Pilatus 1m

SAXS studies were
conducted on 150 ± 10 μm PNAEP₈₅-PtBA₁₅₀-PnBA₄₀₀-PtBA₁₅₀ and PNAEP₈₅-PtBA₁₅₀-PnBA₇₀₀-PtBA₁₅₀ copolymer films using
a Xeuss 2.0 (Xenocs) SAXS instrument equipped with a FOX 3D multilayered
X-ray mirror, two sets of scatterless slits for collimation, a hybrid
pixel area detector (Pilatus 1M, Dectris), and a liquid gallium MetalJet
X-ray source (Excillum, λ = 1.34 Å). SAXS patterns were
recorded at a sample-to-detector distance of approximately 1.20 m
(calibrated using a silver behenate standard). 2D SAXS patterns were
reduced to 1D plots by azimuthal integration using the Foxtrot software
package.
SAXS patterns of 1.0% w/w aqueous tetrablock copolymer
dispersions were collected at Diamond Light Source (station I22, Didcot,
UK) using monochromatic X-ray radiation (wavelength, λ = 0.124
nm, with q ranging from 0.015 to 1.3 nm^–1, where q = 4π sin θ/λ is the
length of the scattering vector and θ is one-half of the scattering
angle) and a 2D Pilatus 2 M pixel detector (Dectris, Switzerland).
Glass capillaries of 2.0 mm diameter were used as a sample holder.
SAXS data were reduced (integration, normalization, and absolute intensity
calibration using a SAXS pattern recorded for deionized water, assuming
that the differential scattering cross section of water is 0.0162
cm^–1) using Dawn software supplied by Diamond Light
Source.^{65 (link)}

Scanning electron microscopy (SEM) studies were performed using a NanoSEM-200 apparatus from FEI Nova (Hillsboro, OR, USA) using mixed secondary electron/back-scattered electron in-lens detection. All the samples were observed after sputter coating with Au/Pd alloy in a 208 HR instrument from Cressington Scientific Instruments (Watford, UK) with high-resolution thickness control.
UV-VIS absorbance spectral measurements were carried out using a 2401PC double-beam spectrophotometer from Shimadzu (Tokyo, Japan) with a thin-film holder that enables the interrogation of the sensing area.
Synchrotron wide- (WAXS) and small-angle X-ray scattering (SAXS) measurements were performed at the NCD-SWEET beamline of the ALBA synchrotron facility in Barcelona, Spain. Two-dimensional detectors were used, namely, LH255-HS (Rayonix, Evanston, IL, USA) and Pilatus 1 M (Dectris, Baden Daettwil, Switzerland), to register the WAXS and SAXS patterns, respectively. The sample-to-detector distance was set to 111.7 mm for WAXS and 2700 mm for SAXS measurements, with the λ of the incident beam being 0.1 nm and the beam size being 0.35 mm × 0.38 mm (h × v). The 2D data were reduced to 1D data using pyFAI software version 0.21.3 [26 (link)]. For the processing of WAXS and SAXS patterns, the commercial package Peakfit 4.12 (2016) by SYSTAT (San Jose, CA, USA) was implemented.

SAXS data were measured at beamline BM29 of the European Synchrotron Radiation Facility (ESRF), Grenoble, France. Fifty microliters of purified protein concentrated to ~8 mg/mL was chromatographed using a size-exclusion chromatography column (superdex-200 increase 10/300 GL column) pre-equilibrated with Tris-HCl, pH 7.5, 150 mM NaCl, 20 mM β-mercaptoethanol, and 0.02% Triton X-100 on an ultra-performance liquid chromatograph (Shimadzu Corporation). Data were collected in-line at 20 °C with X-ray beam at wavelength λ = 1.0 Å, and the distance from the sample to detector (PILATUS 1M, Dectris Ltd.) was 2.867 m, covering a scattering vector range (q = 4πsinθ/λ) from 0.0025 to 0.5 Å⁻¹, with an exposure time of 1 s per frame. The 2D images were reduced to one-dimensional scattering profiles using the software on site. Frames corresponding to dimeric DHDDS were averaged and subtracted from buffer frames using ScÅtter (http://www.bioisis.net/tutorial/9). The experimental radius of gyration (R_g) was calculated from data at low q values in the range of qR_g <1.3, according to the Guinier approximation: lnI(q) ≈ ln(I(0)) − R_g²q²/3 using PRIMUS. The D_max value and the Porod volume were derived from the paired-distance distribution function (PDDF or P(r)) calculated using GNOM. The flexibility analysis was performed using ScÅtter [19 (link)].

In-house SAXS measurements were performed with an Mo GeniX^3D microfocus X-ray tube (Xenocs SA, Sassenage, France) combined with FOX2D single reflection optics delivering a monochromatic beam with an X-ray energy of 17.4 keV (Bruetzel et al., 2016 ▸ ). The sample–detector distance was set to ∼1.11 m, yielding usable q values between 0.05 and 0.35 Å⁻¹. We used a PILATUS 100K detector (DECTRIS Ltd, Switzerland) for X-ray detection. For each experiment, sample and buffer profiles were collected with three to five exposures of 2 h each.
All synchrotron data, except for the data presented in Figs. 6 and 7, were collected at beamline BM29 at the ESRF in Grenoble at an X-ray energy of 12.5 keV and a sample–detector distance of 2.87 m, resulting in a usable q range of 0.05–0.35 Å⁻¹ (Pernot et al., 2013 ▸ ). We used a PILATUS 1M (DECTRIS Ltd, Switzerland) detector for data acquisition. Data were collected in ‘flow’ mode at room temperature with ten measurement frames at an exposure time of between 1 and 4 s in ‘multibunch mode’ or ‘low bunch mode’.

Transmission SAXS measurements were performed at the P03 beamline,
at PETRAIII storage ring at DESY in Hamburg, Germany.^{46 (link)} The measurements were performed with an X-ray wavelength
λ = 0.97 Å and sample-to-detector distance of 9035 mm.
The scattering patterns were recorded by a single-photon counting
detector (Pilatus 1M, Dectris) with the pixel size of 172 × 172
μm². The beam size was 33 × 27 μm² (horizontal × vertical). The same type of flow channel
was used for the SAXS study as for the spinning experiments, but the
Plexiglas covers were replaced by Kapton films. The flow rates were
the same as the ones used for spinning (4.1, 4.7, and 24.9 mL/h for
the core flow, the first sheath flow, and the second sheath flow,
respectively). The Q2 sheath flow was varied (1.5× and 2×
the initial value) to explore the effect on PNF alignment. Alignment
order parameters of the PNFs were calculated from the scattering patterns
as described in previous work.^{17 (link),21 (link),22 (link)}