| dc.description.abstract | Part I – Smart surface with switchable wettability
Nowadays, switchable surface has drawn increasing of attentions for its myriad applications. Which wettability for both aqueous and non-aqueous drops can response to environmental stimuli. Reversible control of the surface properties has been achieved by various methods. In our case, we develop a facile and effective method to achieve the wettability transition on hydroxyl surface at ambient temperature. A fluoro-surfactant solution rinse acts as a stimulus to obtain a hydrophobic and oleophobic surface. Then, CTAB solution rinse can simply lead to the reversal of the surface wettability. The reversible behavior of switchable surface is ascribed to the esterification between the fluoro-surfactant and the hydroxyl surface of materials, such as metal, ceramics, and polymer. In order to enhance the ability of wettability switching, we conduct a series of experiment for surface modification, including roughening and oxidation for improving the esterification. As a result, it shows tremendous wettability changed from superhydrophilicity to superhydrophobicity.
Thus, this switchable surface can be employed to fabricate intelligent devices for controlling mobility and sensing.
Part II – Total wetting behavior on hydrogel surfaces
Extreme wetting behavior have been investigated in a variety of studies in recent decade. Superhydrophilic surface with low water contact angle on it, when a water droplet hen a water droplet contacts the superhydrophilic surfaces, water can spread over them completely. This type of surface is potentially applied to industrial application, such as antifogging、antifouling and droplet transportation. However, the fabrication of superhydrophilic surfaces is complicated and high cost. In this work, we manufacture a superhydrophilic surface with agar gel, which is consist mainly of water. Furthermore, we introduce the anionic surfactant in agar gel, and the wettability on the agar gel surface will be modified effectively, it can improve the wetting behavior on agar gel by the hydrophobic interaction between surfactants and agar molecules. Nevertheless, the mechanical properties of agar gel will not be degraded. This approach provides us an effective method to improve the wetting properties on high agar content agar gel surface. Therefore we can fabricate a superhydrophilic surface with outstanding mechanical and wetting properties by a simple method.
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