Layer-by-lags Syntese og overførsel af Fritstående Konjugerede Mikroporøse 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 store overfladeareal materialer har stigende interesse for nylig, på grund af deres høje variabilitet i inkorporering af funktionelle grupper i kombination med deres fremragende termiske og kemiske stabilitet og lave densiteter. Men deres uopløselige natur forårsager problemer i deres bearbejdning, da normalt anvendte teknikker såsom spin-coating er ikke tilgængelige. Især for membran applikationer, hvor behandlingen af CMP som tynde film er ønskeligt, har problemer med behandlingen hindret deres kommercielle anvendelse.
Her beskriver vi grænsefladespændingen syntese af CMP tynde film på funktionaliserede substrater via molekylær lag-på-lag (LBL) syntese. Denne fremgangsmåde tillader fremstilling af film med ønsket tykkelse og sammensætning og endda ønskede sammensætning gradienter.
Anvendelsen af offer understøtninger tillader fremstilling af fritstående membraner ved opløsning af bæreren eftersyntesen. Til at håndtere sådanne ultra-tynde fritstående membraner beskyttelse med ofringer belægninger viste meget lovende, for at undgå brud på nanomembranes. For at overføre nanomembranes til den ønskede substrat, er de overtrukne membraner upfloated ved luft-væske-grænsefladen og overføres derefter via dip coating.
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
Til syntesen af CMP-film opløsningen af katalysatoren skal være frisk. En brudt katalysator (dvs. oxideret) er angivet med en blå farvning af opløsningen. Den friske væske er farveløs.
Et afgørende punkt er at skære kanterne af glimmer substratet efter spin-coating PMMA. Også skal skæres defekter i substratet, dvs. hver plet var PMMA kan komme i kontakt med glimmer substrat, på grund af en manglende guldlag. Ellers guldlaget kan ikke strippes fra glim…
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 |
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