I15-1-X-ray Pair Distribution Function (XPDF)
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Vahid
Nozari
,
Ayda Nemati Vesali
Azar
,
Roman
Sajzew
,
Celia
Castillo-Blas
,
Ayano
Kono
,
Martin
Oschatz
,
David A.
Keen
,
Philip A.
Chater
,
Georgina P.
Robertson
,
James M. A.
Steele
,
Luis
León-Alcaide
,
Alexander
Knebel
,
Christopher W.
Ashling
,
Thomas D.
Bennett
,
Lothar
Wondraczek
Diamond Proposal Number(s):
[29957]
Open Access
Abstract: Metal-organic framework (MOF) composite materials containing ionic liquids (ILs) have been proposed for a range of potential applications, including gas separation, ion conduction, and hybrid glass formation. Here, an order transition in an IL@MOF composite is discovered using CuBTC (copper benzene-1,3,5-tricarboxylate) and [EMIM][TFSI] (1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide). This transition – absent for the bare MOF or IL – provides an extended super-cooling range and latent heat at a capacity similar to that of soft paraffins, in the temperature range of ≈220 °C. Structural analysis and in situ monitoring indicate an electrostatic interaction between the IL molecules and the Cu paddle-wheels, leading to a decrease in pore symmetry at low temperature. These interactions are reversibly released above the transition temperature, which reflects in a volume expansion of the MOF-IL composite.
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Jul 2024
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Adam F.
Sapnik
,
Duncan N.
Johnstone
,
Sean M.
Collins
,
Giorgio
Divitini
,
Alice M.
Bumstead
,
Christopher W.
Ashling
,
Philip A.
Chater
,
Dean S.
Keeble
,
Timothy
Johnson
,
David A.
Keen
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038, 20198]
Open Access
Abstract: Defect engineering is a powerful tool that can be used to tailor the properties of metal–organic frameworks (MOFs). Here, we incorporate defects through ball milling to systematically vary the porosity of the giant pore MOF, MIL-100 (Fe). We show that milling leads to the breaking of metal–linker bonds, generating additional coordinatively unsaturated metal sites, and ultimately causes amorphisation. Pair distribution function analysis shows the hierarchical local structure is partially retained, even in the amorphised material. We find that solvents can be used to stabilise the MIL-100 (Fe) framework against collapse, which leads to a substantial retention of porosity over the non-stabilised material.
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Mar 2021
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Shichun
Li
,
Shuwen
Yu
,
Sean M.
Collins
,
Duncan N.
Johnstone
,
Christopher W.
Ashling
,
Adam F.
Sapnik
,
Philip A.
Chater
,
Dean S.
Keeble
,
Lauren N.
Mchugh
,
Paul A.
Midgley
,
David A.
Keen
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[20038, 22632, 21979]
Open Access
Abstract: Metal–organic framework crystal–glass composite (MOF CGC) materials consist of a crystalline MOF embedded within a MOF–glass matrix. In this work, a new synthetic route to these materials is demonstrated through the preparation of two ZIF-62 glass-based CGCs, one with crystalline ZIF-67 and the other with crystalline UiO-66. Previous attempts to form these CGCs failed due to the high processing temperatures involved in heating above the melting point of ZIF-62. Annealing of the ZIF-62 glass above the glass transition with each MOF however leads to stable CGC formation at lower temperatures. The reduction in processing temperatures will enable the formation of a greatly expanded range of MOF CGCs.
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Sep 2020
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I15-1-X-ray Pair Distribution Function (XPDF)
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Patrick
Hirschle
,
Christian
Hirschle
,
Konstantin
Böll
,
Markus
Döblinger
,
Miriam
Höhn
,
Joshua M.
Tuffnell
,
Christopher W.
Ashling
,
David
Keen
,
Thomas D.
Bennett
,
Joachim O.
Rädler
,
Ernst
Wagner
,
Michael
Peller
,
Ulrich
Lächelt
,
Stefan
Wuttke
Diamond Proposal Number(s):
[21260]
Abstract: Iron(III) fumarate materials are well suited for biomedical applications as they feature biocompatible building blocks, porosity, chemical functionalizability, and magnetic resonance imaging (MRI) activity. The synthesis of these materials however is difficult to control, and it has been challenging to produce monodisperse particle sizes and morphologies that are required in medical use. Here, we report the optimization of iron(III) fumarate nano- and microparticle synthesis by surfactant-free methods, including room temperature, solvothermal, microwave, and microfluidic conditions. Four variants of iron(III) fumarate with distinct morphologies were isolated and are characterized in detail. Structural characterization shows that all iron(III) fumarate variants exhibit the metal–organic framework (MOF) structure of MIL-88A. Nanoparticles with a diameter of 50 nm were produced, which contain crystalline areas not exceeding 5 nm. Solvent-dependent swelling of the crystalline particles was monitored using in situ X-ray diffraction. Cytotoxicity experiments showed that all iron(III) fumarate variants feature adequate biotolerability and no distinct interference with cellular metabolism at low concentrations. Magnetic resonance relaxivity studies using clinical MRI equipment, on the other hand, proved that the MRI contrast characteristics depend on particle size and morphology. All in all, this study demonstrates the possibility of tuning the morphological appearance of iron(III) fumarate particles and illustrates the importance of optimizing synthesis conditions for the development of new biomedical materials.
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Mar 2020
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[20038, 20195]
Open Access
Abstract: Metal-organic framework crystal-glass composites (MOF-CGCs) are materials in which a crystalline MOF is dispersed within a MOF glass. In this work, we explore the room temperature stabilization of the open-pore form of MIL-53(Al), usually observed at high-temperature, which occurs upon encapsulation within a ZIF-62(Zn) MOF glass matrix. A series of MOF-CGCs containing different loadings of MIL-53(Al) were synthesized and characterized using X-ray diffraction and nuclear magnetic resonance spectroscopy. An upper limit of MIL-53(Al) that can be stabilized in the composite was determined for the first time. The nanostructure of the composites was probed using pair distribution function analysis and scanning transmission electron microscopy. Notably, the distribution and integrity of the crystalline compo-nent in a sample series was determined, and these findings related to the MOF-CGC gas adsorption capacity in order to identify the optimal loading necessary for maximum CO2 sorption capacity.
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Sep 2019
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E02-JEM ARM 300CF
I15-1-X-ray Pair Distribution Function (XPDF)
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Jingwei
Hou
,
Christopher W.
Ashling
,
Sean M.
Collins
,
Andraž
Krajnc
,
Chao
Zhou
,
Louis
Longley
,
Duncan N.
Johnstone
,
Philip
Chater
,
Shichun
Li
,
Marie-Vanessa
Coulet
,
Philip L.
Llewellyn
,
François-Xavier
Coudert
,
David
Keen
,
Paul A.
Midgley
,
Gregor
Mali
,
Vicki
Chen
,
Thomas D.
Bennett
Diamond Proposal Number(s):
[171151, 19130, 16983]
Open Access
Abstract: The majority of research into metal-organic frameworks (MOFs) focuses on their crystalline nature. Recent research has revealed solid-liquid transitions within the family, which we use here to create a class of functional, stable and porous composite materials. Described herein is the design, synthesis, and characterisation of MOF crystal-glass composites, formed by dispersing crystalline MOFs within a MOF-glass matrix. The coordinative bonding and chemical structure of a MIL-53 crystalline phase are preserved within the ZIF-62 glass matrix. Whilst separated phases, the interfacial interactions between the closely contacted microdomains improve the mechanical properties of the composite glass. More significantly, the high temperature open pore phase of MIL-53, which spontaneously transforms to a narrow pore upon cooling in the presence of water, is stabilised at room temperature in the crystal-glass composite. This leads to a significant improvement of CO2 adsorption capacity.
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Jun 2019
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I15-1-X-ray Pair Distribution Function (XPDF)
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Jiayang
Zhang
,
Louis
Longley
,
Hao
Liu
,
Christopher W.
Ashling
,
Philip A.
Chater
,
Kevin A.
Beyer
,
Karena W.
Chapman
,
Haizheng
Tao
,
David A.
Keen
,
Thomas D.
Bennett
,
Yuanzheng
Yue
Diamond Proposal Number(s):
[171151]
Abstract: A pronounced enthalpy release occurs around 1.38 Tg in the prototypical metal-organic framework glass formed from ZIF-4 [Zn(C3H3N2)2], but there is no sign for any crystallization (i.e., long-range ordering) taking place. This behavior is in strong contrast to that for other families of melt-quenched glasses.
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Feb 2019
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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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I15-1-X-ray Pair Distribution Function (XPDF)
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Diamond Proposal Number(s):
[171151]
Abstract: In this work, we explore the thermodynamic evolution in a melt-quenched metal–organic framework glass, formed from ZIF-62 upon heating to the melting point (Tm), and subsequent enthalpy relaxation. The temperature dependence of the difference in Gibbs free energy between the liquid and crystal states of ZIF-62 in the temperature range from the glass transition temperature (Tg) to Tm is found to be weaker than those of other types of glasses, e.g., metallic glasses. Additionally, we find that the stretched exponent of the enthalpy relaxation function in the glass varies significantly (β = 0.44–0.76) upon changing the extent of sub-Tg annealing, compared to metallic and oxide glasses with similar Tgs, suggesting a high degree of structural heterogeneity. Pair distribution function results suggest no significant structural changes during the sub-Tg relaxation in ZIF-62 glass.
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Jun 2018
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