Hau-Shing Shiu

Effects of Nano-SiO2 on Setting Time and Compressive Strength of Alkaliactivated Metakaolin-based Geopolymer

This study presents a discussion on the effects of different solid-to-liquid (S/L) ratios (0.97 to 1.19) and nano- SiO2 (NS) percentages (0% to 3%) on some properties of metakaolin (MK)-based geopolymers. The setting time and compressive strength were investigated. Mercury intrusion porosimetry, fourier transform infrared spectroscopy, and scanning electron microscopy were used to determine the microstructure of the samples. The results show that a MK- based geopolymer sample added 1% NS with the S/L ratio of 1.03 exhibits more strength and less porosity. Applying NS to the geopolymer enhances compactness and increases strength. Therefore, nanotechnology can be used to improve geo- polymers.

Recycling of Solar Panel Waste Glass as a Partial Replacement of Meta-kaolinite in the Production of Geopolymers

This investigation elucidates the mechanical characteristics of geopolymer containing solar panel waste glass. With the SiO2/Na2O molar ratio (S/N = 0.75, 1.0, 1.25, 1.5, 1.75), the percentage of metakaolinite that is replaced by solar panel waste glass (040%), and the curing time of 1, 7, and 28 days as the study variables, the porosity, density, setting time, compressive strength, and flexural strength of the geopolymer were evaluated. The morphology of geopolymer was examined using Scanning Electron Microscopy (SEM), and its microstructural properties were examined through Fourier transform infrared spectroscopy (FTIR) analysis. The results demonstrate that the S/N molar ratio significantly influences the mechanical and morphological characteristics of geopolymers. The geopolymer containing solar panel waste glass with an S/N of 1.75 had the greatest compressive strength. The intensity of the peak that represented Si-O-Al bonding of the geopolymer containing solar panel waste glass increased with the S/N. Analysis of the sample morphology revealed that the microstructures of stronger samples were more homogeneous and appeared denser. Furthermore, solar panel waste glass has the potential to partially replace metakaolinite as a geopolymer material, and to exhibit favorable mechanical characteristics.