I22-Small angle scattering & Diffraction
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Diamond Proposal Number(s):
[35286]
Open Access
Abstract: Benzophenone-based materials remain widely used as photoinitiators for ultraviolet light-induced free radical polymerizations. Traditionally, polymerization is spatially controlled using top-down techniques such as photomasks, which produce well-defined polymeric films. In contrast, we present an alternative method for controlling polymerization by employing supramolecular materials to localize the photoinitiator. This approach uses benzophenone-functionalized dipeptides that are specifically tuned to enable supramolecular gel noodle formation, which act as structural templates. We show that polymerization of acrylate monomers around the gel noodles can increase the Young’s modulus by up to 2 orders of magnitude and produce mechanically robust structures that can be handled. The self-assembly of the supramolecular photoinitiators is also explored using viscosity and SAXS measurements, providing an understanding of why only 4BPAcFF successfully forms gel noodles. Our method offers a simple yet effective technique for localizing polymerization, enabling fine-tuning of mechanical properties and the fabrication of intricate designs such as hollow-core structures.
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May 2025
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B21-High Throughput SAXS
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Jacek K.
Wychowaniec
,
Ezgi Irem
Bektas
,
Marcia
Muerner
,
Jiranuwat
Sapudom
,
Martin
Šrejber
,
Marielle
Airoldi
,
Roland
Schmidt
,
Andrea J.
Vernengo
,
Charlotte J. C.
Edwards-Gayle
,
Paul Sean
Tipay
,
Michal
Otyepka
,
Jeremy
Teo
,
David
Eglin
,
Matteo
D'Este
Diamond Proposal Number(s):
[29767]
Open Access
Abstract: Self-assembling peptides (SAPs) are fully defined nanobiomaterials offering unprecedented opportunities to control nanostructure and chemical attributes to investigate and manipulate cellular signals. To investigate the influence of chemical and morphological characteristics on inflammatory signaling in native immunity, we designed five β-sheet SAPs: EFEFKFEFK (EF8), YEFEFKFEFK (YEF8), EFEFKFEFKY (EF8Y), YEFEFKFEFKY (YEF8Y), and EYEFKFEFK (EYF8) (F: phenylalanine; E: glutamic acid; K: lysine, Y: tyrosine). The position of tyrosine in the peptide sequence dictated the self-assembly into nanostructures, with all SAPs self-assembling into thin constituent nanofibers with d ≈ 3.8 ± 0.4 nm, and sequences YEF8 and EF8 showing a propensity for associative bundling. These distinct SAPs induced contrasting inflammatory responses of monocytic model THP-1 cells-derived macrophages (MΦs). Presence of soluble EF8 nanofibers (at 2 mM) induced an anti-inflammatory response and polarization toward an M2 state, whereas YEF8 (at 2 mM) displayed a tendency for inducing a pro-inflammatory response and polarization toward an M1 state. EF8Y, YEF8Y, and EYF8 SAPs did not induce an inflammatory response in our models. These results were validated using peripheral blood mononuclear cells (PBMCs)-derived MΦs from human donors, confirming the critical role of EF8 and YEF8 SAPs as possible orchestrators of the repair of tissues or inducers of pro-inflammatory state, respectively. The same MΦs polarization responses from THP-1-derived MΦs cultured on 20 mM hydrogels were obtained. These findings will facilitate the utilization of this family of SAPs as immunomodulatory nanobiomaterials potentially changing the course of inflammation during the progression of various diseases.
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Apr 2025
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B22-Multimode InfraRed imaging And Microspectroscopy
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Open Access
Abstract: Low-friction lubricant formulations are urgently needed to improve the energy efficiency of machines. Here, we show that blending 1-dodecanol with a hydrocarbon oil improves lubrication in nonconformal sliding/rolling contacts by simultaneously increasing hydrodynamic film thickness and reducing viscous friction. This is due to pressure-induced polymorphic phase transformations in the 1-dodecanol molecules after they flow through the film-thickness-determining inlet and reach the load-supporting zone. At relatively low pressures, 1-dodecanol forms a lamellar hexagonal solid polymorph that gives durable superlubricity and then, at higher pressures, it forms an orthorhombic polymorph. Both polymorphs cause anomalously low friction when blended into various hydrocarbon base oils over a wide range of speed, pressure, and shear rate conditions representative of rolling bearing and gear contacts. By breaking the ubiquitous tradeoff between friction and film thickness and enabling superlubricity, these blends pave the way for considerable energy efficiency improvements in widespread lubricated contacts.
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Mar 2025
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I15-1-X-ray Pair Distribution Function (XPDF)
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Celia
Castillo-Blas
,
Montaña J.
García
,
Ashleigh M.
Chester
,
Matjaž
Mazaj
,
Shaoliang
Guan
,
Georgina P.
Robertson
,
Ayano
Kono
,
James M. A.
Steele
,
Luis
León-Alcaide
,
Bruno
Poletto-Rodrigues
,
Philip A.
Chater
,
Silvia
Cabrera
,
Andraž
Krajnc
,
Lothar
Wondraczek
,
David A.
Keen
,
Jose
Alemán
,
Thomas
Bennett
Diamond Proposal Number(s):
[29957]
Open Access
Abstract: Metal–organic framework (MOF) composites are proposed as solutions to the mechanical instability of pure MOF materials. Here, we present a new compositional series of recently discovered MOF–crystalline inorganic glass composites. In this case, formed by the combination of a photocatalytic titanium MOF (MIL-125-NH2) and a phosphate-based glass (20%Na2O–10%Na2SO4–70%P2O5). This new family of composites has been synthesized and characterized using powder X-ray diffraction, thermal gravimetric analysis, differential scanning calorimetry, scanning electron microscopy, and X-ray total scattering. Through analysis of the pair distribution function extracted from X-ray total scattering data, the atom–atom interactions at the MOF–glass interface are described. Nitrogen and carbon dioxide isotherms demonstrate good surface area values despite the pelletization and mixing of the MOF with a dense inorganic glass. The catalytic activity of these materials was investigated in the photooxidation of amines to imines, showing the retention of the photocatalytic effectiveness of the parent pristine MOF.
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Mar 2025
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B18-Core EXAFS
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Diamond Proposal Number(s):
[36367]
Abstract: Deuterated compounds have broad applications across various fields, with dehalogenative deuteration serving as an efficient method to obtain these molecules. However, the diverse electronic structures of active sites in the heterogeneous system and the limited recyclability in the homogeneous system significantly hinder the advancement of dehalogenative deuteration. In this study, we present a catalyst composed of copper single-atom sites anchored within an ordered mesoporous nitrogen-doped carbon matrix, synthesized via a mesopore confinement method. The Cu1/OMNC-1100 catalyst, characterized by Cu–N4 sites, demonstrates exceptional performance, high functional group tolerance, and remarkable durability in the deuteration of 2-bromo-6-methoxynaphthalene under relatively mild conditions (80 °C, 2 MPa of CO). Experimental results combined with X-ray absorption fine structure analysis reveal that Cu–N3 sites can be converted into more stable Cu–N4 counterparts at higher pyrolysis temperatures, resulting in enhanced catalytic activity. This work demonstrates a strategy for designing single-atom site catalysts with tunable coordination environments, providing a promising approach to improving catalytic performance in selective dehalogenative reactions under relatively mild conditions.
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Jan 2025
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B21-High Throughput SAXS
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Diamond Proposal Number(s):
[35585]
Open Access
Abstract: Short bioactive peptide sequences are of great interest in biomaterials development. We investigate the self-assembly of a lipopeptide containing both the highly cationic CSK4 toll-like receptor agonist hexapeptide sequence and RGDS integrin-binding motif, i.e., C16-CSK4RGDS, as well as the control containing a scrambled terminal sequence C16-CSK4GRDS. Both lipopeptides are found to form micelles, as revealed by small-angle X-ray scattering and cryogenic transmission electron microscopy, and modeled using atomistic molecular dynamics simulations. We carefully examined methods to probe the aggregation of the molecules, i.e. to obtain the critical micelle concentration (CMC). Fluorescent probe assays using 1-anilino-8-naphthalenesulfonate (ANS) reveal low CMC values, 1–2 μM, which contrast with consistent values more than 2 orders of magnitude larger obtained from surface tension and electrical conductivity as well as unexpected UV/vis absorption spectra discontinuities and fluoresccence probe assays using Nile red. The anomalous results obtained from an ANS fluorescence probe are ascribed to the effect of ANS binding to the cationic (lysine and arginine) residues in the lipopeptide, which leads to a conformational change, as shown by circular dichroism, even at low concentrations below the actual CMC. Despite the small change in the peptide sequence (swapping of G and R residues), there is surprisingly a significant difference in the aggregation propensity and association number, both of which are greater for C16-CSK4GRDS. Both lipopeptides are cytocompatible (with fibroblasts and myoblasts) at low concentration, although cytotoxicity is noted at higher concentration.
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Dec 2024
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B24-Cryo Soft X-ray Tomography
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Diamond Proposal Number(s):
[30471, 33090]
Open Access
Abstract: Iron is a crucial element integral to various fundamental biological molecular mechanisms, including magnetosome biogenesis in magnetotactic bacteria (MTB). Magnetosomes are formed through the internalization and biomineralization of iron into magnetite crystals. However, the interconnected mechanisms by which MTB uptake and regulate intracellular iron for magnetosome biomineralization remain poorly understood, particularly at the single-cell level. To gain insights we employed a holistic multiscale approach, i.e., from elemental iron species to bacterial populations, to elucidate the interplay between iron uptake dynamics and magnetosome formation in Magnetospirillum gryphiswaldense MSR-1 under near-native conditions. We combined a correlative microscopy approach integrating light and X-ray tomography with analytical techniques, such as flow cytometry and inductively coupled plasma spectroscopy, to evaluate the effects of iron and oxygen availability on cellular growth, magnetosome biogenesis, and intracellular iron pool in MSR-1. Our results revealed that increased iron availability under microaerobic conditions significantly promoted the formation of longer magnetosome chains and increased intracellular iron uptake, with a saturation point at 300 μM iron citrate. Beyond this threshold, additional iron did not further extend the magnetosome chain length or increase total intracellular iron levels. Moreover, our work reveals (i) a direct correlation between the labile Fe2+ pool size and magnetosome content, with higher intracellular iron concentrations correlating with increased magnetosome production, and (ii) the existence of an intracellular iron pool, distinct from magnetite, persisting during all stages of biomineralization. This study offers insights into iron dynamics in magnetosome biomineralization at a single-cell level, potentially enhancing the industrial biomanufacturing of magnetosomes.
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Oct 2024
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I19-Small Molecule Single Crystal Diffraction
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Paula
Escamilla
,
Marcello
Monteleone
,
Rita Maria
Percoco
,
Teresa F.
Mastropietro
,
Mariagiulia
Longo
,
Elisa
Esposito
,
Alessio
Fuoco
,
Johannes C.
Jansen
,
Rosangela
Elliani
,
Antonio
Tagarelli
,
Jesus
Ferrando-Soria
,
Valeria
Amendola
,
Emilio
Pardo
,
Donatella
Armentano
Diamond Proposal Number(s):
[28808]
Abstract: Heavy metal ions are a common source of water pollution. In this study, two novel membranes with biobased metal–organic frameworks (BioMOFs) embedded in a polyacrylonitrile matrix with tailored porosity were prepared via nonsolvent induced phase separation methods and designed to efficiently adsorb heavy metal ions from oligomineral water. Under optimized preparation conditions, stable membranes with high MOF loading up to 50 wt % and a cocontinuous sponge-like morphology and a high water permeability of 50–60 L m–2 h–1 bar–1 were obtained. The tortuous flow path in combination with a low water flow rate guarantees maximum contact time between the fluid and the MOFs, and thus a high heavy metal capture efficiency in a single pass. The performances of these BioMOF@PAN membranes were investigated in the dynamic regime for the simultaneous removal of Pb2+, Cd2+, and Hg2+ heavy metals from aqueous environments in the presence of common interfering ions. The new composite adsorbing membranes are capable of reducing the concentration of heavy metal pollutants in a single pass and at much higher efficiency than previously reported membranes. The enhanced performance of the mixed matrix membranes is attributed to the presence of multiple recognition sites which densely decorate the BioMOF channels: (i) the thioether groups, deriving from the S-methyl-l-cysteine and (S)-methionine amino acid residues, able to recognize and capture Pb2+ and Hg2+ ions and (ii) the oxygen atoms of the oxamate moieties, which preferentially interact with Cd2+ ions, as revealed by single crystal X-ray diffraction. The flexibility of the pore environments allows these sites to work synergically for the simultaneous capture of different metal ions. The stability of the membranes for a potential regeneration process, a key-factor for the effective feasibility of the process in real life applications, was also evaluated and confirmed less than 1% capacity loss in each cycle.
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Sep 2024
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B18-Core EXAFS
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Diamond Proposal Number(s):
[34632]
Open Access
Abstract: Metal–organic frameworks (MOFs) are increasingly being investigated as electrocatalysts for the oxygen evolution reaction (OER) due to their unique modular structures that present a hybrid between molecular and heterogeneous catalysts, featuring well-defined active sites. However, many fundamental questions remain open regarding the electrochemical stability of MOFs, structural reconstruction of coordination sites, and the role of in situ-formed species. Here, we report the structural transformation of a surface-grown MOF containing cobalt nodes and 1,1′-ferrocenedicarboxylic acid linkers (denoted as CoFc-MOF) during the OER in alkaline electrolyte. Ex situ and in situ investigations of CoFc-MOF film suggest that the MOF acts as a precatalyst and undergoes a two-step restructuring process under operating conditions to generate a metal oxyhydroxide phase. The MOF-derived metal oxyhydroxide catalyst, supported on nickel foam electrodes, displays high activity toward the OER with an overpotential of 190 mV at a current density of 10 mA cm–2. While this study demonstrates the necessity of investigating structural evolution of MOFs during electrocatalysis, it also shows the potential of using MOFs as precursors in catalyst design.
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Jul 2024
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B07-C-Versatile Soft X-ray beamline: Ambient Pressure XPS and NEXAFS
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Marco
Siniscalchi
,
Joshua S.
Gibson
,
James
Tufnail
,
Jack E. N.
Swallow
,
Jarrod
Lewis
,
Guillaume
Matthews
,
Burcu
Karagoz
,
Matthijs A.
Van Spronsen
,
Georg
Held
,
Robert S.
Weatherup
,
Chris R. M.
Grovenor
,
Susannah C.
Speller
Diamond Proposal Number(s):
[33570]
Open Access
Abstract: The reactivity of Li6.4La3Zr1.4Ta0.6O12 (LLZTO) solid electrolytes to form lithio-phobic species such as Li2CO3 on their surface when exposed to trace amounts of H2O and CO2 limits the progress of LLZTO-based solid-state batteries. Various treatments, such as annealing LLZTO within a glovebox or acid etching, aim at removing the surface contaminants, but a comprehensive understanding of the evolving LLZTO surface chemistry during and after these treatments is lacking. Here, glovebox-like H2O and CO2 conditions were recreated in a near ambient pressure X-ray photoelectron spectroscopy chamber to analyze the LLZTO surface under realistic conditions. We find that annealing LLZTO at 600 °C in this atmosphere effectively removes the surface contaminants, but a significant level of contamination reappears upon cooling down. In contrast, HCl(aq) acid etching demonstrates superior Li2CO3 removal and stable surface chemistry post treatment. To avoid air exposure during the acid treatment, an anhydrous HCl solution in diethyl ether was used directly within the glovebox. This novel acid etching strategy delivers the lowest lithium/LLZTO interfacial resistance and the highest critical current density.
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May 2024
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