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.
Nuclepore and Cyclopore Polycarbonate (PC) membranes are suitable for use in gravimetric analysis. The tare weight of these membranes is low. Also, polycarbonate typically exhibits low water absorption. Under normal circumstances weight change is very low after being exposed to water/moisture. Therefore, the impact of changes in humidity should be small.