Skikt för skikt syntes och överföring av fristående Conjugated mikroporös polymer Nanomembranes
Summary
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.
Abstract
CMP som stora material ytarea har väckt växande intresse nyligen, på grund av deras höga variabiliteten i inkorporeringen av funktionella grupper i kombination med deras enastående termisk och kemisk stabilitet, och låga densiteter. Men orsakar deras olösliga naturen problem i deras bearbetning sedan vanligen används tekniker såsom spinnbeläggning är inte tillgängliga. Speciellt för membrantillämpningar, där behandlingen av CMP som tunna filmer är önskvärd, har bearbetningsproblem hindrade deras kommersiella tillämpningar.
Här beskriver vi gräns syntesen av CMP tunna filmer på funktionaliserade substrat via molekyl skikt-för-skikt (LBL) syntes. Detta förfarande möjliggör framställning av filmer med önskad tjocklek och sammansättning och även önskad sammansättning gradienter.
Användningen av offer stöd möjliggör framställning av fristående membran genom upplösning av stödet eftersyntesen. För att hantera sådana ultratunna fristående membran skydd med offer beläggningar visade stort löfte, för att undvika bristning av nanomembranes. För att överföra de nanomembranes till det önskade substratet, de belagda membranen upfloated vid luft-vätskegränsytan och sedan överföras via doppbeläggning.
Introduction
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.
Protocol
Representative Results
Discussion
För syntesen av CMP-filmen lösningen av katalysatom måste vara färskt. En trasig katalysator (dvs oxiderat) indikeras av en blåfärgning av lösningen. Den färska lösningen är färglös.
En avgörande punkt är att skära kanterna på glimmer substratet efter spinnbeläggning PMMA. Även defekter i substratet bör skäras, dvs varje fläck var PMMA kan komma i kontakt med glimmersubstrat, på grund av en saknad guldskikt. Annars guldskiktet kan inte skalas av från …
Disclosures
The authors have nothing to disclose.
Acknowledgements
The authors have no acknowledgements.
Materials
| Acetone | VWR BDH Prolabo | 20066.330 | AnalR NORMAPUR |
| Potassium iodide | VWR BDH Prolabo | 26846.292 | AnalR NORMAPUR |
| Ethyl acetate | VWR BDH Prolabo | 23882.321 | AnalR NORMAPUR |
| Tetrahydrofurane (THF) | VWR BDH Prolabo | 28559.320 | HiPerSolv CHROMANORM |
| THF waterfree | Merck Millipore | 1.08107.1001 | SeccoSolv |
| Iodine | Sigma-Aldrich | 20,777-2 | |
| Tetrakis(acetonitrile)copper(I)hexafluoro-phosphate | Sigma-Aldrich | 346276-5G | |
| Poly(methyl methacrylate) 996 kDa (PMMA) | Sigma-Aldrich | 182265-25G | |
| 1.1.1.1 Methanetetrayltetrakis(4-azidobenzene) (TPM-azide) | provided by AK Prof. Bräse. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to9 | ||
| 1.1.1.1 Methanetetrayltetrakis(4-ethinylenebenzene) (TPM-alkyne) | provided by AK Prof. Bräse. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to9 | ||
| 11-thioacetyl-undecaneacid propargylamide | provided by AK Prof. Bräse. Institute of organic chemistry, Karlsruhe Institute of Technology. Synthesized according to8 | ||
| gold/titan coated silicium-wafer | Georg Albert PVD, 76857 Silz, Germany | ||
| gold coated mica | Georg Albert PVD, 76857 Silz, Germany |
References
- Lindemann, P., et al. Preparation of Freestanding Conjugated Microporous Polymer Nanomembranes for Gas Separation. Chemistry of Materials. 26 (24), 7193-71 (2014).
- Kim, M., et al. Preparation of Ultrathin Films of Molecular Networks through Layer-by-Layer Cross-Linking Polymerization of Tetrafunctional Monomers. Macromolecules. 44 (18), 7092-7095 (2011).
- Vonhören, B., et al. Ultrafast Layer-by-Layer Assembly of Thin Organic Films Based on Triazolinedione Click Chemistry. ACS Macro Letters. 4 (3), 331-334 (2015).
- Shekhah, O., et al. Step-by-Step Route for the Synthesis of Metal−Organic Frameworks. Journal of the American Chemical Society. 129 (49), 15118-15119 (2007).
- Shekhah, O., Wang, H., Zacher, D., Fischer, R. A., Wöll, C. Growth Mechanism of Metal–Organic Frameworks: Insights into the Nucleation by Employing a Step-by-Step Route. Angewandte Chemie International Edition. 48 (27), 5038-5041 (2009).
- Shekhah, O., Liu, J., Fischer, R. A., Wöll, C. MOF thin films: existing and future applications. Chemical Society Reviews. 40 (2), 1081-1106 (2011).
- Liu, J., et al. Deposition of Metal-Organic Frameworks by Liquid-Phase Epitaxy: The Influence of Substrate Functional Group Density on Film Orientation. Materials. 5 (9), 1581-1592 (2012).
- Such, G. K., Quinn, J. F., Quinn, A., Tjipto, E., Caruso, F. Assembly of Ultrathin Polymer Multilayer Films by Click Chemistry. Journal of the American Chemical Society. 128 (29), 9318-9319 (2006).
- Ai, M., et al. Carbon Nanomembranes (CNMs) Supported by Polymer: Mechanics and Gas Permeation. Advanced Materials. 26 (21), 3421-3426 (2014).
- Jiang, J. -. X., Cooper, A. I. in Functional Metal-Organic Frameworks: Gas Storage, Separation and Catalysis. Topics in Current Chemistry. (ed Martin Schröder) Ch. 293, 1-33 (2010).
- Dawson, R., Cooper, A. I., Adams, D. J. Nanoporous organic polymer networks. Progress in Polymer Science. 37 (4), 530-563 (2012).
- Muller, T., Bräse, S. Click Chemistry Finds Its Way into Covalent Porous Organic Materials. Angewandte Chemie International Edition. 50 (50), 11844-11845 (2011).
- Tsotsalas, M., Addicoat, M. A. Covalently linked organic networks. Frontiers in Materials. 2, (2015).
- Kleinert, M., Winkler, T., Terfort, A., Lindhorst, T. K. A modular approach for the construction and modification of glyco-SAMs utilizing 1,3-dipolar cycloaddition. Organic & Biomolecular Chemistry. 6 (12), 2118-2132 (2008).
- Plietzsch, O., et al. Four-fold click reactions: Generation of tetrahedral methane- and adamantane-based building blocks for higher-order molecular assemblies. Organic & Biomolecular Chemistry. 7, (2009).
- Greenler, R. G. Infrared Study of Adsorbed Molecules on Metal Surfaces by Reflection Techniques. The Journal of Chemical Physics. 44 (1), (1966).
