Please use this identifier to cite or link to this item:
doi:10.22028/D291-42172
Title: | Polymer Hydrogel Sheets with Perpendicular Cross-Linking Gradient: Non-Monotonic Actuation and Ion-Specific Effects on the Actuation Kinetics |
Author(s): | Puza, Fatih Thiel, Marc Christopher Wagner, Yannic Marx, Michael Motz, Christian Lienkamp, Karen |
Language: | English |
Title: | Macromolecular Rapid Communications |
Volume: | 45 (2024) |
Issue: | 3 |
Publisher/Platform: | Wiley |
Year of Publication: | 2023 |
Free key words: | actuators hydrogels non-monotonic actuations polymers specific ion effects |
DDC notations: | 500 Science |
Publikation type: | Journal Article |
Abstract: | Non-monotonous actuation, that is, different kinds of motion in response to a single stimulus, is observed in some natural materials but difficult to implement in synthetic systems. Herein, polymer hydrogel sheets made from polyacrylamide (PAAm) or poly(dimethylacrylamide) (PDMAA) with a cross-linking gradient along the sheet thickness are reported. These are obtained by thermally initiated free radical polymerization using a specially designed Teflon mold with a glass lid. The resulting PAAm hydrogels undergo non-monotonous actuation (rolling into a tube and re-opening) when exposed to aqueous media as a single external stimulus. Their actuation kinetics is tuned with anions that have specific ion effects in their interaction with the surrounding solvent and the polymer itself: structure-breaking chloride enhances the hydration of the polymer backbone, structure-making sulfate decreases it, and is thus slowing down the actuation kinetics of the PAAm hydrogels. The PDMAA gel rolls up instantaneously in aqueous NaCl and only re-opens after 24 h. PDMAA actuation in aqueous Na2SO4 is only moderate as the gel did not swell in that solvent. Bilayer hydrogels made from PAAm and PDMAA (without gradient) show monotonic actuation, closing in NaCl solution and re-opening in Na2SO4. |
DOI of the first publication: | 10.1002/marc.202300539 |
URL of the first publication: | https://onlinelibrary.wiley.com/doi/10.1002/marc.202300539 |
Link to this record: | urn:nbn:de:bsz:291--ds-421724 hdl:20.500.11880/37850 http://dx.doi.org/10.22028/D291-42172 |
ISSN: | 1521-3927 1022-1336 |
Date of registration: | 11-Jun-2024 |
Description of the related object: | Supporting Information |
Related object: | https://onlinelibrary.wiley.com/action/downloadSupplement?doi=10.1002%2Fmarc.202300539&file=marc202300539-sup-0001-SuppMat.pdf |
Faculty: | NT - Naturwissenschaftlich- Technische Fakultät |
Department: | NT - Materialwissenschaft und Werkstofftechnik |
Professorship: | NT - Dr. Karen Lienkamp NT - Prof. Dr. Christian Motz |
Collections: | SciDok - Der Wissenschaftsserver der Universität des Saarlandes |
Files for this record:
File | Description | Size | Format | |
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Macromolecular Rapid Communications - 2023 - Puza - Polymer Hydrogel Sheets with Perpendicular Cross‐Linking Gradient .pdf | 1,14 MB | Adobe PDF | View/Open |
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