| dc.description.abstract | To increase the ability of concrete to restrict water ingress, surfaces of concrete
are often fabricated to be either hydrophobic or super-hydrophobic. Here,
preliminary study of a novel coating approach to make concrete surfaces
superhydrophobic using Octadecyltrichlorosilane (OTS) is reported. Firstly, surfaces
of concrete were coated by OTS in toluene to create the hydrophobic layers along
with water contact angle of 146.5 ± 0.93o. The coating layer was prepared through
a process involving hydrolysis and condensation steps. More importantly, to
synthesize super-hydrophobic layers, concrete surfaces were modified first by the
coal soot and Tetraethoxysilane (TEOS) to create a rough structure and –Si-O-Sinetwork
before coating with OTS. This roughness develops a Cassie–Baxter regime,
enhancing the hydrophobicity of the coating. After the treatment of OTS in toluene,
water contact angle is above 150o, which is considered as super-hydrophobic surface
layer. Therefore, the modified surface with coal soot illustrated greater performance
as compared to unmodified one. These two types of experimental coated layers and
uncoated substrate were investigated on different properties including water contact
angle measurement, stability of water contact angle over 100 days, coefficient of
water capillary absorption measurement, mechanical durability of coating layer over
an eight-day period.
Key words: concrete surface, hydrophobic coating, super-hydrophobic coating,
coal soot, water ingress. | en_US |
