Tuning Pore Size in Square-Lattice Coordination Networks for Size-Selective Sieving of CO2

Diverse crystal engineering principles employed in the discovery of porous coordination networks for the selective separation of C2 gases reveal that control of pore size and pore chemistry emerges as the key to unlock their outstanding performances.

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Solvent-directed control over the topology of entanglement in square lattice (sql) coordination networks

Chemical Communications ◽

10.1039/c8cc09152h ◽

2019 ◽

Vol 55 (10) ◽

pp. 1454-1457 ◽

Cited By ~ 2

Author(s):

Rana Sanii ◽

Carol Hua ◽

Ewa Patyk-Kaźmierczak ◽

Michael J. Zaworotko

Keyword(s):

Solvothermal Synthesis ◽

Square Lattice ◽

Coordination Networks ◽

Imidazole Ligand

We report herein that the mode of entanglement in square lattice, sql, coordination networks formed by an extended bis-imidazole ligand, L, can be controlled by the solvent used during solvothermal synthesis.

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Molecular tectonics: control of pore size and polarity in 3-D hexagonal coordination networks based on porphyrins and a zinc cation

Chemical Communications ◽

10.1039/b812831f ◽

2008 ◽

pp. 5104 ◽

Cited By ~ 22

Author(s):

Elisabeth Kühn ◽

Véronique Bulach ◽

Mir Wais Hosseini

Keyword(s):

Pore Size ◽

Coordination Networks ◽

Zinc Cation ◽

Molecular Tectonics

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Tuning the switching pressure in square lattice coordination networks by metal cation substitution

Materials Advances ◽

10.1039/d1ma00785h ◽

2022 ◽

Author(s):

Michael Zaworotko ◽

Shi-Qiang Wang ◽

Shaza Darwish ◽

Debobroto Sensharma

Keyword(s):

Metal Cation ◽

Sorption Isotherms ◽

Square Lattice ◽

Cation Substitution ◽

Coordination Networks

Coordination networks that undergo guest-induced switching between “closed” nonporous and “open” porous phases are of increasing interest as the resulting stepped sorption isotherms can offer exceptional working capacities for gas...

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Tuning the switching pressure in square lattice coordination networks by metal cation substitution

10.26434/chemrxiv-2021-lhnz8 ◽

2021 ◽

Author(s):

Shi-Qiang Wang ◽

Shaza Darwish ◽

Debobroto Sensharma ◽

Michael J. Zaworotko

Keyword(s):

Metal Cation ◽

Sorption Isotherms ◽

Gas Storage ◽

Square Lattice ◽

Cation Substitution ◽

Coordination Networks ◽

Fast Switching ◽

Switching Event ◽

Co2 Sorption

Coordination networks that undergo guest-induced switching between “closed” nonporous and “open” porous phases are of increasing interest as the resulting stepped sorption isotherms can offer exceptional working capacities for gas storage applications. For practical utility, the gate ad/desorption pressures (Pga/Pgd) must lie between the storage (Pst) and delivery (Pde) pressures and there must be fast switching kinetics. Herein we study the effect of metal cation substitution on the switching pressure of a family of square lattice coordination networks [M(4,4’-bipyridine)2(NCS)]n (sql-1-M-NCS, M = Fe, Co and Ni) with respect to CO2 sorption. The Clausius-Clapeyron equation was used to correlate Pga/Pgd and temperature. At 298 K, Pga/Pgd values were found to vary from 31.6/26.7 bar (M = Fe) to 26.7/20.9 bar (M = Co) and 18.5/14.6 bar (M = Ni). The switching event occurs within 10 minutes as verified by dynamic CO2 sorption tests. In addition, in situ synchrotron PXRD and molecular simulations provided structural insight into the observed switching event, which we attribute to layer expansion of sql-1-M-NCS via intercalation and inclusion of CO2 molecules. This study could pave the way for rational control over Pga/Pgd in switching adsorbent layered materials and enhance their potential utility in gas storage applications.

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Transfer Technique for Electron Microscopy of Membrance Filter Samples

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s042482010005278x ◽

1974 ◽

Vol 32 ◽

pp. 554-555

Author(s):

Lawrence W. Ortiz ◽

Bonnie L. Isom

Keyword(s):

Electron Microscopy ◽

Electron Microscope ◽

Pore Size ◽

Membrane Filters ◽

Size Dependent

A procedure is described for the quantitative transfer of fibers and particulates collected on membrane filters to electron microscope (EM) grids. Various Millipore MF filters (Millipore AA, HA, GS, and VM; 0.8, 0.45, 0.22 and 0.05 μm mean pore size) have been used with success. Observed particle losses have not been size dependent and have not exceeded 10%. With fibers (glass or asbestos) as the collected media this observed loss is approximately 3%.

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The microstructure of functionalized poLyacrylonitrile beads for bioseparations

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100178604 ◽

1990 ◽

Vol 48 (4) ◽

pp. 1094-1095

Author(s):

Eduardo A. Kamenetzky ◽

David A. Ley

Keyword(s):

Aqueous Solution ◽

Affinity Chromatography ◽

Pore Size Distribution ◽

Pore Size ◽

Surface Coverage ◽

Vacuum Impregnation ◽

Thin Sections ◽

Selective Staining ◽

Low Viscosity ◽

Diamond Knife

The microstructure of polyacrylonitrile (PAN) beads for affinity chromatography bioseparations was studied by TEM of stained ultramicrotomed thin-sections. Microstructural aspects such as overall pore size distribution, the distribution of pores within the beads, and surface coverage of functionalized beads affect performance properties. Stereological methods are used to quantify the internal structure of these chromatographic supports. Details of the process for making the PAN beads are given elsewhere. TEM specimens were obtained by vacuum impregnation with a low-viscosity epoxy and sectioning with a diamond knife. The beads can be observed unstained. However, different surface functionalities can be made evident by selective staining. Amide surface coverage was studied by staining in vapor of a 0.5.% RuO4 aqueous solution for 1 h. RuO4 does not stain PAN but stains, amongst many others, polymers containing an amide moiety.

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Statistical Complexity of Boolean Cellular Automata with Short-Term Reaction-Diffusion Memory on a Square Lattice

Complex Systems ◽

10.25088/complexsystems.28.3.357 ◽

2019 ◽

Vol 28 (3) ◽

pp. 357-391

Author(s):

Zakarya Zarezadeh ◽

Giovanni Costantini ◽

Keyword(s):

Cellular Automata ◽

Reaction Diffusion ◽

Square Lattice ◽

Short Term ◽

Statistical Complexity

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Influence of Flexible Side-Chains on the Breathing Phase Transition of Pillared Layer MOFs: A Force Field Investigation

10.26434/chemrxiv.11720679.v1 ◽

2020 ◽

Author(s):

Julian Keupp ◽

Johannes P. Dürholt ◽

Rochus Schmid

Keyword(s):

First Principles ◽

Good Accuracy ◽

Field Investigation ◽

Square Lattice ◽

Side Chain ◽

Second Step ◽

Side Chains ◽

Dynamics Simulations ◽

Complex Phenomena ◽

Closed Pore

The prototypical pillared layer MOFs, formed by a square lattice of paddle- wheel units and connected by dinitrogen pillars, can undergo a breathing phase transition by a “wine-rack” type motion of the square lattice. We studied this not yet fully understood behavior using an accurate first principles parameterized force field (MOF-FF) for larger nanocrystallites on the example of Zn 2 (bdc) 2 (dabco) [bdc: benzenedicarboxylate, dabco: (1,4-diazabicyclo[2.2.2]octane)] and found clear indi- cations for an interface between a closed and an open pore phase traveling through the system during the phase transformation [Adv. Theory Simul. 2019, 2, 11]. In conventional simulations in small supercells this mechanism is prevented by periodic boundary conditions (PBC), enforcing a synchronous transformation of the entire crystal. Here, we extend this investigation to pillared layer MOFs with flexible side-chains, attached to the linker. Such functionalized (fu-)MOFs are experimen- tally known to have different properties with the side-chains acting as fixed guest molecules. First, in order to extend the parameterization for such flexible groups, 1a new parametrization strategy for MOF-FF had to be developed, using a multi- structure force based fit method. The resulting parametrization for a library of fu-MOFs is then validated with respect to a set of reference systems and shows very good accuracy. In the second step, a series of fu-MOFs with increasing side-chain length is studied with respect to the influence of the side-chains on the breathing behavior. For small supercells in PBC a systematic trend of the closed pore volume with the chain length is observed. However, for a nanocrystallite model a distinct interface between a closed and an open pore phase is visible only for the short chain length, whereas for longer chains the interface broadens and a nearly concerted trans- formation is observed. Only by molecular dynamics simulations using accurate force fields such complex phenomena can be studied on a molecular level.

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