The Performance of Microporous Membranes of Different Materials
According to the solvent to be filtered, we need to choose an appropriate material and specifications of the microporous membrane to open the package in the clean area. After selecting the filter membrane, please carefully check whether the filter membrane has holes, cracks and whether there are foreign bodies on the membrane. Wash the membrane with distilled water several times and soak it in water for injection for one day to achieve the best effect.
Classification and application of microporous membrane
Microporous filter membrane according to the characteristics of the target to filter is not the same, can choose different materials and different specifications of the filter membrane, generally divided into polytetrafluoroethylene, polyethersulfone, mixed cellulose ester, nylon, and Polyvinylidene fluoride and so on.
1. PTFE (polytetrafluoroethylene)
The PTFE filter membranes have low solubility and can be used in water system and various organic solvents, which is resistant to all solvents. It has the characteristics of air permeability and water permeability, large air flux, high particle retention rate, good temperature resistance, strong acid, alkali, organic solvent and oxidant resistance, aging resistance, non-stick, non-flammable, and non-toxic, and biocompatibility.
2. Water-based PES (polyethersulfone)
The PES filter membrane has high chemical and thermal stability, fast flow rate, strong acid and alkali resistance (pH range 1-14); high mechanical strength. It has the advantages of high porosity, large dirt holding capacity, recoil and high-temperature sterilization, and good pressure resistance, which can remove insoluble microparticles from aqueous solutions.
The best hydrophilicity and unique microstructure make the polyethersulfone membrane wet quickly and completely, and under the premise of ensuring extremely high particle interception efficiency, it has a higher and stable liquid flow rate, which is suitable for general acid, Alkali, aliphatic hydrocarbons, oils, and alcohols are stable preparations, suitable for physical and chemical sterilization, such as high-pressure steam, gamma-ray, and ethylene oxide sterilization, with high bubble point and excellent membrane integrity. The polyethersulfone membrane material has a very low protein adsorption rate, which can ensure the stability of the filtered liquid components, and is suitable for single-use precision filtration infusion sets and anesthetic liquid filters.
3. Water-based MCE (mixed cellulose ester)
Suitable for aqueous solution, low protein adsorption. High flow rate, strong thermal stability, not suitable for organic solvents, especially suitable for water-based solutions.
The surface is smooth, the texture is light and thin, the porosity is high, and the microporous structure is uniform, so it has the characteristics of fast flow rate and difficult adsorption.
Nylon filter membrane is used for water quality in the pharmaceutical industry, production products, mineral beverages, brewing, clocks, and other industries, and to filter bacteria and particles in medical oil, lubricating oil, fuel oil, and scientific research laboratories.
5. Organic nylon
Organic nylon has good hydrophilicity, acid and alkali resistance, and antioxidants. Not only the acid and alkali aqueous solutions can be used by organic nylon, but also the phenols, alcohols, lipids, and other organic solvents can be used by it. This product is suitable for most organic solvents and aqueous solutions and can be used for strong acids, 70% ethanol, dichloromethane, and other organic solvents.
6. Polyvinylidene fluoride (PVDF)
The polyvinylidene fluoride membrane is chemically stable and inert and is suitable for chemically corrosive organic solvents, strong acid and alkali solutions, and sample preparation in liquid chromatography analysis. It has hydrophobic properties and filters out moisture