Enriching and Quantifying Porous Single Layer 2D Polymers by Exfoliation of Chemically Modified van der Waals Crystals. (23rd January 2020)

• Record Type: Journal Article
• Authors: Lange, Ralph Z.; Synnatschke, Kevin; Qi, Haoyuan; Huber, Niklas; Hofer, Gregor; Liang, Baokun; Huck, Christian; Pucci, Annemarie; Kaiser, Ute; Backes, Claudia; Schlüter, A. Dieter
• Is Part Of: Angewandte Chemie. Volume 132:Number 14(2020)
• Page Start: 5732
• Page End: 5744
• Publication Date: 2020-01-23
• Subjects: Schichtverbindungen -- Flüssigphasen-Exfoliierung -- Monolagen -- Polymere -- Postpolymerisationsmodifikationen; Chemistry -- Periodicals; 540
• DOI: 10.1002/ange.201912705
• Languages: English
• ISSNs: 0044-8249

Abstract

Abstract: 2D polymer sheets with six positively charged pyrylium groups at each pore edge in a stacked single crystal can be transformed into a 2D polymer with six pyridines per pore by exposure to gaseous ammonia. This reaction furnishes still a crystalline material with tunable protonation degree at regular nano‐sized pores promising as separation membrane. The exfoliation is compared for both 2D polymers with the latter being superior. Its liquid phase exfoliation yields nanosheet dispersions, which can be size‐selected using centrifugation cascades. Monolayer contents of ≈30 % are achieved with ≈130 nm sized sheets in mg quantities, corresponding to tens of trillions of monolayers. Quantification of nanosheet sizes, layer number and mass shows that this exfoliation is comparable to graphite. Thus, we expect that recent advances in exfoliation of graphite or inorganic crystals (e.g. scale‐up, printing etc.) can be directly applied to this 2D polymer as well as to covalent organic frameworks. Abstract : Ein 2D‐Polymer mit Pyryliumgruppen wird mittels gasförmigen Ammoniaks in ein 2D‐Polymer mit Pyridingruppen umgewandelt. Durch Flüssigphasen‐Exfoliierung des kristallinen Feststoffes werden Nanoschichten in Dispersionen erhalten, die durch Zentrifugationskaskaden ihrer Größe nach selektiert werden können. Die Dimensionen der Nanoschichten sind vergleichbar mit exfoliiertem Graphit, was das Potenzial dieses Ansatzes zeigt, der auch auf kovalente organische Gerüstverbindungen angewendet werden könnte.