Low temperature preparation of porous materials from TV panel glass compacted via hydrothermal hot pressing

The influence of aqueous solutions (deionized water or Na2CO3 solutions, 0.1–0.5 M) and other processing parameters such as temperature (150–250 °C) for preparing hydrothermal hot-pressed TV panel waste glass compacts was investigated to produce porous glass specimens. Waste powdered glass (5 g) from old analog Philips television panels (Mexico) with particle sizes of <38 µm was mixed with various amounts of the selected aqueous solution (5–20 wt%). The TV glass panel particles dissolved in all of the mineralizer solution that were employed, and the behavior was controlled by the amount of aqueous solution added to the glass powder densification stage. The reactions of the glass particles with water or Na2CO3 solutions produced a solid glass phase that included water molecules or Na+ and CO3−2 ions, respectively. The hydrothermal hot press (HHP)-treated glass compacts prepared at 200 °C for 2 h at a constant loading pressure of 20 MPa exhibited a marked expansion after heat treatment conducted at 700 °C for 1 h in an air atmosphere. The expansion of the HHP compacted TV panel glass specimens was further increased for the samples prepared with 0.5 M Na2CO3 solution; these foamed glasses exhibited the lowest apparent densities that varied from 0.309 to 0.319 g/cm3.