2 research outputs found
Characterization of Underwater Stability of Superhydrophobic Surfaces Using Quartz Crystal Microresonators
We
synthesized porous aluminum oxide nanostructures directly on
a quartz crystal microresonator and investigated the properties of
superhydrophobic surfaces, including the surface wettability, water
permeation, and underwater superhydrophobic stability. After increasing
the pore diameter to 80 nm (AAO80), a gold film was deposited onto
the AAO80 membrane, and the pore entrance size was reduced to 30 nm
(AAO30). The surfaces of the AAO80 and AAO30 were made to be hydrophobic
through chemical modification by incubation with octadecanethiol (ODT)
or octadecyltrichlorosilane (OTS), which produced three different
types of superhydrophobic surfaces on quartz microresonators: OTS-modified
AAO80 (OTS-AAO80), ODT-modified AAO30 (ODT-AAO30), and ODT–OTS-modified
AAO30 (TS-AAO30). The loading of a water droplet onto a microresonator
or the immersion of a resonator into water induced changes in the
resonance frequency that corresponded to the water permeation into
the nanopores. TS-AAO30 exhibited the best performance, with a low
degree of water permeation, and a high stability. These features were
attributed to the presence of sealed air pockets and the narrow pore
entrance diameter
Electronic Nose Based on Multipatterns of ZnO Nanorods on a Quartz Resonator with Remote Electrodes
An electrodeless monolithic multichannel quartz crystal microbalance (MQCM) sensor was developed <i>via</i> the direct growth of ZnO nanorod patterns of various sizes onto an electrodeless quartz crystal plate. The patterned ZnO nanorods acted as independent resonators with different frequencies upon exposure to an electric field. The added mass of ZnO nanostructures was found to significantly enhance the quality factor (QF) of the resonator in electrodeless QCM configuration. The QF increased with the length of the ZnO nanorods; ZnO nanorods 5 μm in length yielded a 7-fold higher QF compared to the QF of a quartz plate without ZnO nanorods. In addition, the ZnO nanorods offered enhanced sensitivity due to the enlarged sensing area. The developed sensor was used as an electronic nose for detection of vapor mixtures with impurities