Lag-på-lag Syntese og overføring av Frittstående Conjugated 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 stort areal materialer har tiltrukket seg økende interesse sist, på grunn av deres høye variasjon i inkorporering av funksjonelle grupper i kombinasjon med sine fremragende termisk og kjemisk stabilitet, og lave densiteter. Men deres uoppløselige natur forårsaker problemer i deres behandling, siden vanligvis anvendt teknikker som spinnbelegging er ikke tilgjengelige. Spesielt for membran applikasjoner, der behandlingen av CMP som tynne filmer er ønskelig, har behandlingsproblemer hindret deres kommersiell anvendelse.
Her beskriver vi grense syntese av CMP tynne filmer på funksjon underlag via molekylære lag-på-lag (lbl) syntese. Denne prosessen gjør utarbeidelse av filmer med ønsket tykkelse og sammensetning, og selv ønsket sammensetning gradienter.
Bruken av offer bærere muliggjør fremstilling av frittstående membraner ved oppløsning av bæreren ettersyntesen. Til å håndtere slike ultra-tynne frittstående membraner beskyttelse med offer belegg viste store løftet, for å unngå brudd på de nanomembranes. For å overføre nanomembranes til det ønskede substrat, blir de belagte membraner upfloated ved luft-væske-grensesnittet, og deretter overføres 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
For syntesen av den CMP-film oppløsningen av katalysatoren må være fersk. En ødelagt katalysator (dvs. oksidert) er angitt med en blåfarging av løsningen. Den friske løsningen er fargeløs.
Et viktig punkt er å klippe kantene av glimmer substratet etter spinnbelegging PMMA. Også defekter i substratet bør kuttes, dvs. ble hver flekk i PMMA kan komme i kontakt med glimmer substratet, på grunn av en manglende gullsjikt. Ellers gullsjiktet kan bli strippet av fra sub…
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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