They are suitable for applications involving aggressive organic solvents, strong acids, and alkalis. PTFE membranes are particularly suitable for preparing samples for HPLC analysis. The hydrophobic nature of the membrane also has applications for air and gas sterilization. The membrane is laminated onto a nonwoven polypropylene support web for improved strength and handling and can be used at temperatures up to 120ºC. Chemically stable and inert
PTFE is the membrane of choice for use with aggressive solvents, liquids, and gases that can attack other membranes. It is resistant to most acids, alkalis, and solvents. Applications
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 0.5 µm pore size is normally used. Air and gas sterilization make use of the hydrophobic characteristics of PTFE membranes and their ability to stop aqueous aerosols. Usual pore sizes are 0.2 µm and 0.5 µm. Sterile venting of vacuum manifolds, fermentation vessels, and sterile filtrate tanks and containers utilize PTFE 0.2 µm membranes. WTP and TE membrane ranges
WTP membranes use a polypropylene grid as the support material whereas the TE range use a randomly arranged polypropylene support material. |
Typical Data - Teflon (PTFE) Membranes | Membrane | Thick-
ness
(µm) | Porosity
(%) | Flow rate
Δp = 0.9 bar (s/100 ml/12.5 cm2) | Liquid flow rate @ 10 psi vacuum
(ml/min/cm2) | Air flow rate Δp = 3 mbar (s/100 ml) | Air flow rate @ 10 psi vacuum
(l/min/cm2) | Bubble point (bar)‡ | Max.
temp.
(οC) | | TE Range | 0.2 µm
(TE 35) | 240 | - | 24* | - | 70 | - | 1.29 | 100 | 0.45 µm
(TE 36) | 220 | - | 12* | - | 60 | - | 0.89 | 100 | 1.0 µm
(TE 37) | 275 | - | 5.4* | - | 24 | - | 0.24 | 100 | 5.0 µm
(TE 38) | 265 | - | 2.2* | - | 3.5 | | 0.19 | 100 | | WTP Range | | 0.2 µm | 130 | 72 | - | 61.4† | - | 4.5 | 0.89 | 120 | | 0.5 µm | 120 | 74 | - | 110† | - | 7.5 | 0.41 | 120 | | 1.0 µm | 90 | 76 | - | 445† | - | 17 | 0.21 | 120 | * Measured with ethanol
† Measured with Acetone
‡ Measured using 2-Propanol |
Ordering Information - Teflon (PTFE) Membranes| Catalog Number | Description | WTP Range
0.2 µm Pore Size |
| | 7582-002 | PTFE membrane circles, 0.2 µm, 25 mm, 100/pk | | 7582-004 | PTFE membrane circles, 0.2 µm, 47 mm, 100/pk | | | 7585-004 | PTFE membrane circles, 0.5 µm, 47 mm, 100/pk | | | 7590-002 | PTFE membrane circles, 1 µm 25 mm, 100/pk | | 7590-003 | PTFE membrane circles, 1 µm, 37 mm, 100/pk | | 7590-004 | PTFE membrane circles, 1 µm 47 mm, 100/pk | | TE Range 0.2 µm Pore Size (TE 35) |
| | 10411405 | PTFE membrane circles, (TE 35), 0.2 µm, 25 mm, 50/pk | | 10411411 | PTFE membrane circles, (TE 35), 0.2 µm, 47 mm, 50/pk | | 10411413 | PTFE membrane circles, (TE 35), 0.2 µm, 50 mm, 50/pk | | 0.45 µm Pore Size (TE 36) |
| | 10411305 | PTFE membrane circles, (TE 36), 0.45 µm, 25 mm, 50/pk | | 10411311 | PTFE membrane circles, (TE 36), 0.45µm, 47 mm, 50/pk | | 10411313 | PTFE membrane circles, (TE 36), 0.45 µm, 50 mm, 50/pk | | | 10411205 | PTFE membrane circles, (TE 37), 1 µm, 25 mm, 50/pk | | 10411211 | PTFE membrane circles. (TE 37), 1 µm, 47 mm, 50/pk | | 10411213 | PTFE membrane circles, (TE 37), 1 µm, 50 mm, 50/pk | | | 10411108 | PTFE membrane circles, (TE 38), 5 µm, 37 mm, 50/pk | | 10411111 | PTFE membrane circles, (TE 38), 5 µm, 47 mm, 50/pk | | 10411113 | PTFE membrane circles, (TE 38), 5 µm, 50 mm, 50/pk | | 10411116 | PTFE membrane circles, (TE 38), 5 µm, 90 mm, 25/pk | | 10411130 | PTFE membrane circles, (TE 38), 5 µm, 150 mm, 25/pk |
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