L.E. 和琼斯 Willars 罗德里格斯感谢 CONACYT 的奖学金。E.A. 查韦斯-Urbiola 感谢 CONACYT 为 "Catedras CONACYT" 计划。作者还承认阿维拉的技术援助, Landaverde, J.E. 乌尔维纳 Alvárez, Jiménez 涅托。

注意: 本议定书中使用的化学品具有毒性和致癌性;因此, 必须认真遵守安全建议和程序。佩戴适当的防护设备, 查阅相关材料安全数据表 (MSDS)。
1. 二 (硫脲) 氯化镉的合成
<ol><li>
前体溶液的制备
	<ol>
<li>将500毫升去离子水倒入1升烧杯中, 持续搅拌;添加0.3 毫升盐酸在36.5% 浓度, 确保溶液的 pH 值尽可能接近 3, 使用 ph 计。 注意: 为了避免任何健康影响, 强烈建议在通风罩内执行此操作。</li>
		<li>倒入50毫升的前体溶液, 如步骤1.1.1 中所示, 进入两个100毫升烧杯 (以下, 这些烧杯将被命名为 A 和 B)。 注: 两个实验 (A 和 B, 依赖于烧杯使用) 同时进行。只有实验 B 才会暴露在紫外线照射下。</li>
	</ol>
</li>
	<li>每个烧杯 (A 和 B) 的重量为2.29 克 CdCl2 。 警告: 在通风罩内执行此操作, 因为所使用的材料被认定为危险的。镉具有剧毒, 在吸入时被认定为致癌物质;必须小心处理。</li>
	<li>对每个烧杯 (A 和 B) 的1.33 克 CS (NH2)2进行称量。 注意: 在通风罩内执行此操作, 因为使用的材料危险不健康。硫脲在吸入时具有剧毒, 必须小心处理。</li>
	<li>将2.29 克 CdCl2和1.33 克的 CS (NH2)2添加到包含前体溶液50毫升的每个烧杯 (A 和 B) 中。</li>
</ol>2. 双 (硫脲) 氯化镉的比较合成
<ol><li>
无紫外线光的实验安排 (A)。
	<ol>
<li>将烧杯 (A) 放在搅拌热板上, 加热至 343 k, 将其设置为适度搅拌速度。 注意: 在通风罩内执行此操作。</li>
		<li>保持溶液在烧杯 (A) 适度搅拌2小时的板材在 343 K。</li>
	</ol>
</li>
	<li>
实验安排与紫外光 (B)。
	<ol>
<li>把烧杯 B 放在盘子上, 加热到 343 k. 在适度水平上设置搅拌速度, 并在 UV 光源上切换。 注意: 实验安排如图 1所示。 注意: 在通风罩内执行此操作。</li>
		<li>保持步骤2.2.1 中所述的温度和搅拌条件为2小时。</li>
	</ol>
</li>
</ol>3. 获得双 (硫脲) 氯化镉晶体
<ol><li>装载2玻璃漏斗与过滤器纸 (40, Ø = 125 毫米), 每一个在100毫升容量瓶, a 和 B。在现阶段避免晶体形成;在过滤之前不要让溶液冷却。</li>
	<li>过滤解决方案 A 和 B 通过纸, 每个到自己的100毫升烧瓶。 注意: 在通风罩内执行此操作。</li>
	<li>让两个溶液内的容积烧瓶冷却到室温。 注: 晶体开始生长在第一分钟内的容积烧瓶。</li>
	<li>用新的过滤纸再次准备过滤组件 (步骤 3.1)。</li>
	<li>通过过滤纸将溶液与晶体过滤成单独的容积烧瓶。 注意: 在通风罩内执行此操作。</li>
	<li>将滤纸上的晶体转移到相应的手表玻璃上。 注: 在这一点上, 有2手表眼镜, 1 为 A 和1的 B。</li>
	<li>通过粉末 X 射线衍射 (XRD) 和拉曼光谱的研究, 证实了双 (硫脲) 氯化镉晶体的存在. 12。</li>
</ol>4. 煅烧晶体以获得 CdS
<ol><li>将步骤3.7 中获得的晶体放置到2不同的坩埚中, 1 用于 A 和1为 B。</li>
	<li>预热电热实验炉, 并将其温度稳定在 773 K 或更高。</li>
	<li>将步骤4.1 的坩埚放入预热炉内。 注意: 煅烧过程中释放的蒸气是有毒的。确保炉子是在通风罩, 因为有毒的烟雾, 它将被耗尽。</li>
	<li>让材料站在炉内1小时在 773 K。然后, 关掉炉子, 让它冷却到室温。然后, 从烤箱中取出坩埚。</li>
</ol>

<ol>
	<li>Venkataramanan, V., Maheswaran, S., Sherwood, J. N., Bhat, H. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Crystal+growth+and+physical+characterization+of+the+semiorganic+bis(thiourea)+cadmium+chloride.">Crystal growth and physical characterization of the semiorganic bis(thiourea) cadmium chloride.</a> Journal of Crystal Growth. 179 (3-4), 605-610 (1997).</li><li>Ushasree, P. M., Muralidharan, R., Jayavel, R., Ramasamy, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+of+bis(thiourea)+cadmium+chloride+single+crystals+a+potential+NLO+material+of+organometallic+complex.">Growth of bis(thiourea) cadmium chloride single crystals a potential NLO material of organometallic complex.</a> Journal of Crystal Growth. 218 (2-4), 365-371 (2000).</li><li>Ushasree, P. M., Jayavel, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+micromorphology+of+as-grown+and+etched+bis(thiourea)+cadmium+chloride+(BTCC)+single+crystals.">Growth and micromorphology of as-grown and etched bis(thiourea) cadmium chloride (BTCC) single crystals.</a> Optical Materials. 21 (1-3), 569-604 (2002).</li><li>Pawar, S. M., Pawar, B. S., Kim, J. H., Joo, O., Lokhande, C. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Recent+status+of+chemical+bath+deposited+metal+chalcogenide+and+metal+oxide+thin+films.">Recent status of chemical bath deposited metal chalcogenide and metal oxide thin films.</a> Current Applied Physics. 11 (2), 117-161 (2011).</li><li>Suriakarthick, R., Kumar, V. N., Shyju, T. S., Gopalakrishnan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+on+post+annealed+copper+sulfide+thin+films+from+photochemical+deposition+technique.">Investigation on post annealed copper sulfide thin films from photochemical deposition technique.</a> Materials Science in Semiconductor Processing. 26 (1), 155-161 (2014).</li><li>Podder, J., Kobayashi, R., Ichimura, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Photochemical+deposition+of+Cu+x+S+thin+films+from+aqueous+solutions.">Photochemical deposition of Cu x S thin films from aqueous solutions.</a> Thin Solid Films. 472 (1-2), 71-75 (2005).</li><li>Gunasekaran, M., Gopalakrishnan, R., Ramasamy, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deposition+of+ZnS+thin+films+by+photochemical+deposition+technique.">Deposition of ZnS thin films by photochemical deposition technique.</a> Materials Letters. 58 (1-2), 67-70 (2004).</li><li>Ichimura, M., Goto, F., Ono, Y., Arai, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deposition+of+CdS+and+ZnS+from+aqueous+solutions+by+a+new+photochemical+technique.">Deposition of CdS and ZnS from aqueous solutions by a new photochemical technique.</a> Journal of Crystal Growth. 198 (1), 308-312 (1999).</li><li>Kumaresan, R., Ichimura, M., Sato, N., Ramasamy, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+novel+photochemical+deposition+technique+for+the+deposition+of+indium+sulfide.">Application of novel photochemical deposition technique for the deposition of indium sulfide.</a> Materials Science Engineering: B. 96 (1), 37-42 (2002).</li><li>Rama, G., Jeevanandam, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Evolution+of+different+morphologies+of+CdS+nanoparticles+by+thermal+decomposition+of+bis(thiourea)cadmium+chloride+in+various+solvents.">Evolution of different morphologies of CdS nanoparticles by thermal decomposition of bis(thiourea)cadmium chloride in various solvents.</a> Journal of Nanoparticle Research. 17 (1), 1-13 (2015).</li><li>Pabitha, G., Dhanasekaran, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+and+characterization+of+a+nonlinear+optical+crystal+-+bis+thiourea+cadmium+chloride.">Growth and characterization of a nonlinear optical crystal - bis thiourea cadmium chloride.</a> International Journal of Innovative Research in Science, Engineering and Technology. 4 (1), 34-38 (2015).</li><li>Trujillo, L. E., 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=Di-thiourea+cadmium+chloride+crystals+synthesis+under+UV+radiation+influence.">Di-thiourea cadmium chloride crystals synthesis under UV radiation influence.</a> Journal of Crystal Growth. 478 (1), 140-145 (2017).</li><li>Elilarassi, R., Maheshwari, S., Chandrasekaran, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+and+optical+characterization+of+CdS+nanoparticles+synthesized+using+a+simple+chemical+reaction+route.">Structural and optical characterization of CdS nanoparticles synthesized using a simple chemical reaction route.</a> Optoelectronics and Advanced Materials - Rapid Communications. 4 (3), 309-312 (2010).</li><li>Selvasekarapandian, S., Vivekanandan, K., Kolandaivel, P., Gundurao, T. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vibrational+Studies+of+Bis(thiourea)+Cadmium+Chloride+and+Tris(thiourea)+Zinc+Sulphate+Semiorganic+Non-linear+Optical+Crystals.">Vibrational Studies of Bis(thiourea) Cadmium Chloride and Tris(thiourea) Zinc Sulphate Semiorganic Non-linear Optical Crystals.</a> Crystal Research &amp; Technology. 32 (2), 299-309 (1997).</li></ol>

作者没有什么可透露的。

本节中提出的讨论只侧重于议定书, 而不是着重于代表结果中已经显示的结果。
该议定书最关键的部分之一是编写前体解决方案。保持酸性 pH 值以避免 Cd (OH)2的形成是至关重要的。如果 pH 不是酸性的, 它导致 CdS 的直接形成由于硫脲离解和 cd (OH)2形成。 第二个最重要的步骤是步骤 3.2, 过滤解决方案之前必须执行的解决方案冷却下来, 因为否则, 冷却导致晶体...

一个重要的研究领域是单一晶体;他们的成长是针对不同的应用。这些材料可作为用于激光技术领域、光电子领域和信息1的非线性光学资料, 为他们的调查提供了一个机会。二 (硫脲) 氯化镉是一种金属有机材料, 可从两个前体、硫脲和氯化镉中合成, 遵循以下化学公式: 2 cs (nh2)2 + CdCl2 CdCl2-[cs2)2]2. 这种金属-有机材料是在不同的反应条件下制备的, 如温度和 pH 值, 但在紫外线 (UV) 光的帮助下从来没有。
报告了 pH 值对晶体结构的影响;在 pH < 6, 有可能获得单晶的形成。这些反过来, 根据 pH 值的范围进行修改。在6到4的间隔时间内, 可以获得六角结构, 因为如果 pH 值为 < 4, 正交晶体结构得到2。离子离解由酸性 pH 值 Cd2 +和 Cl 促进, 因为它防止氢氧化镉形成 [Cd (OH)2]。这稳定了镉: 一个镉原子加入两个无硫自由基和两个氯。
在这里, 采用化学浴沉积技术 (CBD) 进行合成, 控制化学反应时干预的不同条件3。在 CBD 中, 控制化学反应的因素有: 溶液温度、前驱离子、溶液 pH 值、试剂数量和搅拌速度等。另一方面, 这里使用的比较技术称为光化学浴沉积 (PCBD), 因为它使用 UV 光的帮助。有报道称, 紫外线光协助已被用于合成x4、5、ZnS6、CdS7和 InS8等薄膜。市村和 Gunasekaran9目前在他们的工作, 硫酸盐溶液有一个吸收边缘接近 300 nm。由于这种吸收范围, 紫外线辐射的应用, 这导致了类似的排放范围, 与吸收的解决方案。
二 (硫脲) 氯化镉的另一种性质是加热时降解。它在 512 K 和以上的温度下进行初始分解, 形成硫化镉 (CdS)。降解反应如下: [Cd (CS2]2] Cl2 →Δ CdS + HNCS + nh3 + nh4SCN。这种降解产生 thiocyanuric 酸和各种 thiocyanates10,11。此外, 研究组还对紫外线辐射引起的一些影响进行了研究12。最后, 本文介绍了双 (硫脲) 氯化镉晶体的比较合成方法, 以及紫外光的影响。

<table>
	<tbody>
		<tr>
			<td>Reagents</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Cadmium chloride Anh. ACS, 99.4 %</td>
			<td>Fermont</td>
			<td>PQ24291</td>
			<td>Highly toxic</td>
		</tr>
		<tr>
			<td>Thiourea technical grade, 99.9 %</td>
			<td>Reasol</td>
			<td>R5913</td>
			<td>Toxic</td>
		</tr>
		<tr>
			<td>Hydrochloric acid, 36.5 &#8211; 38.0 %</td>
			<td>J.T.Baker</td>
			<td>MFCD00011324</td>
			<td>Highly corrosive liquid</td>
		</tr>
		<tr>
			<td>Material</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Filter paper</td>
			<td>Whatman</td>
			<td>1440 125</td>
			<td>40, Ashless, Circles, 125 mm</td>
		</tr>
		<tr>
			<td>Beaker</td>
			<td>Kimax</td>
			<td>1400</td>
			<td>100 mL</td>
		</tr>
		<tr>
			<td>Volumetric Flask</td>
			<td>Kimax</td>
			<td>28012-100</td>
			<td>Class A 100 mL</td>
		</tr>
		<tr>
			<td>Glass Funnel</td>
			<td>Kimax</td>
			<td>28980-150</td>
			<td>Addition Funnel, Long Stem, 60&#176; Angle, Wide Top. Type I, Class B.</td>
		</tr>
		<tr>
			<td>Watch glasses</td>
			<td>Pyrex</td>
			<td>9985-150</td>
			<td>Corning, 150&#160;mm</td>
		</tr>
		<tr>
			<td>Crucibles</td>
			<td>Fisherbrand</td>
			<td>FB-965-D</td>
			<td>High-Form Porcelain</td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Furnace</td>
			<td>Briteg Instrumentos Cientificos S.A. de C.V.</td>
			<td>1010</td>
			<td></td>
		</tr>
		<tr>
			<td>Fume Hood</td>
			<td>Fisher Alders, S.A. de C.V.</td>
			<td>F1124</td>
			<td></td>
		</tr>
		<tr>
			<td>Light surce</td>
			<td>Philips</td>
			<td>PL-S 9W UV-A/2P 1CT/6X 10 CC</td>
			<td></td>
		</tr>
		<tr>
			<td>pH meter</td>
			<td>OAKTON</td>
			<td>WD-35419-10</td>
			<td></td>
		</tr>
		<tr>
			<td>Hotplate whit magnetic stirrer</td>
			<td>Cole-Parmer</td>
			<td>JZ-04660-75</td>
			<td></td>
		</tr>
	</tbody>
</table>

the effect of ultraviolet radiation on the chemical bath deposition of bis(thiourea) cadmium chloride crystals and the subsequent cds obtention

本文比较研究了用化学浴沉积技术对 367 nm 波长的紫外光照射下双 (硫脲) 氯化镉晶体的制备效果。两个实验进行了比较: 一个没有紫外线光和其他的紫外线光的帮助。两个实验都是在同等条件下进行的, 温度为 343 K, pH 值为3.2。所用的前体为氯化镉 (CdCl2) 和硫脲 [CS (NH2)2], 溶解在50毫升的去离子水中, 酸性 pH 值。在该实验中, 在进行化学反应的时刻, 寻求电磁辐射的相互作用。结果表明晶体与紫外光之间存在相互作用;紫外光协助导致晶体生长在针状的形状。此外, 最终的产品是硫化镉, 并显示没有明显的差异, 当合成与或不使用 UV 光。

在两种前驱体溶液中, a 和 B 的紫外-可见光扩散反射吸收光谱显示了双 (硫脲) 氯化镉络合物-CdCl2-(CS2)2)2的存在。这在图 2c中由 250-500 nm 范围内的广泛吸收带证明。反过来,图 2c是独立 CdCl2和 CS (NH2)2在解决方案中的主要吸收带的组合, 如图 2a和2b...

Watch this Scientific Journal Video about The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bisthiourea Cadmium Chloride Crystals and the Subsequent CdS Obtention at JoVE.com

The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bisthiourea Cadmium Chloride Crystals and the Subsequent CdS Obtention

本文提出了一种用化学浴沉积法合成双 (硫脲) 镉氯化物晶体的协议。两个实验被描述: 一个由紫外光辅助与没有紫外光的一。

紫外辐射对双 (硫脲) 氯化镉晶体化学镀液沉积的影响及随后的 CdS 获得

In this work, the effects on the preparation of bis(thiourea) cadmium chloride crystals when illuminated with ultraviolet (UV) light at a wavelength of ...

the-effect-ultraviolet-radiation-on-chemical-bath-deposition-bis

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The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bis(thiourea) Cadmium Chloride Crystals and the Subsequent CdS Obtention

7.4K 次观看.  Universidad Autónoma del Estado de Hidalgo. 本文提出了一种用化学浴沉积法合成双 (硫脲) 镉氯化物晶体的协议。两个实验被描述: 一个由紫外光辅助与没有紫外光的一。

视频: The Effect of Ultraviolet Radiation on the Chemical Bath Deposition of Bisthiourea Cadmium Chloride Crystals and the Subsequent CdS Obtention

Origami Inspired Self-assembly of Patterned and Reconfigurable Particles

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two dimensional (2D) structures. These technologies are mature, offer high precision and many of them can be implemented in a high-throughput manner. We leverage the advantages of planar lithography and combine them with self-folding methods1-20 wherein physical forces derived from surface tension or residual stress, are used to curve or fold planar structures into three dimensional (3D) structures. In doing so, we make it possible to mass produce precisely patterned static and reconfigurable particles that are challenging to synthesize.
In this paper, we detail visualized experimental protocols to create patterned particles, notably, (a) permanently bonded, hollow, polyhedra that self-assemble and self-seal due to the minimization of surface energy of liquefied hinges21-23 and (b) grippers that self-fold due to residual stress powered hinges24,25. The specific protocol described can be used to create particles with overall sizes ranging from the micrometer to the centimeter length scales. Further, arbitrary patterns can be defined on the surfaces of the particles of importance in colloidal science, electronics, optics and medicine. More generally, the concept of self-assembling mechanically rigid particles with self-sealing hinges is applicable, with some process modifications, to the creation of particles at even smaller, 100 nm length scales22, 26 and with a range of materials including metals21, semiconductors9 and polymers27. With respect to residual stress powered actuation of reconfigurable grasping devices, our specific protocol utilizes chromium hinges of relevance to devices with sizes ranging from 100 &mu;m to 2.5 mm. However, more generally, the concept of such tether-free residual stress powered actuation can be used with alternate high-stress materials such as heteroepitaxially deposited semiconductor films5,7 to possibly create even smaller nanoscale grasping devices.

We describe experimental details of the synthesis of patterned and reconfigurable particles from two dimensional (2D) precursors. This methodology can be used to create particles in a variety of shapes including polyhedra and grasping devices at length scales ranging from the micro to centimeter scale.

折纸灵感的图案和可重构颗粒自组装

There are numerous techniques such as photolithography, electron-beam lithography and soft-lithography that can be used to precisely pattern two ...

科研

化学

Isolation and Chemical Characterization of Lipid A from Gram-negative Bacteria

Lipopolysaccharide (LPS) is the major cell surface molecule of gram-negative bacteria, deposited on the outer leaflet of the outer membrane bilayer. LPS can be subdivided into three domains: the distal O-polysaccharide, a core oligosaccharide, and the lipid A domain consisting of a lipid A molecular species and 3-deoxy-D-manno-oct-2-ulosonic acid residues (Kdo). The lipid A domain is the only component essential for bacterial cell survival. Following its synthesis, lipid A is chemically modified in response to environmental stresses such as pH or temperature, to promote resistance to antibiotic compounds, and to evade recognition by mediators of the host innate immune response. The following protocol details the small- and large-scale isolation of lipid A from gram-negative bacteria. Isolated material is then chemically characterized by thin layer chromatography (TLC) or mass-spectrometry (MS). In addition to matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) MS, we also describe tandem MS protocols for analyzing lipid A molecular species using electrospray ionization (ESI) coupled to collision induced dissociation (CID) and newly employed ultraviolet photodissociation (UVPD) methods. Our MS protocols allow for unequivocal determination of chemical structure, paramount to characterization of lipid A molecules that contain unique or novel chemical modifications. We also describe the radioisotopic labeling, and subsequent isolation, of lipid A from bacterial cells for analysis by TLC. Relative to MS-based protocols, TLC provides a more economical and rapid characterization method, but cannot be used to unambiguously assign lipid A chemical structures without the use of standards of known chemical structure. Over the last two decades isolation and characterization of lipid A has led to numerous exciting discoveries that have improved our understanding of the physiology of gram-negative bacteria, mechanisms of antibiotic resistance, the human innate immune response, and have provided many new targets in the development of antibacterial compounds.

Isolation and characterization of the lipid A domain of lipopolysaccharide (LPS) from gram-negative bacteria provides insight into cell surface based mechanisms of antibiotic resistance, bacterial survival and fitness, and how chemically diverse lipid A molecular species differentially modulate host innate immune responses.

隔离和脂质A的化学表征革兰氏阴性菌

Lipopolysaccharide (LPS) is the major cell surface molecule of gram-negative bacteria, deposited on the outer leaflet of the outer membrane bilayer. LPS ...

Preparation of Hydrophobic Metal-Organic Frameworks via Plasma Enhanced Chemical Vapor Deposition of Perfluoroalkanes for the Removal of Ammonia

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high surface area microporous materials, such as metal-organic frameworks (MOFs), unique challenges present themselves for PECVD treatments. Herein the protocol for development of a MOF that was previously unstable to humid conditions is presented. The protocol describes the synthesis of Cu-BTC (also known as HKUST-1), the treatment of Cu-BTC with PECVD of perfluoroalkanes, the aging of materials under humid conditions, and the subsequent ammonia microbreakthrough experiments on milligram quantities of microporous materials. Cu-BTC has an extremely high surface area (~1,800 m2/g) when compared to most materials or surfaces that have been previously treated by PECVD methods. Parameters such as chamber pressure and treatment time are extremely important to ensure the perfluoroalkane plasma penetrates to and reacts with the inner MOF surfaces. Furthermore, the protocol for ammonia microbreakthrough experiments set forth here can be utilized for a variety of test gases and microporous materials.

Herein the procedures for plasma enhanced chemical vapor deposition of perfluoroalkanes on microporous materials such as metal-organic frameworks to enhance their stability and hydrophobicity are described. Furthermore, breakthrough testing of milligram quantities of samples is described in detail.

增强型氟烷烃的化学气相沉积等离子通过疏水金属 - 有机骨架的制备氨的去除

Plasma enhanced chemical vapor deposition (PECVD) of perfluoroalkanes has long been studied for tuning the wetting properties of surfaces. For high ...

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at &#60;60 &#176;C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

We present the synthesis of the organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x, x~2) via low temperature chemical vapor deposition (CVD). This optimized recipe yields an increase in Curie temperature from 400 K to over 600 K and a dramatic improvement in magnetic resonance properties.

化学气相沉积的有机磁体，钒四氰

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in ...

Preparation of Highly Porous Coordination Polymer Coatings on Macroporous Polymer Monoliths for Enhanced Enrichment of Phosphopeptides

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous polymer monoliths. The developed approach is based on the preparation of a macroporous polymer containing carboxylic acid functional groups and the subsequent step-by-step solution-based controlled growth of a layer of a porous coordination polymer on the surface of the pores of the polymer monolith. The prepared metal-organic polymer hybrid has a high specific micropore surface area. The amount of iron(III) sites is enhanced through metal-organic coordination on the surface of the pores of the functional polymer support. The increase of metal sites is related to the number of iterations of the coating process.
The developed preparation scheme is easily adapted to a capillary column format. The functional porous polymer is prepared as a self-contained single-block porous monolith within the capillary, yielding a flow-through separation device with excellent flow permeability and modest back-pressure. The metal-organic polymer hybrid column showed excellent performance for the enrichment of phosphopeptides from digested proteins and their subsequent detection using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The presented experimental protocol is highly versatile, and can be easily implemented to different organic polymer supports and coatings with a plethora of porous coordination polymers and metal-organic frameworks for multiple purification and/or separation applications.

A procedure for the preparation of porous hybrid separation media composed of a macroporous polymer monolith internally coated by a high surface area microporous coordination polymer is presented.

对磷酸增强富集制备高度多孔配位聚合物涂层的孔聚合物石柱的

We describe a protocol for the preparation of hybrid materials based on highly porous coordination polymer coatings on the internal surface of macroporous ...

Dynamic Electrochemical Measurement of Chloride Ions

This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver chloride electrode is used extensively for potentiometric measurement of chloride ions concentration in electrolyte. In this measurement, long-term and continuous monitoring is limited due to the inherent drift and the requirement of a stable reference electrode. We utilized the chronopotentiometric approach to minimize drift and avoid the use of a conventional reference electrode. A galvanostatic pulse is applied to an Ag/AgCl electrode which initiates a faradic reaction depleting the Cl&#713; ions near the electrode surface. The transition time, which is the time to completely deplete the ions near the electrode surface, is a function of the ion concentration, given by the Nernst equation. The square root of the transition time is in linear relation to the chloride ion concentration. Drift of the response over two weeks is negligible (59 &#181;M/day) when measuring 1 mM [Cl&#713;]using a current pulse of 10 Am-2. This is a dynamic measurement where the moment of transition time determines the response and thus is independent of the absolute potential. Any metal wire can be used as a pseudo-reference electrode, making this approach feasible for long-term measurement inside concrete structures.

Dynamic measurement of chloride ions is presented. Transition time of an Ag/AgCl electrode, during a chronopotentiometric technique, can give the concentration of chloride ions in electrolyte. This method does not require a stable conventional reference electrode.

氯离子的动态电化学测试

This protocol describes the dynamic measurement of chloride ions using the transition time of a silver silver chloride (Ag/AgCl) electrode. Silver silver ...

Photochemical Oxidative Growth of Iridium Oxide Nanoparticles on CdSe@CdS Nanorods

We demonstrate a procedure for the photochemical oxidative growth of iridium oxide catalysts on the surface of seeded cadmium selenide-cadmium sulfide (CdSe@CdS) nanorod photocatalysts. Seeded rods are grown using a colloidal hot-injection method and then moved to an aqueous medium by ligand exchange. CdSe@CdS nanorods, an iridium precursor and other salts are mixed and illuminated. The deposition process is initiated by absorption of photons by the semiconductor particle, which results with formation of charge carriers that are used to promote redox reactions. To insure photochemical oxidative growth we used an electron scavenger. The photogenerated holes oxidize the iridium precursor, apparently in a mediated oxidative pathway. This results in the growth of high quality crystalline iridium oxide particles, ranging from 0.5 nm to about 3 nm, along the surface of the rod. Iridium oxide grown on CdSe@CdS heterostructures was studied by a variety of characterization methods, in order to evaluate its characteristics and quality. We explored means for control over particle size, crystallinity, deposition location on the CdS rod, and composition. Illumination time and excitation wavelength were found to be key parameters for such control. The influence of different growth conditions and the characterization of these heterostructures are described alongside a detailed description of their synthesis. Of significance is the fact that the addition of iridium oxide afforded the rods astounding photochemical stability under prolonged illumination in pure water (alleviating the requirement for hole scavengers).

A protocol for the photochemical oxidative growth of small crystalline iridium oxide nanoparticles on the surface of CdSe@CdS seeded rod nanoparticles is presented.

铱氧化物纳米颗粒对硒化镉硫化镉@纳米棒光化学氧化增长

We demonstrate a procedure for the photochemical oxidative growth of iridium oxide catalysts on the surface of seeded cadmium selenide-cadmium sulfide ...

Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and conformality by taking advantage of self-limiting reactions between vapor-phase precursors and the growing film. Perovskite oxides present potential for next-generation electronic materials, but to-date have mostly been deposited by physical methods. This work outlines a method for depositing SrTiO3 (STO) on germanium using ALD. Germanium has higher carrier mobilities than silicon and therefore offers an alternative semiconductor material with faster device operation. This method takes advantage of the instability of germanium's native oxide by using thermal deoxidation to clean and reconstruct the Ge (001) surface to the 2&#215;1 structure. 2-nm thick, amorphous STO is then deposited by ALD. The STO film is annealed under ultra-high vacuum and crystallizes on the reconstructed Ge surface. Reflection high-energy electron diffraction (RHEED) is used during this annealing step to monitor the STO crystallization. The thin, crystalline layer of STO acts as a template for subsequent growth of STO that is crystalline as-grown, as confirmed by RHEED. In situ X-ray photoelectron spectroscopy is used to verify film stoichiometry before and after the annealing step, as well as after subsequent STO growth. This procedure provides framework for additional perovskite oxides to be deposited on semiconductors via chemical methods in addition to the integration of more sophisticated heterostructures already achievable by physical methods.

This work details the procedures for the growth and characterization of crystalline SrTiO3 directly on germanium substrates by atomic layer deposition. The procedure illustrates the ability of an all-chemical growth method to integrate oxides monolithically onto semiconductors for metal-oxide semiconductor devices.

锗通过原子层沉积钙钛矿型钛酸锶的外延生长

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and ...

The Effect of Interfacial Chemical Bonding in TiO2-SiO2 Composites on Their Photocatalytic NOx Abatement Performance

The chemical bonding of particulate photocatalysts to supporting material surfaces is of great importance in engineering more efficient and practical photocatalytic structures. However, the influence of such chemical bonding on the optical and surface properties of the photocatalyst and thus its photocatalytic activity/reaction selectivity behavior has not been systematically studied. In this investigation, TiO2 has been supported on the surface of SiO2 by means of two different methods: (i) by the in situ formation of TiO2 in the presence of sand quartz via a sol-gel method employing tetrabutyl orthotitanium (TBOT); and (ii) by binding the commercial TiO2 powder to quartz on a surface silica gel layer formed from the reaction of quartz with tetraethylorthosilicate (TEOS). For comparison, TiO2 nanoparticles were also deposited on the surfaces of a more reactive SiO2 prepared by a hydrolysis-controlled sol-gel technique as well as through a sol-gel route from TiO2 and SiO2 precursors. The combination of TiO2 and SiO2, through interfacial Ti-O-Si bonds, was confirmed by FTIR spectroscopy and the photocatalytic activities of the obtained composites were tested for photocatalytic degradation of NO according to the ISO standard method (ISO 22197&#8722;1). The electron microscope images of the obtained materials showed that variable photocatalyst coverage of the support surface can successfully be achieved but the photocatalytic activity towards NO removal was found to be affected by the preparation method and the nitrate selectivity is adversely affected by Ti-O-Si bonding.

The Effect of Interfacial Chemical Bonding in TiO2-SiO2 Composites on Their Photocatalytic NOx Abatement Performance

The focus of the present work is to establish means to generate and quantify levels of Ti-O-Si linkages and to correlate these with the photocatalytic properties of the supported TiO2.

界面化学键合在TiO中的作用<sub&gt; 2</sub&gt; -SiO<sub&gt; 2</sub&gt;复合材料对其光催化NOx消除性能的影响

The chemical bonding of particulate photocatalysts to supporting material surfaces is of great importance in engineering more efficient and practical ...

Extraction of Lignin with High &#946;-O-4 Content by Mild Ethanol Extraction and Its Effect on the Depolymerization Yield

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the emerging elegant procedures to obtain specific aromatic products rely on the lignin substrate having a high content of the readily cleavable &#946;-O-4 linkage as present in the native lignin structure. This provides a miss-match with typical technical lignins that are highly degraded and therefore are low in &#946;-O-4 linkages. Therefore, the extraction yields, and the quality of the obtained lignin are of utmost importance to access new lignin valorization pathways. In this manuscript, a simple protocol is presented to obtain lignins with high &#946;-O-4 content by relatively mild ethanol extraction that can be applied to different lignocellulose sources. Furthermore, analysis procedures to determine the quality of the lignins are presented together with a depolymerization protocol that yields specific phenolic 2-arylmethyl-1,3-dioxolanes, which can be used to evaluate the obtained lignins. The presented results demonstrate the link between lignin quality and potential for the lignins to be depolymerized into specific monomeric aromatic chemicals. Overall, the extraction and depolymerization demonstrates a trade-off between the lignin extraction yield and the retention of the native aryl-ether structure and thus the potential of the lignin to be used as the substrate for the production of chemicals for higher-value applications.

Here, we present a protocol to perform ethanol extraction of lignin from several biomass sources. The effect of the extraction conditions on the lignin yield and &#946;-O-4 content are presented. Selective depolymerization is performed on the obtained lignins to obtain high aromatic monomer products.

轻度乙醇萃取高β-o-4 的木质素及其对解聚产率的影响

Lignin valorization strategies are a key factor for achieving more economically competitive biorefineries based on lignocellulosic biomass. Most of the ...