The pore size of the filter membrane is one of the key factors that determine its filtering effect. According to the specific application requirements, the pore size of the filter membrane is usually carefully selected between 0.1μm and 5μm to ensure that impurities can be effectively removed and the fluid can be kept unobstructed.

In the field of biomedicine, especially in high-precision experiments such as cell culture, vaccine preparation, and gene therapy, the removal of particles, bacteria, viruses, etc. in the fluid is extremely demanding. At this time, it is very important to select a filter membrane with a pore size between 0.1μm and 1μm. This type of filter membrane can efficiently intercept particles with a diameter of less than 1μm, effectively prevent contamination, and ensure the accuracy and reliability of experimental results. For example, in the cell culture process, the use of a 0.22μm sterilization filter membrane can ensure the sterility of the culture medium, prevent cell contamination, and improve the success rate of cell culture.

In industrial fields, such as chemicals, pharmaceuticals, food and beverages, etc., the removal of suspended matter, particulate matter, colloids, etc. in the fluid is equally important. At this time, it is more appropriate to select a filter membrane with a pore size between 1μm and 5μm. This type of filter membrane can maintain a high flow rate while removing larger particles to meet the needs of industrial production. For example, in the pharmaceutical industry, the use of a 2μm particle removal filter membrane can effectively remove insoluble particles in the drug solution and improve the purity and safety of the drug.

The material selection of the filter membrane is also crucial. It not only determines the chemical stability, thermal stability, hydrophilicity and other properties of the filter membrane, but also affects the service life and cost of the filter. At present, the commonly used filter membrane materials for syringe filters include polyvinylidene fluoride (PVDF), polyether sulfone (PES), nylon and polypropylene.

PVDF filter membranes are known for their excellent chemical and thermal stability and can withstand a variety of organic solvents and strong acid and alkali environments. In addition, PVDF filter membranes also have good hydrophobicity and are suitable for filtering non-aqueous solvents. In the field of biomedicine, PVDF filter membranes are often used in high-precision experiments such as virus removal, protein concentration, and cell separation.

PES filter membranes also have excellent chemical and thermal stability, and good hydrophilicity, which is suitable for filtering water-based solutions. The surface of PES filter membrane is smooth and not easy to adsorb biomacromolecules such as proteins. Therefore, in the field of biomedicine, PES filter membrane is often used for filtering biological samples such as cell culture medium, serum, and plasma.

Nylon filter membrane is popular for its good hydrophilicity, pressure resistance, and corrosion resistance. Nylon filter membrane is suitable for filtering a variety of aqueous solutions, such as water sample analysis in environmental monitoring, and removal of suspended matter in food and beverages. In addition, nylon filter membrane also has good flexibility and elasticity, and is easy to process into filters of various shapes and sizes.

Polypropylene filter membrane is widely used in the field of industrial filtration due to its low cost, acid and alkali resistance, and non-deformation. Polypropylene filter membrane is suitable for filtering a variety of fluids, such as circulating filtration of industrial coolants and removal of suspended matter in wastewater treatment. Although the chemical stability and thermal stability of polypropylene filter membrane are slightly inferior to PVDF and PES filter membranes, its economy and practicality make it have broad application prospects in the industrial field.

In practical applications, the selection of filter membrane needs to be comprehensively considered according to the specific application scenario. The following are some typical application scenarios and examples of matching filter membrane selection:
Biomedical field
Cell culture: Select 0.22μm PVDF or PES sterilization filter membrane to ensure the sterility of the culture medium.
Protein purification: Select 0.45μm or 0.22μm PVDF or PES filter membrane to remove particles and impurities in protein solutions.
Virus removal: Select 0.1μm or 0.22μm PVDF filter membrane for efficient retention of virus particles.
Industrial field
Chemical production: Select 1μm to 5μm polypropylene or nylon filter membrane to remove suspended matter and particulate matter in chemical raw materials and finished products.
Pharmaceutical industry: Select 0.22μm PVDF or PES filter membrane for sterilization filtration and particle removal of drug solutions.
Food and beverage: Select 1μm to 5μm nylon or polypropylene filter membrane to remove suspended matter and colloids in food and beverages.
Environmental monitoring and wastewater treatment
Water quality monitoring: Select 0.45μm nylon or PES filter membrane to remove and enrich suspended matter, bacteria, and viruses in water samples.
Wastewater treatment: Select 1μm to 5μm polypropylene filter membrane to remove suspended matter and particulate matter in wastewater and improve wastewater treatment efficiency.