Elucidating the Role of Fluorine Content on Gas Sorption Properties of Fluorinated Polyimides

2020 ◽  
Author(s):  
Albert X. Wu ◽  
James A. Drayton ◽  
Katherine Mizrahi Rodriguez ◽  
Francesco M. Benedetti ◽  
Qihui Qian ◽  
...  
Keyword(s):  
Fluorine Content ◽  
Sorption Properties ◽  
Gas Sorption ◽  
Fluorinated Polyimides

scholarly journals F/OH ratio in a rare fluorine-poor blue topaz from Padre Paraíso (Minas Gerais, Brazil) to unravel topaz’s ambient of formation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
N. Precisvalle ◽  
A. Martucci ◽  
L. Gigli ◽  
J. R. Plaisier ◽  
T. C. Hansen ◽  
...  
Keyword(s):  
Supercritical Fluids ◽  
Fluorine Content ◽  
Minas Gerais ◽  
Hydroxyl Groups ◽  
Exchange Reactions ◽  
Silicate System ◽  
Mullite Phase ◽  
Anomalous Water

AbstractTopaz [Al2SiO4(F,OH)2] is one of the main fluorine-bearing silicates occurring in environments where variably acidic (F)/aqueous (OH) fluids saturate the silicate system. In this work we fully characterized blue topaz from Padre Paraíso (Minas Gerais, Brazil) by means of in situ synchrotron X-Ray and neutron powder diffraction measurements (temperature range 298–1273 K) combined with EDS microanalyses. Understanding the role of OH/F substitution in topaz is important in order to determine the hydrophilicity and the exchange reactions of fluorine by hydroxyl groups, and ultimately to characterize the environmental redox conditions (H2O/F) required for mineral formation. The fluorine content estimated from neutron diffraction data is ~ 1.03 a.f.u (10.34 wt%), in agreement with the chemical data (on average 10.0 wt%). The XOH [OH/(OH + F)] (0.484) is close to the maximum XOH value (0.5), and represents the OH- richest topaz composition so far analysed in the Minas Gerais district. Topaz crystallinity and fluorine content sharply decrease at 1170 K, while mullite phase starts growing. On the basis of this behaviour, we suggest that this temperature may represent the potential initial topaz’s crystallization temperature from supercritical fluids in a pegmatite system. The log(fH2O/fHF)fluid (1.27 (0.06)) is coherent with the fluorine activity calculated for hydrothermal fluids (pegmatitic stage) in equilibrium with the forming mineral (log(fH2O/fHF)fluid = 1.2–6.5) and clearly different from pure magmatic (granitic) residual melts [log(fH2O/fHF)fluid < 1]. The modelled H2O saturated fluids with the F content not exceeding 1 wt% may represent an anomalous water-dominant / fluorine-poor pegmatite lens of the Padre Paraíso Pegmatite Field.

scholarly journals Chemical modification of the polymer of intrinsic microporosity PIM-1 for enhanced hydrogen storage

Adsorption ◽  
2020 ◽  
Vol 26 (7) ◽  
pp. 1083-1091
Author(s):  
Mi Tian ◽  
Sébastien Rochat ◽  
Hamish Fawcett ◽  
Andrew D. Burrows ◽  
Christopher R. Bowen ◽  
...  
Keyword(s):  
Hydrogen Storage ◽  
Surface Area ◽  
Hydrogen Adsorption ◽  
Sorption Properties ◽  
Bet Surface Area ◽  
Polymer Modification ◽  
Gas Sorption ◽  
Chemically Modified ◽  
Polymer Of Intrinsic Microporosity ◽  
Intrinsic Microporosity

Abstract A detailed investigation has been carried out of the pre-polymerisation modification of the polymer of intrinsic microporosity PIM-1 by the addition of two methyl (Me) groups to its spirobisindane unit to create a new chemically modified PIM-1 analogue, termed MePIM. Our work explores the effects of this modification on the porosity of PIM-1 and hence on its gas sorption properties. MePIM was successfully synthesised using either low (338 K) or high (423 K) temperature syntheses. It was observed that introduction of methyl groups to the spirobisindane part of PIM-1 generates additional microporous spaces, which significantly increases both surface area and hydrogen storage capacity. The BET surface area (N2 at 77 K) was increased by ~ 12.5%, resulting in a ~ 25% increase of hydrogen adsorption after modification. MePIM also maintains the advantages of good processability and thermal stability. This work provides new insights on a facile polymer modification that enables enhanced gas sorption properties.

Syntheses, structures and gas sorption properties of two coordination polymers with a unique type of supramolecular isomerism

2015 ◽  
Vol 2 (2) ◽  
pp. 136-140 ◽  
Author(s):  
Xiao-Lin Qi ◽  
Jia-Wen Ye ◽  
Rui-Biao Lin ◽  
Pei-Qin Liao ◽  
Si-Yang Liu ◽  
...  
Keyword(s):  
Coordination Polymers ◽  
Structural Difference ◽  
Sorption Properties ◽  
Gas Sorption ◽  
Unique Type ◽  
Supramolecular Isomerism ◽  
Porous Properties

Two genuine supramolecular isomers with a unique type of structural difference and completely different porous properties have been synthesized and characterized.

Gas-sorption properties of 6FDA-durene/1,4-phenylenediamine (pPDA) and 6FDA-durene/1,3-phenylenediamine (mPDA) copolyimides

2003 ◽  
Vol 90 (8) ◽  
pp. 2187-2193 ◽  
Author(s):  
Si-Xue Cheng ◽  
Tai-Shung Chung ◽  
Rong Wang ◽  
Rohit H. Vora
Keyword(s):  
Sorption Properties ◽  
Gas Sorption

A unique magnesium-based 3D MOF with nanoscale cages and temperature dependent selective gas sorption properties

2013 ◽  
Vol 49 (17) ◽  
pp. 1753 ◽  
Author(s):  
Yong-Liang Huang ◽  
Yun-Nan Gong ◽  
Long Jiang ◽  
Tong-Bu Lu
Keyword(s):  
Sorption Properties ◽  
Gas Sorption ◽  
Temperature Dependent

scholarly journals Vanadium Analogues of Nonfunctionalized and Amino-Functionalized MOFs with MIL-101 Topology - Synthesis, Characterization, and Gas Sorption Properties (Eur. J. Inorg. Chem. 15/2012)

2012 ◽  
Vol 2012 (15) ◽  
pp. n/a-n/a
Author(s):  
Shyam Biswas ◽  
Sarah Couck ◽  
Maciej Grzywa ◽  
Joeri F. M. Denayer ◽  
Dirk Volkmer ◽  
...  
Keyword(s):  
Sorption Properties ◽  
Gas Sorption

Two cationic metal–organic frameworks featuring different cage-to-cage connections: syntheses, crystal structures, photoluminescence and gas sorption properties

CrystEngComm ◽  
2013 ◽  
Vol 15 (40) ◽  
pp. 8139 ◽  
Author(s):  
Zhen-Zhen Xue ◽  
Tian-Lu Sheng ◽  
Qi-Long Zhu ◽  
Da-Qiang Yuan ◽  
Yan-Long Wang ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Metal Organic Frameworks ◽  
Sorption Properties ◽  
Gas Sorption ◽  
Metal Organic
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