TY  - JOUR
A1  - Bekir, Marek
A1  - Sharma, Anjali
A1  - Umlandt, Maren
A1  - Lomadze, Nino
A1  - Santer, Svetlana
T1  - How to make a surface act as a micropump
T2  - Advanced materials interfaces
N2  - In this paper, the phenomenon of light-driven diffusioosmotic (DO) long-range attractive and repulsive interactions between micro-sized objects trapped near a solid wall is investigated. The range of the DO flow extends several times the size of microparticles and can be adjusted to point towards or away from the particle by varying irradiation parameters such as intensity or wavelength of light. The "fuel" of the light-driven DO flow is a photosensitive surfactant which can be photo-isomerized between trans and cis-states. The trans-isomer tends to accumulate at the interface, while the cis-isomer prefers to stay in solution. In combination with a dissimilar photo-isomerization rate at the interface and in bulk, this yields a concentration gradient of the isomers around single particles resulting in local light-driven diffusioosmotic (l-LDDO) flow. Here, the extended analysis of the l-LDDO flow as a function of irradiation parameters by introducing time-dependent development of the concentration excess of isomers near the particle surface is presented. It is also demonstrated that the l-LDDO can be generated at any solid/liquid interface being more pronounced in the case of strongly absorbing material. This phenomenon has plenty of potential applications since it makes any type of surface act as a micropump.
KW  - azobenzene containing surfactant
KW  - light-driven diffusioosmosis
KW  - rate of
KW  - photo-isomerization
Y1  - 2022
UR  - https://publishup.uni-potsdam.de/frontdoor/index/index/docId/57395
SN  - 2196-7350
VL  - 9
IS  - 12
PB  - Wiley-VCH
CY  - Weinheim
ER  -