Abstract
Photoisomerization of azobenzene derivatives is a versatile tool for devising light-responsive materials for a broad range of applications in photonics, robotics, microfabrication, and biomaterials science. Some applications rely on fast isomerization kinetics, while for others, bistable azobenzenes are preferred. However, solid-state materials where the isomerization kinetics depends on the environmental conditions have been largely overlooked. Herein, an approach to utilize the environmental sensitivity of isomerization kinetics is developed. It is demonstrated that thin polymer films containing hydroxyazobenzenes offer a conceptually novel platform for sensing hydrogen-bonding vapors in the environment. The concept is based on accelerating the thermal cis-trans isomerization rate through hydrogen-bond-catalyzed changes in the thermal isomerization pathway, which allows for devising a relative humidity sensor with high sensitivity and quick response to relative humidity changes. The approach is also applicable for detecting other hydrogen-bonding vapors such as methanol and ethanol. Employing isomerization kinetics of azobenzenes for vapor sensing opens new intriguing possibilities for using azobenzene molecules in the future.
| Original language | English |
|---|---|
| Pages (from-to) | 381-386 |
| Number of pages | 6 |
| Journal | ACS Macro Letters |
| Volume | 7 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 20 Mar 2018 |
| MoE publication type | A1 Journal article-refereed |
Funding
This work was supported by the Academy of Finland through Center of Excellence of Molecular Engineering of Biosynthetic Hybrid Materials (HYBER; Decision No. 272361) and the Academy Research Fellowship Program (Decision Nos. 277091 and 284553), as well as by the European Research Council (Starting Grant Project PHOTOTUNE; Agreement No. 679646), the financial support of which A.P. gratefully acknowledges.