*3.3. Characterization Techniques*

The surface morphology was studied by Field Emission Scanning Electron Microscope (FE-SEM, JEOL, JSM-7600F; Tokyo, Japan). The surface roughness of the prepared coatings was evaluated by laser microscopy (KEYENCE, VK-X200 series; Itasca, IL, USA). The chemical composition was studied by Fourier transform infrared spectroscopy (FT-IR, JASCO, FT/IR-6100; Tokyo, Japan). The water contact angles (WCA) were measured at six different locations on same sample by using contact angle meter (KYOWA, Drop Master; Saitama, Japan) and average value is reported as a final contact angle value. The optical transmission of the coatings was measured by UV-VIS spectrophotometer (JASCO, V-670; Tokyo, Japan). The coatings were illuminated by UV light (365 nm, 2 mW/cm2 ). The UV lamps were purchased from TOSHIBA (FL10BLB; Tokyo, Japan) and assembled with proper electric supply inside the wooden box covered by thick black cloth. The adhesion of the coating material on PC substrate was checked at five different spots by using Scratch tester (Nano-Layer Scratch Tester, CSR-2000; Rhesca, Tokyo, Japan). The adhesion of the coatings on PC substrate and the maximum force required to remove the coating material was calculated. The cantilever was moved from right to left side in contact with the coating surface. The force was gradually increased while moving towards left side. The maximum force at which the coating material was removed from the PC substrate was noted as critical force to damage the coating. The optical photographs were recorded using Canon Digital Camera (G 15 series).
