Oleophobic PTFE Membranes


Oleophobic membrane is a super-hydrophobic PTFE membrane modified by hydrophobicity surface treatment (molecular level). Cobetter Oleophobic PTFE membrane meets Oil Rating 8 (AATCC 118 : Oil Repellency: Hydrocarbon Resistance Test), staying hydrophobic against low surface tension liquids like lipids and ethyl alcohol/methyl alcohol.

Surface Tension Comparison of Various Membranes and Solvents

   Material   Surface Tension (Dyn/cm, 20℃)
   Hydrophilic PES Membrane   >85
   5% NaCl   77.5
   Pure water   72.8
   Hydrophobic PTFE Membrane   31
   Chloroform   27.1
   Acetone   23.7
   Methyl Alcohol   22.6
   Ethyl Alcohol   22.3
   Oleophobic PTFE Membrane   19

                                                                                                            Note: 1Dyn/cm=1mN/m



The contact angle is formed between membrane and the tangent to the curve of the liquid droplet. The lower surface tension of the membrane, the greater the contact angle and the easier it is to repel liquid droplets. For example, a 0.2 micron hydrophobic PTFE Membrane could resist 5% NaCl solution as a long term even under certain pressure, but have limited repellent with Ethyl Alcohol. An Oleophobic PTFE membrane could solve this,  and perform stable resistance with non-polar liquids, excellent air permeability, and easy to roll off of droplets.

Cobetter hydrophobic PTFE membrane is qualified for common venting cases, but for most of chemotherapeutic medicine infusion venting applications, to secure long duration of non-wetting status and maintain venting function, the vent membrane is required to have a lower surface tension than that of contacting liquids such as Docetaxel,Paclitaxel,Etoposide.And Oleophobic PTFE membrane is therefore introduced because of its super low surface tension.

Oleophobic option is necessary for chemotherapeutic medicine delivery venting (Alcohol Repellent), and is also recommended for common venting applications because it offers a longer hydrophobic lifetime, a more secured non-leakage promise, and a higher product safety.Any other application which the membrane might be possibily contact extremely low surface tension liquid (i.e. Surfactant, Oils, Alcohol, Cosmetics, benzene), the Oleophobic PTFE membrane will be a better choice.

Cobetter can supply PFOA free membrane filter that do not contain Perfluorooctanoic acid (PFOA), its salts and PFOA-related substances, which comply with relative regulation requirements in European REACH EU2017/1000, EC1907/2006 (REACH), and POP EU2020/784.

Certified Biological Safety (ISO 10993/USP Class VI)

Excellent Air Permeability, Outstanding Air Flow Rates

Optimized Backing Material,Better Sealing Capability

Wide Range of Pore Size (0.02-10μm)

Stable Water Entry Pressure (WEP)


Compatible with Different Sealing Methods

Ultrasonic, Heat, RF Welding, Mechanical, Inserting Molding

Sterilization Compatibility

Autoclave,Ethylene Oxide, E-Beam, Gamma Irradiation

Available Pore Sizes (μm)

0.02,  0.03,  0.05,  0.1,  0.2,  0.45,  0.8,  1.0,  2.0,  5.0,  10.0

Typical Performance Characteristics (*0.2μm)

Filtration Efficiency ≥99.99999% Brevundimonas diminuta
Air Flow Rates Gurley 17-49sec
WEP(60s) >450 KPa
Thickness 280-440μm (Supported)

Typical Applications

- Air Vent / Ventilation
- IV Filter Vent
- Transducer Protector (TP)
- Bacterial Air Vent
- Sensor Protection Cover
- Package Vents
- Drip Chamber Spike Vent
- Dispensing Pin
- Closed System Transfer Devices (CSTDs)
- Urine Meters/Bags
- Ostomy Pouches

Support Type

Polyester, Polypropylene, Polyolefin, or unlaminated (without substrate/lamination)

Membrane Formats

Roll, Sheet, Disc, Adhesive Backing, Customization

For technical data sheet or application inquiry, you are more than welcome to contact our sales representative by sales@cobetterfilter.com or leave a message

  • Hydrophilic PTFE Membranes Cobetter hydrophilic PTFE (polytetrafluorethylene) membrane filter has a durable wide operating temperature range and resistance to the destructive effects of many chemicals. It can be used to filter aqueous fluids without prior wetting.
  • Hydrophobic ePTFE Membrane Cobetter Hydrophobic PTFE membrane is made from pure PTFE membrane bonded to a polypropylene support. The extreme chemical compatibility (pH 1-14) makes them very useful for the filtration of solvents and acids or other aggressive chemicals, for which other membrane filter types are unsuitable. Due to their hydrophobic characteristics, they must be pre-wet with a solvent such as ethanol or methanol before the filtration of aqueous solutions.