DL-SAXS-Offline SAXS and Sample Environment Development
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Diamond Proposal Number(s):
[2617]
Abstract: Utilizing carbon dioxide (CO2) to make polycarbonates through the ring-opening copolymerization (ROCOP) of CO2 and epoxides valorizes and recycles CO2 and reduces pollution in polymer manufacturing. Recent developments in catalysis provide access to polycarbonates with well-defined structures and allow for copolymerization with biomass-derived monomers; however, the resulting material properties are under-investigated. Here, new types of CO2-derived thermoplastic elastomers (TPEs) are described together with a generally applicable method to augment tensile mechanical strength and Young's modulus without requiring material re-design. These TPEs combine high glass transition temperature (Tg) amorphous blocks comprising CO2-derived poly(carbonates) (A-block), with low Tg poly(ε-decalactone), from castor oil, (B-block) in ABA structures. The poly(carbonate) blocks are selectively functionalized with metal-carboxylates, where the metals are Na(I), Mg(II), Ca(II), Zn(II) and Al(III). The colorless polymers, featuring <1 wt% metal, show tunable thermal (Tg), and mechanical (elongation at break, elasticity, creep-resistance) properties. The best elastomers show >50-fold higher Young's modulus and 21-times greater tensile strength, without compromise to elastic recovery, compared with the starting block polymers. They have wide operating temperatures (-20 to 200 ˚C), high creep-resistance and yet remain recyclable. In future, these materials could substitute high-volume petrochemical elastomers and be utilized in high-growth fields like medicine, robotics and electronics.
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May 2023
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I15-Extreme Conditions
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Diamond Proposal Number(s):
[30553]
Open Access
Abstract: BiFeO3-BaTiO3 (BF-BT) ceramics are important multiferroic materials, which are attracting significant attention for potential applications in high temperature lead-free piezoelectric transducers. In the present study, the effects of Sr2+ as an acceptor dopant for Bi3+, in the range from 0 to 1.0 at%, on the structure and ferroelectric/piezoelectric properties of 0.7BiFeO3-0.3BaTiO3 ceramics were evaluated. The use of a post-sintering Ar annealing process was found to be an effective approach to reduce electrical conductivity induced by the presence of electron holes associated with reoxidation during cooling. A low Sr dopant concentration (0.3 at %) yielded enhanced ferroelectric (Pmax ~ 0.37 C m-2, Pr ~ 0.30 C m-2) and piezoelectric (d33 ~ 178 pC N-1, kp ~ 0.27) properties, whereas higher levels led to chemically heterogeneous core-shell structures and secondary phases with an associated decline in performance. The electric field-induced strain of the Sr-doped BF-BT ceramics was investigated using a combination of digital image correlation macroscopic strain measurements and in-situ synchrotron X-ray diffraction. Quantification of the intrinsic (lattice strain) and extrinsic (domain switching) contributions to the electric field induced strain indicated that the intrinsic contribution dominated during the poling process.
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May 2023
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I19-Small Molecule Single Crystal Diffraction
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Diamond Proposal Number(s):
[298766]
Open Access
Abstract: Macroscopic scale hollow microcrystals are a promising group of materials for gas and liquid uptake as well as sensing. In this contribution we describe the structure of hollow hexagonal cross-section crystals formulated as salts of a silicon catecholate anion and a tetramethylenediamine (TEMED) cation. Using a combination of X-ray single crystal diffraction, Raman spectroscopy and quantum chemistry we explore the structural properties of the hollow microcrystals. With the X-ray structural data as a starting point and assisted with quantum chemistry we compute Raman tensors to fit polarisation sensitive spectral responses and predict the orientation and packing of unit cells in respect to the long and short axis of the synthesised microcrystals. Using these newly developed methods for predicting molecular Raman responses in space with dependence on local orientation, we present the quantitative analysis of experimental Raman images of both hexagonal and tetragonal cross section hollow microcrystals formed from silicon catecholate anions using different amines as counterions. We describe the distributions of chemical components at the surfaces and edges of microcrystals, address the effect of catcholate hydrophobicity on water uptake and discuss possible strategies in chemical and post-assembly modifications to widen the functional properties of this group of environmentally friendly silicon organic framework (SOF) materials.
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May 2023
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I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[20481, 27656]
Open Access
Abstract: We outline techniques for the control and measurement of the nucleation of crystalline material.
SAXS/WAXS XRD measurements are presented that demonstrate the impact of low power,
continuous, non-cavitational ultrasound on the nucleation and crystallisation of a wax; n-eicosane
dissolved in heptane/toluene solvent. A mathematical-physical approach based on rectification of
heat and mass transport by such a low power oscillating pressure field is outlined and it is suggested
that this approach be combined with dissipative particle dynamics (DPD) computational modelling to
develop a predictive method capable of modelling the impact of low power oscillating pressure
fields (acoustics and ultrasonics) on a wide range of nucleating systems. Combining ultrasound pitch
and catch speed of sound measurements with low power harmonically oscillating pressure fields to
monitor and control nucleation presents the prospect of entirely new industrially significant
methods of process control in crystallisation. It also offers new insights into nucleation processes in
general. However, for the acoustic control technique to be applied widely, further theoretical and
modelling work will be necessary since at present, we are unable to predict the precise effect of low
power ultrasound in any given situation.
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May 2023
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I04-1-Macromolecular Crystallography (fixed wavelength)
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Diamond Proposal Number(s):
[18598]
Open Access
Abstract: Many secreted eukaryotic proteins are N-glycosylated with oligosaccharides composed of a high-mannose N-glycan core and, in the specific case of yeast cell-wall proteins, an extended α-1,6-mannan backbone carrying a number of α-1,2- and α-1,3-mannose substituents of varying lengths. α-Mannosidases from CAZy family GH92 release terminal mannose residues from these N-glycans, providing access for the α-endomannanases, which then degrade the α-mannan backbone. Most characterized GH92 α-mannosidases consist of a single catalytic domain, while a few have extra domains including putative carbohydrate-binding modules (CBMs). To date, neither the function nor the structure of a multi-domain GH92 α-mannosidase CBM has been characterized. Here, the biochemical investigation and crystal structure of the full-length five-domain GH92 α-1,2-mannosidase from Neobacillus novalis (NnGH92) with mannoimidazole bound in the active site and an additional mannoimidazole bound to the N-terminal CBM32 are reported. The structure of the catalytic domain is very similar to that reported for the GH92 α-mannosidase Bt3990 from Bacteroides thetaiotaomicron, with the substrate-binding site being highly conserved. The function of the CBM32s and other NnGH92 domains was investigated by their sequential deletion and suggested that whilst their binding to the catalytic domain was crucial for the overall structural integrity of the enzyme, they appear to have little impact on the binding affinity to the yeast α-mannan substrate. These new findings provide a better understanding of how to select and optimize other multi-domain bacterial GH92 α-mannosidases for the degradation of yeast α-mannan or mannose-rich glycans.
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May 2023
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I18-Microfocus Spectroscopy
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Alexander P.
Morrell
,
Richard A.
Martin
,
Helen M
Roberts
,
Hiram
Castillo-Michel
,
J. Frederick W.
Mosselmans
,
Kalotina
Geraki
,
Adrian T.
Warfield
,
Paul
Lingor
,
Wasif
Qayyum
,
Daniel
Graf
,
Maria
Febbraio
,
Owen
Addison
Diamond Proposal Number(s):
[17638, 23569]
Open Access
Abstract: Exposures to exogenous particles is of increasing concern to human health. Characterising the concentrations, chemical species, distribution, and involvement of the stimulus with the tissue microanatomy is essential in understanding the associated biological response. However, no single imaging technique can interrogate all these features at once which confounds and limits correlative analyses. Developments of synchronous imaging strategies, allowing multiple features to be identified simultaneously, is essential to assess spatial relationships between these key features with greater confidence. Here we present data to first highlight complications of correlative analysis between the tissue microanatomy and elemental composition associated with imaging serial tissue sections. This is achieved by assessing both the cellular and elemental distribution in 3-dimensional space using optical microscopy on serial sections and confocal X-ray fluorescence spectroscopy on bulk samples respectively. We propose a new imaging strategy using lanthanide tagged antibodies with X-ray fluorescence spectroscopy. Using simulations, a series of lanthanide tags were identified as candidate labels for scenarios where tissue sections are imaged. The feasibility and value of the proposed approach is shown where an exposure of Ti was identified concurrently with CD45 positive cells at sub-cellular resolutions. Significant heterogeneity in the distribution of exogenous particles and cells can be present between immediately adjacent serial sections showing clear need of synchronous imaging methods. The proposed approach enables elemental compositions to be correlated with the tissue microanatomy in a highly multiplexed and non-destructive manner at high spatial resolutions with the opportunity for subsequent guided analysis.
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May 2023
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I14-Hard X-ray Nanoprobe
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Diamond Proposal Number(s):
[20420, 28521]
Open Access
Abstract: All-perovskite tandem solar cells beckon as lower cost alternatives to conventional single-junction cells. Solution processing has enabled rapid optimization of perovskite solar technologies, but new deposition routes will enable modularity and scalability, facilitating technology adoption. Here, we utilize 4-source vacuum deposition to deposit FA0.7Cs0.3Pb(IxBr1–x)3 perovskite, where the bandgap is changed through fine control over the halide content. We show how using MeO-2PACz as a hole-transporting material and passivating the perovskite with ethylenediammonium diiodide reduces nonradiative losses, resulting in efficiencies of 17.8% in solar cells based on vacuum-deposited perovskites with a bandgap of 1.76 eV. By similarly passivating a narrow-bandgap FA0.75Cs0.25Pb0.5Sn0.5I3 perovskite and combining it with a subcell of evaporated FA0.7Cs0.3Pb(I0.64Br0.36)3, we report a 2-terminal all-perovskite tandem solar cell with champion open circuit voltage and efficiency of 2.06 V and 24.1%, respectively. This dry deposition method enables high reproducibility, opening avenues for modular, scalable multijunction devices even in complex architectures.
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May 2023
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I11-High Resolution Powder Diffraction
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F.
Duarte Martinez
,
A.
Syed
,
K.
Dawson
,
G. J.
Tatlock
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N. I.
Morar
,
M.
Kothari
,
C.
Tang
,
J.
Leggett
,
J. C.
Mason-Flucke
,
G.
Gibson
,
J.r.
Nicholls
,
S.
Gray
,
G. M.
Castelluccio
Open Access
Abstract: In the pursuit of more efficient gas turbine engines, components are required to operate for longer times at elevated temperatures. This increased time in service, together with a complex loading regime, can expose the material to environmental attack. This work has demonstrated that the interaction of stress, NaCl and a sulphur-containing environment is critical to cause crack initiation in the early stages of the exposure and accelerated corrosion rates in CMSX-4 at 550°C. The effect of having small concentrations of moisture in the gaseous environment or as water crystallisation in the salt is still to be investigated. A working hypothesis is that the interaction of alkali chlorides with a sulphur-containing atmosphere is the trigger to a self-sustaining cycle where metal chloride formation, vaporisation and oxidation lead to high amounts of hydrogen injection in a rapid manner and, therefore, hydrogen embrittlement.
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May 2023
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I13-1-Coherence
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Valerio
Bellucci
,
Marie-Christine
Zdora
,
Ladislav
Mikes
,
Šarlota
Birnšteinová
,
Peter
Oberta
,
Marco
Romagnoni
,
Andrea
Mazzolari
,
Pablo
Villanueva-Perez
,
Rajmund
Mokso
,
Christian
David
,
Mikako
Makita
,
Silvia
Cipiccia
,
Jozef
Ulicny
,
Alke
Meents
,
Adrian P.
Mancuso
,
Henry N.
Chapman
,
Patrik
Vagovic
Diamond Proposal Number(s):
[17739]
Open Access
Abstract: The characterisation of fast phenomena at the microscopic scale is required for the understanding of catastrophic responses of materials to loads and shocks, the processing of materials by optical or mechanical means, the processes involved in many key technologies such as additive manufacturing and microfluidics, and the mixing of fuels in combustion. Such processes are usually stochastic in nature and occur within the opaque interior volumes of materials or samples, with complex dynamics that evolve in all three dimensions at speeds exceeding many meters per second. There is therefore a need for the ability to record three-dimensional X-ray movies of irreversible processes with resolutions of micrometers and frame rates of microseconds. Here we demonstrate a method to achieve this by recording a stereo phase-contrast image pair in a single exposure. The two images are combined computationally to reconstruct a 3D model of the object. The method is extendable to more than two simultaneous views. When combined with megahertz pulse trains of X-ray free-electron lasers (XFELs) it will be possible to create movies able to resolve 3D trajectories with velocities of kilometers per second.
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May 2023
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B21-High Throughput SAXS
B23-Circular Dichroism
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Philip
Bardelang
,
Ewan J.
Murray
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Isobel
Blower
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Sara
Zandomeneghi
,
Alice
Goode
,
Rohanah
Hussain
,
Divya
Kumari
,
Giuliano
Siligardi
,
Katsuaki
Inoue
,
Jeni
Luckett
,
James
Doutch
,
Jonas
Emsley
,
Weng C.
Chan
,
Philip
Hill
,
Paul
Williams
,
Boyan B.
Bonev
Diamond Proposal Number(s):
[5098, 12923, 13185, 13634, 15146]
Open Access
Abstract: Virulence gene expression in the human pathogen, S. aureus is regulated by the agr (accessory gene regulator) quorum sensing (QS) system which is conserved in diverse Gram-positive bacteria. The agr QS signal molecule is an autoinducing peptide (AIP) generated via the initial processing of the AgrD pro-peptide by the transmembrane peptidase AgrB. Since structural information for AgrB and AgrBD interactions are lacking, we used homology modelling and molecular dynamics (MD) annealing to characterise the conformations of AgrB and AgrD in model membranes and in solution. These revealed a six helical transmembrane domain (6TMD) topology for AgrB. In solution, AgrD behaves as a disordered peptide, which binds N-terminally to membranes in the absence and in the presence of AgrB. In silico, membrane complexes of AgrD and dimeric AgrB show non-equivalent AgrB monomers responsible for initial binding and for processing, respectively. By exploiting split luciferase assays in Staphylococcus aureus, we provide experimental evidence that AgrB interacts directly with itself and with AgrD. We confirmed the in vitro formation of an AgrBD complex and AIP production after Western blotting using either membranes from Escherichia coli expressing AgrB or with purified AgrB and T7-tagged AgrD. AgrB and AgrD formed stable complexes in detergent micelles revealed using synchrotron radiation CD (SRCD) and Landau analysis consistent with the enhanced thermal stability of AgrB in the presence of AgrD. Conformational alteration of AgrB following provision of AgrD was observed by small angle X-ray scattering from proteodetergent micelles. An atomistic description of AgrB and AgrD has been obtained together with confirmation of the AgrB 6TMD membrane topology and existence of AgrBD molecular complexes in vitro and in vivo.
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May 2023
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