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Zhang Z, Chen C, Zhang S, Ye X, Zhou J, Wang Y. Large-area homoporous membranes (HOMEs) enabled by multiple annealing. J Memb Sci 2022. [DOI: 10.1016/j.memsci.2022.121021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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Müller M, Abetz V. Nonequilibrium Processes in Polymer Membrane Formation: Theory and Experiment. Chem Rev 2021; 121:14189-14231. [PMID: 34032399 DOI: 10.1021/acs.chemrev.1c00029] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Porous polymer and copolymer membranes are useful for ultrafiltration of functional macromolecules, colloids, and water purification. In particular, block copolymer membranes offer a bottom-up approach to form isoporous membranes. To optimize permeability, selectivity, longevity, and cost, and to rationally design fabrication processes, direct insights into the spatiotemporal structure evolution are necessary. Because of a multitude of nonequilibrium processes in polymer membrane formation, theoretical predictions via continuum models and particle simulations remain a challenge. We compiled experimental observations and theoretical approaches for homo- and block copolymer membranes prepared by nonsolvent-induced phase separation and highlight the interplay of multiple nonequilibrium processes─evaporation, solvent-nonsolvent exchange, diffusion, hydrodynamic flow, viscoelasticity, macro- and microphase separation, and dynamic arrest─that dictates the complex structure of the membrane on different scales.
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Affiliation(s)
- Marcus Müller
- Georg-August Universität, Institut für Theoretische Physik, 37073 Göttingen, Germany
| | - Volker Abetz
- Helmholtz-Zentrum Hereon, Institut für Membranforschung, 21502 Geesthacht, Germany.,Universität Hamburg, Institut für Physikalische Chemie, 20146 Hamburg, Germany
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Zhong D, Zhou J, Wang Y. Hollow-fiber membranes of block copolymers by melt spinning and selective swelling. J Memb Sci 2021. [DOI: 10.1016/j.memsci.2021.119374] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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Rahman MM. Selective Swelling and Functionalization of Integral Asymmetric Isoporous Block Copolymer Membranes. Macromol Rapid Commun 2021; 42:e2100235. [PMID: 34057263 DOI: 10.1002/marc.202100235] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 05/07/2021] [Indexed: 11/12/2022]
Abstract
SNIPS stands for a membrane fabrication technique that combines the evaporation induced self-assembly of the block copolymers and the classical nonsolvent induced phase separation. It is a one-step readily scalable technique to fabricate integral asymmetric isoporous membranes. The prominent developments in the last decade have carved out a niche for SNIPS as a potential technique to fabricate next generation isoporous membranes. In the last decade, a rich polymer library and variety of membrane postmodification routes have been successfully implemented to fabricate SNIPS membranes having the desired pore functionality. Some of these membranes form soft nanochannels in hydrated state due to swelling of the pore wall, i.e., the pore forming block of the block copolymer. These membranes having soft nanochannels have demonstrated the potential to perform several challenging separation tasks in ultrafiltration and nanofiltration. This paper highlights the currently accessible pore functionality, the strategies to tune the swelling of the soft nanochannels, the potential applications, and future perspectives of these membranes.
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Affiliation(s)
- Md Mushfequr Rahman
- Helmholtz-Zentrum Hereon, Institute of Membrane Research, Max-Planck-Straße 1, Geesthacht, 21502, Germany
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Bucher T, Clodt JI, Abetz C, Bajer B, Filiz V. Spraying of Ultrathin Isoporous Block Copolymer Membranes-A Story about Challenges and Limitations. MEMBRANES 2020; 10:E404. [PMID: 33297532 PMCID: PMC7762335 DOI: 10.3390/membranes10120404] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 12/03/2020] [Indexed: 12/11/2022]
Abstract
Isoporous membranes can be prepared by a combination of self-assembly of amphiphilic block copolymers and the non-solvent induced phase separation process. As the general doctor-blade technique suffers from high consumption of expensive block copolymer, other methods to reduce its concentration in the casting solution are sought after. Decreasing the block copolymer concentration during membrane casting and applying the block copolymer solution on a support membrane to obtain ultrathin isoporous membrane layers with e.g., spraying techniques, can be an answer. In this work we focused on the question if upscaling of thin block copolymer membranes produced by spraying techniques is feasible. To upscale the spray coating process, three different approaches were pursued, namely air-brush, 1-fluid nozzles and 2-fluid nozzles as generally used in the coating industry. The different spraying systems were implemented successfully in a membrane casting machine. Thinking about future development of isoporous block copolymer membranes in application it was significant that a continuous preparation process can be realised combining spraying of thin layers and immersion of the thin block copolymer layers in water to ensure phase-separation. The system was tested using a solution of polystyrene-block-poly(4-vinylpyridine) diblock copolymer. A detailed examination of the spray pattern and its homogeneity was carried out. The limitations of this method are discussed.
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Affiliation(s)
| | - Juliana Isabel Clodt
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany; (T.B.); (C.A.); (B.B.); (V.F.)
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6
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Sankhala K, Koll J, Abetz V. Facilitated Structure Formation in Isoporous Block Copolymer Membranes upon Controlled Evaporation by Gas Flow. MEMBRANES 2020; 10:E83. [PMID: 32353997 PMCID: PMC7281245 DOI: 10.3390/membranes10050083] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 01/26/2023]
Abstract
The conventional fabrication of isoporous membranes via the evaporation-induced self-assembly of block copolymers in combination with non-solvent induced phase separation (SNIPS) is achieved under certain environmental conditions. In this study, we report a modification in the conventional fabrication process of (isoporous) flat sheet membranes in which the self-assembly of block copolymers is achieved by providing controlled evaporation conditions using gas flow and the process is introduced as gSNIPS. This fabrication approach can not only trigger and control the microphase separation but also provides isoporous structure formation in a much broader range of solution concentrations and casting parameters, as compared to fabrication under ambient, uncontrolled conditions. We systematically investigated the structure formation of the fabrication of integral asymmetric isoporous membranes by gSNIPS. A quantitative correlation between the evaporation conditions (causing solvent evaporation and temperature drop) and the self-assembly of block copolymers beginning from the top layer up to a certain depth, orientation of pores in the top layer and the substructure morphology has been discussed empirically.
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Affiliation(s)
- Kirti Sankhala
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Strasse 1, 21502 Geesthacht, Germany
| | - Joachim Koll
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Strasse 1, 21502 Geesthacht, Germany
| | - Volker Abetz
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Strasse 1, 21502 Geesthacht, Germany
- Institute of Physical Chemistry, Universität Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany
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8
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Müller M. Process-directed self-assembly of copolymers: Results of and challenges for simulation studies. Prog Polym Sci 2020. [DOI: 10.1016/j.progpolymsci.2019.101198] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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9
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Sankhala K, Wieland DCF, Koll J, Radjabian M, Abetz C, Abetz V. Self-assembly of block copolymers during hollow fiber spinning: an in situ small-angle X-ray scattering study. NANOSCALE 2019; 11:7634-7647. [PMID: 30698584 DOI: 10.1039/c8nr06892e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We investigated the self-assembly of block copolymers during hollow fiber membrane (HFM) fabrication by conducting in situ small angle X-ray scattering (SAXS) and ex situ scanning electron microscopy (SEM) studies. SAXS enables us to follow the structural rearrangements after extrusion at different distances from the spinning nozzle. The kinetics of the spinning process is examined as a function of the composition of block copolymer solutions and the spinning parameters. We studied the influence of the extrusion rate on the block copolymer microdomains and their self-assembly in weakly segregated and ordered solutions. The addition of magnesium acetate (MgAc2) leads to the ordering of micelles in the block copolymer solution already at lower polymer concentrations and shows an increased number of micelles with larger domain spacing as compared to the pristine solution. The SAXS data show the effect of shear within the spinneret on the self-assembly of block copolymers and the kinetics of phase separation after extrusion. It is observed that the ordering of micelles in solutions is decreased as indicated by the loss of crystallinity while high extrusion rates orient the structures perpendicular to the fiber direction. The structural features obtained from in situ SAXS experiments are correlated to the structure in the block copolymer solutions in the absence of shear and the morphologies in flat sheet and HF membranes obtained by ex situ SEM. This allows a systematic and comparative study of the effects varying the microdomain ordering within different block copolymer solutions and the formed membrane structures.
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Affiliation(s)
- Kirti Sankhala
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Strasse 1, 21502 Geesthacht, Germany.
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Zhang Z, Rahman MM, Abetz C, Bajer B, Wang J, Abetz V. Quaternization of a Polystyrene‐
block
‐poly(4‐vinylpyridine) Isoporous Membrane: An Approach to Tune the Pore Size and the Charge Density. Macromol Rapid Commun 2018; 40:e1800729. [DOI: 10.1002/marc.201800729] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2018] [Revised: 10/30/2018] [Indexed: 01/22/2023]
Affiliation(s)
- Zhenzhen Zhang
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
| | - Md. Mushfequr Rahman
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
| | - Clarissa Abetz
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
| | - Barbara Bajer
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
| | - Jiali Wang
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
| | - Volker Abetz
- Institute of Polymer ResearchHelmholtz‐Zentrum Geesthacht Max‐Planck‐Str. 1 21502 Geesthacht Germany
- Institute of Physical ChemistryUniversity of Hamburg Martin‐Luther‐King‐Platz 6 20146 Hamburg Germany
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Abetz V, Kremer K, Müller M, Reiter G. Functional Macromolecular Systems: Kinetic Pathways to Obtain Tailored Structures. MACROMOL CHEM PHYS 2018. [DOI: 10.1002/macp.201800334] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Affiliation(s)
- Volker Abetz
- Institute of Polymer Research; Helmholtz-Zentrum Geesthacht Max-Planck-Straße 1 21502 Geesthacht Germany
- Institute of Physical Chemistry; University of Hamburg; Martin-Luther-King-Platz 6 20146 Hamburg Germany
| | - Kurt Kremer
- Polymer Theory; Max Planck Institute for Polymer Research; Ackermannweg 10 55128 Mainz Germany
| | - Marcus Müller
- Institute for Theoretical Physics; Georg-August University of Göttingen; Friedrich-Hund-Platz 1 37077 Göttingen Germany
| | - Günter Reiter
- Institute of Physics; Albert-Ludwigs-University of Freiburg; Hermann-Herder-Str. 3 79104 Freiburg Germany
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Bucher T, Filiz V, Abetz C, Abetz V. Formation of Thin, Isoporous Block Copolymer Membranes by an Upscalable Profile Roller Coating Process-A Promising Way to Save Block Copolymer. MEMBRANES 2018; 8:E57. [PMID: 30082598 PMCID: PMC6161133 DOI: 10.3390/membranes8030057] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Revised: 07/25/2018] [Accepted: 07/30/2018] [Indexed: 11/17/2022]
Abstract
In this work we present a method to manufacture flat sheet membranes with a thin isoporous block copolymer (BCP) layer (thickness <3 µm) by profile roller coating (breadth: 30 cm) on top of a porous support membrane. Highly diluted BCP-solutions were used for this coating process. While we cast membranes with dimensions of 30 cm × 50 cm in this work, the procedure can easily be extended to endless dimensions in this roll to roll (R2R) process. The method offers the possibility to save >95% of BCP raw material compared to common doctor blade casting, by strongly decreasing the layer thickness to below 3 µm in combination with a highly open substructure. Additionally, we report a straightforward method to investigate the influence of the solvent evaporation time between coating and precipitation (phase inversion) on the membrane morphology using one sample only, which also ensures that all other influencing parameters remain constant.
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Affiliation(s)
- Thomas Bucher
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
| | - Volkan Filiz
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
| | - Clarissa Abetz
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
| | - Volker Abetz
- Helmholtz-Zentrum Geesthacht, Institute of Polymer Research, Max-Planck-Str. 1, 21502 Geesthacht, Germany.
- Institute of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146 Hamburg, Germany.
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