8 w uv lamp

For UV measurements an 8 W UV-lamp (Camag; Berlin, Germany) was used at 254 nm wavelength with a camera EOS D60 (Canon; Krefeld, Germany) for imaging in manual mode with the settings f-number F5.6, ISO1000, focal lengths 18 mm and shutter speed 1 s, carried out in a Camag UV-cabinet (Camag; Berlin, Germany). We increased the contrast between the PAN-support membrane and the PS-b-P4VP top layer by using a UV-lamp (254 nm). While the PAN backscatters parts of the UV-light, which then appears purple, PS-b-P4VP partially absorbs this wavelength and appears black. If the PS-b-P4VP layer thickness is low the UV-light will penetrate this layer, backscatter at the PAN-support membrane, and not absorb completely on its way back. In consequence, deviations of PS-b-P4VP layer thickness can be seen as purple light with changing intensity. To gain this effect, the shutter speed of the camera was increased to 1 s, which was enough for our purpose.

An 8°W UV-lamp (Camag, Berlin, Germany) was used at a wavelength of 254 nm for imaging under UV light conditions. An EOS D60 camera (Canon, Krefeld, Germany) was used for imaging in manual mode with the settings f-number F5.6, ISO1000 and shutter speed 5 s, in dark room conditions.