Dresden 2026 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 17: Poster I
CPP 17.49: Poster
Montag, 9. März 2026, 19:00–21:00, P5
Controlling Surface Wetting through Light- and Electric-Fields — •Billura Shakhayeva1, Bas ter Beest2, Frieder Mugele2, and Björn Braunschweig1 — 1University of Münster, Institute of Physical Chemistry, Germany — 2University of Twente, Physics of Complex Fluids
Electro-dewetting (EDeW) enables reversible control of surface wettability using ionic surfactants. Using dodecyl tetraethyl ammonium bromide (DTAB) as a cationic surfactant, previous studies achieved a change in the apparent contact angle (CA) of up to 30∘. We used vibrational sum-frequency generation (SFG) spectroscopy and ellipsometry to probe the molecular structure close to the three-phase contact line under initial and EDeW conditions. Using 0.15 mM DTAB we observed the largest changes in contact angle and observed spreading of surfactant even at larger distances from the contact line. Further, we extended this approach from DTAB to photoswitchable arylazopyrazole triethylammonium bromide (AAP-TB) surfactants. AAP-TB can undergo E/Z photoisomerization and allows to change the surface activity through the choice of the configurational isomer with the Z being less surface active compared to the E. We demonstrate that EDeW with AAP-TB surfactants is possible similar to DTAB, but with a smaller maximum change in contact of about 13∘ once a potential of +3 V is applied. In addition, photo-isomerization of AAP-TB allows to further finetune the CA reversibly by about 4∘.
Keywords: Photoswitchables; Wetting