scholarly journals Dielectric relaxation and anhydrous proton conduction in [C2H5NH3][Na0.5Fe0.5(HCOO)3] metal–organic frameworks

2017 ◽  
Vol 46 (11) ◽  
pp. 3681-3687 ◽  
Author(s):  
A. Sieradzki ◽  
S. Pawlus ◽  
S. N. Tripathy ◽  
A. Gągor ◽  
M. Ptak ◽  
...  
Keyword(s):  
Dielectric Relaxation ◽  
Direct Evidence ◽  
Ferroelectric Phase ◽  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Metal Organic ◽  
Anhydrous Proton Conduction ◽  
Metal Formate

First experimental direct evidence of anhydrous conductivity in the perovskite-like metal-formate framework in its ferroelectric phase.

scholarly journals Elastic Properties and Energy Loss Related to the Disorder–Order Ferroelectric Transitions in Multiferroic Metal–Organic Frameworks [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3]

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3125
Author(s):  
Zhiying Zhang ◽  
Hongliang Yu ◽  
Xin Shen ◽  
Lei Sun ◽  
Shumin Yue ◽  
...  
Keyword(s):  
Phase Transition ◽  
Energy Loss ◽  
Elastic Properties ◽  
Ferroelectric Phase ◽  
Loss Modulus ◽  
Structural Phase ◽  
Metal Organic Frameworks ◽  
First Order ◽  
Metal Organic ◽  
Elastic Anomalies

Elastic properties are important mechanical properties which are dependent on the structure, and the coupling of ferroelasticity with ferroelectricity and ferromagnetism is vital for the development of multiferroic metal–organic frameworks (MOFs). The elastic properties and energy loss related to the disorder–order ferroelectric transition in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] were investigated using differential scanning calorimetry (DSC) and dynamic mechanical analysis (DMA). The DSC curves of [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] exhibited anomalies near 256 K and 264 K, respectively. The DMA results illustrated the minimum in the storage modulus and normalized storage modulus, and the maximum in the loss modulus, normalized loss modulus and loss factor near the ferroelectric transition temperatures of 256 K and 264 K, respectively. Much narrower peaks of loss modulus, normalized loss modulus and loss factor were observed in [(CH3)2NH2][Mg(HCOO)3] with the peak temperature independent of frequency, and the peak height was smaller at a higher frequency, indicating the features of first-order transition. Elastic anomalies and energy loss in [NH4][Mg(HCOO)3] near 256 K are due to the second-order paraelectric to ferroelectric phase transition triggered by the disorder–order transition of the ammonium cations and their displacement within the framework channels, accompanied by the structural phase transition from the non-polar hexagonal P6322 to polar hexagonal P63. Elastic anomalies and energy loss in [(CH3)2NH2][Mg(HCOO)3] near 264 K are due to the first-order paraelectric to ferroelectric phase transitions triggered by the disorder–order transitions of alkylammonium cations located in the framework cavities, accompanied by the structural phase transition from rhombohedral R3¯c to monoclinic Cc. The elastic anomalies in [NH4][Mg(HCOO)3] and [(CH3)2NH2][Mg(HCOO)3] showed strong coupling of ferroelasticity with ferroelectricity.

Void Space vs. Surface Functionalization for Proton Conduction in Metal–Organic Frameworks

2021 ◽  
Author(s):  
Marvin K Sarango-Ramírez ◽  
Junkil Park ◽  
Jihan Kim ◽  
Yukihiro Yoshida ◽  
Dae-Woon Lim ◽  
...  
Keyword(s):  
Surface Functionalization ◽  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Void Space ◽  
Metal Organic

UiO-66 derivatives and their composite membranes for effective proton conduction

2020 ◽  
Vol 49 (47) ◽  
pp. 17130-17139
Author(s):  
Lu Feng ◽  
Hao-Bo Hou ◽  
Hong Zhou
Keyword(s):  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Metal Organic Frameworks ◽  
Composite Membranes ◽  
Proton Conduction ◽  
Proton Exchange ◽  
Proton Conducting ◽  
Conducting Materials ◽  
Metal Organic ◽  
Exchange Membrane

As newly emerging proton-conducting materials, metal–organic frameworks (MOFs) have been attracting wide attention in the field of proton exchange membrane fuel cells.

Proton Conduction and Long-Range Ferrimagnetic Ordering in Two Isostructural Copper(II) Mesoxalate Metal–Organic Frameworks

2015 ◽  
Vol 54 (4) ◽  
pp. 1597-1605 ◽  
Author(s):  
Beatriz Gil-Hernández ◽  
Stanislav Savvin ◽  
Gamall Makhloufi ◽  
Pedro Núñez ◽  
Christoph Janiak ◽  
...  
Keyword(s):  
Long Range ◽  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Metal Organic ◽  
Ferrimagnetic Ordering

scholarly journals The role of lattice vibration in the terahertz region for proton conduction in 2D metal–organic frameworks

2020 ◽  
Vol 11 (6) ◽  
pp. 1538-1541
Author(s):  
Tomoya Itakura ◽  
Hiroshi Matsui ◽  
Tomofumi Tada ◽  
Susumu Kitagawa ◽  
Aude Demessence ◽  
...  
Keyword(s):  
Proton Conductivity ◽  
Electronic Structures ◽  
Lattice Vibration ◽  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Terahertz Region ◽  
Metal Organic

Terahertz-regime vibrations of 2D MOFs dominate the intrinsic proton conductivity, and the motions depend on the valence electronic structures.

Tuning Intrinsic and Extrinsic Proton Conduction in Metal–Organic Frameworks by the Lanthanide Contraction

2017 ◽  
Vol 139 (41) ◽  
pp. 14676-14683 ◽  
Author(s):  
Norman E. Wong ◽  
Padmini Ramaswamy ◽  
Andrew S. Lee ◽  
Benjamin S. Gelfand ◽  
Kamila J. Bladek ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Lanthanide Contraction ◽  
Metal Organic

Tuning the functional substituent group and guest of metal–organic frameworks in hybrid membranes for improved interface compatibility and proton conduction

2017 ◽  
Vol 5 (7) ◽  
pp. 3464-3474 ◽  
Author(s):  
Xi-Yan Dong ◽  
Jing-Juan Li ◽  
Zhen Han ◽  
Pei-Gao Duan ◽  
Lin-Ke Li ◽  
...  
Keyword(s):  
Metal Organic Frameworks ◽  
Proton Conduction ◽  
Hybrid Membranes ◽  
Functional Substituent ◽  
Substituent Group ◽  
Metal Organic

The improved interface compatibility and proton conduction of hybrid membranes of metal–organic frameworks (MOFs) and chitosan (CS) are obtained by tuning the functional sulfonic substituent group and guest acids of MOFs.

Anhydrous proton conduction at 150 °C in a crystalline metal–organic framework

2009 ◽  
Vol 1 (9) ◽  
pp. 705-710 ◽  
Author(s):  
Jeff A. Hurd ◽  
Ramanathan Vaidhyanathan ◽  
Venkataraman Thangadurai ◽  
Christopher I. Ratcliffe ◽  
Igor L. Moudrakovski ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Proton Conduction ◽  
Metal Organic ◽  
Anhydrous Proton Conduction ◽  
Crystalline Metal ◽  
Organic Framework
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