Morphology of Membrane Structures and Surfaces

Surface and structural features can be revealed by several visibly comprehensible techniques including various microscopy methods, lliose tools provide direct guidance for the optimization of materials and processing parameters during membrane preparation. 

The principle involved in this type of multi-layered design is to ideally (1) impart the retention function to a layer of the separating membrane as thin as possible (so long as it 

Most SEMs today except those low end models are equipped with a spectrometer to perform X-ray microanalysis. This type of analysis, commonly known as energy-dispersive X-ray analysis DX or EDXRA), can reveal the elemental composition of a small spot (less than a square micron) in a membrane specimen. It can analyze a large number of elements except light elements such as carbon, nitrogen and oxygen. It is possible to carry out some analysis on some light elements with a light element detector. 

For TEM observation, more complicated and careful sample preparation procedures are involved. Extreme care must be taken during sample preparation to avoid crosscontamination. The sample sometimes needs to be embedded in a medium such as epoxy resin that cures at 50X overnight before cutting by a microtome equipped with a diamond knife or thinning by electropolishing or ion beam. 

Atomic force microscopy. Scanning electron microscopes do not provide the necessary resolution for analyzing detail morphology of certain membrane layers of very fine pore sizes such as those suitable for ultrafiltration and gas separation. While transmission electron microscopes are capable of examining very small scale structures, the technique is limited to only very thin specimens. This makes sample preparation for a multilayered membrane very difficult and tedious. 

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