- Smart, fully orthogonal switching was realized in a highly biocompatible diblock copolymer system with variable trigger-induced aqueous self-assembly. The polymers are composed of nonionic and zwitterionic blocks featuring lower and upper critical solution temperatures (LCSTs and UCSTs). In the system investigated, diblock copolymers from poly(N-isopropyl methacrylamide) (PNIPMAM) and a poly(sulfobetaine methacrylamide), systematic variation of the molar mass of the latter block allowed for shifting the UCST of the latter above the LCST of the PNIPMAM block in a salt-free condition. Thus, successive thermal switching results in "schizophrenic" micellization, in which the roles of the hydrophobic core block and the hydrophilic shell block are interchanged depending on the temperature. Furthermore, by virtue of the strong electrolyte-sensitivity of the zwitterionic polysulfobetaine block, we succeeded to shift its UCST below the LCST of the PNIPMAM block by adding small amounts of an electrolyte, thus inverting the pathway of switching.Smart, fully orthogonal switching was realized in a highly biocompatible diblock copolymer system with variable trigger-induced aqueous self-assembly. The polymers are composed of nonionic and zwitterionic blocks featuring lower and upper critical solution temperatures (LCSTs and UCSTs). In the system investigated, diblock copolymers from poly(N-isopropyl methacrylamide) (PNIPMAM) and a poly(sulfobetaine methacrylamide), systematic variation of the molar mass of the latter block allowed for shifting the UCST of the latter above the LCST of the PNIPMAM block in a salt-free condition. Thus, successive thermal switching results in "schizophrenic" micellization, in which the roles of the hydrophobic core block and the hydrophilic shell block are interchanged depending on the temperature. Furthermore, by virtue of the strong electrolyte-sensitivity of the zwitterionic polysulfobetaine block, we succeeded to shift its UCST below the LCST of the PNIPMAM block by adding small amounts of an electrolyte, thus inverting the pathway of switching. This superimposed orthogonal switching by electrolyte addition enabled us to control the switching scenarios between the two types of micelles (i) via an insoluble state, if the LCST-type cloud point is below the UCST-type cloud point, which is the case at low salt concentrations or (ii) via a molecularly dissolved state, if the LCST-type cloud point is above the UCST-type cloud point, which is the case at high salt concentrations. Systematic variation of the block lengths allowed for verifying the anticipated behavior and identifying the molecular architecture needed. The versatile and tunable self-assembly offers manifold opportunities, for example, for smart emulsifiers or for sophisticated carrier systems.…
MetadatenVerfasserangaben: | Natalya S. Vishnevetskaya, Viet HildebrandGND, Noverra Mardhatillah NizardoORCiDGND, Chia-Hsin Ko, Zhenyu Di, Aurel RadulescuORCiD, Lester C. BarnsleyORCiD, Peter Müller-BuschbaumORCiDGND, André LaschewskyORCiDGND, Christine M. PapadakisORCiDGND |
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DOI: | https://doi.org/10.1021/acs.langmuir.9b00241 |
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ISSN: | 0743-7463 |
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Pubmed ID: | https://pubmed.ncbi.nlm.nih.gov/31017439 |
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Titel des übergeordneten Werks (Englisch): | Langmuir |
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Verlag: | American Chemical Society |
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Verlagsort: | Washington |
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Publikationstyp: | Wissenschaftlicher Artikel |
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Sprache: | Englisch |
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Datum der Erstveröffentlichung: | 24.04.2019 |
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Erscheinungsjahr: | 2019 |
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Datum der Freischaltung: | 08.02.2021 |
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Band: | 35 |
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Ausgabe: | 19 |
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Seitenanzahl: | 12 |
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Erste Seite: | 6441 |
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Letzte Seite: | 6452 |
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Fördernde Institution: | Deutsche Forschungsgemeinschaft (DFG)German Research Foundation (DFG) [PA 771/14-1, MU 1487/17-1, LA 611/11-1]; Deutscher Akademischer Austauschdienst DAAD (German Academic Exchange Service)Deutscher Akademischer Austausch Dienst (DAAD) |
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Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät / Institut für Chemie |
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DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
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Peer Review: | Referiert |
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