Abstract
Polyampholyte (PA) hydrogels are a fascinating class of soft materials that can exhibit high toughness while retaining self-healing characteristics. This behavior results from the random distribution of oppositely charged monomers along the polymer chains that form transient bonds with a range of bond strengths. PAs can be dissolved in aqueous salt solutions and then recast via immersion precipitation, making them particularly useful as surface coatings in biomedical applications. Moreover, this immersion precipitation technique allows these PA hydrogels to be fabricated into films less than 100 nm. One critical challenge to this aqueous processing method is the recrystallization of the salt upon water evaporation. Such recrystallization can disrupt the hydrogel morphology especially in thin films. In this study, a deep eutectic solvent (DES) formed from urea and choline chloride was used to dissolve PAs made from p-styrenesulfonic acid sodium salt and 3-(methacryloylamino)propyl trimethylammonium chloride. This DES has a freezing point of 12 °C, allowing it to remain stable and liquid-like at room temperatures. Thus, these PAs can be processed in DES solutions, without this issue of recrystallization and with simple methods such as spin coating and dip coating. These methods allow these hydrogels to be used in thin (<100 nm)-film coating applications. Finally, the complete miscibility of DES in water allows a wider range of one-phase compositions and expands the processing window of these polyampholyte materials.
Original language | English (US) |
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Pages (from-to) | 43191-43200 |
Number of pages | 10 |
Journal | ACS Applied Materials and Interfaces |
Volume | 12 |
Issue number | 38 |
DOIs | |
State | Published - Sep 23 2020 |
Funding
David Delgado thanks Global Station for Soft Matter Global Institution for Collaborative Research, Hokkaido University for financial support of his stay at Hokkaido University. This work was supported by the National Science Foundation (NSF DMR-1710491) and made use of the MatCI Facility which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at Northwestern University. This work made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research was also supported by Grant-in-Aid for Scientific Research no. JP17H06144 from the Japan Society for the Promotion of Science (JSPS). The Institute for Chemical Reaction Design and Discovery (ICReDD) was established by World Premier International Research Initiative (WPI), MEXT, Japan. David Delgado thanks Global Station for Soft Matter, Global Institution for Collaborative Research, Hokkaido University, for financial support of his stay at Hokkaido University. This work was supported by the National Science Foundation (NSF DMR-1710491) and made use of the MatCI Facility which receives support from the MRSEC Program (NSF DMR-1720139) of the Materials Research Center at Northwestern University. This work made use of the EPIC facility of Northwestern University’s NUANCE Center, which has received support from the Soft and Hybrid Nanotechnology Experimental (SHyNE) Resource (NSF ECCS-1542205); the International Institute for Nanotechnology (IIN); the Keck Foundation; and the State of Illinois, through the IIN. This research was also supported by Grant-in-Aid for Scientific Research no. JP17H06144 from the Japan Society for the Promotion of Science (JSPS). The Institute for Chemical Reaction Design and Discovery (ICReDD) was established by World Premier International Research Initiative (WPI), MEXT, Japan.
Keywords
- deep eutectic solvents
- ionic liquids
- polyampholytes
- polyelectrolyte complexes
ASJC Scopus subject areas
- General Materials Science