Size, shapes and superstructures of nanomaterials with a SAXS/WAXS instrument

S. Rodrigues, P. Panine, M.l Fernandez- Martinez, P. Høghøj, F. Bossan, R. Mahé
Xenocs SA, FR

Keywords: nanomaterials, characterization

Summary:

Nanostructured materials hold major expectations but understanding their properties requires the investigation of a large number of compositions or process combinations necessitating characterization requirements over broad length scales. Moreover new materials based on a bottom up approach, i.e. self-assembly of complex materials as such as block copolymer are of significant interest for a wide range of applications but still require control and understanding of their morphology, both for fundamental studies or for routine quality verification. Small Angle X-ray Scattering (SAXS) is a powerful measuring method for investigating nanostructured materials providing information in the range from 1 nm to beyond 150 nm such as nanoscale morphology, mesoscale phase identification, surface to volume ratio of internal structures as few examples. The method requires little sample preparation, is non-destructive and in contrast to microscopy probes a large volume of the sample enabling a statistically meaningful result. However, the same technique can be applied to surface only in the so-called “grazing incidence geometry”. When combined with Wide Angle X-ray Scattering (WAXS) one can also get information on crystalline structure. Major developments in components and subassemblies achieved the past years offer capabilities for fast routine measurements, screening process parameters or samples. Moreover, most of the time such experiment can be conducted with sample maintained in normal atmospheric conditions, without further preparation, enabling a simplified access to the nanostructure information. Wet or solvent containing samples can then be easily studied. This presentation will summarize major developments on SAXS/WAXS instrumentation emphasizing impact for nanomaterials characterization. Capability to measure simultaneously nanoscale structure and crystalline features during in-situ studies such as temperature controlled measurements will be highlighted. Also high throughput characterization of microinjected semicrystalline polymers will be shown emphasizing the nanostructure and processing relationships. Finally GISAXS measurements on block copolymers will be shown as an example of characterization of self-assembled structures.