Synthesis, Transfer, and Gas Separation Characteristics of MOF-Templated Polymer Membranes
Authors: Alexander Welle
Sergey Shishatskiy
Peter Krolla
Qi An
Volker Abetz
Tawheed Hashem
Salma Begum
Christof Wöll
Sylvain Grosjean
Manuel Tsotsalas
Sophia Schmitt
Stefan Bräse
Journal: Membranes (2019)
Discipline: CHEMISTRY
Keywords: gas separation; metal–organic framework (MOF); selective layer transfer; thin films.
Affiliations: Institute of Functional Interfaces (IFG), Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. ., Institute of Polymer Research, Helmholtz-Zentrum Geesthacht (HZG), Max-Planck-Street 1, 21502 Geesthacht, Germany. ., Karlsruhe Nano Micro Facility (KNMF), Karlsruhe Institute of Technology (KIT), Hermann-von-Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. ., Institute of Physics and Technology, International X-ray Optics Lab, National Research Tomsk Polytechnic University (TPU), 30 Lenin ave., Tomsk 634050, Russia. ., Institute for Organic Chemistry (IOC), Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe, Germany. ., Soft Matter Synthesis Lab, Institute of Biological Interfaces 3 (IBG3), Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. ., Institute of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany. ., Institute of Toxicology and Genetics (ITG), Karlsruhe Institute of Technology (KIT), Hermann-von Helmholtz-Platz 1, 76344 Eggenstein-Leopoldshafen, Germany. .

Abstract:  This paper discusses the potential of polymer networks, templated by crystalline metal-organic framework (MOF), as novel selective layer material in thin film composite membranes. The ability to create mechanically stable membranes with an ultra-thin selective layer of advanced polymer materials is highly desirable in membrane technology. Here, we describe a novel polymeric membrane, which is synthesized via the conversion of a surface anchored metal-organic framework (SURMOF) into a surface anchored gel (SURGEL). The SURGEL membranes combine the high variability in the building blocks and the possibility to control the network topology and membrane thickness of the SURMOF synthesis with high mechanical and chemical stability of polymers. Next to the material design, the transfer of membranes to suitable supports is also usually a challenging task, due to the fragile nature of the ultra-thin films. To overcome this issue, we utilized a porous support on top of the membrane, which is mechanically stable enough to allow for the easy membrane transfer from the synthesis substrate to the final membrane support. To demonstrate the potential for gas separation of the synthesized SURGEL membranes, as well as the suitability of the transfer method, we determined the permeance for eight gases with different kinetic diameters. 

Retracted: No

PubPeer comments:
 **Figure 3. Left: Two representative atomic force microscopy (AFM) images of the SURGEL por-PMMA membranes on top of the PAN PDMS support.** For the record, these two images widely overlap. Could the authors confirm that they are indeed taken from a single (larger) AFM image? ![file] , 
 Dear Dr. Coudert, Thank you for comment. The images are from two separate AFM scans. However, the scanned areas overlap, which I did not notice when preparing the Figure. I am happy to provide the original AFM files to anyone interested. As the intention of the Figure is only to provide a representative impression of the sample, I hope it is clear there was no intention from our side to manipulate the data in any way. Best regards Manuel Tsotsalas , 
 Thank you Dr. Tsotsalas for clarifying this point in response to my question. ,