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

2016 ◽  
Vol 128 (35) ◽  
pp. 10424-10428 ◽  
Author(s):  
Kai-Jie Chen ◽  
David G. Madden ◽  
Tony Pham ◽  
Katherine A. Forrest ◽  
Amrit Kumar ◽  
...  
Keyword(s):  
Pore Size ◽  
Square Lattice ◽  
Coordination Networks

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

2016 ◽  
Vol 55 (35) ◽  
pp. 10268-10272 ◽  
Author(s):  
Kai-Jie Chen ◽  
David G. Madden ◽  
Tony Pham ◽  
Katherine A. Forrest ◽  
Amrit Kumar ◽  
...  
Keyword(s):  
Pore Size ◽  
Square Lattice ◽  
Coordination Networks

scholarly journals Crystal engineering of porous coordination networks to enable separation of C2 hydrocarbons

2020 ◽  
Vol 56 (72) ◽  
pp. 10419-10441 ◽  
Author(s):  
Soumya Mukherjee ◽  
Debobroto Sensharma ◽  
Kai-Jie Chen ◽  
Michael J. Zaworotko
Keyword(s):  
Pore Size ◽  
Crystal Engineering ◽  
Selective Separation ◽  
Coordination Networks ◽  
C2 Hydrocarbons

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.

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

2019 ◽  
Vol 55 (10) ◽  
pp. 1454-1457 ◽  
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.

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

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...

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

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.

Transfer Technique for Electron Microscopy of Membrance Filter Samples

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%.

The microstructure of functionalized poLyacrylonitrile beads for bioseparations

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.

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

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

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