The need to make clean water accessible and affordable for low-income countries is crucial. This study examines the suitability of various clays for Ceramic Pot Water Filters production and groundwater treatment for effective microbe and fluoride removal. For this study, three clays were collected from different geographical locations in Ethiopia,i.e., Hosaenna Clay, Babawuha Clay, and Leku Clay. Organic additives such as sawdust and eragrostis tef husks were used to increase the porosity of the Ceramic Pot Water Filters. The Atterberg limit and particle size distribution tests revealed that BC and HC have moderate to high plasticity and mouldability, making them suitable for CPWF production. The clay chemical composition, phase analysis, and thermal properties were determined using XRF, XRD, and TGA/DTA. The turbidity, fluoride level, total dissolved solids, and pH of the groundwater decreases, from 13 to 0.45 NTU, from 3.4 to 0.053 mg/100 mL, from 1245 to 360 mg/l, and from 8.4 to 7.3, respectively; all of which are within the acceptable range of WHO drinking water standards. Microbial removal tests show that the CPWFs removed 99.3%-100% of total coliform bacteria and 98.48%-100% of fecal coliform bacteria from groundwater. Therefore, this work paves the way to fabricate a clay-based ceramic water filter for low-income countries to provide affordable household groundwater treatment technology for microbial and excess fluoride removal.

In this article, highly porous and transparent silicon oxycarbide (SiOC) gels are synthesized from Bis(Triethoxysilyl) methane (BTEM). The gels are synthesized by the sol-gel technique followed by both ambient pressure and supercritical drying. Then, the portion of wet gels have been pyrolyzed in a hydrogen atmosphere at 800 and 1100 °C. The FT-IR spectroscopy analysis and nitrogen sorption results indicate the successful synthesis of Si-O-Si bonds and the formation of mesopores. From a hysteresis loop, the SiOC ceramics showed the H₁ type characteristic with well-defined cylindrical pore channels for the aerogel and the H₂ type for the ambigel samples, indicating that the pores are distorted due to the capillary stress. The produced gels are mesoporous materials having high surface areas with a maximum of 1140 m²/g and pore volume of 2.522 cm³/g obtained from BTEM aerogels. The pyrolysis of BTEM aerogels at 800 °C results in the production of a bulk and transparent sample with a slightly pale white color, while BTEM xerogels are totally transparent and colorless at the same temperature. At 1100 °C, all the aerogels become opaque brown, confirming the formation of free carbon and crystalline silicon.

Transparent SiOC aerogels with ultralow thermal conductivity and high NIR transmittance are demonstrated as promising candidates for solar power applications, combining thermal insulation with excellent stability up to 1000 °C.

The transformation of a methyl‐siloxane into a SiOC glass in Ar and reactive CO₂ atmosphere was studied through positron annihilation spectroscopy, infrared spectroscopy, density, and calorimetric measurements, whereas the mechanical properties were monitored by nanoindentation and the thermal diffusivity measured by the laser flash method. Two types of micropores were detected at the beginning of the ceramization (700°C); one is related to the voids present in the parent polymer structure (≈0.8 nm in diameter), and the other to the polymer decomposition (≈1.2 nm in diameter at 700°C). The interconnected microporosity collapses, forming isolated pores at 800°C. These progressively sinter at higher temperatures with a final size between 0.3 and 0.7 nm at 1250°C. The porosity evolution kinetics correlates with the SiOC compositions, the densification occurring at lower temperatures in CO₂ where the matrix is close to SiO₂. However, the amorphous network obtained in Ar, leading to a heavy anionic substitution C⁴⁻ → 2O²⁻, is denser than that obtained in CO₂ at 1250°C. In both atmospheres, the correlation length at 1250°C is about 2.7‒2.9 nm, well below the typical values of amorphous SiO₂. The porosity and structure evolution cause a progressive increase in the nanomechanical properties and thermal conductivity as the pyrolysis temperature increases. The thermal conductivity of the SiOC obtained at 1250°C in CO₂ and Ar atmosphere is about 1 and 1.8 W m⁻¹ K⁻¹, respectively, such figures are symmetric to the values usually reported for amorphous silica (about 1.4 W m⁻¹ K⁻¹). It is argued that the low thermal conductivity of the SiOC pyrolyzed in CO₂ is related to the presence of the free carbon phase rather than to the anionic substitution of the glass network.