- Autor
- Salzmann, Paul
- Perrotta, Alberto
- Coclite, Anna Maria
- TitelDifferent Response Kinetics to Temperature and Water Vapor of Acrylamide Polymers Obtained by Initiated Chemical Vapor Deposition
- Datei
- DOI10.1021/acsami.7b18878
- Persistent Identifier
- Erschienen inACS Applied Materials & Interfaces
- Band10
- Erscheinungsjahr2018
- Seiten6636-6645
- LicenceCC BY
- ISSN1944-8244
- Download Statistik1897
- Peer ReviewJa
- AbstractThermoresponsive polymers undergo a rever- sible phase transition at their lower critical solution temper- ature (LCST) from a hydrated hydrophilic state at temper- atures below the LCST to a collapsed hydrophobic state at higher temperatures. This results in a strong response to temperature when in aqueous environment. This study shows that hydrogel thin films synthesized by initiated chemical vapor deposition show fast and strong response to temperature also in water vapor environment. Thin films of cross-linked poly(N-isopropylacrylamide), p(NIPAAm), were found to have a sharp change in thickness by 200% in water vapor at temperatures above and below the LCST. Additionally, the stimuli-responsive poly(N,N-diethylacrylamide) was investigated and compared to results found for p(NIPAAm). Analysis of the swelling kinetics performed with in situ spectroscopic ellipsometry with variable stage temperature shows differences for swelling and deswelling processes, and a hysteresis in the thickness profile was found as a function of temperature and of temperature change rate.