Strain-Dependent Kinetics in the Cis-to-Trans Isomerization of Azobenzene in Bulk Elastomers.

Published

Journal Article

The cis-to-trans isomerization of azobenzene is accelerated in a bulk PDMS elastomer under uniaxial tension. The kinetics are cleanly described by a single-exponential first-order process (k = 2.7 × 10-5 s-1) in the absence of tension but become multiexponential under constant strains of 40-90%. The complex kinetics can be reasonably modeled as a two-component process. The majority (∼92%) process is slower and occurs with a rate constant that is similar to that of the unstrained system (k = 2.3-2.7 × 10-5 s-1), whereas the rate constant of the minority (∼8%) process increases from k = 10.1 × 10-5 s-1 at 40% strain to k = 21.3 × 10-5 s-1 at 90% strain. Simple models of expected force-rate relationships suggest that the average force of tension per strand in the minority component ranges from 28 to 44 pN across strains of 40-90%.

Full Text

Duke Authors

Cited Authors

  • Lin, Y; Hansen, HR; Brittain, WJ; Craig, SL

Published Date

  • October 2019

Published In

Volume / Issue

  • 123 / 40

Start / End Page

  • 8492 - 8498

PubMed ID

  • 31525921

Pubmed Central ID

  • 31525921

Electronic International Standard Serial Number (EISSN)

  • 1520-5207

International Standard Serial Number (ISSN)

  • 1520-6106

Digital Object Identifier (DOI)

  • 10.1021/acs.jpcb.9b07088

Language

  • eng