| Membrane | Hydrophilic/ Hydrophobic |
Chemical Compatibility | Protein Binding | Flow Rate | Applications | Limitations |
|---|---|---|---|---|---|---|
| PTFE (Polytetrafluoro- ethylene) |
Hydrophobic (can be hydrophilic) | Excellent resistance to strong acids, bases, and organic solvents | Very Low | Moderate | Filtration of aggressive organic solvents, gases, and non-aqueous samples | Not suitable for aqueous solutions unless treated to be hydrophilic |
| PES (Polyether- sulfone) |
Hydrophilic | Resistant to aqueous solutions, moderate organic solvents | Low | High | Filtration of biological fluids, buffers, cell culture media, HPLC prep | Not resistant to strong organic solvents like acetone or chloroform |
| Nylon | Hydrophilic | Broad compatibility with aqueous and organic solvents | Moderate | Moderate | General laboratory filtration, environmental testing, HPLC | Moderate protein binding, may affect sensitive proteins |
| PVDF (Polyvinylidene Fluoride) | Hydrophobic (can be hydrophilic) | Excellent resistance to organic solvents, acids, bases | Low | Moderate | Sterile air/gas filtration, biological sample filtration, protein filtration | More expensive than other membranes, may need to be hydrophilic for aqueous |
| CA (Cellulose Acetate) | Hydrophilic | Limited to aqueous solutions and mild chemicals | Low | Very High | Microbiological and sterile filtration of aqueous solutions, cell culture media | Poor chemical resistance to organic solvents and aggressive chemicals |
| RC (Regenerated Cellulose) | Hydrophilic | Compatible with aqueous and some organic solvents | Low | Moderate | Protein filtration, HPLC sample prep, filtration of aqueous/organic mixtures | Less mechanical strength, not ideal for aggressive chemicals |
| GF (Glass Fiber) | Hydrophilic | Suitable for high particle loads, but not for sterile filtration | N/A | Very High | Pre-filtration of samples with high particulates, air pre-filtration | Not suitable for final sterile filtration due to large pore size |
Best for Sterile Air Filtration:
- PVDF and PTFE are the top choices due to their hydrophobic properties, low protein binding, and excellent chemical resistance.
- GF may be used as a pre-filter in air filtration systems but would not be suitable for sterile final filtration.