Abstract: Marbles are usually hydrophilic, and have contact angle values between 40-60°C. This makes marble surfaces susceptible to attack from water, which is the main instigator of stone decay causing salt crystallization inside the pores of the stone. Alkoxysilanes are widely used in the protection of stones such as marbles, granites or limestones. Nevertheless, gels made of alkoxysilanes are not always hydrophobic. In this research, we imparted hydrophobic character into the marbles by the addition of polydimethysiloxane, and further improved this hydrophobicity by adding different amounts of (%0,1, %1, %3 , %5 w/w)  nanosilica with respect to the alcohol content. We measured the contact angle values of the coated marble samples and corrolated these results with AFM measurements, and SEM images. We exposed the coated samples humidity, and UV aging tests to evaluate the protective efficiency of the coatings.

Keywords: Nanosilica, Contact Angle, Sol-Gel, Hydrophobic, Marble

| DOI: 10.17148/IARJSET.2019.6203