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Features and usage precautions of organic and aqueous filter membranes: I. Comparison of key features Category Organic filter membranes Aqueous filter membranes Raw materials Organic materials such as polyurethane and polyamide; hydrophilic materials such as polypropylene and polyethylene Corrosion resistance Resistant to acids, bases, and organic solvents; high chemical stability. Primarily resistant to water; poor tolerance to organic solvents Filtering precision Micropore size: 0.01–50 microns, capable of filtering tiny particles. Pore size: usually 0.2–3 microns, suitable for filtering small impurities Strength and durability High strength; not prone to damage or deformation. Thin in structure, resulting in low resistance but lower mechanical strength Surface properties Some types have surface charge, enabling them to adsorb ions and molecules. High hydrophilicity, fast flow rate, and low levels of dissolution products. II. Usage precautions 1. Applications for organic filter membranes: Filtering organic solvents, acidic/basic solutions, and high-temperature fluids； Removes tiny particles from aqueous solutions (such as impurities in the 0.01 micron range). Contraindications: Avoid prolonged contact with strong oxidizing agents, as this may lead to material degradation ； Although water solutions can be filtered, it is necessary to verify the hydrophilicity of the filter membrane (some organic membranes require pretreatment to improve water compatibility). Operation advice: Select the pore size based on the properties of the solution (e.g., 0.22 microns for sterilization, 5 microns for coarse filtration) ； When used at high temperatures, it is necessary to refer to the material’s maximum tolerance limit (for example, polyamide membranes generally tolerate temperatures below 60°C). 2. Application scenarios of water system filtration membranes: water treatment for pure water, drinking water, wastewater, etc., to remove microorganisms and suspended solids ； Tiny particles in aqueous solutions (e.g., a filtration efficiency of over 95% for particles at 0.2 microns). Contraindications: Strictly prohibited for use in filtering organic solvents, as it may cause the membrane to dissolve or its structure to be damaged ； Avoid extreme pH environments (e.g., mixed cellulose ester membranes are not resistant to strong acids and bases). Operation suggestion: Prefer hydrophilic materials (such as polyethersulfone PES) to increase flow rate ； Avoid wrinkles during installation to prevent leakage from affecting filtration efficiency. III. Additional notes on the selection of special materials: Among organic filter membranes, polyethersulfone (PES) combines heat resistance with hydrophilicity, making it suitable for high-precision filtration of aqueous solutions ； In aqueous filtration membranes, mixed cellulose esters (MCE) are low in cost but brittle, requiring careful handling. Substitution relationship: Organic filter membranes can be used to filter aqueous solutions in place of water-based filter membranes (water resistance must be verified), but water-based filter membranes cannot be used in organic phases.