Name: synthesis and exfoliation of discotic zirconium phosphates to obtain colloidal liquid crystals
Uploaded: 2016-05-25T13:00:00.000+00:00
Duration: 8 min 54 s
Description: Watch this Scientific Journal Video about Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals at JoVE.com

This work is partially supported by NSF (DMR-1006870) and NASA (NASA-NNX13AQ60G). X. Z. Wang acknowledges support from the Mary Kay O'Connor Process Safety Center (MKOPSC) at Texas A&amp;M University. We also thank Min Shuai for her guidance.

水熱合成法を用いたα-ZrPの1.合成<ol><li>塩化ジルコニル八水和物（のZrOCl 2・8H 2 O）150ミリリットル丸底フラスコ内の脱イオン3.75ミリリットル（DI）中の水の6グラムを溶かします。 </li><li>激しく攪拌しながら脱イオン（DI）水8.25 mlで添加すること、続いて、ステップ1.1で調製したのZrOCl 2溶液に15 Mリン酸（H 3 PO 4）を滴下し、48 mLを加え。 </li><li> 80ミリリットルの容量のテフロンでライニング圧力容器内にゲル状の混合物を生じた注ぎます。ステンレス鋼殻と蓋、圧力プレートで構成される熱水オートクレーブ内に容器を配置し、うまく締めます。 </li><li> 24時間200℃の対流式オーブンの中に水熱オートクレーブを置きます。 </li><li>反応後、水熱オートクレーブは周囲の冷却下、室温に8時間を冷却することができます。 </li><li> 2で遠心分離機を用いて冷却した後、遠心分離管中のα-ZrPのディスクを収集し、10分間、500×gで。上澄み液は腐食性のある未反応のリン酸を含有しているので廃棄物処理容器内の液体部分を収集します。 <ol><li>その後、再び10分間、2500×gで1分間遠心のための渦-のZrPをαに水40mlを加えます。酸のすべてが洗い流されることを確実にするために、この手順を3回繰り返します。 </li></ol></li><li> 8時間、65℃のオーブンで乾燥したZrP-水粘着性混合した後、乳棒と乳鉢を用いて、それを挽きます。 </li></ol>逆流法によるα-ZrPの2.合成<ol><li> 150ミリリットル丸底フラスコ中で50ミリリットルM 12のリン酸とのZrOCl 2の6グラム・8H 2 Oを混ぜます。 </li><li>ステップ2.1で調製した混合物を24時間94℃の油浴中で還流します。 </li><li>ステップ1.6において同じプロトコルに従って脱イオン水で3回、生成物を洗浄し、次いで、8時間65℃のオーブン中で乾燥させました。 </li><li>グラインドは乳棒と乳鉢を用いて粉末にかさばるサンプルを乾燥させ、株式F以降を使用。 </li></ol>マイクロ波アシスト法によるα-ZrPを3.合成<ol><li> 12 Mリン酸溶液の9ミリリットルへのZrOCl 2・8H 2 Oの1グラムを追加し、20ミリリットルのシンチレーションバイアル中でも、得られた混合物を攪拌。 </li><li>マイクロ波反応器に指定された10mlのガラス容器に上記混合物を5ml注ぎます。 </li><li> 150℃の反応温度を設定する300 psiの圧力限界、反応物を1時間にわたって起こることを可能にします。 </li><li>反応後、ガラス容器を約15分間冷却した後、α-ZrPの結晶の酸洗浄、乾燥のための手順1.6から1.7と同じ手順に従ってみましょう。 </li></ol>単分子膜への層状α-ZrPを4.剥離<ol><li> 20mLのシンチレーションバイアル中で脱イオン水10ml中にα-ZrPの1gを分散させます。 </li><li>それにTBAOHの2.2ミリリットル（40重量％）を追加して、少なくとも40秒間ボルテックス。 Zrとのモル比に注目してください：1：TBAOHを1として保持されます。 </li><li> 1-2時間のために、得られた濃縮懸濁液を超音波処理し、TBA +イオンと結晶の完全な剥離の完全なインターカレーションを可能にするために、3日間のまま。任意に、濃縮された懸濁液は、より良好な剥離を得るために水（2〜3倍希釈）に希釈することができます。 </li><li>底に沈降し、部分的に剥離した結晶を除去するために、1時間高速回転（2500 XG）で剥離したサンプルを遠心します。別の容器に（ZrPの剥離）上部を収集し、何の沈殿物が見つからなくなるまで手順を繰り返します。 </li></ol>

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There is nothing to disclose.

還流法は、均一な直径と厚さのα-ZrPのの小さいサイズを作るための良いオプションです。水熱合成法と同様に、還流法は、準備時間によって制限されます。一般に、結晶が成長するための時間がかかります。 還流法に必要な長い反応時間は、より大きなサイズを有するナノディスクをもたらすことができます。剥離したナノディスクの平均サイズは、動的光散乱（DLS）?...

円盤状コロイド粘土、アスファルテン、赤血球、及び真珠層の形で天然に豊富です。ポリマーナノコンポジット1、バイオミメティック材料、機能性膜2、ディスコティック液晶の研究3および4は 、円盤状のコロイドナノディスクに基づいて開発されたピッカリングエマルション安定剤を含む多くの工学的システムでのアプリケーションの範囲。均一性と低い多分散性を有するナノディスクは、液晶の位相と変換を研究するために重要です。リン酸ジルコニウム（ZrPのは）整然とした層構造と制御可能なアスペクト比（直径以上の厚さ）を有する合成ナノディスクです。したがって、ZrPのの異なる合成の探査は、ディスコティック液晶システムの基本的な理解を確立するのに役立ちます。 ZrPのの構造は、1964年5でクリアフィールドとStynes ​​によって明らかにされた。たZrPの層状結晶の合成のために、熱水と逆流の方法は、一般的に6,7を採用しています。還流法が同じ持続時間のためのより小さな結晶を与えながら、水熱法は、400から25％6内の1500 nmおよび多分散性に至るまでのサイズに良好な制御を提供します。マイクロ波加熱は、ナノ材料8の合成のための有望な方法であることが証明されています。しかし、マイクロ波支援経路に基づいてのZrPの合成を記載ない論文はありません。サイズ、アスペクト比、水熱法による結晶成長の機構上の効果的な制御を系統的我々のグループ6で検討しました。 ZrPのは、簡単に、水性懸濁液中で単層に剥離することができ、剥離したZrPはよくチェンのグループ3,9-13に液晶材料として確立されています。これまで、様々な直径を持つ剥離したZrPナノディスクは、異なるアスペクト比が大きいのZrPが低いコンでI（等方性）-N（ネマチック）移行を持っていたと結論するために研究されてきた、と言います小さ ​​いZrPの3に比べてセンタリング。多分散度3は 、ネマチック液晶相の形成の塩9及び温度10,11効果も検討されています。また、このような警告となる液晶相などの他の相は、同様に13,14が検討されています。 この記事では、このようなコロイド状のZrPナノディスクサスペンションの実験的な実現を示しています。層状たZrP結晶は、異なる方法を介して合成され、その後、単層ナノディスクを得るために、水性媒体中で剥離されます。最後に、我々は、このシステムが示す液晶相転移を示します。これらのディスクの注目すべき側面は、直径比の厚さは0.0007ディスク3の大きさに応じて0.05の範囲にあることを、それらの非常に異方性です。異方性の高い単層のナノディスクは、ナノディスクの懸濁液に相転移を研究するためのモデルシステムを確立します。

<table><tbody><tr><td>&lt;strong&gt;Material&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Zirconyl Chloride Octahydrate</td><td>Fischer Scientific (Acros Organics)</td><td>AC20837-5000</td><td>98% +</td></tr><tr><td>&lt;em&gt;o&lt;/em&gt;-Phosphoric Acid</td><td>Fischer Scientific</td><td>A242-1</td><td>&amp;#8805; 85%</td></tr><tr><td>Tetra Butyl Ammonium Hydroxide</td><td>Acros Organics (Acros Organics)</td><td>AC176610025</td><td>40% wt. (1.5&amp;nbsp;M)</td></tr><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>Reaction Oven</td><td>Fischer Scientific</td><td>CL2 centrifuge</td><td>Isotemperature Oven (Temperature up to 350&amp;nbsp;&amp;#176;C)</td></tr><tr><td>Centrifuge</td><td>Thermo Scientific</td><td>Not Available</td><td>Rotation Speed: 100 - 4,000 rpm</td></tr><tr><td>Microwave Reactor</td><td>CEM Corporation</td><td>Discover and Explorer SP</td><td>Temp. up to 300&amp;nbsp;&amp;#176;C, power up to 300&amp;nbsp;W, pressure up to 30&amp;nbsp;bar</td></tr></tbody></table>

synthesis and exfoliation of discotic zirconium phosphates to obtain colloidal liquid crystals

Due to their abundance in natural clay and potential applications in advanced materials, discotic nanoparticles are of interest to scientists and engineers. Growth of such anisotropic nanocrystals through a simple chemical method is a challenging task. In this study, we fabricate discotic nanodisks of zirconium phosphate [Zr(HPO4)2&#183;H2O] as a model material using hydrothermal, reflux and microwave-assisted methods. Growth of crystals is controlled by duration time, temperature, and concentration of reacting species. The novelty of the adopted methods is that discotic crystals of size ranging from hundred nanometers to few micrometers can be obtained while keeping the polydispersity well within control. The layered discotic crystals are converted to monolayers by exfoliation with tetra-(n)-butyl ammonium hydroxide [(C4H9)4NOH, TBAOH]. Exfoliated disks show isotropic and nematic liquid crystal phases. Size and polydispersity of disk suspensions is highly important in deciding their phase behavior.

α-ZrPのナノディスクの図1A-Cに示すSEM画像は、それぞれ、水、還流、およびマイクロ波支援方法から得られます。これは、α-ZrPのナノディスク形状と合成条件と準備方法に応じて異なる厚さの六角形示すことが観察されました。我々のグループ6から以前に報告された研究では、結晶成長時間48時間以上のために、ディスクのエッジがシャープにな?...

Watch this Scientific Journal Video about Synthesis and Exfoliation of Discotic Zirconium Phosphates to Obtain Colloidal Liquid Crystals at JoVE.com

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

A two dimensional model material of discotic zirconium phosphate was developed. The inorganic crystal with lamellar structure was synthesized by hydrothermal, reflux, and microwave-assisted methods. On exfoliation with organic molecules, layered crystals can be converted to monolayers, and nematic liquid crystal phase was formed at sufficient concentration of monolayers.

コロイド液の結晶を得ることが合成とディスコティックリン酸ジルコニウムの剥離

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

synthesis-exfoliation-discotic-zirconium-phosphates-to-obtain

Universidad de Cartagena UDEC

Research

JoVE Journal

Chemistry

8.4K ビュー.  Texas A&M University. A two dimensional model material of discotic zirconium phosphate was developed. The inorganic crystal with lamellar structure was synthesized by hydrothermal, reflux, and microwave-assisted methods. On exfoliation with organic molecules, layered crystals can be converted to monolayers, and nematic liquid crystal phase was formed at sufficient concentration of monolayers. 

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

Preparation of Macroporous Epitaxial Quartz Films on Silicon by Chemical Solution Deposition

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step process based on the preparation of a sol in a one-pot synthesis which is followed by the deposition of a gel film on Si(100) substrates by evaporation induced self-assembly using the dip-coating technique and ends with a thermal treatment of the material to induce the gel crystallization and the growth of the quartz film. The formation of a silica gel is based on the reaction of a tetraethyl orthosilicate and water, catalyzed by HCl, in ethanol. However, the solution contains two additional components that are essential for preparing mesoporous epitaxial quartz films from these silica gels dip-coated on Si. Alkaline earth ions, like Sr2+ act as glass melting agents that facilitate the crystallization of silica and in combination with cetyl trimethylammonium bromide (CTAB) amphiphilic template form a phase separation responsible of the macroporosity of the films. The good matching between the quartz and silicon cell parameters is also essential in the stabilization of quartz over other SiO2 polymorphs and is at the origin of the epitaxial growth.

A protocol is presented for the preparation of piezoelectric macroporous epitaxial films of quartz on silicon by solution chemistry using dip-coating and thermal treatments in air.

化学溶液法によるシリコン上のマクロポーラスエピタキシャル石英薄膜の作製

This work describes the detailed protocol for preparing piezoelectric macroporous epitaxial quartz films on silicon(100) substrates. This is a three-step ...

化学

Synthesis and Characterization of Supramolecular Colloids

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical properties for applications in photonics, drug delivery and coating technology. Here we present a new family of colloidal building blocks, coined supramolecular colloids, whose self-assembly is controlled through surface-functionalization with a benzene-1,3,5-tricarboxamide (BTA) derived supramolecular moiety. Such BTAs interact via directional, strong, yet reversible hydrogen-bonds with other identical BTAs. Herein, a protocol is presented that describes how to couple these BTAs to colloids and how to quantify the number of coupling sites, which determines the multivalency of the supramolecular colloids. Light scattering measurements show that the refractive index of the colloids is almost matched with that of the solvent, which strongly reduces the van der Waals forces between the colloids. Before photo-activation, the colloids remain well dispersed, as the BTAs are equipped with a photo-labile group that blocks the formation of hydrogen-bonds. Controlled deprotection with UV-light activates the short-range hydrogen-bonds between the BTAs, which triggers the colloidal self-assembly. The evolution from the dispersed state to the clustered state is monitored by confocal microscopy. These results are further quantified by image analysis with simple routines using ImageJ and Matlab. This merger of supramolecular chemistry and colloidal science offers a direct route towards light- and thermo-responsive colloidal assembly encoded in the surface-grafted monolayer.

A protocol for the synthesis and characterization of colloids coated with supramolecular moieties is described. These supramolecular colloids undergo self-assembly upon the activation of the hydrogen-bonds between the surface-anchored molecules by UV-light.

超分子コロイドの合成とキャラクタリゼーション

Control over colloidal assembly is of utmost importance for the development of functional colloidal materials with tailored structural and mechanical ...

From Molecules to Materials: Engineering New Ionic Liquid Crystals Through Halogen Bonding

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid crystals (ILCs). Taking advantages of the high specificity of XB for haloperfluorocarbons and the ability of anions to act as XB-acceptors, we obtained supramolecular complexes based on 1-alkyl-3-methylimidazolium iodides and iodoperfluorocarbons, overcoming the well-known immiscibility between hydrocarbons (HCs) and perfluorocarbons (PFCs). The high directionality of the XB combined with the fluorophobic effect, allowed us to obtain enantiotropic liquid crystals where a rigid, non-aromatic, XB supramolecular anion acts as mesogenic core.
X-ray structure analysis of the complex between 1-ethyl-3-methylimidazolium iodide and iodoperfluorooctane showed the presence of a layered structure, which is a manifestation of the well-known tendency to segregation of perfluoroalkyl chains. This is consistent with the observation of smectic mesophases. Moreover, all the reported complexes melt below 100 &#176;C, and most are mesomorphic even at room temperature, despite that the starting materials were non-mesomorphic in nature.
The supramolecular strategy reported here provides new design principles for mesogen design allowing a totally new class of functional materials.

A protocol for the synthesis of a new type of mesogens, based on the halogen-bonded supramolecular anion [CnF2n+1-I&#183;&#183;&#183;I&#183;&#183;&#183;I-CnF2n+1]&#8722;, is reported.

分子から素材まで: ハロゲン結合を介して新しいイオン液体結晶工学

Herein, we demonstrate that a bottom-up approach, based on halogen bonding (XB), can be successfully applied for the design of a new type of ionic liquid ...

High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia (YSZ) Scaffolds by In Situ Carbon Templating Xerogels

We demonstrate a method for the high temperature fabrication of porous, nanostructured yttria-stabilized-zirconia (YSZ, 8 mol% yttria - 92 mol% zirconia) scaffolds with tunable specific surface areas up to 80 m2&#183;g-1. An aqueous solution of a zirconium salt, yttrium salt, and glucose is mixed with propylene oxide (PO) to form a gel. The gel is dried under ambient conditions to form a xerogel. The xerogel is pressed into pellets and then sintered in an argon atmosphere. During sintering, a YSZ ceramic phase forms and the organic components decompose, leaving behind amorphous carbon. The carbon formed in situ serves as a hard template, preserving a high surface area YSZ nanomorphology at sintering temperature. The carbon is subsequently removed by oxidation in air at low temperature, resulting in a porous, nanostructured YSZ scaffold. The concentration of the carbon template and the final scaffold surface area can be systematically tuned by varying the glucose concentration in the gel synthesis. The carbon template concentration was quantified using thermogravimetric analysis (TGA), the surface area and pore size distribution was determined by physical adsorption measurements, and the morphology was characterized using scanning electron microscopy (SEM). Phase purity and crystallite size was determined using X-ray diffraction (XRD). This fabrication approach provides a novel, flexible platform for realizing unprecedented scaffold surface areas and nanomorphologies for ceramic-based electrochemical energy conversion applications, e.g. solid oxide fuel cell (SOFC) electrodes.

High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia YSZ Scaffolds by In Situ Carbon Templating Xerogels

A protocol for fabricating porous, nanostructured yttria-stabilized-zirconia (YSZ) scaffolds at temperatures between 1,000 &#176;C and 1,400 &#176;C is presented.

によってナノ構造イットリア安定化ジルコニア（YSZ）足場の高温製作<em&gt;その場での</em&gt;カーボンテンプレート化キセロゲル

We demonstrate a method for the high temperature fabrication of porous, nanostructured yttria-stabilized-zirconia (YSZ, 8 mol% yttria - 92 mol% zirconia) ...

工学

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve desired molecular orientation states in LC displays, the "static" surface property of LCs, so-called surface anchoring, has been intensively studied. As a rule of thumb, once the initial orientation of LCs is "locked" by specific surface treatments, such as rubbing or treatment with a specific alignment layer, it hardly changes with temperature. Here, we present a system exhibiting an orientational transition upon temperature variation, which conflicts with the consensus. Right on the transition, the bulk LC molecules experience the orientational rotation, with 90&#176; between the planar (P) orientation at high temperatures and the vertical (V) orientation at low temperatures in the first-order transitional manner. We have tracked thermodynamic surface anchoring behavior by means of polarizing optical microscopy (POM), dielectric spectroscopy (DS), high-resolution differential scanning calorimetry (HR-DSC), and grazing incidence X-ray diffraction (GI-XRD) and reached a plausible physical explanation: that the transition is triggered by a growth of surface wetting sheets, which impose the V orientation locally against the P orientation in the bulk. This landscape would provide a general link explaining how the equilibrium bulk orientation is affected by surface-localized orientation in many LC systems. In our characterization, POM and DS are advantageous by offering information on the spatial distribution of the orientation of LC molecules. HR-DSC gives information about the precise thermodynamic information on transitions, which cannot be addressed by conventional DSC instruments due to limited resolution. GI-XRD provides information on surface-specific molecular orientation and short-range orderings. The goal of this paper is to present a protocol for preparing a sample that exhibits the transition and to demonstrate how the thermodynamic structural variation, both in the bulk and on surfaces, can be analyzed through the abovementioned methods.

Here, we present a protocol to trigger an orientational transition of a liquid crystal in response to temperature. Methodologies are described for preparing a sample in order to observe the transition and the detailed transitional evolution.

界面湿潤シートの熱力学的成長によって引き起こされる液晶の配向転移

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve ...

Preparation of Liquid Crystal Networks for Macroscopic Oscillatory Motion Induced by Light

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous light irradiation. The photo-excitation of dopants that can quickly dissipate light into heat, coupled with anisotropic thermal expansion and self-shadowing of the film, gives rise to the self-sustained deformation. The oscillations observed are influenced by the dimensions and the modulus of the film, and by the directionality and intensity of the light. The system developed offers applications in energy conversion and harvesting for soft-robotics and automated systems.
The general method described here consists of creating free-standing liquid crystalline films and characterizing the mechanical and thermal effects observed. The molecular alignment is achieved using alignment layers (rubbed polyimide), commonly used in the display manufacturing industry. To obtain actuators with large deformation, the mesogens are aligned and polymerized in a splay/bend configuration, i.e., with the director of the liquid crystals (LCs) going gradually from planar to homeotropic through the film thickness. Upon irradiation, the mechanical and thermal oscillations obtained are monitored with a high-speed camera. The results are further quantified by image analysis using an image processing program.

The goal of the protocol is to create liquid crystalline polymer films that can mechanically oscillate under continuous light irradiation. We describe in great detail the conception of free-standing films, from the liquid crystal alignment method to the photo-actuation. The experimental protocol applied to prepare this material is broadly applicable.

巨視的揺動運動の光によって誘起される液晶ネットワークの準備

A strategy based on doped liquid crystalline networks is described to create mechanical self-sustained oscillations of plastic films under continuous ...

Electrophoretic Crystallization of Ultrathin High-performance Metal-organic Framework Membranes

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and non-porous supports (polymer, ceramic, metal, carbon, and graphene). We developed a novel crystallization technique, which is termed the ENACT approach: the electrophoretic nuclei assembly for the crystallization of highly intergrown thin films (ENACT). This approach allows for a high density of heterogeneous nucleation of MOFs on a chosen substrate via the electrophoretic deposition (EPD) directly from the precursor sol. The growth of well-packed MOF nuclei leads to a highly intergrown polycrystalline MOF film. We show that this simple approach can be used for the synthesis of thin, intergrown zeolite imidazole framework (ZIF)-7 and ZIF-8 films. The resulting 500 nm-thick ZIF-8 membranes show a considerably high H2 permeance (8.3 x 10-6 mol m-2 s-1 Pa-1) and ideal gas selectivities (7.3 for H2/CO2, 15.5 for H2/N2, 16.2 for H2/CH4, and 2655 for H2/C3H8). An attractive performance for C3H6/C3H8 separation is also achieved (a C3H6 permeance of 9.9 x 10-8 mol m-2 s-1 Pa-1 and a C3H6/C3H8 ideal selectivity of 31.6 at 25 &#176;C). Overall, the ENACT process, owing to its simplicity, can be extended to synthesize intergrown thin films of a wide range of nanoporous crystalline materials.

A simple, reproducible, and versatile approach for the synthesis of intergrown, polycrystalline metal-organic framework membranes on a wide range of unmodified porous and non-porous supports is presented.

極薄高性能金属有機性フレームワーク膜の電気泳動の結晶化

We report the synthesis of thin, highly intergrown, polycrystalline metal-organic framework (MOF) membranes on a wide range of unmodified porous and ...

Preparation of Monodomain Liquid Crystal Elastomers and Liquid Crystal Elastomer Nanocomposites

LCEs are shape-responsive materials with fully reversible shape change and potential applications in medicine, tissue engineering, artificial muscles, and as soft robots. Here, we demonstrate the preparation of shape-responsive liquid crystal elastomers (LCEs) and LCE nanocomposites along with characterization of their shape-responsiveness, mechanical properties, and microstructure. Two types of LCEs &#8212; polysiloxane-based and epoxy-based &#8212; are synthesized, aligned, and characterized. Polysiloxane-based LCEs are prepared through two crosslinking steps, the second under an applied load, resulting in monodomain LCEs. Polysiloxane LCE nanocomposites are prepared through the addition of conductive carbon black nanoparticles, both throughout the bulk of the LCE and to the LCE surface. Epoxy-based LCEs are prepared through a reversible esterification reaction. Epoxy-based LCEs are aligned through the application of a uniaxial load at elevated (160 &#176;C) temperatures. Aligned LCEs and LCE nanocomposites are characterized with respect to reversible strain, mechanical stiffness, and liquid crystal ordering using a combination of imaging, two-dimensional X-ray diffraction measurements, differential scanning calorimetry, and dynamic mechanical analysis. LCEs and LCE nanocomposites can be stimulated with heat and/or electrical potential to controllably generate strains in cell culture media, and we demonstrate the application of LCEs as shape-responsive substrates for cell culture using a custom-made apparatus.

We demonstrate the preparation of siloxane-based and epoxy-based liquid crystal elastomers (LCEs) and LCE nanocomposites. The LCEs are characterized with respect to reversible strain, liquid crystal ordering, and stiffness. As a potential application, we demonstrate their use as shape-responsive substrates in a custom device for active cell culture.

モノドメイン液晶エラストマーおよび液晶エラストマーナノコンポジットの調製

LCEs are shape-responsive materials with fully reversible shape change and potential applications in medicine, tissue engineering, artificial muscles, and ...

生物工学

Epitaxial Nanostructured &alpha;-Quartz Films on Silicon: From the Material to New Devices

In this work, we show a detailed engineering route of the first piezoelectric nanostructured epitaxial quartz-based microcantilever. We will explain all the steps in the process starting from the material to the device fabrication. The epitaxial growth of &#945;-quartz film on SOI (100) substrate starts with the preparation of a strontium doped silica sol-gel and continues with the deposition of this gel into the SOI substrate in a thin film form using the dip-coating technique under atmospheric conditions at room temperature. Before crystallization of the gel film, nanostructuration is performed onto the film surface by nanoimprint lithography (NIL). Epitaxial film growth is reached at 1000 &#176;C, inducing a perfect crystallization of the patterned gel film. Fabrication of quartz crystal cantilever devices is a four-step process based on microfabrication techniques. The process starts with shaping the quartz surface, and then metal deposition for electrodes follows it. After removing the silicone, the cantilever is released from SOI substrate eliminating SiO2 between silicon and quartz. The device performance is analyzed by non-contact laser vibrometer (LDV) and atomic force microscopy (AFM). Among the different cantilever&#8217;s dimensions included in the fabricated chip, the nanostructured cantilever analyzed in this work exhibited a dimension of 40 &#181;m large and 100 &#181;m long and was fabricated with a 600 nm thick patterned quartz layer (nanopillar diameter and separation distance of 400 nm and 1 &#181;m, respectively) epitaxially grown on a 2 &#181;m thick Si device layer. The&#160;measured&#160;resonance frequency was&#160;267 kHz and the estimated quality factor, Q, of the whole mechanical structure was Q ~ 398 under low vacuum conditions. We observed the voltage-dependent linear displacement of cantilever with both techniques (i.e., AFM contact measurement and LDV). Therefore, proving that these devices can be activated through the indirect piezoelectric effect.

Epitaxial Nanostructured &#945;-Quartz Films on Silicon: From the Material to New Devices

This work presents a detailed protocol for the microfabrication of nanostructured &#945;-quartz cantilever on a Silicon-On-Insulator(SOI) technology substrate starting from the epitaxial growth of quartz film with the dip coating method and then nanostructuration of the thin film via nanoimprint lithography.

シリコン上のエピタキシャルナノ構造α-クオーツフィルム:材料から新しいデバイスへ

In this work, we show a detailed engineering route of the first piezoelectric nanostructured epitaxial quartz-based microcantilever. We will explain all ...

Synthesis of Biocompatible Liquid Crystal Elastomer Foams as Cell Scaffolds for 3D Spatial Cell Cultures

Here, we present a step-by-step preparation of a 3D, biodegradable, foam-like cell scaffold. These scaffolds were prepared by cross-linking star block co-polymers featuring cholesterol units as side-chain pendant groups, resulting in smectic-A (SmA) liquid crystal elastomers (LCEs). Foam-like scaffolds, prepared using metal templates, feature interconnected microchannels, making them suitable as 3D cell culture scaffolds. The combined properties of the regular structure of the metal foam and of the elastomer result in a 3D cell scaffold that promotes not only higher cell proliferation compared to conventional porous templated films, but also better management of mass transport (i.e., nutrients, gases, waste, etc.). The nature of the metal template allows for the easy manipulation of foam shapes (i.e., rolls or films) and for the preparation of scaffolds of different pore sizes for different cell studies while preserving the interconnected porous nature of the template. The etching process does not affect the chemistry of the elastomers, preserving their biocompatible and biodegradable nature. We show that these smectic LCEs, when grown for extensive time periods, enable the study of clinically relevant and complex tissue constructs while promoting the growth and proliferation of cells.

This study presents a methodology to prepare 3D, biodegradable, foam-like cell scaffolds based on biocompatible side-chain liquid crystal elastomers (LCEs). Confocal microscopy experiments show that foam-like LCEs allow for cell attachment, proliferation, and the spontaneous alignment of C2C12s myoblasts.

3D空間の細胞培養のための細胞骨格などの生体適合性液晶エラストマー発泡体の合成

Here, we present a step-by-step preparation of a 3D, biodegradable, foam-like cell scaffold. These scaffolds were prepared by cross-linking star block ...