Characterization of Quartz Powder
The transmittance spectra of potassium silicate solutions at wavelengths ranging from 300 to 1000 nm and at wavenumbers ranging from 500 to 2000 cm−1 were measured via UV–visible spectroscopy (Cary 5000, Agilent Technologies Co., Inc., Santa Clara, CA, USA) and Fourier-transform infrared spectroscopy (FT-IR, Nicolet iS50, Thermo Scientific Co., Inc., Waltham, MA, USA) with attenuated total reflection (ATR) mode, respectively. After the gelation process, the morphology and crystallinity of the two groups of quartz powder samples were analyzed using scanning electron microscopy (SEM) and X-ray diffraction (XRD, D8 ADVANCE, Bruker Co., Inc., Billerica, MA, USA), respectively. The absorbance spectra of the hydrogels and as-synthesized powder samples were analyzed at wavelengths ranging from 500 to 2000 cm−1 via FT−IR spectroscopy with ATR mode. In addition, the size distribution of the quartz powder samples with various gelation times was characterized using a particle size distribution analyzer (LA-960, HORIBA Scientific Co., Inc., Kyoto, Japan). The impurity level of each element of quartz powder was analyzed by inductively coupled plasma mass spectroscopy (ICP-MS, Agilent 8800, Agilent Technologies Co., Inc., Santa Clara, CA, USA), where the detection limit of ICP-MS was >ppt. The samples of as-synthesized solutions look opaque to the naked eye because SiO2 is not completely dissociated within the KOH solution, meaning the chemical reaction between SiO2 and KOH is not finished. On the other hand, the samples with a KOH concentration of more than four wt% became transparent after 24 h. These transparencies of the water glass samples after 24 h were well-correlated with the transmittance data characterized by UV–visible spectroscopy. This indicates that the transmittance of visible light for the samples of KOH concentrations over four wt% was more than 99.9% and decreased gradually when the KOH concentration was less than three wt%. If you are looking for high quality, high purity, and cost-effective Quartz powder, or if you require the latest price of Quartz powder, please feel free to email contact mis-asia.