Porous silicon carbide (SiC)‐based ceramics are widely used in numerous applications of technical importance owing to their exceptional structural (e.g., excellent chemical, mechanical, and thermal stability) and functional (e.g., controlled electrical resistivity) properties. Porous SiC with controlled electrical resistivity is required for various advanced applications, for example, power electronic devices, semiconductor processing parts, fusion reactors, thermoelectric energy conversion, electromagnetic shielding, and environmental applications such as heatable filters. The electrical properties of sintered porous SiC are significantly affected by its chemical composition, processing conditions, and microstructure. This article reviews the influence of certain critical factors, such as the polytype, doping conditions, porosity (%), additive composition (oxide additives, element additives, metal nitride/carbide additives, etc.), and processing conditions on the electrical resistivity of porous SiC. Novel applications of porous SiC with controlled electrical resistivity are also discussed in this review.

For enhanced antifouling surface properties, the alumina membranes were modified through a simple silanization process. Three organosilanes presenting neutral, positive, and negative charges were allowed to graft onto alumina membranes. A small decrease in the pore size and the successful chemical binding of organosilanes were confirmed, respectively. The membrane filtration test using humic acid (HA) was conducted to evaluate the effect of surface charges on fouling resistance. The neutral and negatively charged membranes achieved remarkable flux behaviour due to no charge interaction and electrostatic repulsion force, respectively. Especially, the negatively charged membranes presented the lowest flux decline, the highest flux recovery, and the lowest membrane fouling.

Numerous reports have elucidated that TiO₂ nanoparticles (TiO₂-NPs) exhibit respectable photocatalytic degradation capacities due to their high specific surface areas. However, the current recovery process leads to a loss of TiO₂-NPs; therefore, there is a need to immobilize TiO₂-NPs on the substrate used. Herein, TiO₂-coated yttria-stabilized zirconia/silica nanofiber (TiO₂-coated YSZ/silica NF) was prepared by coating TiO₂ on the surface of YSZ/silica NF using a sol–gel process. The TiO₂ coating layer on the nanofiber surface improved the separation ability of the membrane as well as the photocatalytic degradation ability. The pore size of the TiO₂-coated YSZ/silica NF membrane was less than that of the pristine YSZ/silica NF membrane, and it rejected over 99.6% of the 0.5 μm polymeric particles. In addition, the TiO₂-coated YSZ/silica NF membrane showed excellent adsorption/degradation of humic acid (HA, 88.2%), methylene blue (MB, 92.4%), and tetracycline (TC, 99.5%). Six recycling tests were performed to evaluate the reusability of the TiO₂-coated YSZ/silica NF membrane. The adsorption/degradation efficiency for HA, MB, and TC decreased by 3.7%, 2.8%, and 2.2%, respectively. We thus verified the high separation ability, excellent photocatalytic degradation ability, and excellent reusability of the TiO₂-coated YSZ/silica NF membranes.

We introduced a modified sol-gel method using polyvinyl alcohol (PVA) as an additive to improve the permeability of γ-Al₂O₃ membranes by minimizing the thickness of the selective layer and maximizing the porosity. First, the analysis revealed that the thickness of γ-Al₂O₃ decreased as the concentration of PVA increased in the boehmite sol. Second, the properties of the γ-Al₂O₃ mesoporous membranes were greatly influenced by the modified route (method B) compared to the conventional route (method A). The results showed that the porosity and surface area of the γ-Al₂O₃ membrane increased, and the tortuosity decreased considerably using method B. This effect was attributed to the adsorption of PVA molecules on the surface of the boehmite particles, which depended on the synthesis route. The experimentally determined pure water permeability trend and the Hagen–Poiseuille mathematical model confirmed that the modified method improved the performance of the γ-Al₂O₃ membrane. Finally, the γ-Al₂O₃ membrane fabricated via a modified sol-gel method with a pore size of 2.7 nm (MWCO = 5300 Da) exhibited a pure water permeability of over 18 LMH/bar, which is three times higher than that of the γ-Al₂O₃ membrane prepared using the conventional method.

Membrane technology has become a highly efficient separation technology for industrial applications over the past few decades. The key requirements for porous ceramic membranes are mechanical stability, controlled pore morphology, and high permeability. However, only a few studies have been conducted to optimise commercial membrane filters. In this study, a multichannel cylindrical-tube-type support with a microfiltration (MF) coating was prepared. To design a reliable porous structure and avoid shrinkage defects, the support layer was extruded using a combination of different-sized Al₂O₃ particles. The alumina microfiltration coating was developed using multiple dip-coatings to control the membrane thickness. An inorganic surface modification was conducted for the first time on an extruded membrane using a SiO₂ sol-gel technique to enhance the antifouling properties. Furthermore, the membrane properties were investigated with scanning electron microscopy, mercury porosimetry, and a dead-end microfiltration system.