Особливості одержання селективних металоксидних шарів для керамічних мембран золь-гель методом

The object of research is metal oxide layers based on SiO₂, TiO₂, ZrO₂ for creating intermediate and selective layers on ceramic matrices. One of the most problematic areas is the difficulty of obtaining a uniform, dense, and stable selective layer determines the operational characteristics of the membrane – selectivity, productivity, and fouling resistance. The sol-gel method was used for synthesizing colloidal solutions of SiO₂, TiO₂, ZrO₂ and the spin-coating method for applying the resulting suspensions to ceramic matrices. The sizes of SiO₂, TiO₂, ZrO₂ particles were determined by turbidimetry, with diameters of 159 nm, 79 nm, and 99 nm, respectively. The results of IR spectroscopy show that the application of TiO₂ selective layer by spin-coating allows for complete coverage of the membrane surface, while the application of ZrO₂ layer results in incomplete coverage with confirmation of the formation of a hydrated precipitate. Studies of morphology by scanning electron microscopy indicate a coarse-grained matrix structure and a more homogeneous medium-grained structure after applying an intermediate SiO2 layer. The transport properties of ceramic matrices and membranes were determined by their permeability to pure water indicates high permeability of both matrices and membranes. Thus, the sol-gel method in combination with spin-coating has several features, in particular, controlled hydrolysis of precursors and the possibility of step-by-step formation of uniform layers makes it possible to obtain membranes with high water permeability (over 560 cm³/min) and a stable microfiltration structure after applying only 5 layers. Compared to similar methods, the proposed approach provides uniform coverage, less particle agglomeration, increased process reproducibility, enabling the creation of ceramic microfiltration membranes for water purification processes.