A facile approach to synthesis of silica nanoparticles from silica sand and their application as superhydrophobic material

We present a facile method to produce silica nanoparticles as a superhydrophobic material
which has been successfully synthesized by mechanical milling and the sol–gel method. The
powder obtained was characterized using scanning electronic microscopy, X-Ray Diffraction,
particle size distribution, and zeta potential. The effects of alcohol solvents on synthesis, such
as on particle size, particle size distribution, and zeta potential, were examined thoroughly. To
evaluate the surface modification of silica nanoparticles from hydrophilic to hydrophobic
properties, IR spectra was applied. Surface modification was conducted prior to the evaluation
of the superhydrophobic properties of silica nanoparticles on the glass substrate. In this study,
silica nanoparticles in the ethanol solvent achieved optimum results with a particle size of
170.3 ± 14.3 nm and the highest zeta potential of −50.4 ± 0.3 mV, which is the best superhydrophobic effect on the glass substrate. In addition, the superhydrophobic effect of the silica
nanoparticles was also applied to the bitumen, as both coating and mixing with the water
contact angle was increased to 149.2° and 148.1° compared to the bitumen without silica
nanoparticles. Due to their simplicity and low-cost, modified silica nanoparticles show great
potential for industrial applications as superhydrophobic material on the bitumen.