</td>
		</tr>
		<tr>
			<td>Norland Optical Adhesive 65, 81</td>
			<td>Norland Products</td>
			<td></td>
			<td>Photoreactive adhesions</td>
		</tr>
		<tr>
			<td>OmniCure S2000</td>
			<td>Excelitas Technologies</td>
			<td></td>
			<td>A commericial high-pressure mercury vapor short arc lamp. Maximum 70 mW/cm^2.</td>
		</tr>
		<tr>
			<td>PILATUS 6M</td>
			<td>Dectris</td>
			<td></td>
			<td>Hybrid photon counting detector for X-ray diffraction dectection</td>
		</tr>
		<tr>
			<td>S1126</td>
			<td>Matsunami Glass</td>
			<td></td>
			<td>Glass substrate</td>
		</tr>
		<tr>
			<td>SC-158H</td>
			<td>EHC</td>
			<td></td>
			<td>Spin coater</td>
		</tr>
		<tr>
			<td>SCAT-20X</td>
			<td>DKS</td>
			<td></td>
			<td>Alkaline detergent</td>
		</tr>
		<tr>
			<td>SLUV-4</td>
			<td>AS ONE</td>
			<td></td>
			<td>Low-pressure mercury vapor short arc lamp</td>
		</tr>
		<tr>
			<td>UV-208</td>
			<td>Technovision</td>
			<td></td>
			<td>Ultraviolet-ozone (UV-O3) cleaner</td>
		</tr>
	</tbody>
</table>

high-contrast and fast photorheological switching of a twist-bend nematic liquid crystal

响应特定刺激的智能粘弹性材料是未来技术中最具吸引力的材料类别之一，例如按需可切换粘附技术、执行器、分子离合器和纳米/微观质量转运 蛋白。最近发现，通过特殊的固液过渡，流变特性可以表现出显著的变化，从而提供合适的智能粘弹性材料。然而，使用这种特性设计材料是复杂的，向前和向后切换时间通常很长。因此，探索新的工作机制，实现固体-液体转换，缩短开关时间，增强开关过程中的流变特性对比，具有十分重要的意义。在这里，观察到光诱导的液晶相变，其特点是偏振光显微镜（POM）、光热测量、光差扫描热度（光DSC）和X射线衍射（XRD）。光诱导的液晶相变具有以下关键特征：（1）前后反应的液晶相快速切换，以及（2）粘弹性的高对比度。在表征中，POM在提供有关LC分子方向的空间分布信息、确定材料中出现的液晶相的类型以及研究LC的方向方面具有优势。允许在光刺激下测量材料的流变特性，并可以揭示材料的光河开关特性。Photo-DSC是一种在黑暗和光照射下研究材料热力学信息的技术。最后，XRD允许研究材料的微观结构。本文的目的是清楚地介绍如何准备和测量光河学材料的讨论性质。

POM 图像、光测量数据、光 DSC 数据和 XRD 强度曲线是在温度变化和照射紫外线时在黑暗中收集的。图 1a，b表示 CB6OABOBu 的结构，其相序和可能的一致性由建模程序中 MM2 力场优化（例如，ChemBio3D）。
当CB6OABOBu处于跨态时，会出现两种能量可感的构象状态，而扭曲的构象是促进结核病阶段形成的最稳定的构象。当 CB6OABOBu 在暴露于紫外线时对顺...

Watch this Scientific Journal Video about High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal at JoVE.com

High-Contrast and Fast Photorheological Switching of a Twist-Bend Nematic Liquid Crystal

该协议演示了光热材料的制备，该材料通过增加温度来显示固体相、各种液晶相和各向异性液相。这里介绍了测量材料的结构-粘弹性关系的方法。

扭曲弯曲的液晶的高对比度和快速光圈开关

Smart viscoelastic materials that respond to specific stimuli are one of the most attractive classes of materials important to future technologies, such ...

该协议解释了如何描述液晶的粘弹性拉伸特性，并有助于回答有关如何开发新的光热材料关键问题。该方法的主要优点是流变特性和相关结构特性可以在光刺激下实时测量，从而可以记录光热开关行为。在开始手术之前，使用基于金刚石的玻璃切割机切割平均尺寸为一厘米的玻璃基材，并在碱性洗涤剂中以 38 或 42 千赫的洗涤。接下来，每次洗涤用新鲜蒸馏水进行 10 次 5 分钟洗涤，然后用声波冲洗基材，使基材受紫外线臭氧至少 10 分钟。要添加平面对齐层，请使用移液器将 20 微升液滴中的聚酰胺平面对齐溶液的一毫升分配到每个清洁的玻璃基板上。立即使用旋转涂布器将大约 20 纳米厚的对齐层旋转到基材上。在旋转结束时，在 80 摄氏度下将涂层玻璃基板烘烤 60 分钟以去除溶剂，随后在 180 摄氏度下固化至少 60 分钟。然后使用人造丝布摩擦机以适当的参数摩擦基材。将 100 微升光反应胶粘剂和 0.1 毫克直径的 5 微米玻璃颗粒添加到新的玻璃基材上，并使用回形针尖混合材料。将混合材料转移到玻璃基板电池的四个角落以调整电池间隙，并使用低压汞蒸气短弧灯或紫外线引导以 365 纳米波长照亮电池。照明后，将细胞放在一个热的舞台上，并设置该阶段的目标温度，将细胞加热到同向性液体内相过渡的温度之上。在相变结束时，将整个 0.2 至 10 微升液晶材料转移到细胞的一个开放表面上。使用微帕特拉将材料推向细胞入口，以获得液晶材料和细胞入口之间的接触。然后等待液晶材料用毛细管力填充细胞。对于液晶细胞的纹理表征，请将样品置于热舞台上，在偏振光显微镜下以正负 0.1 开尔文精度控制样品温度。使用数字彩色摄像机和 UV 光照器在冷却和加热期间按顺序记录纹理，带无紫外线照射。对于样品的流变测量，首先根据制造商的说明在软件中执行几何惯性和零间隙校准。然后称出250毫克的粉状CB6OABOBU样品。接下来将样品加载到流变仪的基石英板上，将样品室的温度设置为高于等向异性-内相过渡点的值。然后设置一个间隙值，用于接近测量板到基础石英板以夹夹样品。当测量板停止修剪位置时，使用纸张实验室擦拭来修剪间隙外的任何多余的样品。为了执行测量，将样品照射在365纳米，使用高压汞蒸气短弧灯测量CB6OABOBU的光石开关。在神经相中，实现了分子的单轴对齐。当在黑暗中将温度降低到扭曲弯曲时，会形成条纹图案，其中条纹与液晶电池的摩擦方向平行。温度的进一步降低会导致结晶。使用紫外光照射会改变从跨到 cis 状态的构象，从而产生相位变化，从而产生纹理变化，当从扭曲弯曲阶段开始时，UV 光将条纹纹理转换为神经相的单轴对齐状态。关闭紫外光允许分子放松并重新进入跨状态，从而改变扭曲弯曲相的条纹纹理。在各种条件下测量CB6OABOBU的有效粘度，可以揭示有效剪切粘度的温度依赖性。在这里，可以观察到第一次和第二次运行期间不同温度下有效剪切粘度的剪切应力依赖性。在此图中，显示了不同温度下紫外线照射触发的有效剪切粘度的变化。这些图表说明了在两种不同温度下，在日志刻度中有效剪切粘度的开关曲线。为了获得可靠的数据，在获取测量值之前校准流变仪至关重要。未来研究感光二丁二角的一个想法是检查宽带介电光谱，该光谱可以深入了解不同相位和照明条件下的分子动力学。

Research

JoVE Journal

Chemistry

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry (UPLC-HRMS)

Untargeted Metabolomics from Biological Sources Using Ultraperformance Liquid Chromatography-High Resolution Mass Spectrometry UPLC-HRMS

不相关的代谢组学，生物源使用超高效液相色谱 - 高分辨质谱（UPLC-HRMS）

Here we present a workflow to analyze the metabolic profiles for biological samples of interest including; cells, serum, or tissue. The sample is first ...

科研

化学

Isolation and Preparation of Bacterial Cell Walls for Compositional Analysis by Ultra Performance Liquid Chromatography

通过超性能液相色谱对细菌细胞壁进行隔离和制备，进行组成分析

The bacterial cell wall is critical for the determination of cell shape during growth and division, and maintains the mechanical integrity of cells in the ...

Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals

合成与盘状磷酸盐锆剥落获取胶体液晶

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and ...

A Method to Manipulate Surface Tension of a Liquid Metal via Surface Oxidation and Reduction

方法通过表面氧化还原操纵液态金属的表面张力

Controlling interfacial tension is an effective method for manipulating the shape, position, and flow of fluids at sub-millimeter length scales, where ...

Microfluidic Pneumatic Cages: A Novel Approach for In-chip Crystal Trapping, Manipulation and Controlled Chemical Treatment

微流控气动笼：在芯片水晶捕获，处理的新方法和控制化学处理

The precise localization and controlled chemical treatment of structures on a surface are significant challenges for common laboratory technologies. ...

High Pressure Single Crystal Diffraction at PX^2

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 ...

A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography (HPLC)

A Straightforward Method for Glucosinolate Extraction and Analysis with High-pressure Liquid Chromatography HPLC

简捷方法对硫甙的提取与分析用高压液相色谱法（HPLC）

Glucosinolates are a well-studied and highly diverse class of natural plant compounds. They play important roles in plant resistance, rapeseed oil ...

A Convenient Method for Extraction and Analysis with High-Pressure Liquid Chromatography of Catecholamine Neurotransmitters and Their Metabolites

用高压液相色谱法提取和分析儿茶酚胺神经递质及其代谢物的简便方法

The extraction and analysis of catecholamine neurotransmitters in biological fluids is of great importance in assessing nervous system function and ...

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

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

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 ...

Using Graphene Liquid Cell Transmission Electron Microscopy to Study in Situ Nanocrystal Etching

Using Graphene Liquid Cell Transmission Electron Microscopy to Study in Situ Nanocrystal Etching

用石墨烯液细胞透射电镜研究原位纳米晶蚀刻

Graphene liquid cell electron microscopy provides the ability to observe nanoscale chemical transformations and dynamics as the reactions are occurring in ...