The authors have no acknowledgements.

1. Synthese von CMP Thin Films durch sequentielle Zugabe <ol><li> Selbstorganisierten Monoschicht (SAM) Funktionalisierung von Gold auf Glimmer. <ol><li> Bereiten 1 mM Lösung von 11-Thioacetyl-undecan säure Propargyl Amid 14 in Ethanol (SAM-Lösung). Mischen Sie mit Ultraschallbad, bis die Lösung klar ist. Schützen Sie die Flasche aus Licht mit Aluminiumfolie. </li><li> Erhalten Gold beschichtete Glimmer Wafer unter Argon. Nach dem Herausziehen aus dem Vorratsbehälter eintauchen Glimmer Wafer direkt an die SAM-Lösung für 18 Std. </li><li> Nehmen Sie die vorbereiteten Au-Glimmer-Wafer aus der SAM-Lösung gründlich mit Ethanol und trocken unter einem Stickstoffstrom. Danach speichern Sie das Substrat vor Licht und unter Schutzgas geschützt. </li></ol></li><li> Vorläuferlösungen. <ol><li> Wiegen 18,64 mg Cu-Katalysator (Tetrakis (Acetonitril) Kupfer (I) Hexafluor-Phosphat), 20,83 mg Tetraphenylmethan (TPM) -Alkin und 24.22 mg TPM-Azid und füllen Sie jede Komponente in eine separate Schlenk-Kolben.Siehe Abbildung 1 für die TPM-Alkin und TPM-Azid wird die Synthese in Referenz 15 beschrieben. Evakuieren und füllen mit Inertgas (N 2 oder Argon) 3-mal. </li><li> 25 ml wasserfreies Tetrahydrofuran (THF) zu jedem Schlenkkolben. Schützen Sie die Flaschen mit TPM-Azid und TPM-Alkin von Licht mit Aluminiumfolie. </li></ol></li><li> Bereiten Vorrichtung zum CMP Fertigung. Anmerkung: Die Synthese Vorrichtung ist in Abbildung 2 dargestellt. <ol><li> Verwenden Sie einen 250-ml-Rundkolben. Füllen Sie 130 ml THF. Legen Sie den vorbereiteten Untergrund mit Alkin beschichtet beendet SAM im Probenraum. Verwenden einen Probenhalter, so daß das Substrat senkrecht steht. </li><li> Das Gerät wird an den Schlenk-Leitung über der Kreuzung auf der Oberseite der Rückflusskühler. </li><li> Evakuieren und belüften mit Inertgas 3 mal. </li></ol></li><li> Sequentielle Zugabe unter inerten Bedingungen. <ol><li> Stellen Sie die Heizung auf 90 ° C und warten Sie, bis das THF WiederFluss. </li><li> Stieß THF aus der Probenkammer über den Auslass am Boden des Probenbehältnisses. Schließen Sie die Steckdose. </li><li> Gib 1 ml der hergestellten TPM-Azid-Lösung und 0,5 ml der Cu (I) Katalysatorlösung zu der Probenkammer über den Schraubdeckel mit Septum. Verwenden Sie eine Spritze mit einer Hohlnadel, um die Lösungen der Reihe nach von der Schlenkkolben in die Reaktionsvorrichtung zu übertragen. Hinweis: Die Reihenfolge keinen Einfluss auf die Reaktion hat. </li><li> Warten Sie ca. 30 min. </li><li> Ließ sich die Reaktionslösung über den Auslass am Boden des Probenbehältnisses. Schließen Sie die Steckdose und sammeln die kondensierte THF zur Spülung der Probe. Warten Sie ca. 30 min. </li><li> Lassen sich die Spüllösung über den Auslass am Boden des Probenbehältnisses. Schließen Sie die Steckdose. </li><li> Gib 1 ml der hergestellten TPM-Alkin-Lösung und 0,5 ml der Cu (I) Katalysatorlösung zu der Probenkammer über den Schraubdeckel mit Septum. Verwenden Sie eine Spritze mit einer HohlNadel, um die Lösungen der Reihe nach von der Schlenkkolben in die Reaktionsvorrichtung zu übertragen. Hinweis: Die Reihenfolge keinen Einfluss auf die Reaktion hat. </li><li> Warten Sie ca. 30 min. </li><li> Ließ sich die Reaktionslösung über den Auslass am Boden des Probenbehältnisses. Schließen Sie die Steckdose und sammeln die kondensierte THF zur Spülung der Probe. Warten Sie ca. 30 min. </li><li> Die Schritte 1.4.3 bis 1.4.9, bis die gewünschte Menge an Schichten erreicht ist. Hinweis: Eine Schicht ist etwa 1 nm dick. </li><li> Nehmen Sie die CMP-beschichteten Glimmersubstrat, spülen Sie ihn mit THF, Ethanol und trocknen Sie es unter einem Stickstoffstrom. </li></ol></li></ol> 2. Transfer von CMP Nanomembranen <ol><li> Poly (methylmethacrylat) (PMMA) Lösung. <ol><li> Es wird eine Lösung von 4% (Gewicht) PMMA (M 996 kDa) in Ethylacetat. Man löst das PMMA mit Ultraschallbad, bis die Lösung klar ist. </li></ol></li><li> Aufschleudern PMMA-Lösung. <ol><li> Stellen Sie die Schleuderbeschichtungsvorrichtung auf Ramp Zeit 10 sec von 0 bis 4.000 min, Haltezeit 40 sec und Rampenzeit 10 s von 4000 bis 0 min. </li><li> Legen Sie die CMP beschichtete Glimmersubstrat auf dem Spin-Coater und legte die PMMA-Lösung auf dem Wafer, bis es vollständig bedeckt ist. Starten Sie den Spin-Coater. </li><li> Nach der Schleuderbeschichtung abgeschlossen ist, legen Sie die Probe für 5 min auf einer Heizplatte bei 90 ° C. </li><li> Abgeschnitten 1 mm von jeder Kante des beschichteten Glimmersubstrat. Verwenden Sie eine Schere, um die Kanten zu schneiden. </li></ol></li><li> Transfer von PMMA beschichtet CMP Nanomembran. <ol><li> Vorzubereiten Lösung von I 2 / KI / H 2 O (1: 4: 40 m / m / m) und der KI / H 2 O (1:10 m / m). </li><li> Füllen Sie den I 2 / KI H 2 O-Lösung in einem 150 ml Kristallisierschale und füllen Sie die KI / H 2 O-Lösung in einen 100-ml Kristallisierschale. Legen Sie die PMMA beschichtet CMP Gold auf Glimmer-Substrat, mit Glimmer in Kontakt zu Lösung, auf der Oberseite des I 2 / KI / H 2 O-Lösung. Seien Sie vorsichtig, dass sie nicht sinken.Warten Sie mindestens 5 min. </li><li> Legen Sie die PMMA beschichtet CMP gold Glimmer-Substrat von der I 2 / KI / H 2 O-Lösung auf der Oberseite des KI / H 2 O-Lösung, mit Glimmer in Kontakt zu Lösung. Seien Sie vorsichtig, dass sie nicht sinken. Warten Sie mindestens 5 min. </li><li> Füllen Sie destilliertes Wasser in einem 250 ml Kristallisierschale. Isolieren Sie die PMMA / CMP / Goldfolie von der Glimmer. Tun Sie dies durch leichtes Eintauchen des Substrats, beginnend von einer Kante, in destilliertem Wasser. Halten des Substrats, so daß der Glimmer wird dem Wasser zeigt. Anmerkung: Das Verfahren ist in Abbildung 3 dargestellt. </li><li> Tauchbeschichtung der PMMA / CMP / Gold auf dem Siliciumwafer. Tun Sie dies durch Annäherung an die PMMA / CMP / gold langsam mit dem Wafer, bis er Rand des Schwimm PMMA / CMP / gold Membran berührt. Langsam Ziehen des Silizium-Wafers, nachdem der Si-Wafer wird in Kontakt mit der PMMA / CMP / Goldmembran. </li><li> Isolieren Sie das PMMA / CMP / Goldfilm von der Silizium-Wafer. Tun Sie dies durch leichtes Eintauchen des Substrats, beginnend von einem edge, in der I 2 / KI / H 2 O Lösung. Warten Sie 15 min. </li><li> Nachdem das Gold vollständig geätzt, übertragen Sie die PMMA / CMP-Membran, um Wasser über die Silizium-Wafer. Warten Sie 15 min. </li><li> Wiederholen Sie Schritt 2.3.7 dreimal, um die Membran mit Wasser zu waschen. </li><li> Übertragen des gewaschenen PMMA / CMP-Membran auf das gewünschte Substrat, beispielsweise einen Objektträger oder eine mit Gold beschichtete Siliziumwafer über den im Schritt 2.3.5 beschriebenen Verfahren. Lassen Sie das PMMA / CMP-Substrat an der Luft trocknen für mindestens 2 Std. </li></ol></li><li> Auflösen von PMMA. <ol><li> Setzen Sie das PMMA / CMP-Substrat in Aceton. Warten Sie 30 min. Nehmen Sie das Substrat und spülen Sie ihn mit Aceton. </li><li> Wiederholen Sie Schritt 2.4.1 dreimal. </li><li> Lassen Sie die CMP Substrat trocken für mindestens 2 Std. </li></ol></li></ol>

<ol>
	<li>Lindemann, P., 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=Preparation+of+Freestanding+Conjugated+Microporous+Polymer+Nanomembranes+for+Gas+Separation.">Preparation of Freestanding Conjugated Microporous Polymer Nanomembranes for Gas Separation.</a> Chemistry of Materials. 26 (24), 7193-71 (2014).</li><li>Kim, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Preparation+of+Ultrathin+Films+of+Molecular+Networks+through+Layer-by-Layer+Cross-Linking+Polymerization+of+Tetrafunctional+Monomers.">Preparation of Ultrathin Films of Molecular Networks through Layer-by-Layer Cross-Linking Polymerization of Tetrafunctional Monomers.</a> Macromolecules. 44 (18), 7092-7095 (2011).</li><li>Vonh&#246;ren, B., 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=Ultrafast+Layer-by-Layer+Assembly+of+Thin+Organic+Films+Based+on+Triazolinedione+Click+Chemistry.">Ultrafast Layer-by-Layer Assembly of Thin Organic Films Based on Triazolinedione Click Chemistry.</a> ACS Macro Letters. 4 (3), 331-334 (2015).</li><li>Shekhah, O., 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=Step-by-Step+Route+for+the+Synthesis+of+Metal&#8722;Organic+Frameworks.">Step-by-Step Route for the Synthesis of Metal&#8722;Organic Frameworks.</a> Journal of the American Chemical Society. 129 (49), 15118-15119 (2007).</li><li>Shekhah, O., Wang, H., Zacher, D., Fischer, R. A., W&#246;ll, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Growth+Mechanism+of+Metal&#8211;Organic+Frameworks:+Insights+into+the+Nucleation+by+Employing+a+Step-by-Step+Route.">Growth Mechanism of Metal&#8211;Organic Frameworks: Insights into the Nucleation by Employing a Step-by-Step Route.</a> Angewandte Chemie International Edition. 48 (27), 5038-5041 (2009).</li><li>Shekhah, O., Liu, J., Fischer, R. A., W&#246;ll, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MOF+thin+films:+existing+and+future+applications.">MOF thin films: existing and future applications.</a> Chemical Society Reviews. 40 (2), 1081-1106 (2011).</li><li>Liu, 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=Deposition+of+Metal-Organic+Frameworks+by+Liquid-Phase+Epitaxy:+The+Influence+of+Substrate+Functional+Group+Density+on+Film+Orientation.">Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation.</a> Materials. 5 (9), 1581-1592 (2012).</li><li>Such, G. K., Quinn, J. F., Quinn, A., Tjipto, E., Caruso, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Assembly+of+Ultrathin+Polymer+Multilayer+Films+by+Click+Chemistry.">Assembly of Ultrathin Polymer Multilayer Films by Click Chemistry.</a> Journal of the American Chemical Society. 128 (29), 9318-9319 (2006).</li><li>Ai, M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Carbon+Nanomembranes+(CNMs)+Supported+by+Polymer:+Mechanics+and+Gas+Permeation.">Carbon Nanomembranes (CNMs) Supported by Polymer: Mechanics and Gas Permeation.</a> Advanced Materials. 26 (21), 3421-3426 (2014).</li><li>Jiang, J. -. X., Cooper, A. I. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=in+Functional+Metal-Organic+Frameworks:+Gas+Storage,+Separation+and+Catalysis.">in Functional Metal-Organic Frameworks: Gas Storage, Separation and Catalysis.</a> Topics in Current Chemistry. (ed Martin Schr&#246;der) Ch. 293, 1-33 (2010).</li><li>Dawson, R., Cooper, A. I., Adams, D. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanoporous+organic+polymer+networks.">Nanoporous organic polymer networks.</a> Progress in Polymer Science. 37 (4), 530-563 (2012).</li><li>Muller, T., Br&#228;se, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Click+Chemistry+Finds+Its+Way+into+Covalent+Porous+Organic+Materials.">Click Chemistry Finds Its Way into Covalent Porous Organic Materials.</a> Angewandte Chemie International Edition. 50 (50), 11844-11845 (2011).</li><li>Tsotsalas, M., Addicoat, M. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Covalently+linked+organic+networks.">Covalently linked organic networks.</a> Frontiers in Materials. 2, (2015).</li><li>Kleinert, M., Winkler, T., Terfort, A., Lindhorst, 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=A+modular+approach+for+the+construction+and+modification+of+glyco-SAMs+utilizing+1,3-dipolar+cycloaddition.">A modular approach for the construction and modification of glyco-SAMs utilizing 1,3-dipolar cycloaddition.</a> Organic &amp; Biomolecular Chemistry. 6 (12), 2118-2132 (2008).</li><li>Plietzsch, O., 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=Four-fold+click+reactions:+Generation+of+tetrahedral+methane-+and+adamantane-based+building+blocks+for+higher-order+molecular+assemblies.">Four-fold click reactions: Generation of tetrahedral methane- and adamantane-based building blocks for higher-order molecular assemblies.</a> Organic &amp; Biomolecular Chemistry. 7, (2009).</li><li>Greenler, 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=Infrared+Study+of+Adsorbed+Molecules+on+Metal+Surfaces+by+Reflection+Techniques.">Infrared Study of Adsorbed Molecules on Metal Surfaces by Reflection Techniques.</a> The Journal of Chemical Physics. 44 (1), (1966).</li></ol>

The authors have nothing to disclose.

Für die Synthese von CMP-Film der Lösung des Katalysators hat frisch. Ein gebrochener Katalysator (dh oxidiert) wird durch eine Blaufärbung der Lösung angezeigt. Die frische Lösung ist farblos. Ein entscheidender Punkt ist, um die Kanten des Glimmer-Substrat nach der Schleuderbeschichtung PMMA geschnitten. Auch Defekte in dem Substrat geschnitten werden soll, das heißt, jeder Punkt waren die PMMA kann in Kontakt mit dem Glimmer-Substrat wegen einer fehlenden ...

The preparation of ultra-thin polymer membranes is of high interest for applications in gas separation and nanofiltration. Challenges in the synthesis are represented by (a) the control of the membrane thickness and the homogeneity and (b) transfer of such fragile membranes. To overcome challenge (a), molecular layer-by-layer synthesis1 has shown great promise in controlling the thickness and homogeneity of thin films grown at the solid-liquid interface.2,3 Controlling the number of layers linearly controls the film thickness. The l-b-l method has been successfully used to fabricate surface mounted metal organic frameworks (SURMOFs),4-7 also the synthesis of thin polymer films via l-b-l reaction of polymer chains was demonstrated.8 The challenge (b) concerns the handling of these ultra-thin membranes. To avoid rupture or wrinkling of the nanomembranes sacrificial supports of coatings have shown great promise. 9
Here we will present a detailed protocol for synthesis of conjugated microporous polymer (CMP)10-13 thin films through sequential addition of the molecular building blocks, with desired thickness and composition. The preparation of free-standing CMP nanomembranes is achieved by using a sacrificial support. To handle and transfer the CMP nanomembranes to other supports we will describe a simple protocol to protect the membranes with sacrificial coatings and their upfloating to the liquid air interface and subsequent transfer using dip-coating.

<table><tbody><tr><td>Acetone</td><td>VWR BDH Prolabo</td><td>20066.330</td><td>AnalR NORMAPUR</td></tr><tr><td>Potassium iodide</td><td>VWR BDH Prolabo</td><td>26846.292</td><td>AnalR NORMAPUR</td></tr><tr><td>Ethyl acetate</td><td>VWR BDH Prolabo</td><td>23882.321</td><td>AnalR NORMAPUR</td></tr><tr><td>Tetrahydrofuran (THF)</td><td>VWR BDH Prolabo</td><td>28559.320</td><td>HiPerSolv CHROMANORM</td></tr><tr><td>THF waterfree</td><td>Merck Millipore</td><td>1.08107.1001</td><td>SeccoSolv</td></tr><tr><td>Iodine</td><td>Sigma-Aldrich</td><td>20,777-2</td><td></td></tr><tr><td>Tetrakis(acetonitrile) copper(I) hexafluoro-phosphate</td><td>Sigma-Aldrich</td><td>346276-5G</td><td></td></tr><tr><td>Poly(methyl methacrylate) 996 kDa (PMMA)</td><td>Sigma-Aldrich</td><td>182265-25G</td><td></td></tr><tr><td>1.1.1.1 Methanetetrayltetrakis(4-azidobenzene) (TPM-azide)</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;9&lt;/sup&gt;.</td></tr><tr><td>1.1.1.1 Methanetetrayltetrakis(4-ethinylenebenzene) (TPM-alkyne)</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;9&lt;/sup&gt;.</td></tr><tr><td>11-thioacetyl-undecaneacid propargylamide</td><td></td><td></td><td>Provided by AK Prof. Br&amp;auml;se. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to &lt;sup&gt;8&lt;/sup&gt;.</td></tr><tr><td>gold/titan coated silicium-wafer</td><td>Georg Albert PVD, 76857 Silz, Germany</td><td></td><td></td></tr><tr><td>gold coated mica</td><td>Georg Albert PVD, 76857 Silz, Germany</td><td></td><td></td></tr></tbody></table>

layer-by-layer synthesis and transfer of freestanding conjugated microporous polymer nanomembranes

CMP große Oberfläche Materialien angezogen zunehmendes Interesse vor kurzem auf Grund ihrer hohen Variabilität bei der Einarbeitung von funktionellen Gruppen in Kombination mit ihrer hervorragenden thermischen und chemischen Stabilität und niedrigen Dichten. Jedoch verursacht ihre Unlöslichkeit Probleme bei ihrer Verarbeitung da üblicherweise angewandte Techniken wie Schleuderbeschichtung sind nicht verfügbar. Besonders für Membrananwendungen, wobei die Verarbeitung der CMP als dünne Filme wünschenswert sind die Verarbeitungsprobleme ihre kommerzielle Anwendung verhindert. Hier beschreiben wir die Grenzflächensynthese von CMP Dünnschichten auf funktionalisierten Substraten über molekulare Schicht-für-Schicht (LBL) Synthese. Dieses Verfahren erlaubt die Herstellung von Filmen mit einer gewünschten Dicke und Zusammensetzung und sogar gewünschten Zusammensetzungsgradienten. Die Verwendung von Opfer Trägern ermöglicht die Herstellung von freistehenden Membranen durch Auflösen des Trägers nachdie Synthese. Um solche ultradünnen Membranen freistehenden Griff der Schutz mit Opferbeschichtungen zeigten großes Versprechen, zum Bruch der Nanomembranen zu vermeiden. Um die Nanomembranen auf das gewünschte Substrat übertragen werden die beschichteten Membranen an der Luft-Flüssigkeit-Grenzfläche upfloated und dann über Tauchbeschichtung überführt.

Die Membranen werden durch Infrarotreflexionsabsorptionsspektroskopie (IRRAS). Gekennzeichnet 16 Abbildung 4 zeigt IRRA-Spektren von einem CMP-Membran auf eine Gold-Wafer übertragen. Typische Banden aus den Schwingungen des aromatischen Rückgrat sind 1.605 cm -1, 1.515 cm -1 und 1,412 cm -1. Nicht umgesetztem Alkin- und Azidgruppen können durch charakteristische Banden bei 2.125 cm -1 und 1,227 cm -1 beobachtet werden. 5 zeigt ...

Watch this Scientific Journal Video about Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes at JoVE.com

Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes

In this paper we describe the interfacial synthesis of conjugated microporous polymers (CMP) on sacrificial substrates, and the dissolution of the substrate for the preparation of freestanding CMP nanomembranes. In addition, we will describe how the fragile nanomembranes can be transferred to other substrates.

Layer-by-Layer-Synthese und Übertragung von Freestanding konjugierte mikroporöse Polymernanomembranen

CMP as large surface area materials have attracted growing interest recently, due to their high variability in the incorporation of functional groups in ...

layer-layer-synthesis-transfer-freestanding-conjugated-microporous

Research

JoVE Journal

Chemistry

9.3K Aufrufe.  Karlsruhe Institute of Technology. In this paper we describe the interfacial synthesis of conjugated microporous polymers (CMP) on sacrificial substrates, and the dissolution of the substrate for the preparation of freestanding CMP nanomembranes. In addition, we will describe how the fragile nanomembranes can be transferred to other substrates.

Serie: Layer-by-layer Synthesis and Transfer of Freestanding Conjugated Microporous Polymer Nanomembranes

Fabrication of Large-area Free-standing Ultrathin Polymer Films

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films. Typically, ultrathin films are prepared using either sacrificial layers, which may damage the film or affect its mechanical properties, or they are made on freshly cleaved mica, a substrate that is difficult to scale. Further, the size of ultrathin film is typically limited to a few square millimeters. In this method, we modify a surface with a polyelectrolyte that alters the strength of adhesion between polymer and deposition substrate. The polyelectrolyte can be shown to remain on the wafer using spectroscopy, and a treated wafer can be used to produce multiple films, indicating that at best minimal amounts of the polyelectrolyte are added to the film. The process has thus far been shown to be limited in scalability only by the size of the coating equipment, and is expected to be readily scalable to industrial processes. In this study, the protocol for making the solutions, preparing the deposition surface, and producing the films is described.

We describe a method for the fabrication of large-area (up to 13 cm diameter) and ultrathin (as thin as 8 nm) polymer films. Instead of using a sacrificial interlayer to delaminate the film from its substrate, we use a self-limiting surface treatment suitable for arbitrarily large areas.

Herstellung von großflächigen Freistehende ultradünne Polymerfilme

This procedure describes a method for the fabrication of large-area and ultrathin free-standing polymer films.  Typically, ultrathin films are prepared ...

Forschung

Chemie

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.

Vorbereitung hoch poröser Koordinationspolymerbeschichtungen auf makroporösen Monoliths für verbesserte Anreicherung von Phosphopeptiden

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

Fabrication of the Thermoplastic Microfluidic Channels

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using polymer/nanoparticle composite microscale lysis and solid phase extraction columns. The recovered samples are concentrated, small volume samples that are PCRable, without any additional cleanup. Here, we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then, we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns. We demonstrate grafting and polymerization of a carbon nanotube/polymer composite column for bacterial cell lysis. We then show the lysis process followed by solid phase extraction of nucleic acids from the sample on chip using a silica/polymer composite column. The attached protocols contain detailed instructions on how to make both lysis and solid phase extraction columns.

Here we demonstrate how to fabricate thermoplastic microfluidic chips using hot embossing and heat sealing. Then we demonstrate how to use in situ light directed surface grafting and polymerization through the sealed chip to form the composite solid phase columns.

Die Herstellung der thermoplastischen Mikrofluidikkanälen

In our lab, we have successfully isolated nucleic acids directly from microliter and submicroliter volumes of human blood, urine and stool using ...

Biologie

Facile Synthesis of Worm-like Micelles by Visible Light Mediated Dispersion Polymerization Using Photoredox Catalyst

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins with the synthesis of a hydrophilic poly(oligo(ethylene glycol) methyl ether methacrylate) (POEGMA) homopolymer using reversible addition-fragmentation chain-transfer (RAFT) polymerization. Under mild visible light irradiation (&#955; = 460 nm, 0.7 mW/cm2), this macro-chain transfer agent (macro-CTA) in the presence of a ruthenium based photoredox catalyst, Ru(bpy)3Cl2 can be chain extended with a second monomer to form a well-defined block copolymer in a process known as Photoinduced Electron Transfer RAFT (PET-RAFT). When PET-RAFT is used to chain extend POEGMA with benzyl methacrylate (BzMA) in ethanol (EtOH), polymeric nanoparticles with different morphologies are formed in situ according to a polymerization-induced self-assembly (PISA) mechanism. Self-assembly into nanoparticles presenting POEGMA chains at the corona and poly(benzyl methacrylate) (PBzMA) chains in the core occurs in situ due to the growing insolubility of the PBzMA block in ethanol. Interestingly, the formation of highly pure worm-like micelles can be readily monitored by observing the onset of a highly viscous gel in situ due to nanoparticle entanglements occurring during the polymerization. This process thereby allows for a more reproducible synthesis of worm-like micelles simply by monitoring the solution viscosity during the course of the polymerization. In addition, the light stimulus can be intermittently applied in an ON/OFF manner demonstrating temporal control over the nanoparticle morphology.

This article describes a process for producing polymeric self-assembled nanoparticles using visible light mediated dispersion polymerization. Using low energy visible light to control the polymerization allows for the reproducible formation of self-assembled worm-like micelles at high solids content.

Einfache Synthese von wurmartigen Mizellen durch sichtbares Licht Mediated Dispersion Polymerisation mit Photoredox Katalysator

Presented herein is a protocol for the facile synthesis of worm-like micelles by visible light mediated dispersion polymerization. This approach begins ...

Creating Sub-50 Nm Nanofluidic Junctions in PDMS Microfluidic Chip via Self-Assembly Process of Colloidal Particles

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its transparency. Due to the softness of the PDMS material, however, it is challenging to use PDMS for building nanochannels. The channels tend to collapse easily during plasma bonding. In this paper, we present an evaporation-driven self-assembly method of silica colloidal nanoparticles to create nanofluidic junctions with sub-50 nm pores between two microchannels. The pore size as well as the surface charge of the nanofluidic junction is tunable simply by changing the colloidal silica bead size and surface functionalization outside of the assembled microfluidic device in a vial before the self-assembly process. Using the self-assembly of nanoparticles with a bead size of 300 nm, 500 nm, and 900 nm, it was possible to fabricate a porous membrane with a pore size of ~45 nm, ~75 nm and ~135 nm, respectively. Under electrical potential, this nanoporous membrane initiated ion concentration polarization (ICP) acting as a cation-selective membrane to concentrate DNA by ~1,700 times within 15 min. This non-lithographic nanofabrication process opens up a new opportunity to build a tunable nanofluidic junction for the study of nanoscale transport processes of ions and molecules inside a PDMS microfluidic chip.

We propose a simple self-assembly technique of silica colloidal nanoparticles to create a nanofluidic junction between two microchannels in polydimethylsiloxane (PDMS). Using this technique, a nanoporous bead membrane with a pore size down to ~45 nm was built inside a microchannel and applied to electrokinetic preconcentration of DNA samples.

Erstellen von Unter 50 Nm nanofluidische Junctions in PDMS mikrofluidischen Chip über Selbstorganisation von kolloidalen Teilchen

Polydimethylsiloxane (PDMS) is the prevailing building material to make microfluidic devices due to its ease of molding and bonding as well as its ...

Ingenieurwesen

Preparation of Light-responsive Membranes by a Combined Surface Grafting and Postmodification Process

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is presented. The polymerization from the membrane surface is induced by plasma treatment of the membrane, followed by reacting the membrane surface with a methanolic solution of 2-hydroxyethyl methacrylate (HEMA). Special attention is given to the process parameters for the plasma treatment prior to the polymerization on the surface. For example, the influence of the plasma-treatment on different types of membranes (e.g.&#160;polyester, polycarbonate, polyvinylidene fluoride) is studied. Furthermore, the time-dependent stability of the surface-grafted membranes is shown by contact angle measurements. When grafting poly(2-hydroxyethyl methacrylate) (PHEMA) in this way, the surface can be further modified by esterification of the alcohol moiety of the polymer with a carboxylic acid function of the desired substance. These reactions can therefore be used for the functionalization of the membrane surface. For example, the surface tension of the membrane can be changed or a desired functionality as the presented light-responsiveness can be inserted. This is demonstrated by reacting PHEMA with a carboxylic acid functionalized spirobenzopyran unit which leads to a light-responsive membrane. The choice of solvent plays a major role in the postmodification step and is discussed in more detail in this paper. The permeability measurements of such functionalized membranes are performed using a Franz cell with an external light source. By changing the wavelength of the light from the visible to the UV-range, a change of permeability of aqueous caffeine solutions is observed.

A plasma-induced polymerization procedure is described for the surface-initiated polymerization on polymer membranes. Further postmodification of the grafted polymer with photochromic substances is presented with a protocol of conducting permeability measurements of light-responsive membranes.

Herstellung der lichtreaktions Membranen durch eine Kombinierte Oberflächen-Pfropfen und Postmodification Prozess

In order to modify the surface tension of commercial available track-edged polymer membranes, a procedure of surface-initiated polymerization is ...

Biotechnik

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.

Elektrophoretische Kristallisation von ultradünnen Hochleistungs-Metall-organischen Rahmen Membranen

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

Procedure for the Transfer of Polymer Films Onto Porous Substrates with Minimized Defects

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support substrates. Accomplishing this transfer in a highly controlled, mechanized, and reproducible manner can eliminate the creation of macroscale defect structures (e.g., tears, cracks, and wrinkles) within the thin film that compromise device performance and the usable area per sample. Here, we describe a general protocol for the highly controlled and mechanized transfer of a polymeric thin film onto an arbitrary porous support substrate for eventual use as a water filtration membrane device. Specifically, we fabricate a block copolymer (BCP) thin film on top of a sacrificial, water-soluble poly(acrylic acid) (PAA) layer and silicon wafer substrate. We then utilize a custom-designed, 3D-printed transfer tool and drain chamber system to deposit, lift-off, and transfer the BCP thin film onto the center of a porous anodized aluminum oxide (AAO) support disc. The transferred BCP thin film is shown to be consistently placed onto the center of the support surface due to the guidance of the meniscus formed between the water and the 3D-printed plastic drain chamber. We also compare our mechanized transfer-processed thin films to those that have been transferred by hand with the use of tweezers. Optical inspection and image analysis of the transferred thin films from the mechanized process confirm that little-to-no macroscale inhomogeneities or plastic deformations are produced, as compared to the multitude of tears and wrinkles produced from manual transfer by hand. Our results suggest that the proposed strategy for thin film transfer can reduce defects when compared to other methods across many systems and applications.

We present a procedure for highly controlled and wrinkle-free transfer of block copolymer thin films onto porous support substrates using a 3D-printed drain chamber. The drain chamber design is of general relevance to all procedures involving transfer of macromolecular films onto porous substrates, which is normally done by hand in an irreproducible fashion.

Verfahren zur Übertragung von Polymerfolien auf poröse Substrate mit minimierten Defekten

The fabrication of devices containing thin film composite membranes necessitates the transfer of these films onto the surfaces of arbitrary support ...

Synthesis of Hydrogels with Antifouling Properties As Membranes for Water Purification

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and thus achieving stable water permeability through membranes over time. Here, we report a facile method to prepare hydrogels based on zwitterions for membrane applications. Freestanding films can be prepared from sulfobetaine methacrylate (SBMA) with a crosslinker of poly(ethylene glycol) diacrylate (PEGDA) via photopolymerization. The hydrogels can also be prepared by impregnation into hydrophobic porous supports to enhance the mechanical strength. These films can be characterized by attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) to determine the degree of conversion of the (meth)acrylate groups, using goniometers for hydrophilicity and differential scanning calorimetry (DSC) for polymer chain dynamics. We also report protocols to determine the water permeability in dead-end filtration systems and the effect of foulants (bovine serum albumin, BSA) on membrane performance.

This paper reports practical methods to prepare hydrogels in freestanding films and impregnated membranes and to characterize their physical properties, including water transport properties.

Synthese von Hydrogelen mit Antifouling-Eigenschaften als Membranen für die Wasserreinigung

Hydrogels have been widely utilized to enhance the surface hydrophilicity of membranes for water purification, increasing the antifouling properties and ...

Selbstorganisation von polymergepfropften metallorganischen Gerüst-Monoschichten

Synthesis and Characterization of Self-Assembled Metal-Organic Framework Monolayers Using Polymer-Coated Particles

Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. Attempts to enhance the utility of MOFs have involved the preparation of various composites, including polymer-grafted MOFs. By directly grafting polymers to the external surface of MOFs, issues of incompatibility between polymers and MOFs can be overcome. Polymer brushes grafted from the surface of MOFs can serve to stabilize the MOF while enabling particle assembly into self-assembled metal-organic framework monolayers (SAMMs) via polymer-polymer interactions.
Control over the chemical composition and molecular weight of the grafted polymer can allow for tuning of the SAMM characteristics. In this work, instructions are provided on how to immobilize a chain transfer agent (CTA) onto the surface of the MOF UiO-66 (UiO = Universitetet i Oslo). The CTA&#160;serves as initiation sites for the growth of polymers. Once polymer chains are grown from the MOF surface, the formation of SAMMs is achieved through self-assembly at an air-water interface. The resulting SAMMs are characterized and shown to be freestanding by scanning electron microscopy imaging. The methods presented in this paper are expected to make the preparation of SAMMs more accessible to the research community and thereby expand their potential use as a&#160;MOF-polymer composite.

Autor im Rampenlicht: Erforschung selbstorganisierter MOF-Polymer-Verbundwerkstoffe

A protocol for the synthesis and characterization of self-assembled metal-organic framework monolayers is provided using polymer-grafted, metal-organic framework (MOF) crystals. The procedure shows that polymer-grafted MOF particles can be self-assembled at an air-water interface resulting in well-formed, free-standing, monolayer structures as evidenced by scanning electron microscopy imaging.

Synthese und Charakterisierung von selbstorganisierten metallorganischen Gerüstmonolagen unter Verwendung polymerbeschichteter Partikel

Metal-organic frameworks (MOFs) are materials with potential applications in fields such as gas adsorption and separation, catalysis, and biomedicine. ...