scholarly journals Compositional Inhomogeneity and Tuneable Thermal Expansion in Mixed-Metal ZIF-8 Analogues

2018 ◽  
Author(s):  
Adam Sapnik ◽  
Harry Geddes ◽  
Emily Reynolds ◽  
Hamish Yeung ◽  
Andrew Goodwin
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Cation Substitution ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Complete Miscibility ◽  
Expansion Behaviour

<div>We study the structural and thermomechanical effects</div><div>of cation substitution in the compositional family of</div><div>metal–organic frameworks Zn1􀀀xCdx(mIm)2 (HmIm = 2-</div><div>methylimidazole). We find complete miscibility for all</div><div>compositions x, with evidence of inhomogeneous distributions of Cd and Zn that in turn affect framework aperture characteristics. Using variable-temperature X-ray powder diffraction measurements, we show that Cd substitution drives a threefold reduction in the magnitude of thermal expansion behaviour. We interpret this effect in terms of an increased density of negative thermal expansion modes in the more flexible Cd-rich frameworks.</div>

scholarly journals Compositional Inhomogeneity and Tuneable Thermal Expansion in Mixed-Metal ZIF-8 Analogues

2018 ◽  
Author(s):  
Adam Sapnik ◽  
Harry Geddes ◽  
Emily Reynolds ◽  
Hamish Yeung ◽  
Andrew Goodwin
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Cation Substitution ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Complete Miscibility ◽  
Expansion Behaviour

<div>We study the structural and thermomechanical effects</div><div>of cation substitution in the compositional family of</div><div>metal–organic frameworks Zn1􀀀xCdx(mIm)2 (HmIm = 2-</div><div>methylimidazole). We find complete miscibility for all</div><div>compositions x, with evidence of inhomogeneous distributions of Cd and Zn that in turn affect framework aperture characteristics. Using variable-temperature X-ray powder diffraction measurements, we show that Cd substitution drives a threefold reduction in the magnitude of thermal expansion behaviour. We interpret this effect in terms of an increased density of negative thermal expansion modes in the more flexible Cd-rich frameworks.</div>

scholarly journals A five-fold interpenetrated metal–organic framework showing a large variation in thermal expansion behaviour owing to dramatic structural transformation upon dehydration–rehydration

2017 ◽  
Vol 53 (5) ◽  
pp. 861-864 ◽  
Author(s):  
Himanshu Aggarwal ◽  
Raj Kumar Das ◽  
Emile R. Engel ◽  
Leonard J. Barbour
Keyword(s):  
Thermal Expansion ◽  
Thermal Expansion Coefficient ◽  
Metal Organic Framework ◽  
Negative Thermal Expansion ◽  
Considerable Change ◽  
Thermal Expansion Coefficients ◽  
Thermal Expansion Behaviour ◽  
Metal Organic ◽  
Expansion Coefficients ◽  
Expansion Behaviour

A five-fold interpenetrated MOF has the highest uniaxial negative thermal expansion coefficient reported for any interpenetrated MOF to date. Upon dehydration, the framework shows considerable change in the magnitudes of the thermal expansion coefficients.

A hybrid with uniaxial negative thermal expansion behaviour: the synergistic role of organic and inorganic components

2014 ◽  
Vol 50 (95) ◽  
pp. 14960-14963 ◽  
Author(s):  
Kai-Yao Wang ◽  
Mei-Ling Feng ◽  
Liu-Jiang Zhou ◽  
Jian-Rong Li ◽  
Xing-Hui Qi ◽  
...  
Keyword(s):  
Thermal Expansion ◽  
Negative Thermal Expansion ◽  
Thermal Expansion Behaviour ◽  
Inorganic Components ◽  
Expansion Behaviour

Through the study on a new Mn2(api)Sb2S5compound, we propose a strategy for designing a novel hybrid with uniaxial NTE behaviour based on the synergistic role of organic and inorganic components.

Variable-Temperature Microcrystal X-ray Diffraction Studies of Negative Thermal Expansion in the Pure Silica Zeolite IFR

2001 ◽  
Vol 123 (23) ◽  
pp. 5453-5459 ◽  
Author(s):  
Luis A. Villaescusa ◽  
Philip Lightfoot ◽  
Simon J. Teat ◽  
Russell E. Morris
Keyword(s):  
Thermal Expansion ◽  
Variable Temperature ◽  
Negative Thermal Expansion ◽  
X Ray Diffraction ◽  
X Ray ◽  
Pure Silica

Assessing Negative Thermal Expansion in Mesoporous Metal-Organic Frameworks by Molecular Simulation

2019 ◽  
Author(s):  
Jack D. Evans ◽  
Johannes P. Dürholt ◽  
Stefan Kaskel ◽  
Rochus Schmid
Keyword(s):  
Thermal Expansion ◽  
Molecular Simulation ◽  
Mechanical Stability ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Considerable Effect ◽  
Vibrational Modes ◽  
Opposite Behavior ◽  
Metal Organic ◽  
Mesoporous Metal

Most conventional materials display expansion upon heating, so there is considerable interest in identifying materials that display the opposite behavior, negative thermal expansion (NTE). In the current study, seven mesoporous metal-organic frameworks (MOFs) of varying topology and composition, which exhibit outstanding porosity, were investigated using molecular simulation for temperature-induced contraction. We find exceptional NTE for the most porous MOFs and a correlation between the coefficient of NTE and porosity. The large molecular subunits of the MOFs were further studied to find they intrinsically display NTE, corresponding to terahertz vibrational modes. As a result, NTE has a considerable effect on the mechanical properties of these MOFs and is an important consideration for understanding the mechanical stability of new extremely porous materials.

Anomalous thermal expansion behaviour of Na8[AlSiO4]6(NO3)2-sodalite: P4̅3n to Pm3̅n phase transition by untilting and contraction of TO4 units

2003 ◽  
Vol 218 (5) ◽  
Author(s):  
C. H. Rüscher ◽  
Th.M. Gesing ◽  
J.-Ch. Buhl
Keyword(s):  
Phase Transition ◽  
Thermal Expansion ◽  
Single Crystal ◽  
Specific Heat ◽  
X Ray ◽  
Thermal Expansion Behaviour ◽  
Anomalous Thermal Expansion ◽  
Expansion Behaviour

AbstractX-ray single crystal, X-ray powder and specific heat investigations were carried out on alumosilicate NaNO(

Exceptional Negative Thermal Expansion in Isoreticular Metal–Organic Frameworks

2007 ◽  
Vol 119 (24) ◽  
pp. 4580-4583 ◽  
Author(s):  
David Dubbeldam ◽  
Krista S. Walton ◽  
Donald E. Ellis ◽  
Randall Q. Snurr
Keyword(s):  
Thermal Expansion ◽  
Metal Organic Frameworks ◽  
Negative Thermal Expansion ◽  
Metal Organic
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