## 2 Materials and Methods  
The raw material used in this research were SLS glass waste bottle, ES as a foaming agent and polyvinyl alcohol (PVA) as a binder. The SLS glass waste was collected from the glass bottle of sauce (Brand: Life) from Pizza Hut IOI City Mall Putrajaya, Malaysia. The waste glass is usually contaminated from dirt and it must be washed before crushing. ES was collected from recycling containers located at Sri Serdang, Selangor, Malaysia restaurants which then rinsed with water and dried for 24 h in the dry oven before crushing. This process used to completely remove all dirt on the ES. Waste SLS glass and ES were crushed into the small glass cullet. The glass cullet then placed into milling jar with ceramic balls and was left at milling machine (US Stoneware Corp) for 24 h at the speed of 50 rpm to get a fine glass powder. Then, the glass powder was filtered to obtain the powder with 45 \(\upmu\)m particle size using stainless steel sieve while the ES ground using pestle and mortar and sieve into 45 \(\upmu\)m size. Figure 1 shows the flowchart of the sample preparation. First, SLS glass and ES powder were prepared with different weight percentages and weighed using a digital analytical balance. Both powders were put in a bottle according to the empirical formula and mix by using pestle and mortar. Then, the homogenous powder was pressed using a (Specac, Ltd., Orpington, UK) hydraulic pressing machine, with an applied load of 5 MPa for 10-15 min and transformed into pellet form,  
13.10-mm diameter. The pellets placed into the alumina boat and went for the heat-treatment process. All samples were heat-treated at 800 \({}^{\circ}\)C for 1 h by using the electric furnace. After the heat treatment process, the pellets were grounded into 45 \(\upmu\)m in size and were sent to characterization. Wavelength dispersive X-ray fluorescence (WD-XRF), ([PERSON], S8 Tiger, Billerica, MA, USA) was used to analyze SLS and ES powder to identify chemical composition in both raw materials. Thermogravimetric Analyzer-Mettler Toledo (TGA/SDTA 851, Columbus, OH, USA) was used to determine the weight loss decomposition of ES with the temperature in the range of 27-1000 \({}^{\circ}\)C. The finding results as shown in Table 1 and Figure 1 for XRF and TGA analysis, respectively. The bulk density (\(\rho\)) of the produced foam was measured by the Archimedes principle and the formula as shown in Equation (1). \[\rho_{b}=\frac{m}{v}=\left[\frac{W_{air}}{W_{air}-W_{water}}\right]x\ \rho_{water} \tag{1}\]  
where \(W_{air}\) is a weighted sample in air, \(W_{water}\) is a weighted sample in water and \(p\) is a density of water. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Raw**} & \multicolumn{6}{c}{**Constituents Oxides (wt \%)**} \\ \cline{2-7}  & **SiO\({}_{2}\)** & **CaO** & **Na\({}_{2}\)O** & **Al\({}_{2}\)O\({}_{3}\)** & **MgO** & **Others** \\ \hline SLS & 70.5 \(\pm\) 0.1 & 11.3 \(\pm\) 0.1 & 12.5 \(\pm\) 0.1 & 2.8 \(\pm\) 0.1 & 2.0 \(\pm\) 0.1 & 0.9 \(\pm\) 0.1 \\ ES & – & 54.2 (96.8) a \(\pm\) 0.1 & 0.4 \(\pm\) 0.1 & – & 0.8 \(\pm\) 0.1 & 2.0 \(\pm\) 0.1 \\ \hline \hline \end{tabular}  
* a value in the original represents the CaCO\({}_{3}\) content in the eggshell.  
\end{table} 
Table 1: Chemical composition of SLS glass and ES. Figure 1: Schematic diagram of sample preparation. The porosity was evaluated by comparing Archimedes analysis to true density using Brunauer-Emmett-Teller (BET) surface analysis. The ratio between density as follows:  
\[\varepsilon=\left(1-\frac{\rho_{b}}{\rho_{t}}\right)x\ 100\% \tag{2}\]  
where \(p_{b}\) is a bulk density, \(p_{t}\) is a true density. The linear expansion (LE) of the produced material was measured by subtracting the diameter of the glass-ceramic pellet (D\({}_{t}\)) after it was treated to the diameter of the glass-ceramic before treated (D\({}_{i}\)) using digital vernier caliper (Mitutoyo 500-196-20, Kanagawa, Japan). The percentage linear expansion of the treated foam glass-ceramic sample was determined using Equation (3).