Speaker
Description
Industrial oil-containing wastewaters, derived from the petrochemical, pharmaceutical industries, etc., have become one of the wide-reaching environmental problems. Commonly conventional methods, such as in situ burning, etc., are used for the separation of oil from water. But high cost and low efficiency discourage the use of such conventional methods, especially for large-scale applications. Alternatively, hydrophobic/oleophilic absorbent materials have been developed for oil/water separation due to their low cost and ease of use. However, these materials mostly suffer from lack of good selectivity and recoverability. Therefore, there is a strong demand for oil/water-separation materials that can selectively absorb the oil whereas repel the water. One needs to combine surface topography and surface chemistry to achieve an extreme non-wetting regime. Recently, we have shown that metal and metal oxide micro/nanostructured surfaces can be used to tune wetting properties.[1,2]
In this current study, Ag microstructures were deposited on TiO2 thin film via photocatalytic reduction to create a unique surface topography composed of flower-like structures. These structures showed extremely superhydrophilic behaviour (Contact Angle CA ~0) due to the hydrophilic nature of TiO2. However, following the surface modification [ Polytetrafluoroethylene (PTFE), poly(1,3,5-Trivinyl-1,3,5-Trimethylcyclotrisiloxane) (p-V3D3)] via initiative chemical vapor deposition (iCVD), a superhydrophobic surface (CA > 155°) was achieved. Results showed that not only the iCVD layer, but also unique surface topography of Ag structures promoted the superhydrophobic behaviour. Furthermore, prepared surface exhibited high selectivity for the adsorption of the oil from the oil-water mixture. Especially p-V3D3 coated Ag-TiO2 surface may find application in self-cleaning, oil-water separation, etc., due to its high selectivity and stability under ultra-violet radiation.
[1] Appl. Surf. Sci. 2021, 537, 147795.
[2] Adv. Mater. Interfaces 2019, 6, 1801967.
| Speaker Country | Germany |
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