Characterization of a porous membrane by AFM and GISAXS
A polymer membrane with a pore structure perpendicular to a substrate has been characterized by the Tosca™ 400 and the SAXSpoint 2.0 system.
Anton Paar - Membrane research made easy
Membranes with nanoscale pores have high potential in e. g., modern battery and energy conversion applications as well as water treatment. The characterization of such samples regarding their pore structure is of vital importance for their performance. Here we show the characterization of a 100 nm thick porous polymer membrane with a pore structure that is perpendicular to a silicon substrate surface. Grazing-incidence small-angle X-ray scattering (GISAXS) is a highly sensitive method for analyzing surface structures on the nanoscale, giving averaged information over a large sample area. Atomic force microscopy (AFM) can provide direct visual information on the local surface structure at high spatial resolution. This makes both methods perfectly complementary for the characterization of nanostructured surfaces.
Fig. 1: 2D GISAXS pattern with horizontal 1D cut (left) and AFM topography image (right) of a nanoporous PE/PEG thin film
The image on the left shows the GISAXS pattern of the investigated structure recorded by the SAXSpoint 2.0 system. The pore-to-pore distance is about 50 nm as calculated from the reflections. From the relative reflection positions (see inset), the hexagonal arrangement of the pores becomes visible. The image on the right shows the corresponding AFM topography image of the sample acquired by Tosca™ 400, the new AFM by Anton Paar. It confirms the hexagonal ordering of the pores with a 50 nm periodicity and an average pore diameter of 20 nm.
Sample courtesy of Prof. Yong Wang (Nanjing Tech University)