Ultrasonic Studies of Solid Azobenzene-Decorated Polymer Thin Films.
| Autor: | Moniruzzaman M; Centre for Defence Chemistry, Cranfield University, Defence Academy of the United Kingdom, Shrivenham SN6 8LA, U.K., Christogianni P; Centre for Defence Chemistry, Cranfield University, Defence Academy of the United Kingdom, Shrivenham SN6 8LA, U.K., Vrcelj RM; Centre for Defence Chemistry, Cranfield University, Defence Academy of the United Kingdom, Shrivenham SN6 8LA, U.K., Gill PP; Centre for Defence Chemistry, Cranfield University, Defence Academy of the United Kingdom, Shrivenham SN6 8LA, U.K. |
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| Jazyk: | angličtina |
| Zdroj: | ACS omega [ACS Omega] 2018 Dec 19; Vol. 3 (12), pp. 17693-17699. Date of Electronic Publication: 2018 Dec 19 (Print Publication: 2018). |
| DOI: | 10.1021/acsomega.8b02048 |
| Abstrakt: | This work investigates the effect of ultrasound on switching of cis azobenzene isomers to their trans counterparts in solid films of methyl methacrylate and methacryloyloxyazobenzene copolymers [P(MMA/MOAB)]. Ultraviolet-visible and 1 H nuclear magnetic resonance spectroscopies demonstrate that 46% of the cis isomer converts to the trans form purely by ultrasonic agitation and 46% converts to the trans isomer by localized ultrasound-induced heating effects. Comparative studies of isomerization by ultrasound wave, heat, and visible irradiation show that ultrasound exposure requires a longer time to switch the cis-to-trans conformation. The estimated activation energy for the cis-to-trans conversion in solid polymer films is shown to be comparable to previous values of azobenzene isomerization, indicating that incorporation of the chromophore in a polymeric system affects the kinetics of transition but not the barriers to conformational change. Competing Interests: The authors declare no competing financial interest. |
| Databáze: | MEDLINE |
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