scholarly journals Quantification of gas-accessible microporosity in metal-organic framework glasses

2021 ◽  
Author(s):  
Louis Frentzel-Beyme ◽  
Pascal Kolodzeiski ◽  
Jan-Benedikt Weiß ◽  
Sebastian Henke
Keyword(s):  
Metal Organic Framework ◽  
Glassy State ◽  
Glass Network ◽  
Zeolitic Imidazolate Frameworks ◽  
Sorption Data ◽  
Design Concepts ◽  
New Class ◽  
Microporous Glass ◽  
Metal Organic ◽  
Organic Framework

Metal-organic framework (MOF) glasses are a new class of microporous glass materials with immense potential for applications ranging from gas separation to optics and solid electrolytes. Due to the inherent difficulty to determine the atomistic structure of amorphous glasses, the intrinsic structural porosity of MOF glasses is only poorly understood. In this work, the porosity features of a series of prototypical MOF glass formers from the family of zeolitic imidazolate frameworks (ZIFs) and their corresponding glasses is investigated comprehensively. CO2 gas sorption at 195 K allows to follow the evolution of microporosity when transforming from the crystalline to the glassy state of these materials. Based on these data, the pore volume and the real density of the ZIF glasses is quantified for the first time. Additional hydrocarbon sorption data (n-butane, propane and propylene) together with X-ray total scattering experiments prove that the porosity features (in particular the pore size and the pore limiting diameter) of the ZIF glasses depend on the types of organic linkers present in the glass network. This allows formulating first design principles for a targeted tuning of the intrinsic microporosity of MOF glasses. Importantly, these principles are counterintuitive and contrary to established porosity design concepts for crystalline MOFs but show similarities to strategies previously developed for porous polymers.

scholarly journals Metal–Organic Framework-Based Chemo-Photothermal Combinational System for Precise, Rapid, and Efficient Antibacterial Therapeutics

Pharmaceutics ◽  
2019 ◽  
Vol 11 (9) ◽  
pp. 463 ◽  
Author(s):  
Wu ◽  
Fu ◽  
Zhou ◽  
Wang ◽  
Feng ◽  
...  
Keyword(s):  
Laser Irradiation ◽  
Photothermal Therapy ◽  
Metal Organic Framework ◽  
Global Public Health ◽  
Zeolitic Imidazolate Frameworks ◽  
Porous Carrier ◽  
Metal Organic ◽  
Organic Framework

Rapid increase of antimicrobial resistance has become an urgent threat to global public health. In this research, since photothermal therapy is a potential antibacterial strategy, which is less likely to cause resistance, a metal–organic framework-based chemo-photothermal combinational system was constructed. Zeolitic imidazolate frameworks-8 (ZIF-8), a porous carrier with unique features such as high loading and pH-sensitive degradation, was synthesized, and then encapsulated photothermal agent indocyanine green (ICG). First, ICG with improved stability in ZIF-8 (ZIF-8-ICG) can effectively produce heat in response to NIR laser irradiation for precise, rapid, and efficient photothermal bacterial ablation. Meanwhile, Zn2+ ions released from ZIF-8 can inhibit bacterial growth by increasing the permeability of bacterial cell membrane and further strengthen photothermal therapy efficacy by reducing the heat resistance of bacteria. Study showed that bacteria suffered from significant changes in morphology after treatment with ZIF-8-ICG under laser irradiation. The combinational chemo-hyperthermia therapy of ZIF-8-ICG could thoroughly ablate murine subcutaneous abscess induced by methicillin-resistant Staphylococcus aureus (MRSA), exhibiting a nearly 100% bactericidal ratio. Both in vitro and in vivo safety evaluation confirmed that ZIF-8-ICG was low toxic. Overall, our researches demonstrated that ZIF-8-ICG has great potential to be served as an alternative to antibiotics in combating multidrug-resistant bacterial pathogens.

scholarly journals Discovery of Superbroad Mid-Infrared Luminescent Metal-Organic Framework Glass

2019 ◽  
Author(s):  
Mohamed. A. Ali ◽  
Jinjun Ren ◽  
Xiaofeng Liu ◽  
Youjie Hua ◽  
Yuanzheng Yue ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Zeolitic Imidazolate Frameworks ◽  
Melt Quenching ◽  
Mid Infrared ◽  
Amorphous Phases ◽  
Glass Forming ◽  
Metal Organic ◽  
Ir Emission ◽  
Luminescent Behavior ◽  
Organic Framework

<p>Metal-organic framework (MOF) glasses are a newly discovered family of melt-quenched glasses. However, so far it is not known whether these glasses exhibit photonic functionalities. Here, we show the discovery of the luminescent behavior of a MOF glass, i.e., the cobalt doped zeolitic imidazolate frameworks-62 (ZIF-62) glass (Zn<sub>1-<i>x</i></sub> Co<i><sub>x</sub></i> (Im)<sub>1.9</sub> (bIm)<sub>0.1</sub>, <i>x</i> = 0, 0.1 and 0.5), which was obtained by melt-quenching its corresponding ZIF-62 crystal. The synthesized crystal was precipitated in the form of spherical nano/micro-crystalline structure, which collapses structurally to form laminated glass with ultrahigh glass forming ability and the same short range molecular structure of the parent crystalline MOF. We observed the super-broadband mid-infrared (Mid-IR) luminescence (in the wavelength range of 1.5 µm – 4.8 µm) both in the crystalline and amorphous phases. The observed Mid-IR emission originates from d-d transition of Co<sup>2+</sup> ions that is protected by the strong Co-N coordination. The discovery of the luminescent glasses may pave the way towards new photonic applications of bulk MOF glasses, such as Mid-IR lasers. </p>

Functional Porphyrinic Metal‐Organic Framework as a New Class of Heterogeneous Halogen Bond Donor Catalyst

2021 ◽  
Author(s):  
Weijie Zhang ◽  
Ayman Nafady ◽  
Chuan Shan ◽  
Lukasz Wojtas ◽  
Yu-Sheng Chen ◽  
...  
Keyword(s):  
Halogen Bond ◽  
Metal Organic Framework ◽  
New Class ◽  
Metal Organic ◽  
Organic Framework

Photonic metal–organic framework composite spheres: a new kind of optical material with self-reporting molecular recognition

Nanoscale ◽  
2014 ◽  
Vol 6 (20) ◽  
pp. 11995-12001 ◽  
Author(s):  
Jiecheng Cui ◽  
Ning Gao ◽  
Chen Wang ◽  
Wei Zhu ◽  
Jian Li ◽  
...  
Keyword(s):  
Molecular Recognition ◽  
Metal Organic Framework ◽  
Colloidal Crystals ◽  
Spatial Arrangement ◽  
Optical Material ◽  
General Strategy ◽  
New Class ◽  
Metal Organic ◽  
Host Matrices ◽  
Organic Framework

By using spherical colloidal crystals as 3D-ordered host matrices, a general strategy for efficient spatial arrangement of MOF materials has been developed, affording a new class of highly tunable MOF composite spheres.

Anomalous Cracking in a Metal-Organic Framework Glass

2019 ◽  
Author(s):  
Malwina Stepniewska ◽  
Kacper Januchta ◽  
Chao Zhou ◽  
Ang Qiao ◽  
Morten M. Smedskjaer ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Shear Bands ◽  
Zeolitic Imidazolate Frameworks ◽  
Cracking Behavior ◽  
Surface Cracking ◽  
Force Microscopy ◽  
Atomic Force ◽  
Afm Analysis ◽  
Metal Organic ◽  
Organic Framework

<p>Metal-organic framework (MOF) glasses is a newly discovered family of melt-quenched glasses. Recently, several intriguing features (e.g., ultrahigh glass forming ability and low liquid fragility) have been discovered in the glasses obtained from zeolitic imidazolate frameworks (ZIFs) that are a subset of MOFs. However, the fracture behavior of ZIF glasses remains elusive. Here, we report on the first important finding, namely, the anomalous crack behavior in a representative ZIF glass, i.e., ZIF-62 glass with the chemical composition of<a> ZnIm<sub>2-<i>x</i></sub>bIm<i><sub>x</sub></i></a>, where the central node – zinc - is coordinated to imidazolate (Im) and benzimidazole (bIm) ligands. By performing micro- and nano-indentation and atomic force microscopy (AFM) analysis, we observe a unique sub-surface cracking phenomenon with induced shear bands on the indent faces, in contrast to the cracking behavior of other types of network glasses. The occurrence of shear bands could be attributed to the breakage of coordinative bonds that are much weaker than ionic and covalent The observed anomalous cracking behavior accords with the high Poisson’s ratio (=0.34) of the ZIF-62 glass. </p>

Ferroelasticity in a metal–organic framework perovskite; towards a new class of multiferroics

2013 ◽  
Vol 61 (13) ◽  
pp. 4928-4938 ◽  
Author(s):  
Wei Li ◽  
Zhiying Zhang ◽  
Erica G. Bithell ◽  
Andrei S. Batsanov ◽  
Phillip T. Barton ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
New Class ◽  
Metal Organic ◽  
Organic Framework

scholarly journals Discovery of Superbroad Mid-Infrared Luminescent Metal-Organic Framework Glass

2019 ◽  
Author(s):  
Mohamed. A. Ali ◽  
Jinjun Ren ◽  
Xiaofeng Liu ◽  
Youjie Hua ◽  
Yuanzheng Yue ◽  
...  
Keyword(s):  
Metal Organic Framework ◽  
Zeolitic Imidazolate Frameworks ◽  
Melt Quenching ◽  
Mid Infrared ◽  
Amorphous Phases ◽  
Glass Forming ◽  
Metal Organic ◽  
Ir Emission ◽  
Luminescent Behavior ◽  
Organic Framework

<p>Metal-organic framework (MOF) glasses are a newly discovered family of melt-quenched glasses. However, so far it is not known whether these glasses exhibit photonic functionalities. Here, we show the discovery of the luminescent behavior of a MOF glass, i.e., the cobalt doped zeolitic imidazolate frameworks-62 (ZIF-62) glass (Zn<sub>1-<i>x</i></sub> Co<i><sub>x</sub></i> (Im)<sub>1.9</sub> (bIm)<sub>0.1</sub>, <i>x</i> = 0, 0.1 and 0.5), which was obtained by melt-quenching its corresponding ZIF-62 crystal. The synthesized crystal was precipitated in the form of spherical nano/micro-crystalline structure, which collapses structurally to form laminated glass with ultrahigh glass forming ability and the same short range molecular structure of the parent crystalline MOF. We observed the super-broadband mid-infrared (Mid-IR) luminescence (in the wavelength range of 1.5 µm – 4.8 µm) both in the crystalline and amorphous phases. The observed Mid-IR emission originates from d-d transition of Co<sup>2+</sup> ions that is protected by the strong Co-N coordination. The discovery of the luminescent glasses may pave the way towards new photonic applications of bulk MOF glasses, such as Mid-IR lasers. </p>

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