I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[21476, 27911]
Open Access
Abstract: Hierarchical porous phosphate-based glasses (PPG) have great potential in biomedicine. Micropores (pore size < 2 nm) increase the surface area, mesopores (pore size 2 to 50 nm) facilitate the absorption and diffusion of therapeutic ions and molecules making them ideal controlled delivery systems, while macropores (pore size > 50 nm) facilitate the movement and diffusion of cells and fluids. In addition, the bioresorbability of PPG allows for their complete solubility in body fluid, alongside simultaneous formation of new tissue. Making PPG via the traditional melt-quenching (MQ) synthesis method used for phosphate-based glasses (PG), is not straightforward. Hence, we present here a route for preparing such glasses using a combination of sol-gel (SG) and templating methods. Hierarchical porous PPG in the P2O5-CaO-Na2O system with the addition of 1, 3 and 5 mol % of Zn2+ were prepared with pore dimensions ranging from the micro- to the macro scales using Pluronic 123 (P123) as a surfactant. The presence of micropores (0.30-0.46 nm), mesopores (1.75 to 9.35 nm) and macropores (163-207 nm) was assessed via synchrotron-based Small-Angle X-ray Scattering (SAXS), with the presence of the latter two confirmed by Scanning Electron Microscopy (SEM). Structural characterisation performed using 31P solid state magic angle spinning nuclear magnetic resonance (MAS NMR) and Fourier Transform Infra-red (FT-IR) spectroscopies shows the presence of Q2, Q1 and Q0 phosphate species with a predominance of Q1 species in all compositions. Dissolution studies in deionised (DI) water confirm that controlled release of phosphates, Ca2+, Na+ and Zn2+ is achieved over a period of 7 days. In particular, the release of Zn2+ is proportional to its loading, making its delivery particularly easy to control.
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Jul 2024
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I22-Small angle scattering & Diffraction
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Open Access
Abstract: Organic phosphates (OP) are important nutrient components for living cells in natural environments, where they readily interact with ubiquitous iron phases such as hydrous ferric oxide, ferrihydrite (FHY). FHY partakes in many key bio(geo)chemical reactions including iron-mediated carbon storage in soils, or iron-storage in living organisms. However, it is still unknown how OP affects the formation, structure and properties of FHY. Here, we document how β-glycerophosphate (GP), a model OP ligand, affects the structure and properties of GP–FHY nanoparticles synthesized by coprecipitation at variable nominal molar P/Fe ratios (0.01 to 0.5). All GP–FHY precipitates were characterized by a maximum solid P/Fe ratio of 0.22, irrespective of the nominal P/Fe ratio. With increasing nominal P/Fe ratio, the specific surface area of the GP–FHY precipitates decreased sharply from 290 to 3 m2 g−1, accompanied by the collapse of their pore structure. The Fe–P local bonding environment gradually transitioned from a bidentate binuclear geometry at low P/Fe ratios to monodentate mononuclear geometry at high P/Fe ratios. This transition was accompanied by a decrease in coordination number of edge-sharing Fe polyhedra, and the loss of the corner-sharing Fe polyhedra. We show that Fe(III) polymerization is impeded by GP, and that the GP–FHY structure is highly dependent on the P/Fe ratio. We discuss the role that natural OP-bearing Fe(III) nanophases have in biogeochemical reactions between Fe–P and C species in aquatic systems.
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Apr 2024
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I22-Small angle scattering & Diffraction
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Brian R.
Pauw
,
Glen J.
Smales
,
Andy
Anker
,
Venkatasamy
Annadurai
,
Daniel M.
Balazs
,
Ralf
Bienert
,
Wim G.
Bouwman
,
Ingo
Breßler
,
Joachim
Breternitz
,
Erik S.
Brok
,
Gary
Bryant
,
Andrew
Clulow
,
Erin R.
Crater
,
Frédéric
De Geuser
,
Alessandra
Del Giudice
,
Jérôme
Deumer
,
Sabrina
Disch
,
Shankar
Dutt
,
Kilian
Frank
,
Emiliano
Fratini
,
Paulo R. A. F.
Garcia
,
Elliot P.
Gilbert
,
Marc B.
Hahn
,
James
Hallett
,
Max
Hohenschutz
,
Martin J.
Hollamby
,
Steven
Huband
,
Jan
Ilavsky
,
Johanna K.
Jochum
,
Mikkel
Juelsholt
,
Bradley W.
Mansel
,
Paavo
Penttilä
,
Rebecca K.
Pittkowski
,
Giuseppe
Portale
,
Lilo D.
Pozzo
,
Leonhard
Rochels
,
Julian M.
Rosalie
,
Patrick E. J.
Saloga
,
Susanne
Seibt
,
Andrew J.
Smith
,
Gregory N.
Smith
,
Glenn A.
Spiering
,
Tomasz M.
Stawski
,
Olivier
Taché
,
Andreas F.
Thünemann
,
Kristof
Toth
,
Andrew E.
Whitten
,
Joachim
Wuttke
Open Access
Abstract: A round-robin study has been carried out to estimate the impact of the human element in small-angle scattering data analysis. Four corrected datasets were provided to participants ready for analysis. All datasets were measured on samples containing spherical scatterers, with two datasets in dilute dispersions and two from powders. Most of the 46 participants correctly identified the number of populations in the dilute dispersions, with half of the population mean entries within 1.5% and half of the population width entries within 40%. Due to the added complexity of the structure factor, far fewer people submitted answers on the powder datasets. For those that did, half of the entries for the means and widths were within 44 and 86%, respectively. This round-robin experiment highlights several causes for the discrepancies, for which solutions are proposed.
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Dec 2023
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Open Access
Abstract: Mesoporous glasses are a promising class of bioresorbable biomaterials characterized by high surface area and extended porosity in the range of 2 to 50 nm. These peculiar properties make them ideal materials for the controlled release of therapeutic ions and molecules. Whilst mesoporous silicate-based glasses (MSG) have been widely investigated, much less work has been done on mesoporous phosphate-based glasses (MPG). In the present study, MPG in the P2O5–CaO–Na2O system, undoped and doped with 1, 3, and 5 mol% of Cu ions were synthesized via a combination of the sol–gel method and supramolecular templating. The non-ionic triblock copolymer Pluronic P123 was used as a templating agent. The porous structure was studied via a combination of Scanning Electron Microscopy (SEM), Small-Angle X-ray Scattering (SAXS), and N2 adsorption–desorption analysis at 77 K. The structure of the phosphate network was investigated via solid state 31P Magic Angle Spinning Nuclear Magnetic Resonance (31P MAS-NMR) and Fourier Transform Infrared (FTIR) spectroscopy. Degradation studies, performed in water via Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES), showed that phosphates, Ca2+, Na+ and Cu ions are released in a controlled manner over a 7 days period. The controlled release of Cu, proportional to the copper loading, imbues antibacterial properties to MPG. A significant statistical reduction of Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) bacterial viability was observed over a 3 days period. E. coli appeared to be more resistant than S. aureus to the antibacterial effect of copper. This study shows that copper doped MPG have great potential as bioresorbable materials for controlled delivery of antibacterial ions.
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Jun 2023
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[29806]
Open Access
Abstract: Small-angle X-ray scattering (SAXS) can be used for structural determination of biological macromolecules and polymers in their native states (e.g. liquid phase). This means that the structural changes of (bio-)polymers, such as proteins and DNA, can be monitored in situ to understand their sensitivity to changes in chemical environments. In an attempt to improve the reliability of such experiments, the reduction of radiation damage occurring from exposure to X-rays is required. One such method, is to use scavenger molecules to protect macromolecules against radicals produced during radiation exposure, such as reactive oxygen species (ROS). In this study we investigate the feasibility of applying the compatible solute, osmolyte and radiation protector Ectoine (THP(B)), as a scavenger molecule during SAXS measurements of the single-stranded DNA-binding protein Gene-V Protein (G5P/GVP). In this case, we monitor the radiation induced changes of G5P during bio-SAXS measurments and the resulting microscopic energy-damage relation was determined from microdosimetric calculations by Monte-Carlo based particle scattering simulations with TOPAS/Geant4 and a custom target-model. This resulted in a median-lethal energy deposit of pure G5P at 4 mg mL−1 of E1/2 = 7 ± 5 eV, whereas a threefold increase of energy-deposit was needed under the presence of Ectoine to reach the same level of damage. This indicates that Ectoine increases the possible exposure time before radiation-damage to G5P is observed. Furthermore, the dominant type of damage shifted from aggregation in pure solutions towards a fragmentation for solutions containing Ectoine as a cosolute. These results are interpreted in terms of indirect radiation damage by reactive secondary species, as well as post-irradiation effects, related to preferential-exclusion of the cosolute from the protein surface. Hence, Ectoine is shown to provide a non-disturbing way to improve structure-determination of proteins via bio-SAXS in future studies.
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Jan 2023
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I22-Small angle scattering & Diffraction
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Brian R.
Pauw
,
Andrew
Smith
,
Tim
Snow
,
Olga
Shebanova
,
John P.
Sutter
,
Jan
Ilavsky
,
Daniel
Hermida-Merino
,
Glen J.
Smales
,
Nicholas J.
Terrill
,
Andreas F.
Thünemann
,
Wim
Bras
Open Access
Abstract: Ultra-SAXS can enhance the capabilities of existing synchrotron SAXS/WAXS beamlines. A compact ultra-SAXS module has been developed, which extends the measurable q-range with 0.0015 ≤ q (nm−1) ≤ 0.2, allowing structural dimensions in the range 30 ≤ D (nm) ≤ 4000 to be probed in addition to the range covered by a high-end SAXS/WAXS instrument. By shifting the module components in and out on their respective motor stages, SAXS/WAXS measurements can be easily and rapidly interleaved with USAXS measurements. The use of vertical crystal rotation axes (horizontal diffraction) greatly simplifies the construction, at minimal cost to efficiency. In this paper, the design considerations, realization and synchrotron findings are presented. Measurements of silica spheres, an alumina membrane, and a porous carbon catalyst are provided as application examples.
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May 2021
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I22-Small angle scattering & Diffraction
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Louis
Longley
,
Sean M.
Collins
,
Shichun
Li
,
Glen J.
Smales
,
Ilknur
Erucar
,
Ang
Qiao
,
Jingwei
Hou
,
Cara M.
Doherty
,
Aaron W.
Thornton
,
Anita J.
Hill
,
Xiao
Yu
,
Nicholas J.
Terrill
,
Andrew J.
Smith
,
Seth M.
Cohen
,
Paul A.
Midgley
,
David A.
Keen
,
Shane G.
Telfer
,
Thomas
Bennett
Diamond Proposal Number(s):
[18236]
Open Access
Abstract: Recent demonstrations of melting in the metal–organic framework (MOF) family have created interest in the interfacial domain between inorganic glasses and amorphous organic polymers. The chemical and physical behaviour of porous hybrid liquids and glasses is of particular interest, though opportunities are limited by the inaccessible melting temperatures of many MOFs. Here, we show that the processing technique of flux melting, ‘borrowed’ from the inorganic domain, may be applied in order to melt ZIF-8, a material which does not possess an accessible liquid state in the pure form. Effectively, we employ the high-temperature liquid state of one MOF as a solvent for a secondary, non-melting MOF component. Differential scanning calorimetry, small- and wide-angle X-ray scattering, electron microscopy and X-ray total scattering techniques are used to show the flux melting of the crystalline component within the liquid. Gas adsorption and positron annihilation lifetime spectroscopy measurements show that this results in enhanced, accessible porosity to a range of guest molecules in the resultant flux melted MOF glass.
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Feb 2019
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B18-Core EXAFS
I22-Small angle scattering & Diffraction
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Elizabeth
Raine
,
Adam
Clark
,
Glen
Smales
,
Andrew
Smith
,
Diego
Gianolio
,
Tong
Li
,
Jianwei
Zheng
,
Benjamin
Griffith
,
Timothy I.
Hyde
,
Mark
Feaviour
,
Paul
Collier
,
John V.
Hanna
,
Gopinathan
Sankar
,
Shik Chi Edman
Tsang
Diamond Proposal Number(s):
[16316, 16583]
Abstract: The strong directing effects and difficulties in the removal of organic based surfactants makes the templated synthesis of nanoparticles in solid porous structures of defined molecular sizes such as SBA-15, without the use of surfactants, considerably attractive. However, the effects of their internal surface structures, adsorption affinities and lattice mis-match on the particle morphology grown therein have not been fully appreciated. Here, we report the internal surface of the silica preferentially hosts isolated tetrahedrally coordinated oxidic Zn species on the molecular walls of the SBA-15 channels from wet impregnated Zn2+ and Pt2+ species. This leads to less thermodynamic stable but kinetic controlled configuration of atomic zinc deposition on core platinum nanoparticles with unique confined lattice changes and surface properties to both host and guest structures at the interface upon reduction of the composite. This method for the formation templated nanoparticles may generate interests to form new tunable materials as dehydrogenation catalysts.
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Nov 2018
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I15-1-X-ray Pair Distribution Function (XPDF)
I22-Small angle scattering & Diffraction
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Chao
Zhou
,
Louis
Longley
,
Andraž
Krajnc
,
Glen J.
Smales
,
Ang
Qiao
,
Ilknur
Erucar
,
Cara M.
Doherty
,
Aaron W.
Thornton
,
Anita J.
Hill
,
Christopher W.
Ashling
,
Omid T.
Qazvini
,
Seok J.
Lee
,
Philip A.
Chater
,
Nicholas J.
Terrill
,
Andrew J.
Smith
,
Yuanzheng
Yue
,
Gregor
Mali
,
David A.
Keen
,
Shane G.
Telfer
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[18236]
Open Access
Abstract: To date, only several microporous, and even fewer nanoporous, glasses have been produced, always via post synthesis acid treatment of phase separated dense materials, e.g. Vycor glass. In contrast, high internal surface areas are readily achieved in crystalline materials, such as metal-organic frameworks (MOFs). It has recently been discovered that a new family of melt quenched glasses can be produced from MOFs, though they have thus far lacked the accessible and intrinsic porosity of their crystalline precursors. Here, we report the first glasses that are permanently and reversibly porous toward incoming gases, without post-synthetic treatment. We characterize the structure of these glasses using a range of experimental techniques, and demonstrate pores in the range of 4 – 8 Å. The discovery of MOF glasses with permanent accessible porosity reveals a new category of porous glass materials that are elevated beyond conventional inorganic and organic porous glasses by their diversity and tunability.
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Nov 2018
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I15-1-X-ray Pair Distribution Function (XPDF)
I22-Small angle scattering & Diffraction
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Louis
Longley
,
Sean
Collins
,
Chao
Zhou
,
Glen J.
Smales
,
Sarah E.
Norman
,
Nick J.
Brownbill
,
Christopher W.
Ashling
,
Philip A.
Chater
,
Robert
Tovey
,
Carola-Bibiane
Schönlieb
,
Thomas F.
Headen
,
Nicholas J.
Terrill
,
Yuanzheng
Yue
,
Andrew J.
Smith
,
Frédéric
Blanc
,
David
Keen
,
Paul A.
Midgley
,
Thomas
Bennett
Diamond Proposal Number(s):
[171151, 18236]
Open Access
Abstract: The liquid and glass states of metal–organic frameworks (MOFs) have recently become of interest due to the potential for liquid-phase separations and ion transport, alongside the fundamental nature of the latter as a new, fourth category of melt-quenched glass. Here we show that the MOF liquid state can be blended with another MOF component, resulting in a domain structured MOF glass with a single, tailorable glass transition. Intra-domain connectivity and short range order is confirmed by nuclear magnetic resonance spectroscopy and pair distribution function measurements. The interfacial binding between MOF domains in the glass state is evidenced by electron tomography, and the relationship between domain size and Tg investigated. Nanoindentation experiments are also performed to place this new class of MOF materials into context with organic blends and inorganic alloys.
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Jun 2018
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