FAQ
Yes. Filters will perform very differently in a gas/air stream than in a liquid stream. These differences can be observed by comparing flow rates and retention ratings between gas /air and liquid for the same medium. In liquid, particles generally follow the flow of the solution as it travels through the filter, and it is primarily particles that are directly intercepted by the filter matrix which will be retained. In gas/air filtration, direct interception also applies, but there are other additional mechanisms that can cause particles to be captured by the filter. These mechanisms include inertial impaction, gravitational settling, electrostatic interaction, and Brownian Motion.
No. It is not possible to produce Anopore membranes at pore sizes greater than 0.2 µm.
The 0.1 µm and 0.02 µm Anopore membranes are asymmetric, with the nominal pore size (0.02 µm or 0.1 µm) on one side and 0.2 µm pores on the other side. The 0.2 µm pore goes through nearly the entire cross-section (i.e., thickness) of the membrane. The 0.2 µm pore then branches into the 0.1 µm or 0.02 µm capillaries. This asymmetric layer is less than 1 micron in thickness.
No. Because the membrane is asymmetric, we do not recommend using the membrane in the reverse direction, particularly when collecting material on the membrane surface for optical analysis.
No. Our 0.02 µm Anopore membrane is asymmetric, with a 0.02 µm pore on one side and a 0.2 µm pore on the other side. Only the 0.2 µm membrane has uniform 0.2 µm pore channels extending through the entire thickness of the membrane.
The side to which the polypropylene support ring is attached is the nominal pore side and should be positioned uppermost when using Anodisc with funnel-type membrane holders. With in-line holders, the support ring side should face the upstream side of the holder. When in doubt, the scratch test may be used: scratch the membrane very lightly with a needle at the edge of the membrane, at a right angle to the circumference. The scratch should be no more than 1–2 mm long. Examine against a white background. Scratching the 0.02 µm side will be difficult, and the line will be almost imperceptible; scratching the 0.2 µm side will be easier, and line will be noticeable and dark.
No. Anopore is quite fragile, and ultrasonic vibration will likely affect its pore structure.