This research involved comprehensive studies on thermal, physical, and morphological properties of SiO 2-Na 2 O-CaO-P 2 O 5 (SNCP) glass-ceramic at various sintering temperatures. The study in SNCP glass-ceramic using soda-lime-silica (SLS) wastes glass and clam shell (CS) wastes as the main raw of materials via conventional melt-quenching technique and solid state sintering are interesting and challenging by considering the research using waste materials to fabricate novel SNCP glass-ceramic. The main peaks, Na 3 PO 4 and Ca 3 Na 6 Si 6 O 18 were assigned to high crystallization temperature (Tc) at 650-950 °C. The density of samples increases at 550-750 °C and decreases at 850-950 °C due to the increase of sample thickness and higher specific volume at high sintering temperature. FESEM micrograph showed that existed porous increased at sintering temperature 850-950 °C contributes effect to low densification of the sample.

Currently, many researchers interested studying waste materials to recycle them or reuse them in new products. From the sustainable perspective development, it is necessary to implement new technologies to help reduce waste and thus minimize the environmental problems associated with disposal. In this study, the preparation of SiO2-Na2O-CaO-P2O5 (SNCP) glass-ceramic is composed of Soda Lime Silicate (SLS), Clam Shell (CS), Na2CO3 and P2O5 in the ratio of 50: 25: 20: 5 respectively. The waste materials that were used for fabricate glass-ceramic are SLS and CS. All the compounds were mixed to fabricate the SNCP glass-ceramic through solid state reaction. The samples were investigated through X-ray diffraction (XRD), field emission microscope (FESEM) and density measurement. The samples were sintered at temperature 550°C, 650°C, 750°C, 850°C until 950°C. The main phase obtained from XRD analysis is Sodium Calcium Silicate, Na2CaSiO4 with cubic crystal system at 550°C. The highest intensity phase of the diffraction peak is (220) and at the angle 33.7°. There was new peak presence at right side of the main phase Na2CaSiO4, which belong to Silicon Phosphate, SiP2O7 at 650°C and 750°C.When heat treatment increased at 850°C - 950°C, the main phase is Combeite, Na4Ca4(Si6O18) at diffraction peak (220) with rhombohedral crystal system which is assigned to high crystallization temperature (Tc). The density of samples increases at 550°C - 750°C and decreases when heat treatment 850°C - 950°C. Sample density decreases at heat treatment 850°C - 950°C due to increases of sample lattice parameter. FESEM analysis showed that the grain size and porosity increased when the heat treatment increased.

This paper presents a small angle neutron scattering (SANS) study of a novel porous gehlenite-based ceramic, synthesised from a homogeneous powder mixture of soda-lime-silicate (SLS) glass, α-alumina, calcite and calcium fluoride via solid-state sintering at 1200 °C. The products of sintering at single temperatures from 600 to 1200 °C are examined by X-ray diffraction (XRD). Sintering of the mixture below 1200 °C forms two intermediate phases (Na2CaSi3O8 and Ca4Si2O7F2). Nepheline and α-alumina are minor phases in the gehlenite-based ceramic fabricated through sintering at 1200 °C. The microstructure of the gehlenite-based ceramic is investigated using field-emission scanning electron microscopy (FESEM) and SANS at the Australian Centre for Neutron Scattering. This study also evaluated the specific surface area of the gehlenite-based ceramic (~3.0 m2 cm–3) from quantitative analysis of SANS data.

Activated carbon (AC) derived from agricultural by-products, such as Terminalia catappa (TC) fruit waste has been demonstrated as a potential AC material in reducing the production cost in the industry. It also retains the benefits of agricultural by-products, such as being abundant and renewable, environmentally safe, and structurally porous. Several studies have been conducted on the materials’ properties of the prepared ACs from TC fruits at various particle sizes. The top-down approach of high energy ball milling (HEBM) is a simple technique used in reducing the particle size of TC to the nanoscale. Moreover, the ACs have been successfully synthesized by pre-carbonization methods, as well as chemical and physical activations. The pre-carbonization process was performed at 400 oC for 4 hours. The chemical activation was conducted using the KOH impregnation ratio as an activating agent, and a further physical process to activate the carbon was performed in a horizontal tube furnace at 750 oC for two hours with N2 gas flow. The properties and characteristics of Terminalia catappa fruits as ACs were obtained by calculating the percentage yield of ACs and analysis of the surface morphology and elemental composition, particle size, phase analysis, structural analysis, and surface area by using FESEM-EDX, TEM, XRD, Raman spectroscopy, and BET respectively. The percentage yield of ACs was increased with reduced particle size from TC powder, which was in the range of 30–71%. The surface morphology of the prepared ACs reflected the porous structure and the most abundant elements found in the ACs were C, O, and K. The average particle size of all crushed samples obtained was less than 100 nm. The XRD result confirmed the formation of crystalline structures of the graphitic carbon. The results of surface area analysis indicate that the pore size of the activated carbon is mostly in the range of mesopore, whereas the structural analysis depicts that the ratio of ID/IG of AC is nearly the same in between 0.8 to 0.92 and is slightly lower than TC. Thus, the development of agricultural waste-derived mesoporous activated carbon materials is potentially useful for various applications.

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