Customizing the properties of borosilicate foam glasses via additions under low sintering temperatures with insights from molecular dynamics simulations

The Impact of Foaming Effect on the Physical and Mechanical Properties of Foam Glasses with Molecular-Level Insights

“…On the basis of our previous studies [ 17 ], the effects of foaming agents on the physical and mechanical properties of foam glass materials is significant. Dextrin ( ) is one kind of oxidation-type foaming agent that decomposes at high temperatures and releases gas to create pore structures.…”

“…Oxidation-type foaming agents usually facilitate closed-pore structures in glass melts, leading to lower density which is suitable for artificial floating material needs [ 4 ]. First, we calculated the amounts of foaming agent needed to obtain a superior sample density of 0.35 g/cm 3 , as per our previous work [ 17 ], due to the empirical carbon loss of ~60% during the sintering. This led to the amount of carbon 1 wt.% [ 17 ], dextrin 2.5 wt.%, or a mixture of carbon 0.5 wt.% and dextrin 1.75 wt.%, together with the previously determined basic composition of H 3 BO 3 13 wt.%, SiO 2 60 wt.%, Na 2 CO 3 17 wt.%, K 2 CO 3 5 wt.%, and Al 2 O 3 5 wt.% for the foam glass samples [ 17 ].…”

“…First, we calculated the amounts of foaming agent needed to obtain a superior sample density of 0.35 g/cm 3 , as per our previous work [ 17 ], due to the empirical carbon loss of ~60% during the sintering. This led to the amount of carbon 1 wt.% [ 17 ], dextrin 2.5 wt.%, or a mixture of carbon 0.5 wt.% and dextrin 1.75 wt.%, together with the previously determined basic composition of H 3 BO 3 13 wt.%, SiO 2 60 wt.%, Na 2 CO 3 17 wt.%, K 2 CO 3 5 wt.%, and Al 2 O 3 5 wt.% for the foam glass samples [ 17 ]. Then, we systematically investigated the compressive strength, density, porosity, and volume-absorption rate of the prepared foam glass samples ( Table 1 ).…”

“…Then, we systematically investigated the compressive strength, density, porosity, and volume-absorption rate of the prepared foam glass samples ( Table 1 ). The samples with pure dextrin as the foaming agent showed relatively low strength and density as compared with those using pure carbon as the foaming agent [ 17 ]. Nonetheless, dextrin can enable a relatively lower volume-absorption rate (1.15%) which is beneficial for applications based on water.…”

“…A high sintering temperature of 1500 is usually needed [ 16 ] to yield superior mechanical performance. We previously prepared types of foam glass samples with selected agents and additions [ 15 , 17 ] with similar or even superior physical properties and mechanical performance with much lower sintering temperatures of only 775 or 780 , which were cost-effective and environmentally friendly. However, there is a limited fundamental understanding of the nature of the foaming effect at the molecular level, which delays an efficient experimental design of high-performance foam glass materials by effectively screening foaming agents and additions at a low sintering temperature.…”