Fig. 2: SEM images of the Matrimid-Cyclen membranes.

a photograph, and b, c cross section of the Matrimid-Cyclen-n% membranes (n% is the Cyclen mass loading and was varied from 0 to 15 wt%, n = 0, 1, 3, 5, 10, 15). d Cross-sectional SEM-EDS nitrogen (N) mapping of Matrimid-Cyclen membranes.