Superhydrophobic coating solutions were prepared using fumed silica nanoparticles and trimethylethoxysilane (TMES) as precursors. At this time, the surface of silica nanoparticles was modified by TMES from hydrophilic to hydrophobic in various types of catalysts and organic solvents. The prepared coating solutions were coated on a cold rolled steel sheet by using a spin coater, and then superhydrophobic coating films were prepared by thermal curing. In this process, the effects of the amount of silica nanoparticles added, the type of catalysts, and the type of organic solvents were observed on the hydrophobicity of the coating films. As the content of silica nanoparticles added increased from 0 g to 0.08 g, the contact angle of the coating films increased from 93° to 151°, and when 0.08 g of silica nanoparticle was added, it showed superhydrophobicity of 151°. On the other hand, when nitric acid and hydrochloric acid, strong acids, were used as catalysts, the coating films showed low hydrophobicity of 73° and 86°, respectively. However, when oxalic acid, a weak acid, was used, the coating film showed superhydrophobicity of 151°. In addition, with methanol as an organic solvent, the coating film showed superhydrophobicity of 151°, while when i-propanol and n-butanol were used, the coating films exhibited low hydrophobicity of 97° and 91°.

Silica Nanoparticles Trimethylethoxysilane Superhydrophobic Coating Films Surface Modification

Gu H, Zhang Q, Gu J, Li N, Xiong J, J. Sol-Gel Sci. Technol., 87, 478 (2018)
Barthlott W, Neinhuis C, Planta, 202, 1 (1997)
Latthe SS, Imai H, Ganesan V, Rao AV, Appl. Surf. Sci., 256(1), 217 (2009)
Liu XM, He JH, Langmuir, 25(19), 11822 (2009)
Wang RG, Kaneko J, Surf. Eng., 29, 255 (2013)
Mahadik SA, Pedraza F, Vhatkar RS, J. Alloy. Compd., 663, 487 (2016)
Shang QQ, Zhou YH, Xiao GM, J. Coat. Technol. Res., 11, 509 (2014)
Kim DG, Lee BH, Song KC, Korean Chem. Eng. Res., 57(2), 177 (2019)
Kim DG, Lee BW, Song KC, Korean Chem. Eng. Res., 57(6), 749 (2019)
Wang Z, Yang W, Sun F, Zhang P, He Y, Wang X, Luo D, Ma W, Sergio GC, Sur. Eng., 35, 418 (2019)
Chang CC, Lin JH, Cheng LP, J. Appl. Sci. Eng., 19, 401 (2016)
Huang FH, Chang CC, Oyang TY, Chen CC, Cheng LP, J. Nanopart. Res., 13, 3885 (2011)
Toh MJ, Oh PC, Ahmad AL, Caille J, Korean J. Chem. Eng., 36(11), 1854 (2019)
Song KC, Park JK, Kang HU, Kim SH, J. Sol-Gel Sci. Technol., 27, 53 (2003)
Raghavan SR, Walls HJ, Khan SA, Langmuir, 16(21), 7920 (2000)
Raghavan SR, Khan SA, J. Colloid Interface Sci., 185(1), 57 (1997)
Saiz CA, Darvishmanesh S, Buekenhoudt A, Van der Bruggen B, J. Membr. Sci., 546, 120 (2018)