The influence of alumino-silicate matrix composition on surface hydrophobic properties
The purpose of this investigation is to investigate the hydrophobicity of geopolymers, new alumino-silicate materials and the influence of Si/Al ratio on their surface properties. Contact angle measurement (CAM) as reliable indicator of hydrophobicity was determined for synthesized geopolymers using water and ethylene-glycol as reference liquids. Geopolymers were synthesized from various precursors: kaolin, bentonite and diatomite. Characterization of phase structure and microstructure was performed by XRD, FTIR, SEM/EDX methods. Contact angle measurements confirmed that the geopolymers synthesized from metakaolin are the most porous, which can be explained by the smallest Si/Al ratio. The maximum value of contact angle and free surface energy (110.2 mJ/m2) has been achieved for geopolymer synthesized by diatoms (GPMD). SEM micrograph of GPMD shows a homogeneous surface with some longitudinal cavities in the gel and is significantly different from the micrographs of other two geopolymer samples, GPMB and GPMK.
Authors retain copyright of the published article and have the right to use the article in the ways permitted to third parties under the Creative Commons Attribution 4.0 International license. Full bibliographic information (authors, article title, journal title, volume, issue, pages) about the original publication must be provided and a link must be made to the article's DOI. This license allows to copy and redistribute the material in any medium or format, remix, transform, and build upon it for any purpose, even commercially, as long as appropriate credit is given to the original author(s), a link to the license is provided and it is indicated if changes were made.