Durability Against Alkali Solutions Of Cao-Bao-Sio2-Tio2 Gel Coatings

The aim of this paper is to prepare an alkaline resistant coating for glass fibre used in cement reinforcement. The dip coatings of CaO-BaO-SiO2-Ti-2 compositions have been produced on glass substrates by the sol-gel process. The alkaline durability in three kinds of alkaline solution with different pH values is performed. Regression equations have been established to give the mean of weight loss per hour for the samples immersed in NaOH by using the least square method. The attack procedure is investigated by weight loss analysis and SEM micro-graphs. ARD patterns confirm that different kinds of crystals are formed after attack. Infrared reflectivity spectra give information about chemical bonds of the coated substrates before and after immersion in alkaline solution. The experimental results demonstrate that the dip coating in this system can display a protective role in preventing alkaline attack.