The research on hydrophobic and superhydrophobic surface has been extensively studied by many groups around the world. The parameter determined the wetting ability of a surface is value of water contact angle. Measuring contact angle become extremely important for both academic and industrial field. In this study, we propose a simple and affordable methodology to calculate contact angle. This approach used portable microscope of Koolertron for droplet images capturing and free software of ImageJ for contact angle fitting and calculation. The contact angles of bare and Octadecyl trichlorosilane (OTS) modified glass slide are approximately 27° and 107°, respectively. The results were compared and confirmed with the published literatures. In addition, the superhydrophobic state was achieved by applying OTS on a glass microfiber filter. We have proven that the proposed method could be applied in a wide range of surface from hydrophilicity to superhydrophobicity.
