tailieunhanh - Affordable method for water contact angle measurement

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. | Tạp chí Khoa học Công nghệ và Thực phẩm 19 1 2019 11-18 AFFORDABLE METHOD FOR WATER CONTACT ANGLE MEASUREMENT Giang Ngoc Ha Tran Thi Tuyet Trinh Nguyen Xuan Truyen Huynh Van Tien Tran Hoai Lam Ho Chi Minh City University of Food Industry Email giangngocha@ Received 22 July 2019 Accepted for publication 5 September 2019 ABSTRACT 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. Keywords ImageJ contact angle hydrophobic hydrophilic portable microscope. 1. INTRODUCTION Contact angle value is a useful parameter to evaluate the surface tension and wetting property of a surface 1 2 . A drop of water placed on a solid surface in ambient atmosphere induces competitive forces which decides the shape of the formed droplet. The first one is the internal adhesive force of molecules inside of the liquid itself. This force could make the liquid maintain a sphere shape in the space where the gravity has no effect. The second one is the interaction force between the molecules of the liquid and molecules of the solid surface. If the interaction force is stronger than the .