The TE range of filters by Whatman feature polypropylene support material for improved strength and handling, while the PTFE filter is chemically stable and inert making them suitable for use with aggressive organic solvents, strong acids and alkalis.
Temperature resistant up to 120°C
Can withstand aggressive solvents, liquids and gases that may damage other membranes
Polypropylene support material for improved strength and handling
One of the major applications for the PTFE membrane is the clarification of corrosives, solvents and aggressive fluids. This includes the important requirement in HPLC analysis for sample filtration where any solid particles can cause permanent damage to the column. The 0.45µm pore size is normally used for HPLC applications.
Air and gas sterilization make use of the hydrophobic characteristics of PTFE membrane filters and their ability to stop aqueous aerosols. Pore sizes of 0.2µm and 0.45µm are typically used in these tasks.
Sterile venting of vacuum manifolds, fermentation vessels and filtrate tanks and containers use PTFE 0.2µm membranes.
The TE range use a randomly arranged polypropylene support material.
Identifying the filter material most suitable for your application based upon the nature of the liquid or gas you are filtering will ensure the best performance of your filter. Each membrane filter material has differing chemical and physical properties such as hydrophobicity, flow rate, extractables and protein retention making them suited to differing applications. Once you have selected the most compatible filter material, you will need to consider what pore size is most appropriate.
Membrane Material | Protein binding | Hydrophilic/Hydrophobic | Chemical resistance | Applications |
Hydrophilic PTFE | Low | Hydrophilic | High | Purification of HPLC organic and solvent/aqueous solutions |
Hydrophobic PTFE | Low | Hydrophobic | High | Filtration of solvents |
PES | Low | Hydrophilic | Low/Medium | Purification of tissue culture solutions, buffers |
PVDF | Low | Hydrophilic | Medium | Filtration of protein solutions |
NYL | Medium | Hydrophilic | Medium | Filtration of aqueous and solvent/aqueous mixtures |
CA | Low | Hydrophilic | Low | Filtration of protein solutions |
CN | High | Hydrophilic | Low | Filtration of aqueous solutions where protein binding is not a concern and microbioloigical applications. |
RC | Low | Hydrophilic | Medium | Filtration of aqueous and organic solvents and protein recovery applications. |