Ran Taoは、米国商務省の国立標準技術研究所からの助成金70NANB15H112からの資金提供に感謝したいと思います。アーロンM.フォースターへの資金は、国立標準技術研究所への議会予算を通じて提供されました。

<ol>
	<li>Macosko, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Rheology: principles, measurements, and applications. , (1994).</li><li>Larson, R. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> The Structure and Rheology of Complex Fluids. , (1999).</li><li>Vermant, J., Moldenaers, P., Mewis, J., Ellis, M., Garritano, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthogonal+superposition+measurements+using+a+rheometer+equipped+with+a+force+rebalanced+transducer.">Orthogonal superposition measurements using a rheometer equipped with a force rebalanced transducer.</a> Review of Scientific Instruments. 68 (11), 4090-4096 (1997).</li><li>Ferry, J. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Viscoelastic Properties of Polymers. , (1980).</li><li>Yamamoto, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rate-dependent+relaxation+spectra+and+their+determination.">Rate-dependent relaxation spectra and their determination.</a> Transactions of the Society of Rheology. 15 (2), 331-344 (1971).</li><li>Simmons, J. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+servo-controlled+rheometer+for+measurement+of+the+dynamic+modulus+of+viscoelastic+liquids.">A servo-controlled rheometer for measurement of the dynamic modulus of viscoelastic liquids.</a> Journal of Scientific Instruments. 43 (12), 887-892 (1966).</li><li>Tanner, R. I., Williams, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+orthogonal+superposition+of+simple+shearing+and+small-strain+oscillatory+motions.">On the orthogonal superposition of simple shearing and small-strain oscillatory motions.</a> Rheologica Acta. 10 (4), 528-538 (1971).</li><li>Schoukens, G., Mewis, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nonlinear+rheological+behaviour+and+shear-dependent+structure+in+colloidal+dispersions.">Nonlinear rheological behaviour and shear-dependent structure in colloidal dispersions.</a> Journal of Rheology. 22 (4), 381-394 (1978).</li><li>Zeegers, J., 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+sensitive+dynamic+viscometer+for+measuring+the+complex+shear+modulus+in+a+steady+shear+flow+using+the+method+of+orthogonal+superposition.">A sensitive dynamic viscometer for measuring the complex shear modulus in a steady shear flow using the method of orthogonal superposition.</a> Rheologica Acta. 34 (6), 606-621 (1995).</li><li>Mewis, J., Schoukens, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mechanical+spectroscopy+of+colloidal+dispersions.">Mechanical spectroscopy of colloidal dispersions.</a> Faraday Discussions of the Chemical Society. 65, 58-64 (1978).</li><li>Lin, N. Y. C., Ness, C., Cates, M. E., Sun, J., Cohen, I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Tunable+shear+thickening+in+suspensions.">Tunable shear thickening in suspensions.</a> Proceedings of the National Academy of Sciences. 113 (39), 10774-10778 (2016).</li><li>Gracia-Fern&#225;ndez, C., 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=Simultaneous+application+of+electro+and+orthogonal+superposition+rheology+on+a+starch/silicone+oil+suspension.">Simultaneous application of electro and orthogonal superposition rheology on a starch/silicone oil suspension.</a> Journal of Rheology. 60 (1), 121-127 (2015).</li><li>Sung, S. H., Kim, S., Hendricks, J., Clasen, C., Ahn, K. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthogonal+superposition+rheometry+of+colloidal+gels:+time-shear+rate+superposition.">Orthogonal superposition rheometry of colloidal gels: time-shear rate superposition.</a> Soft Matter. 14 (42), 8651-8659 (2018).</li><li>Colombo, G., 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=Superposition+rheology+and+anisotropy+in+rheological+properties+of+sheared+colloidal+gels.">Superposition rheology and anisotropy in rheological properties of sheared colloidal gels.</a> Journal of Rheology. 61 (5), 1035-1048 (2017).</li><li>Jacob, A. R., Poulos, A. S., Kim, S., Vermant, J., Petekidis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Convective+Cage+Release+in+Model+Colloidal+Glasses.">Convective Cage Release in Model Colloidal Glasses.</a> Physical Review Letters. 115 (21), 218301 (2015).</li><li>Jacob, A. R., Poulos, A. S., Semenov, A. N., Vermant, J., Petekidis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Flow+dynamics+of+concentrated+starlike+micelles:+A+superposition+rheometry+investigation+into+relaxation+mechanisms.">Flow dynamics of concentrated starlike micelles: A superposition rheometry investigation into relaxation mechanisms.</a> Journal of Rheology. 63 (4), 641-653 (2019).</li><li>Moghimi, E., Vermant, J., Petekidis, G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Orthogonal+superposition+rheometry+of+model+colloidal+glasses+with+short-ranged+attractions.">Orthogonal superposition rheometry of model colloidal glasses with short-ranged attractions.</a> Journal of Rheology. 63 (4), 533-546 (2019).</li><li>Tao, R., Forster, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=End+effect+correction+for+orthogonal+small+strain+oscillatory+shear+in+a+rotational+shear+rheometer.">End effect correction for orthogonal small strain oscillatory shear in a rotational shear rheometer.</a> Rheologica Acta. 59 (2), 95-108 (2020).</li><li>Schrag, J. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Deviation+of+velocity+gradient+profiles+from+the+"gap+loading"+and+"surface+loading"+limits+in+dynamic+simple+shear+experiments.">Deviation of velocity gradient profiles from the "gap loading" and "surface loading" limits in dynamic simple shear experiments.</a> Transactions of the Society of Rheology. 21 (3), 399-413 (1977).</li><li>Ewoldt, R. H., Johnston, M. T., Caretta, L. M., Spagnolie, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Complex Fluids in Biological Systems. Biological and Medical Physics, Biomedical Engineering. , 207-241 (2015).</li></ol>

このホワイト ペーパーで使用されている手順の完全な説明では、特定の商用製品とそのサプライヤーを特定する必要があります。そのような情報を含めることは、そのような製品またはサプライヤーがNISTによって承認されている、またはNISTによって推奨されていること、またはそれらが説明されている目的にとって必ずしも最良の材料、機器、ソフトウェア、またはサプライヤーであることを示すものと解釈されるべきではありません。

このプロトコルでは、二重壁同心円柱形状を備えた市販の直交重ね合わせレオロジー技術のために、ニュートン流体を使用して粘度校正測定を実行するための詳細な実験手順を提示します。キャリブレーション係数、すなわち一次最終効果係数CLと直交最終効果係数CLは、定常せん断速度掃引および直交周波数掃引試験を実施することによって独立?...

複雑な流体のレオロジー特性を理解することは、信頼性が高く再現性のある製品の開発と製造のために多くの産業にとって不可欠です1。これらの「複雑な流体」には、パーソナルケア製品、食品、化粧品、家庭用品など、私たちの日常生活に広く存在する懸濁液、ポリマー液体、および泡が含まれます。レオロジー特性または流動特性(粘度など)は、最終用途と加工性の性能指標を確立する上で重要な量ですが、流動特性は複雑な流体内に存在する微細構造と相互に関連しています。複雑な流体が単純な液体と区別される顕著な特徴の1つは、複数の長さスケールにまたがる多様な微細構造を持っていることです2。これらの微細構造は、さまざまな流動条件の影響を受けやすく、その結果、巨視的特性が変化します。流れと変形に応答する複雑な流体の非線形粘弾性挙動を介してこの構造-特性ループを解き放つことは、実験レオロジストにとって依然として困難な作業です。
直交重ね合わせ(OSP)レオロジー3 は、この測定の課題に対処するための堅牢な手法です。この手法では、小振幅の振動せん断流を一方向の一次定常せん断流に直交して重ね合わせることで、課せられた一次せん断流の下で粘弾性緩和スペクトルを同時に測定することができます。具体的には、線形粘弾性4の理論を用いて小さな振動せん断摂動を解析することができ、非線形流れ条件は一次定常せん断流によって達成される。2つの流れ場は直交しており、したがって結合されていないため、摂動スペクトルは、一次非線形流れ5の下での微細構造の変化に直接関係する可能性があります。この高度な測定技術は、複雑な流体の構造-特性-処理の関係を解明し、それらの定式化、処理、およびアプリケーションを最適化する機会を提供します。
現代のOSPレオロジーの実装は、突然のひらめきの結果ではありませんでした。むしろ、それはカスタムデバイスの何十年にもわたる開発に基づいています。最初のカスタムメイドのOSP装置は、シモンズ6によって1966年にさかのぼり、その後7,8,9,10に多くの努力が払われました。これらの初期のカスタムビルドデバイスには、アライメントの問題、ポンピングフロー効果(直交振動を提供するためのボブの軸方向の動きによる)、機器の感度の制限など、多くの欠点があります。1997年、Vermantら3は、市販の独立したモータートランスデューサレオメーターのフォースリバランストランスデューサ(FRT)を変更し、以前のデバイスよりも広い粘度範囲の流体のOSP測定を可能にしました。この変更により、垂直力リバランストランスデューサは応力制御レオメーターとして機能し、軸力の測定に加えて軸方向の振動を課すことができます。最近、OSP測定に必要な形状は、Vermantによる方法論の後、市販の別のモータートランスデューサレオメーター用にリリースされました。
市販のOSPレオロジーの出現以来、この技術をさまざまな複雑な流体の調査に適用することに関心が高まっています。例としては、コロイド懸濁液11、12、コロイドゲル13、14およびガラス15、16、17が挙げられる。市販の機器の入手可能性はOSP研究を促進しますが、複雑なOSP形状は、他の日常的なレオロジー技術よりも測定のより深い理解を必要とします。OSPフローセルは、二重壁同心円柱(またはクエット)ジオメトリに基づいています。上部が開き、下部が開いた設計により、環状のギャップとリザーバの間を流体が行き来することができます。メーカーによる形状設計の最適化にもかかわらず、OSP操作を行うと、流体は不均一な流れ場、幾何学的端効果、および残留ポンプ流を経験し、これらすべてがかなりの実験誤差を引き起こす可能性があります。我々の以前の研究18は、この技術のためのニュートン流体を用いた重要な最終効果補正手順を報告した。正しい粘度結果を得るには、一次方向と直交方向の両方に適切な最終効果係数を適用する必要があります。このプロトコルでは、OSPレオロジー技術の詳細な校正方法を提示し、測定誤差を低減するためのベストプラクティスの推奨事項を提供することを目的としています。OSP形状のセットアップ、サンプルのローディング、およびOSPテストの設定に関するこのホワイトペーパーで説明されている手順は、ニュートン流体以外の測定に簡単に採用および変換できます。流体分類(ニュートンまたは非ニュートン)のOSP測定の前に、ここで説明する校正手順を利用して、アプリケーションの最終効果補正係数を決定することをお勧めします。エンドファクターのキャリブレーション手順は以前に報告されていないことに注意してください。本稿で提供されるプロトコルでは、レオメーターユーザーが見落としがちな「生」データと「測定」データの理解に関する技術リソースについて、一般的な正確なレオロジー測定を実行する方法に関するステップバイステップガイドとヒントについても説明します。

<table>
	<tbody>
		<tr>
			<td>Advanced Peltier System</td>
			<td>TA Instruments</td>
			<td>402500.901</td>
			<td>Enviromental control device</td>
		</tr>
		<tr>
			<td>ARES-G2 Rheometer</td>
			<td>TA Instruments</td>
			<td>401000.501</td>
			<td>Rheometer</td>
		</tr>
		<tr>
			<td>Brookfield Silicone Fluid, 12500cP</td>
			<td>AMTEK Brookfield</td>
			<td>12500 cps</td>
			<td>Viscosity standard liquid</td>
		</tr>
		<tr>
			<td>OSP Slotted Bob, 33 mm</td>
			<td>TA Instruments</td>
			<td>402796.902</td>
			<td>Bob, upper geometry</td>
		</tr>
		<tr>
			<td>OSP Slotted Double Gap Cup, 34 mm</td>
			<td>TA Instruments</td>
			<td>402782.901</td>
			<td>Double wall cup, lower geometry</td>
		</tr>
		<tr>
			<td>Pipette (1 &#8211; 10 mL)</td>
			<td>Eppendorf</td>
			<td>3120000089</td>
			<td>To load test materials</td>
		</tr>
		<tr>
			<td>Pipette (100 &#8211; 1,000 &#181;L)</td>
			<td>Eppendorf</td>
			<td>3123000063</td>
			<td>To load test materials</td>
		</tr>
		<tr>
			<td>Pipette Tips (0.5 &#8211; 10 mL)</td>
			<td>Eppendorf</td>
			<td>022492098</td>
			<td>To load test materials</td>
		</tr>
		<tr>
			<td>Pipette Tips (50 &#8211; 1,000 &#181;L)</td>
			<td>Eppendorf</td>
			<td>022491555</td>
			<td>To load test materials</td>
		</tr>
		<tr>
			<td>Spatula</td>
			<td>VWR</td>
			<td>82027-532</td>
			<td>To load test materials</td>
		</tr>
		<tr>
			<td>TRIOS</td>
			<td>TA Instruments</td>
			<td>v4.3.1.39215</td>
			<td>Rheometer software</td>
		</tr>
	</tbody>
</table>

calibration procedures for orthogonal superposition rheology

直交重ね合わせ(OSP)レオロジーは、一次せん断流に直交する小振幅振動せん断変形を重ね合わせる高度なレオロジー手法です。この手法は、非線形流れ条件下での複雑な流体の構造ダイナミクスの測定を可能にし、広範囲の複雑な流体の性能の理解と予測に重要です。OSPレオロジー技術は、主にこの技術の力を強調したカスタムビルドのデバイスを通じて、1960年代から長い開発の歴史があります。OSP技術は現在、レオロジーコミュニティに市販されています。OSP形状の複雑な設計と理想的でない流れ場を考えると、ユーザーは測定誤差の大きさと原因を理解する必要があります。この研究では、ニュートン流体を使用したキャリブレーション手順を示し、測定誤差を減らすためのベストプラクティスの推奨事項を示します。具体的には、最終効果因子の決定方法、サンプル充填手順、および適切な測定範囲(せん断速度、周波数など)の特定に関する詳細情報が提供されます。

12.2 Pa sのシリコーン粘度標準での粘度校正測定の代表的な結果を図5と図6に示します。キャリブレーション実行では、一次最終効果係数と直交最終効果係数の両方が1.00に設定されていることに注意してください。図5は、二重y軸プロット上のせん断速度の関数としての定常せん断粘度とトルクを示しています。シリコーン液?...

Watch this Scientific Journal Video about Calibration Procedures for Orthogonal Superposition Rheology at JoVE.com

Calibration Procedures for Orthogonal Superposition Rheology

ニュートン流体を使用した市販の直交重ね合わせレオロジー手法の詳細な校正プロトコルを提示し、エンドエフェクト補正係数の決定方法と実験誤差を減らすためのベストプラクティスの推奨事項を示します。

直交重ね合わせレオロジーの校正手順

Orthogonal superposition (OSP) rheology is an advanced rheological technique that involves superimposing a small-amplitude oscillatory shear deformation ...

calibration-procedures-for-orthogonal-superposition-rheology

Research

JoVE Journal

Engineering

2.0K ビュー.  National Institute of Standards and Technology. ニュートン流体を使用した市販の直交重ね合わせレオロジー手法の詳細な校正プロトコルを提示し、エンドエフェクト補正係数の決定方法と実験誤差を減らすためのベストプラクティスの推奨事項を示します。

ビデオ: Calibration Procedures for Orthogonal Superposition Rheology

Compact Quantum Dots for Single-molecule Imaging

Single-molecule imaging is an important tool for understanding the mechanisms of biomolecular function and for visualizing the spatial and temporal heterogeneity of molecular behaviors that underlie cellular biology 1-4. To image an individual molecule of interest, it is typically conjugated to a fluorescent tag (dye, protein, bead, or quantum dot) and observed with epifluorescence or total internal reflection fluorescence (TIRF) microscopy. While dyes and fluorescent proteins have been the mainstay of fluorescence imaging for decades, their fluorescence is unstable under high photon fluxes necessary to observe individual molecules, yielding only a few seconds of observation before complete loss of signal. Latex beads and dye-labeled beads provide improved signal stability but at the expense of drastically larger hydrodynamic size, which can deleteriously alter the diffusion and behavior of the molecule under study.
Quantum dots (QDs) offer a balance between these two problematic regimes. These nanoparticles are composed of semiconductor materials and can be engineered with a hydrodynamically compact size with exceptional resistance to photodegradation 5. Thus in recent years QDs have been instrumental in enabling long-term observation of complex macromolecular behavior on the single molecule level. However these particles have still been found to exhibit impaired diffusion in crowded molecular environments such as the cellular cytoplasm and the neuronal synaptic cleft, where their sizes are still too large 4,6,7.
Recently we have engineered the cores and surface coatings of QDs for minimized hydrodynamic size, while balancing offsets to colloidal stability, photostability, brightness, and nonspecific binding that have hindered the utility of compact QDs in the past 8,9. The goal of this article is to demonstrate the synthesis, modification, and characterization of these optimized nanocrystals, composed of an alloyed HgxCd1-xSe core coated with an insulating CdyZn1-yS shell, further coated with a multidentate polymer ligand modified with short polyethylene glycol (PEG) chains (Figure 1). Compared with conventional CdSe nanocrystals, HgxCd1-xSe alloys offer greater quantum yields of fluorescence, fluorescence at red and near-infrared wavelengths for enhanced signal-to-noise in cells, and excitation at non-cytotoxic visible wavelengths. Multidentate polymer coatings bind to the nanocrystal surface in a closed and flat conformation to minimize hydrodynamic size, and PEG neutralizes the surface charge to minimize nonspecific binding to cells and biomolecules. The end result is a brightly fluorescent nanocrystal with emission between 550-800 nm and a total hydrodynamic size near 12 nm. This is in the same size range as many soluble globular proteins in cells, and substantially smaller than conventional PEGylated QDs (25-35 nm).

We describe the preparation of colloidal quantum dots with minimized hydrodynamic size for single-molecule fluorescence imaging. Compared to conventional quantum dots, these nanoparticles are similar in size to globular proteins and are optimized for single-molecule brightness, stability against photodegradation, and resistance to nonspecific binding to proteins and cells.

1分子蛍光イメージングのためのコンパクトな量子ドット

Single-molecule imaging is an important tool for  understanding the mechanisms of biomolecular function and for visualizing the  spatial and temporal ...

工学

Hyperpolarized Xenon for NMR and MRI Applications

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 T generate only a small detectable net-magnetization of the sample at room temperature 1. Hence, most NMR and MRI applications rely on the detection of molecules at relative high concentration (e.g., water for imaging of biological tissue) or require excessive acquisition times. This limits our ability to exploit the very useful molecular specificity of NMR signals for many biochemical and medical applications. However, novel approaches have emerged in the past few years: Manipulation of the detected spin species prior to detection inside the NMR/MRI magnet can dramatically increase the magnetization and therefore allows detection of molecules at much lower concentration 2.
Here, we present a method for polarization of a xenon gas mixture (2-5% Xe, 10% N2, He balance) in a compact setup with a ca. 16000-fold signal enhancement. Modern line-narrowed diode lasers allow efficient polarization 7 and immediate use of gas mixture even if the noble gas is not separated from the other components. The SEOP apparatus is explained and determination of the achieved spin polarization is demonstrated for performance control of the method.
The hyperpolarized gas can be used for void space imaging, including gas flow imaging or diffusion studies at the interfaces with other materials 8,9. Moreover, the Xe NMR signal is extremely sensitive to its molecular environment 6. This enables the option to use it as an NMR/MRI contrast agent when dissolved in aqueous solution with functionalized molecular hosts that temporarily trap the gas 10,11. Direct detection and high-sensitivity indirect detection of such constructs is demonstrated in both spectroscopic and imaging mode.

The production of hyperpolarized xenon by means of spin exchange optical pumping (SEOP) is described. This method yields a ~10000-fold enhancement of the nuclear spin polarization of Xe-129 and has applications in nuclear magnetic resonance spectroscopy and imaging. Examples of gas phase and solution state experiments are given.

NMRやMRIのアプリケーションのための過分極キセノン

Nuclear magnetic resonance (NMR) spectroscopy and imaging (MRI) suffer from intrinsic low sensitivity because even strong external magnetic fields of ~10 ...

Concurrent Quantitative Conductivity and Mechanical Properties Measurements of Organic Photovoltaic Materials using AFM

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. Thus, understanding of spatial variations in composition as well as electrical properties of OPV materials is of paramount importance for moving PV technology forward.1,2 In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution. Currently, materials properties measurements performed using commercially available AFM-based techniques (PeakForce, conductive AFM) generally provide only qualitative information. The values for resistance as well as Young's modulus measured using our method on the prototypical ITO/PEDOT:PSS/P3HT:PC61BM system correspond well with literature data. The P3HT:PC61BM blend separates onto PC61BM-rich and P3HT-rich domains. Mechanical properties of PC61BM-rich and P3HT-rich domains are different, which allows for domain attribution on the surface of the film. Importantly, combining mechanical and electrical data allows for correlation of the domain structure on the surface of the film with electrical properties variation measured through the thickness of the film.

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.

同時定量伝導率およびAFMを用いた有機太陽電池材料の機械的特性の測定

Organic photovoltaic  (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale  inhomogeneity of OPV materials affects performance ...

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

検出とパラジウムの回収は、都市鉱山からの金やコバルト金属は、ナノスケールワゴンホイール形の細孔を有する指定小説センサ/吸着剤を使用しました

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

A Simple Dewar/Cryostat for Thermally Equilibrating Samples at Known Temperatures for Accurate Cryogenic Luminescence Measurements

The design and operation of a simple liquid nitrogen Dewar/cryostat apparatus based upon a small fused silica optical Dewar, a thermocouple assembly, and a CCD spectrograph are described. The experiments for which this Dewar/cryostat is designed require fast sample loading, fast sample freezing, fast alignment of the sample, accurate and stable sample temperatures, and small size and portability of the Dewar/cryostat cryogenic unit. When coupled with the fast data acquisition rates of the CCD spectrograph, this Dewar/cryostat is capable of supporting cryogenic luminescence spectroscopic measurements on luminescent samples at a series of known, stable temperatures in the 77-300 K range. A temperature-dependent study of the oxygen quenching of luminescence in a rhodium(III) transition metal complex is presented as an example of the type of investigation possible with this Dewar/cryostat. In the context of this apparatus, a stable temperature for cryogenic spectroscopy means a luminescent sample that is thermally equilibrated with either liquid nitrogen or gaseous nitrogen at a known measureable temperature that does not vary (&#916;T &#60; 0.1 K) during the short time scale (~1-10 sec) of the spectroscopic measurement by the CCD. The Dewar/cryostat works by taking advantage of the positive thermal gradient dT/dh that develops above liquid nitrogen level in the Dewar where h is the height of the sample above the liquid nitrogen level. The slow evaporation of the liquid nitrogen results in a slow increase in h over several hours and a consequent slow increase in the sample temperature T over this time period. A quickly acquired luminescence spectrum effectively catches the sample at a constant, thermally equilibrated temperature.

A simple liquid nitrogen Dewar/cryostat apparatus comprised of a small fused silica optical Dewar, a thermocouple, and a charge-coupled device (CCD) spectrograph are described. The experiments for which this Dewar/cryostat is designed require fast sample loading, freezing, and alignment, accurate and stable sample temperatures, and small size/portability.

正確な低温ルミネッセンス測定のための既知の温度で熱的に平衡化サンプルのための簡単​​なデュワー/クライオスタット

The design and operation of a simple liquid nitrogen Dewar/cryostat apparatus based upon a small fused silica optical Dewar, a thermocouple assembly, and ...

Dielectric RheoSANS &#8212; Simultaneous Interrogation of Impedance, Rheology and Small Angle Neutron Scattering of Complex Fluids

A procedure for the operation of a new dielectric RheoSANS instrument capable of simultaneous interrogation of the electrical, mechanical and microstructural properties of complex fluids is presented. The instrument consists of a Couette geometry contained within a modified forced convection oven mounted on a commercial rheometer. This instrument is available for use on the small angle neutron scattering (SANS) beamlines at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). The Couette geometry is machined to be transparent to neutrons and provides for measurement of the electrical properties and microstructural properties of a sample confined between titanium cylinders while the sample undergoes arbitrary deformation. Synchronization of these measurements is enabled through the use of a customizable program that monitors and controls the execution of predetermined experimental protocols. Described here is a protocol to perform a flow sweep experiment where the shear rate is logarithmically stepped from a maximum value to a minimum value holding at each step for a specified period of time while frequency dependent dielectric measurements are made. Representative results are shown from a sample consisting of a gel composed of carbon black aggregates dispersed in propylene carbonate. As the gel undergoes steady shear, the carbon black network is mechanically deformed, which causes an initial decrease in conductivity associated with the breaking of bonds comprising the carbon black network. However, at higher shear rates, the conductivity recovers associated with the onset of shear thickening. Overall, these results demonstrate the utility of the simultaneous measurement of the rheo-electro-microstructural properties of these suspensions using the dielectric RheoSANS geometry.

Here, we present a procedure for the measurement of simultaneous impedance, rheology and neutron scattering from soft matter materials under shear flow.

誘電RheoSANS  - インピーダンス、レオロジー及び複雑流体の小角中性子散乱の同時尋問

A procedure for the operation of a new dielectric RheoSANS instrument capable of simultaneous interrogation of the electrical, mechanical and ...

Resonance Fluorescence of an InGaAs Quantum Dot in a Planar Cavity Using Orthogonal Excitation and Detection

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). Resonant excitation without fluorescence detection &#8211; for example, a differential transmission measurement &#8211; can determine some properties of the emitting system, but does not allow applications or measurements based on the emitted photons. For example, the measurement of photon correlations, observation of the Mollow triplet, and realization of single photon sources all require collection of the fluorescence. Incoherent excitation with fluorescence detection &#8211; for example, above band-gap excitation &#8211; can be used to create single photon sources, but the disturbance of the environment due to the excitation reduces the indistinguishability of the photons. Single photon sources based on QDs will have to be resonantly excited to have high photon indistinguishability, and simultaneous collection of the photons will be necessary to make use of them. We demonstrate a method to resonantly excite a single QD embedded in a planar cavity by coupling the excitation beam into this cavity from the cleaved face of the sample while collecting the fluorescence along the sample&#39;s surface normal direction. By carefully matching the excitation beam to the waveguide mode of the cavity, the excitation light can couple into the cavity and interact with the QD. The scattered photons can couple to the Fabry-Perot mode of the cavity and escape in the surface normal direction. This method allows complete freedom in the detection polarization, but the excitation polarization is restricted by the propagation direction of the excitation beam. The fluorescence from the wetting layer provides a guide to align the collection path with respect to the excitation beam. The orthogonality of the excitation and detection modes enables resonant excitation of a single QD with negligible laser scattering background.

Resonant excitation of a single self-assembled quantum dot can be achieved using an excitation mode orthogonal to the fluorescence collection mode. We demonstrate a method using the waveguide and Fabry-Perot modes of a planar microcavity surrounding the quantum dots. The method allows complete freedom in the detection polarization.

直交の励起と検出を用いた平面キャビティ内 InGaAs 量子ドットの共鳴蛍光

The ability to perform simultaneous resonant excitation and fluorescence detection is important for quantum optical measurements of quantum dots (QDs). ...

Fabrication Procedures and Birefringence Measurements for Designing Magnetically Responsive Lanthanide Ion Chelating Phospholipid Assemblies

Bicelles are tunable disk-like polymolecular assemblies formed from a large variety of lipid mixtures. Applications range from membrane protein structural studies by nuclear magnetic resonance (NMR) to nanotechnological developments including the formation of optically active and magnetically switchable gels. Such technologies require high control of the assembly size, magnetic response and thermal resistance. Mixtures of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) and its lanthanide ion (Ln3+) chelating phospholipid conjugate, 1,2-dimyristoyl-sn-glycero-3-phospho-ethanolamine-diethylene triaminepentaacetate (DMPE-DTPA), assemble into highly magnetically responsive assemblies such as DMPC/DMPE-DTPA/Ln3+ (molar ratio 4:1:1) bicelles. Introduction of cholesterol (Chol-OH) and steroid derivatives in the bilayer results in another set of assemblies offering unique physico-chemical properties. For a given lipid composition, the magnetic alignability is proportional to the bicelle size. The complexation of Ln3+ results in unprecedented magnetic responses in terms of both magnitude and alignment direction. The thermo-reversible collapse of the disk-like structures into vesicles upon heating allows tailoring of the assemblies&#39; dimensions by extrusion through membrane filters with defined pore sizes. The magnetically alignable bicelles are regenerated by cooling to 5 &#176;C, resulting in assembly dimensions defined by the vesicle precursors. Herein, this fabrication procedure is explained and the magnetic alignability of the assemblies is quantified by birefringence measurements under a 5.5 T magnetic field. The birefringence signal, originating from the phospholipid bilayer, further enables monitoring of polymolecular changes occurring in the bilayer. This simple technique is complementary to NMR experiments that are commonly employed to characterize bicelles.

Fabrication procedures for highly magnetically responsive lanthanide ion chelating polymolecular assemblies are presented. The magnetic response is dictated by the assembly size, which is tailored by extrusion through nanopore membranes. The assemblies&#39; magnetic alignability and temperature-induced structural changes are monitored by birefringence measurements, a complimentary technique to nuclear magnetic resonance and small angle neutron scattering.

製作手順と磁気応答性ランタノイド イオンのキレート リン脂質アセンブリを設計するための複屈折測定

Bicelles are tunable disk-like polymolecular assemblies formed from a large variety of lipid mixtures. Applications range from membrane protein structural ...

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for applications in two-dimensional nanoelectronics devices. Although many methods to synthesize SnSe nanocrystals have been developed, a simple way to fabricate large-sized single-layer SnSe flakes remains a great challenge. Herein, we show the experimental method to directly grow large-sized single-layer rectangular SnSe flakes on commonly used SiO2/Si insulating substrates using a straightforward two-step fabrication method in an atmospheric pressure quartz tube furnace system. The single-layer rectangular SnSe flakes with an average thickness of ~6.8 &#197; and lateral dimensions of about 30 &#181;m &#215; 50 &#181;m were fabricated by a combination of vapor transport deposition technique and nitrogen etching route. We characterized the morphology, microstructure, and electrical properties of the rectangular SnSe flakes and obtained excellent crystallinity and good electronic properties. This article about the two-step fabrication method can help researchers grow other similar two-dimensional, large-sized, single-layer materials using an atmospheric pressure system.

A protocol is presented demonstrating a two-step fabrication technique to grow large-sized single-layer rectangular shaped SnSe flakes on low-cost SiO2/Si dielectrics wafers in an atmospheric pressure quartz tube furnace system.

大型単層長方形 SnSe フレークの大気圧作製

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for ...

Cutting Procedures, Tensile Testing, and Ageing of Flexible Unidirectional Composite Laminates

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, where the yarns in each layer are oriented parallel to each other and held in place using binder resins and thin polymer films. The armor is constructed by stacking the unidirectional layers in different orientations. To date, only very preliminary work has been performed to characterize the ageing of the binder resins used in unidirectional laminates and the effects on their performance. For example, during the development of the conditioning protocol used in the National Institute of Justice Standard-0101.06, UD laminates showed visual signs of delamination and reductions in V50, which is the velocity at which half of the projectiles are expected to perforate the armor, after ageing. A better understanding of the material property changes in UD laminates is necessary to comprehend the long-term performance of armors constructed from these materials. There are no current standards recommended for mechanically interrogating unidirectional (UD) laminate materials. This study explores methods and best practices for accurately testing the mechanical properties of these materials and proposes a new test methodology for these materials. Best practices for ageing these materials are also described.

The goal of the study was to develop protocols to prepare consistent specimens for accurate mechanical testing of high-strength aramid or ultra-high-molar-mass polyethylene-based flexible unidirectional composite laminate materials and to describe protocols for performing artificial ageing on these materials.

柔軟な単方向複合ラミネートの切断手順、引張試験、およびエージング

Many body armor designs incorporate unidirectional (UD) laminates. UD laminates are constructed of thin (&#60;0.05 mm) layers of high-performance yarns, ...

直交重ね合わせレオロジーの校正手順

要約

さらに動画を探す

この動画の章

1分子蛍光イメージングのためのコンパクトな量子ドット

NMRやMRIのアプリケーションのための過分極キセノン

同時定量伝導率およびAFMを用いた有機太陽電池材料の機械的特性の測定

検出とパラジウムの回収は、都市鉱山からの金やコバルト金属は、ナノスケールワゴンホイール形の細孔を有する指定小説センサ/吸着剤を使用しました

正確な低温ルミネッセンス測定のための既知の温度で熱的に平衡化サンプルのための簡単なデュワー/クライオスタット

誘電RheoSANS - インピーダンス、レオロジー及び複雑流体の小角中性子散乱の同時尋問

直交の励起と検出を用いた平面キャビティ内 InGaAs 量子ドットの共鳴蛍光

製作手順と磁気応答性ランタノイドイオンのキレートリン脂質アセンブリを設計するための複屈折測定

大型単層長方形 SnSe フレークの大気圧作製

柔軟な単方向複合ラミネートの切断手順、引張試験、およびエージング

直交重ね合わせレオロジーの校正手順

要約

さらに動画を探す

この動画の章

1分子蛍光イメージングのためのコンパクトな量子ドット

NMRやMRIのアプリケーションのための過分極キセノン

同時定量伝導率およびAFMを用いた有機太陽電池材料の機械的特性の測定

検出とパラジウムの回収は、都市鉱山からの金やコバルト金属は、ナノスケールワゴンホイール形の細孔を有する指定小説センサ/吸着剤を使用しました

正確な低温ルミネッセンス測定のための既知の温度で熱的に平衡化サンプルのための簡単​​なデュワー/クライオスタット

誘電RheoSANS - インピーダンス、レオロジー及び複雑流体の小角中性子散乱の同時尋問

直交の励起と検出を用いた平面キャビティ内 InGaAs 量子ドットの共鳴蛍光

製作手順と磁気応答性ランタノイド イオンのキレート リン脂質アセンブリを設計するための複屈折測定

大型単層長方形 SnSe フレークの大気圧作製

柔軟な単方向複合ラミネートの切断手順、引張試験、およびエージング

正確な低温ルミネッセンス測定のための既知の温度で熱的に平衡化サンプルのための簡単なデュワー/クライオスタット

製作手順と磁気応答性ランタノイドイオンのキレートリン脂質アセンブリを設計するための複屈折測定