Hydrophobic coating water contact angles

Such polymers are as hydrophobic as poly(tetrafluoroethylene) (Teflon), with water contact angles in the range of 107°. But, unlike Teflon, polyphosphazenes of this type are easy to fabricate, are flexible or elastomeric, and can be used as coatings for other materials. ... 

For deposition of hydrophobic coatings, a mixture of CHVHe gases was used in the plasma. Superhydrophobic coatings were created with a Cp4/H2/He plasma. The deposited coatings were analyzed with PM-RAIRS, x-ray photoelectron spectroscopy, scanning electron microscopy (SEM, JEOL 6700 F - FESEM), atomicforce microscopy (AFM, Molecular Imaging SPM microscope with RHK controllers), ellipsometiy, and water contact angle measurements. 

Figure 6. Water contact angles on hydrophobic coating produced with scanning atmospheric CH/He plasma (rf power = 250 W).(l 7)...

Figure 4. Experimentally obtained relationship between the wetting parameter kb and the (apparent) water contact angle. The measurements refer to a number of different types of rough surfaces with same hydrophobic material properties (all samples were coated with a thin RF sputtered Au layer and a molecular decanethiol film to obtain intrinsic CA about 110 ).

Here we describe two simple fabrication processes to modify the surface of the device to achieve a very high water contact angle. In the first approach, the device was first coated with a thin film of hydrophobic materials, fluoropolymer in this case, and then oxygen plasma was used to create superhydrophobic surfaces. However, only in some cases, the chemical properties of the hydrophobic materials could be altered by the oxygen plasma treatment [19]. Therefore, a second technique has been developed where the nanostructures can be created on the device surfaces by a nanoimprint process [20]. Both of these approaches are compatible with the micro-fabrication process. 

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