Water repellent coating of masonry materials with sol-gel method

ABSTRACT WATERREPELLENT COATING OF MASONRY MATERIALS WITH SOL-GEL METHOD Muharrem GÜN M.S. Thesis, Department of Chemistry Advisor : Prof. Dr. Ertuğrul ARPAÇ May 2002, 107 pages In this study, it is aimed to prevent water absorbtion of the masonry materials. Brick, concrete, and gas concrete metarials were coated with solutions, which contains organically modified silanes (ORMOSIL) ((Methyltriethoxysilane (MTEOS), Propyltrimethoxysilane (PTMOS), Phenyltriethoxysilane (pHTEOS), Vmyltrimethoxysilane (VTMOS)) in different ratios, using sol-gel method. Coating solutions were prepared in concentration of 10-30 %in grams of total silane, (ORMOSIL and Tetraethoxysilane (TEOS)) and have a ratio 4:1 for ORMOSIL:TEOS. Also solutions of 3,3,4,4,5,5,6,6,7,7,8,8-Tridecafluorooctyltriethoxysilane (F-Silanes) in concentration 5 % and 10 % in moles of TEOS, were used for coating. 0,1 N HC1 was used to hydrolyze silanes and absolute ethyl alcohol was used as a solvent. To compair the performance of the prepared coatings brick, concrete, and gas concrete materials were also coated with commercial coating solutions in different ratio. All coating were applied to the samples in two conditions as vacuumed and non- vacuumed medium. Water absobrtion, moisture content at room temperature, condensation tests of coated surface were determined. Additionally, contact angles of water on surfaces coated with different solutions were measured with goniometer and the results were compared. It is concluded that the all hydrophobic coatings applied to the masonry materials prevented water penetration. KEY WORDS : Sol-gel, Water reppellent coating, Alkylsilane, Flour Silane, Brick, Concrete, Gas concrete COMMITTEE : Prof. Dr. Ertuğrul ARPAÇ Ş/ Prof. Dr. Suphi KORMALI ^//^>^y?A^~- Yrd. Dç. Dr. Birsen BÜYÜKTAŞ Jsh