Das, G., Nagaraja, S., Sridurai, V., Shinde, D.B., Addicoat, M. ORCID: 0000-0002-5406-7927, Prakasam, T., Gándara, F., Ravaux, F., Sharma, S.K., Nair, G.G., Lai, Z., Jagannathan, R., Olson, M.A. and Trabolsi, A., 2019. Redox-triggered buoyancy and size modulation of a dynamic covalent gel. Chemistry of Materials, 31 (11), pp. 4148-4155. ISSN 0897-4756
|
Text
13892_Addicoat.pdf - Post-print Download (10MB) | Preview |
Abstract
The development of stimuli-responsive materials capable of transducing external stimuli into mechanical and physical changes has always been an intriguing challenge and an inspiration for scientists. Several stimuli-responsive gels have been developed and applied to biomimetic actuators or artificial muscles. Redox active actuators in which the mechanical motion is driven chemically or electrochemically have attracted much interest and their actuation mechanism is based on the change in electrostatic repulsion and the loss or gain of counterions to balance newly formed charges. Actuation can also be promoted by changing the hydration state of the material leading to the release/adsorption of water molecules from the network, inducing a direct shrinking/swelling of the material respectively. A cationic crystalline dynamic covalent gel was obtained via the formation of imine bonds between 2,6-diformyl pyridine and triamino guanidinium chloride. The gel exhibits a reversible contraction/expansion behavior in response to base (oxidation, –H+, –e–) and acid (reduction +H+, +e–) respectively. The oxidation induces a color change and contraction of the gel with a concomitant increase in its strength. As synthesized, the cationic gel is denser than water and sinks when placed in water. Upon oxidation, the radical cationic gel expels water molecules rendering it less dense than water and the gel is propelled to the surface without any loss of its structural integrity. These results demonstrate that a careful choice of amine and aldehyde linkers can give rise to imine-linked materials capable of tolerating and resisting extreme acidic and basic conditions while performing work.
Item Type: | Journal article | ||||
---|---|---|---|---|---|
Publication Title: | Chemistry of Materials | ||||
Creators: | Das, G., Nagaraja, S., Sridurai, V., Shinde, D.B., Addicoat, M., Prakasam, T., Gándara, F., Ravaux, F., Sharma, S.K., Nair, G.G., Lai, Z., Jagannathan, R., Olson, M.A. and Trabolsi, A. | ||||
Publisher: | American Chemical Society | ||||
Date: | 11 June 2019 | ||||
Volume: | 31 | ||||
Number: | 11 | ||||
ISSN: | 0897-4756 | ||||
Identifiers: |
|
||||
Divisions: | Schools > School of Science and Technology | ||||
Record created by: | Jonathan Gallacher | ||||
Date Added: | 09 May 2019 08:04 | ||||
Last Modified: | 02 Jul 2021 13:01 | ||||
URI: | https://irep.ntu.ac.uk/id/eprint/36436 |
Actions (login required)
Edit View |
Views
Views per month over past year
Downloads
Downloads per month over past year