Xeuss 2.0 system

The structural characterization was performed
in the 1W2A beamline
of the Beijing Synchrotron radiation Facility (BSRF). Selected samples
were previously fractionated in a Linkam THMS600 hot stage connected
to a liquid nitrogen station. The final heating was performed from
25 to 140 °C at 5 °C/min in a Linkam TST350 hot stage, and
the WAXS patterns were taken simultaneously. An exposure time of 25
s was used, and the patterns were taken every 30 s (i.e., every 2.5
°C). A Pilatus 1M detector collected the scattering patterns
with a resolution of 981 × 1043 pixels (pixel size = 79 ×
79 μm²). The sample-to-detector distance was 121.8
mm, and the wavelength was 1.54 Å.
WAXS experiments, on
selected samples, were performed with transmission geometry at RT.
These experiments were performed on a Xeuss 2.0 system (Xenocs SA),
equipped with a microfocus Cu Kα X-ray source (GeniX3D, 50 kV,
0.6 mA), generating X-ray radiation of a wavelength of 1.54 Å.
The detector used was a Pilatus 300K (DECTRIS, Swiss) with a resolution
of 487 × 619 pixels (pixel size = 172 × 172 μm²). The sample-to-detector distance was 138.61 mm, and exposure
time of 1800 s. The 1D intensity profiles were integrated from background-corrected
2D WAXS patterns with an azimuthal angle range of 0–90°.

SAXS studies of reference samples (wt-HCC and its variants) were performed using a laboratory SAXS/WAXS XEUSS 2.0 system (XENOCS, France). X-ray radiation (λ = 0.134 nm) was generated by the MetalJet microfocus X-ray source with a liquid metal (gallium alloy) target (Excillum AB, Sweden) and collimated using a Fox 3D Ga ultra-low divergence mirror. The HCC samples were measured using a low-noise flow cell and a PILATUS 3 R 1 M hybrid photon counting detector with an active sensor area (width × height) of 169 × 179 mm² (DECTRIS AG, Switzerland). The sample-to-detector distance was 1200 mm, which in the high-flux mode of X-ray optics, covers the scattering vector range 0.08 < s < 4.7 nm⁻¹. The X-ray photon flux on the sample was 2 × 10⁸ photons/s. For each sample, 15 frames (600 s/frame) were collected. The collected frames were checked for radiation damage and processed using FOXTROT^{33 (link),34} , and the buffer scattering was subtracted using PRIMUS^{28 (link)}. The low-resolution parameters (R_g, pair distance distribution functions) were then analysed from the SAXS data using the software described above.