Innovative Geopolymer Tiles for Indoor Humidity Control: A Comparative Study of Moisture Buffering Performance

Geopolymers have attracted increasing attention due to their unique properties in the construction industry. In this work, innovative geopolymer tiles were evaluated regarding their potential to control indoor relative humidity as a passive construction material. Our production process systematically develops geopolymer tiles with elevated moisture buffering capabilities using four distinct metakaolins and one commercial metakaolin to make a comparison. A critical metric for evaluating hygroscopic materials' capacity to control the indoor humidity change is the moisture buffer value (MBV). The geopolymer tiles' MBV was determined by the Nordtest method in a controlled climate chamber. Additionally, a custom-designed moisture buffer test and strength measurements were conducted, including inspections of the physical appearance after the tiles were submerged in water for 7 days. The results indicate that the geopolymer tiles exhibit exceptional moisture buffering performance, with MBV values ranging between 5.68 and 7.94 (g/m² Δ%HR). These are the highest and one of the first values for geopolymer tile moisture buffer values in the literature so far. The text discusses the advantages and superior performance of these tiles compared with conventional methods, supported by mechanical, morphological, and structural analyses.