Subject Number : S-16-NM-0046
Support Type : 機器利用
Proposal Title (English) : Anti-fouling modification of superhydrophobic ZnO/silicon coatings
Username (English) :Kevin Daumann1)
Affiliation (English) :1) Technical Chemistry II, University of Duisburg-Essen.

1. Summary
Development of antifouling coating is important for reducing consumption of fuels of ships. We have developed silicone-based polymer coating with combination of inorganic nanowhiskers. Aiming to improve antifouling property, modification of nanowiskers with antifouling polymers was demopstrated.
2. Experimental
FT-IR was used to determine the immobilization of polymer on the inorganic nanowiskers.
3. Results and Discussion
Two different antifouling modifications was tested, which are similar in synthesis but very different in their antifouling properties. The first polymer will be poly(sulfobetaine methacrylate) (PSBMA) and the second a copolymer of poly(dimethyloctylammonium methacrylate) (PDMOAEMA) and poly(trimethyl-ammonium methacrylate) (PTMAEMA).

Fig. 1. Sulfobetainization of PDMAEMA.
Both polymers were synthesized by a grafting-from method and by the use of atom transfer radical polymerization (ATRP). The length of the polymer chains is not set, so just the bare existence of polymer on the surface was sufficient for success.
The sulfobetainization of the PDMAEMA is like the previous step only verified by the FT-IR spectrum. The signals at (cm-1) 1203 (ν –SO3), 1043 (ν –SO3) and 650 (ν –C–Br) are clearly showing the formation of the sulfonate and thus the zwitterions. This proves the successful synthesis of PSBMA-modified ZnO NW by the grafting-from method via ATRP.
The IR spectrum for the octylation/methylation did not show any significant difference to identify the resulting ammonium group. Some differences are visible, but they cannot be directly assigned to a specific functional group. This can only be used as an indication, that the reaction might have worked, but further analysis is definitely necessary to verify the last modification step.
The coatings have been tested in several ways. It generally consists of ZnO NW and silicone as coating materials and n-hexane as a solvent. Coatings with different amount of ZnO NW (0 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt%, 30 wt%) have shown an increasing contact angle and higher amounts of stored air on the surface, when water is placed on the surface (graph for contact angles is shown in figure x). More than 30 wt% was not possible to coat with the used parameters.

Fig. 2. Contact angle measurements in dependency of the amount of NW in the coating. Volume of n-hexane used was 4 times higher than the mass of NW used.
4. Others
Platform staffs kindly provided instructions of how to use instruments.
5. Publication/Presentation
N/A
6. Patent
N/A