Author: Maryna Kavalenka

Maryna’s presentation

TE membranes were first embedded in plastic material and then these samples were cut with microtome and imaged. The images below are of the 30nm and 80nm pore diameter membranes. 30nm ones came out better. It looks like the diameter isn’t really 30nm, look at the second picture. The dark spots are either tears or…

The graph below is air permeabilities for four samples from wafers 344,338,342,345 without and with 15 nm thick deposited oxide on the front side. All of this samples don’t have pinholes.Look at the data for samples 2 and 4 on the graph. The approximate porosities of these samples are 2.7 and 4.6% which is the…

I tested those membranes from w335 and w341 with approximately 40 nm of deposited oxide on both sides for air permeability and burst pressures. There was tiny amount of air flow (I checked for leak) from few of them which I didn’t expect with such thick oxide. The burst pressures are higher then without the…

I tested ozone treatment influence on the membrane strength and air permeability. The result: didn’t see any difference between ozone treated and non-treated samples. Burst pressure experiments description: tried wafers 391, 393, 344, and 345. Ozone treatment for 5 and 15 min didn’t show any difference. Air permeability: tested samples from wafers 344, 345 with…

I tested five types of track-etched membranes (with pore diameters 0.1, 0.08, 0.05, 0.03 and 0.01micron). All of them are 6micron thick and usually have 14-16% porosity. First experiment was to confirm the official air flow rates data with our setup. The measurements are taken at 10psi (as the ones that company did). The results…

These are low burst results but samples have lots of pinholes on them many of which are on the edges. I also checked porosity of the wafers 338 and 340. They indeed have porosities close to 7%. Wafer 340 (0,5) 0.0656 porosity

Theoretical molar flow is calculated for membranes with different porosities and is based on data extracted from TEM images using Mike’s program. Experimental data is calculated using air permeability test results. It is associated with porosity only through TEM data. Correlation between two is very good but some points do not agree. One of the…

I measured burst pressures on two non-unifrom wafers w391, w393. They have lots of pinholes (especially w391) but the pressure they withstand is pretty high. I expected it to be much lower after looking at the membranes in the microscope.