Optimization of strength and physical filtration performance of boron nitride alloyed polymeric membranes

The primary objective of this thesis is to expand the utilization areas of boron, which is abundantly available in our country and widely used as an alloying raw material in composite materials and products, as well as in various industrial applications, while contributing to the enhancement of the technical properties of existing polymeric membranes and, consequently, to the improvement of their physical filtration performance. Hexagonal boron nitride (h-BN), derived from boron, is widely employed in the industry for the production of ceramics, refractory materials, cutting tools, and coating technologies due to its high thermal resistance, chemical inertness, thermal conductivity, high hardness, and mechanical durability. In this study, the incorporation of h-BN into polymeric membrane structures was investigated in order to evaluate its effects on the mechanical strength, surface properties, hydrophilicity, and physical filtration performance of the membranes. Polyethersulfone (PES)-based membrane solutions were prepared with various h-BN loadings (0%, 0.1%, 0.25%, 0.50%, and 1% by weight), and flat-sheet membranes were fabricated. The produced membranes were evaluated through multiple characterization techniques, including FTIR spectroscopy, contact angle measurements, zeta potential analysis, pure water flux testing, SEM imaging, and DMA tensile testing. The obtained results demonstrated that low and moderate BN loadings improved the surface properties of the membranes, enhanced hydrophilicity, increased mechanical strength, and elevated pure water flux, thereby positively influencing overall filtration performance. However, excessive BN loadings resulted in particle agglomeration, leading to a decline in performance. Consequently, an optimal additive concentration was identified, and the study revealed the potential applicability of this additive in polymeric membrane technologies.