Hydrophobic Membrane Filter
Hydrophobic filter paper is also called a hydrophobic membrane filter. The pores of the microporous membrane act as small capillaries. When the hydrophobic membrane filter comes into contact with water, the hydrophobic membrane is relatively repellent to water, the surface tension will act to drive the water out of the pores.
Unless the applied water pressure is greater than the water inlet pressure of the hydrophobic membrane filter, water will not enter the pores and the membrane will act as a barrier to water flow. Liquids with low surface tension (such as alcohol) will spontaneously enter and fill the pores of the hydrophobic filter paper.
Once all the air in the hole is replaced, there is no longer any surface tension, and water can easily enter the hole, displacing the low surface tension fluid and passing through the membrane.
Then, as long as the holes remain full of water, the membrane will allow large amounts of water to flow. If the hydrophobic membrane filter is allowed to dry (that is, air enters the pores), it should be pre-wetted again with a low surface tension fluid before using water.
| Filter Media | Pore Size | Diameter | Sterilize | Price |
|---|---|---|---|---|
| PVDF | 0.1μm, 0.22μm, 0.45μm, 0.65μm, 1.0μm, 3.0μm, 5.0μm | 13mm, 25mm, 47mm, 90mm, 142mm, 293mm | No | |
| PP | 0.1μm, 0.22μm, 0.45μm, 0.65μm, 0.8μm, 1.0μm, 3.0μm, 5.0μm, 10μm | 13mm, 25mm, 47mm, 90mm, 142mm, 293mm | No | |
| Hydrophobic glass fiber | 0.45μm, 1.0μm, 1.6μm | 13mm, 25mm, 47mm, 90mm, 142mm, 293mm | No | |
| Hydrophobic PTFE | 0.1μm, 0.22μm, 0.45μm, 1.0μm, 3.0μm, 5.0μm, 10.0μm | 13mm, 25mm, 47mm, 90mm, 142mm, 293mm | No |
Applications of Hydrophobic filter paper
Venting and Air Filtration: Hydrophobic membrane filters are used in applications where it is necessary to allow the passage of air or gases while preventing the entry of liquids. This is crucial in venting systems, especially in medical devices, laboratory equipment, and industrial processes.
Protection of Sensitive Components: They are employed to protect sensitive components in devices and equipment from exposure to moisture, which could potentially damage or interfere with their performance.
Air Sampling and Monitoring: Hydrophobic membrane filters are used in environmental monitoring and air sampling applications to capture airborne particles and microorganisms while allowing air to flow through.
Laboratory Filtration: They find use in laboratory applications where it is necessary to filter gases, solvents, or non-aqueous solutions without absorbing or allowing the passage of water.
Vacuum Systems: Hydrophobic membrane filters are used in vacuum systems to prevent the backflow of liquids into the vacuum pump.
Respiratory Devices: In respiratory equipment, hydrophobic filters are used to allow the passage of air during inhalation while preventing moisture from entering the system.
Battery Venting: They are employed in batteries and energy storage systems to allow for the venting of gases while preventing the entry of moisture.
For example, the lipophilic components of the printing plate graphics and printing inks have good hydrophobicity. In organic matter, it shows hydrophobicity of the alkyl group and benzene ring, that is, they make the organic matter difficult to dissolve in water.
Hydrophobic membrane filters are usually used with compatible non-aqueous fluids.
They are also commonly used as air, gas, or ventilation filters. Hydrophobic membrane filters are sometimes used with water or aqueous solutions; in these applications, they are pre-wetted with a low surface tension water-miscible liquid before use.
