Superhydrophobic SiO2/Trimethylchlorosilane Coating for Self-Cleaning Application of Construction Materials

Abstract

This study has demonstrated, for the first time, the potential application of coatings to protect bricks or architectures against detrimental atmospheric effects via a self-cleaning approach. In this research, a facile fabrication method was developed to produce amorphous SiO2 particles and their hierarchical structures via applying trimethylchlorosilane (TMCS). They were fully characterized by various surface analytic tools, including a goniometer, SEM, AFM, zeta sizer, and a spectroscopic technique (FTIR), and then applied as super hydrophobic coatings on glass and sand. The characterization results revealed that the SiO2 particles are amorphous, quasi-spherical particles with an average diameter of 250–300 nm, and the hierarchical structures in the film were assembled from building blocks of SiO2 and TMCS. The wettability of the films can be controlled by changing the pH of the SiO2/TCMS dispersion. A super hydrophobic surface with a water contact angle of 165° ± 1° was achieved at the isoelectric point of the films. The obtained translucent super hydrophobic SiO2/TMCS coatings show good self-cleaning performances for glass and sand as construction materials. This study indicated that the superhydrophobic coatings may have potential applications in the protection of buildings and construction architectures in the future.

Surface Modification of ZnO Nanorods using Stearic Acid and their Self‐cleaning and Photocatalytic Applications

“…The band gap of unmodified ZnO NRs, ZnO(SA1), ZnO(SA2), and ZnO(SA3) is 3.31 eV, 3.29 eV, 3.27 eV, and 3.26 eV respectively. There is no appreciable change in band gap of ZnO NRs after surface modification with stearic acid [78] . This suggests that the light response (absorption) is not changed much on going from unmodified ZnO NRs to stearic acid modified ZnO NRs.…”

“…This indicates better self‐cleaning property of SA modified ZnO NRs compared to unmodified ZnO NRs. A comparison of different surface modification methods of metal oxide nanoparticles used for self‐cleaning is given in Table S2 [72–78] . It can be noted that the present surface modification method requires less time (5 minutes), no heating and economical.…”

“…A comparison of different surface modification methods of metal oxide nanoparticles used for self-cleaning is given in Table S2. [72][73][74][75][76][77][78] It can be noted that the present surface modification method requires less time (5 minutes), no heating and economical.…”

“…There is no appreciable change in band gap of ZnO NRs after surface modification with stearic acid. [78] This suggests that the light response (absorption) is not changed much on going from unmodified ZnO NRs to stearic acid modified ZnO NRs.…”

Preparation and Characterization of Biomimetic SiO2-TiO2-PDMS Composite Hydrophobic Coating with Self-Cleaning Properties for Wall Protection Applications

“…Building walls are exposed to the air, and the surfaces are washed by rainwater, which makes the walls prone to peeling and cracking. At the same time, organic and inorganic contaminants can easily adhere to the surface of building walls and accumulate to produce black spots, which affect the aesthetics of the walls [2,3]. It was found that the humidity and cleanliness of the walls are closely related to environmental health [4], and it is urgent to improve the hydrophobicity and cleanliness of building wall surfaces [5].…”