Robust self-cleaning surface coating for green architecture : sol-gel cross-linked polymeric coating.

• Main Author: Tey, Yvonne Yee Ting.
• Other Authors: Tan Thatt Yang Timothy
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Chemical engineering::Biotechnological production
• Online Access: http://hdl.handle.net/10356/16469
• Institution: Nanyang Technological University

Robust self-cleaning surface coating was created using economical and simple means. In this work, glass substrates were coated by two different methods. The first method was done by coating in sequence (multilayer) while the second method was achieved by mixing (composite films). All coatings were prepared by dip coating. Sol-gel technique was used in the coating since it is easy and effective. After the films were calcined at 500oC for an hour, they were subjected to adhesive, superhydrophilic, and photocatalytic activity tests, and the surface morphology was characterized by Atomic Force Microscope (AFM). Composite films turned white after dip coating while multilayer films remained transparent. Based on the ASTM 3359 standards, most of the samples attained high level of adhesiveness. Among all the samples tested, SiO2/TiO2 and SiO2-0.05%PEG/TiO2 achieved superhydrophilic property (contact angle ≈ 0o). Photocatalytic activity was not enhanced when the thickness of TiO2 was increased but it was increased when polyethylene glycol (PEG) was incorporated into the polymeric matrix. High number of pores was created and this was seen in the AFM images. PEG increased the surface roughness of coating. From the tests conducted, we concluded that SiO2-0.05%PEG/TiO2 with a layer of TiO2 produced the most robust self-cleaning surface.