Efficiency of Novel Photocatalytic Coating and Consolidants for Protection of Valuable Mineral Substrates

Materials (Basel). 2019 Feb 9;12(3):521. doi: 10.3390/ma12030521.

Abstract

In the process of protection and consolidation of valuable materials, the efficiency is the crucial property that needs to be considered. TiO₂/ZnAl layered double hydroxide (LDH) coating and silicate- and carbonate-based consolidants were synthesized and proposed to be used for protection and consolidation of four porous mineral substrates: brick, stone, render and mortar. The photocatalytic efficiency of TiO₂/ZnAl LDH coating, as well as consolidation efficiency of two consolidants, both applied on model substrates, were studied. The photocatalytic coating showed significant activity and performed well after the durability tests involving rinsing and freezing/thawing procedures. After treatment with both consolidants, a serious enhancement of consolidation of the used substrates was found. On the other hand, the application of TiO₂/ZnAl LDH, as well as consolidants, caused negligible changes in the water vapour permeability values and in appearance of the porous mineral substrates, indicating a high level of compatibility.

Keywords: conservation; consolidant; cultural heritage; photocatalytic coating; porous substrate; protection.