Discussion on the material of saltwater filtration membranes and their filtering efficiency

A Gore membrane is a filter bag made by combining an expanded polytetrafluoroethylene film with a thickness of several micrometers and a pore size of 0.5 μm with 2–3 mm thick polypropylene or polyester non-woven fabric (resembling felt), which is then fitted over a rigid support to serve as a membrane filtration element. Kai membrane is a pure polytetrafluoroethylene tubular porous membrane. The dense, porous, and smooth PTFE film reduces particle penetration to near zero. Its low friction coefficient, chemical stability, and smooth surface ensure that the filtration pressure is only 0.05–0.11 MPa, and the surface of the film is extremely easy to clean. Polytetrafluoroethylene is also a material with high strength, which **extends the lifespan of the filter media compared to conventional filter media**. The polytetrafluoroethylene tube is formed in one step, which reduces the likelihood of membrane detachment caused by saltwater erosion of the welds, resulting in a longer service life. Inorganic ceramic membranes are asymmetric membranes made from highly pure inorganic ceramic materials, produced using specialized processes at high temperatures of 1600°C and through advanced technical methods, resulting in a tubular or multi-channel structure. The geometric structure consists of three parts: a support layer, a transition layer, and a membrane layer. The support and transition layer materials are α-Al2O3 (corundum crystal form) with a purity of ≥99%, while the film layer material is ZrO2. Al2O3 has different crystal forms due to its varying molecular structures; the common ones are α-Al2O3 and γ-Al2O3. γ-Al2O3 is a cubic close-packed crystal that is insoluble in water, but soluble in acids and bases; it is a typical amphoteric oxide. In nature, α-Al2O3 is commonly known as corundum; it has a hexagonal close-packed crystal structure and exhibits a glassy or diamond-like luster. The melting point of α-Al2O3 is 2015±15°C, its density is 3.965 g/cm3, and its hardness is 9. It is insoluble in water, acids, or bases, and it is resistant to high temperatures. α-Al2O3 synthesized through high-temperature sintering, known as synthetic corundum or synthetic gemstone, can be used to make mechanical bearings or diamonds in watches. The membrane material of the ceramic membrane is imported ZrO2 with a purity of ≥99.5%, which is sintered at a high temperature of 1600°C. It possesses excellent properties such as a high melting point and high hardness, as well as good chemical stability, offering sufficient resistance to strong acids, strong bases, and strong oxidizing agents. ZrO2 in nature is commonly known as zircon, while ZrO2 that has been sintered at high temperatures is referred to as synthetic diamond. Therefore, ceramic membranes are not affected by acids, bases, oxidizing agents, etc., and are resistant to high pressures; they can operate for extended periods under a working pressure of 1 MPa. There are no issues such as peeling, tearing, corrosion, or expansion of pore sizes on their surface, resulting in high efficiency and long service life. In saline environments, their lifespan is expected to be over five years.

The explanation was excellent, but I didn’t give any points. I’m sorry.

The Gore membrane has been replaced by a new generation of ZF membranes; this can be seen on the advertising pages of the chlor-alkali industry.