Regulation Technology Of Ceramic Surface Free Energy And Its Easy-Cleaning Property

This work mainly focuses on the regulation of ceramic surface energy. The effect of glaze composition on its surface free energy (SFE) was studied, and the effect of surface free energy on easy-cleaning property of household porcelains was discussed.Ceramic samples were obtained by adjusting the chemical compositions of glaze. Then surface free energies and their components of the samples were determined by Dataphysics OCA-30 contact angle measurement for water and ethylene glycol, in which OWRK model was selected. The effect of topography on easy-cleaning property was analyzed by using scanning electron microscope (SEM).The results show: Si/Al ratio has much influence on ceramic surface energy. With increasing the Si/Al ratio, SFE decreases at first, then increases. When Si/Al ratio is 6.0, the SFE reaches to the lowest point (54.9mJ/m2). At that time, the proportion of polar shares in SFE is also the lowest, which is 82.4%. When Si/Al ratio is up to 7.5, the SFE reaches to the highest point (72.04mJ/m2); When Si/Al ratio is more than 10.0, the SFE has the tendency to decrease. The contents of SiO2 have also much influence on SFE. Ceramic surface energies are very low within the scope of 2.7~2.9mol, the lowest point is 60.25 mJ/m2, the proportion of polar shares is 97.8%. Within the scope of 3.0~3.2mol, the SFE reaches to the highest point (79.57mJ/m2), the proportion of polar shares is 99.9%.Fusing agents can make SFE decrease, while the proportion of polar shares decreases at the same time. This is because alkali oxide make the bond of Si—O—Si break, which induce network structure to damage. Tourmalines are minor to SFE, but polar shares decrease while adding tourmalines. This is because tourmalines decompose to impurities (B, Fe) at high temperature.Surface free energy has much effect on easy-cleaning property of household porcelains. The higher the surface free energy of ceramic was, the larger the contact angle of oil made under water, the smaller the work of adhesion was, the easier the oil could be removed from the surface, then the better the easy-cleaning property of household porcelains had. By studying the self-emigrant of water approaching into the oil-ceramic interface, we found that household porcelains with good easy-cleaning property have surface free energy no less than 72.8mJ/m2, of which polar shares are greater than 58.0mJ/m2. At this time, the self-emigrant of water extended to the whole oil-ceramic interface and then the interface disappeared. It was replaced by water-ceramic interface. So the oil had no tendency to adhere.