Publications [#346689] of Stephen L Craig

Journal Articles

1. Lin, Y; Hansen, HR; Brittain, WJ; Craig, SL, Strain-Dependent Kinetics in the Cis-to-Trans Isomerization of Azobenzene in Bulk Elastomers., The journal of physical chemistry. B, vol. 123 no. 40 (October, 2019), pp. 8492-8498 [doi]
   (last updated on 2026/01/16)

   Abstract:
   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%.