TY  - JOUR
A1  - Arya, Pooja
A1  - Jelken, Joachim
A1  - Lomadze, Nino
A1  - Santer, Svetlana
A1  - Bekir, Marek
T1  - Kinetics of photo-isomerization of azobenzene containing surfactants
JF  - The journal of chemical physics : bridges a gap between journals of physics and journals of chemistry
N2  - We report on photoisomerization kinetics of azobenzene containing surfactants in aqueous solution. The surfactant molecule consists of a positively charged trimethylammonium bromide head group, a hydrophobic spacer connecting via 6 to 10 CH2 groups to the azobenzene unit, and the hydrophobic tail of 1 and 3CH(2) groups. Under exposure to light, the azobenzene photoisomerizes from more stable trans- to metastable cis-state, which can be switched back either thermally in dark or by illumination with light of a longer wavelength. The surfactant isomerization is described by a kinetic model of a pseudo first order reaction approaching equilibrium, where the intensity controls the rate of isomerization until the equilibrated state. The rate constants of the trans-cis and cis-trans photoisomerization are calculated as a function of several parameters such as wavelength and intensity of light, the surfactant concentration, and the length of the hydrophobic tail. The thermal relaxation rate from cis- to trans-state is studied as well. The surfactant isomerization shows a different kinetic below and above the critical micellar concentration of the trans isomer due to steric hindrance within the densely packed micelle but does not depend on the spacer length.
KW  - genomic DNA conformation
KW  - water-interface
KW  - light photocontrol
KW  - driven
KW  - manipulation
KW  - photoisomerization
KW  - molecules
Y1  - 2020
U6  - https://doi.org/10.1063/1.5135913
SN  - 0021-9606
SN  - 1089-7690
VL  - 152
IS  - 2
PB  - American Institute of Physics
CY  - Melville
ER  -