Photoresponsive hierarchical ZnO-PDMS surfaces with azobenzene-polydopamine coated nanoparticles for reversible wettability tuning.

Kallweit, C., Bremer, M., Smazna, D., Karrock, T., Adelung, Rainer and Gerken, M. (2017) Photoresponsive hierarchical ZnO-PDMS surfaces with azobenzene-polydopamine coated nanoparticles for reversible wettability tuning. Vacuum, 146 . pp. 386-395. DOI 10.1016/j.vacuum.2017.03.023.

Full text not available from this repository.

Supplementary data:

Abstract

Azobenzene-bearing surfaces are promising for light-controlled wettability switching in microfluidic systems. We investigate the wettability and stability of flat glass, flat polydimethylsiloxane (PDMS) and hierarchical ZnO-PDMS surfaces functionalized with azobenzene bearing polydopamine coated nanoparticles (Azo-PDA-NP). We analyse the stability of the contact-angle switching when using new droplet locations for each measurement and for using the same droplet location with compressed-nitrogen drying between measurements. For flat glass surfaces we observed a wettability change of 15° and 60° for spin-coating and drop-casting deposition of the Azo-PDA-NP, respectively. For the PDMS samples, 60° contact-angle change are obtained, but these surfaces show degradation for repeated switching cycles. In contrast the hierarchical ZnO-PDMS surfaces exhibit a wettability switch of 50° and no degradation for five switching cycles at the same droplet location. We captured water drops during ultra-violet (UV) irradiation on video and obtained a one-sided flowing motion with a speed of 1.9 μm/s. Contact-angle hysteresis measurements show that the minimum criterion for droplet movement is fulfilled for the Azo-PDA-NP functionalized hierarchical ZnO-PDMS surfaces.

Document Type: Article
Keywords: Azobenzene Hierarchical surface Photo responsivity Smart surface Wettability change
Research affiliation: Kiel University > Kiel Marine Science
OceanRep > The Future Ocean - Cluster of Excellence
Refereed: Yes
Open Access Journal?: No
DOI etc.: 10.1016/j.vacuum.2017.03.023
ISSN: 0042-207X
Projects: Future Ocean
Date Deposited: 12 Dec 2017 13:30
Last Modified: 29 Apr 2019 15:14
URI: http://oceanrep.geomar.de/id/eprint/40544

Actions (login required)

View Item View Item