A large molecular cluster with high proton release capacity

2020 ◽  
Vol 56 (84) ◽  
pp. 12849-12852
Author(s):  
Dongdi Zhang ◽  
Hui Li ◽  
Chen Li ◽  
Zehao Wang ◽  
Tao Li ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Molecular Cluster ◽  
Proton Release ◽  
Release Capacity ◽  
High Proton

A single polyoxometalate cluster with controllable and reversible proton release/absorption capability (∼40 per molecule) in its aqueous solution is presented.

Facile synthesis of a water stable 3D Eu-MOF showing high proton conductivity and its application as a sensitive luminescent sensor for Cu2+ ions

2016 ◽  
Vol 4 (42) ◽  
pp. 16484-16489 ◽  
Author(s):  
Xin Wang ◽  
Tao Qin ◽  
Song-Song Bao ◽  
Yu-Chi Zhang ◽  
Xuan Shen ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Proton Conductivity ◽  
Quantitative Yield ◽  
Facile Synthesis ◽  
High Proton Conductivity ◽  
Luminescent Sensor ◽  
High Proton ◽  
Solution Reaction

An oxalate-based multifunctional MOF material is synthesized with a quantitative yield by a simple aqueous solution reaction of cheap reactants.

scholarly journals Chitosan Biocomposites for the Adsorption and Release of H2S

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6701
Author(s):  
Mary Batista ◽  
Moisés L. Pinto ◽  
Fernando Antunes ◽  
João Pires ◽  
Silvia Carvalho
Keyword(s):  
Aqueous Solution ◽  
Activated Carbons ◽  
Nanoporous Materials ◽  
Release Time ◽  
Therapeutic Effects ◽  
Cytotoxicity Assays ◽  
Release Capacity ◽  
H2s Adsorption ◽  
Pore Opening ◽  
Chitosan Composite

The search for H2S donors has been increasing due to the multiple therapeutic effects of the gas. However, the use of nanoporous materials has not been investigated despite their potential. Zeolites and activated carbons are known as good gas adsorbents and their modification with chitosan may increase the material biocompatibility and simultaneously its release time in aqueous solution, thus making them good H2S donors. Herein, we modified with chitosan a series of A zeolites (3A, 4A and 5A) with different pore sizes and an activated carbon obtained from glycerin. The amount of H2S adsorbed was evaluated by a volumetric method and their release capacity in aqueous solution was measured. These studies aimed to verify which of the materials had appropriate H2S adsorption/release properties to be considered a potential H2S donor. Additionally, cytotoxicity assays using HeLa cells were performed. Considering the obtained results, the chitosan composite with the A zeolite with the larger pore opening was the most promising material to be used as a H2S donor so a further cytotoxicity assay using H2S loaded was conducted and no toxicity was observed.

Kinetics of Proton Release after Flash Photolysis of 1-(2-Nitrophenyl)ethyl Sulfate (Caged Sulfate) in Aqueous Solution

2005 ◽  
Vol 127 (27) ◽  
pp. 9865-9874 ◽  
Author(s):  
Stefania Abbruzzetti ◽  
Silvia Sottini ◽  
Cristiano Viappiani ◽  
John E. T. Corrie
Keyword(s):  
Aqueous Solution ◽  
Flash Photolysis ◽  
Proton Release ◽  
Ethyl Sulfate ◽  
Kinetics Of

Light-Driven Proton Release of Spirobenzopyran-Derived Protonated Photomerocyanine in Cyclodextrin Aqueous Solution

2017 ◽  
Vol 2 (34) ◽  
pp. 11288-11292
Author(s):  
Tatsuya Takeshita ◽  
Atsushi Yano ◽  
Michihiro Hara
Keyword(s):  
Aqueous Solution ◽  
Proton Release

Reperfusion arrhythmias are associated with high proton release

2008 ◽  
Vol 44 (4) ◽  
pp. 756-757
Author(s):  
V. Bourahla ◽  
X. Leverve ◽  
L. Demaison
Keyword(s):  
Proton Release ◽  
Reperfusion Arrhythmias ◽  
High Proton

Structures Formed by Cryoprotective Agents Used in Freezc-Etching

1971 ◽  
Vol 29 ◽  
pp. 448-449
Author(s):  
G. G. Cocks ◽  
C. E. Cluthe
Keyword(s):  
Aqueous Solution ◽  
Polyethylene Oxide ◽  
Liquid Nitrogen Temperature ◽  
Ice Crystals ◽  
Etching Technique ◽  
Structural Constituent ◽  
Cryoprotective Agents ◽  
Quick Freezing ◽  
Freeze Etching ◽  
Fractured Surface

The freeze etching technique is potentially useful for examining dilute solutions or suspensions of macromolecular materials. Quick freezing of aqueous solutions in Freon or propane at or near liquid nitrogen temperature produces relatively large ice crystals and these crystals may damage the structures to be examined. Cryoprotective agents may reduce damage to the specimem, hut their use often results in the formation of a different set of specimem artifacts.In a study of the structure of polyethylene oxide gels glycerol and sucrose were used as cryoprotective agents. The experiments reported here show some of the structures which can appear when these cryoprotective agents are used.Figure 1 shows a fractured surface of a frozen 25% aqueous solution of sucrose. The branches of dendritic ice crystals surrounded hy ice-sucrose eutectic can be seen. When this fractured surface is etched the ice in the dendrites sublimes giving the type of structure shown in Figure 2. The ice-sucrose eutectic etches much more slowly. It is the smooth continuous structural constituent surrounding the branches of the dendrites.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

TEM observation of iron oxide pillars in montmorillonite

1990 ◽  
Vol 48 (4) ◽  
pp. 882-883
Author(s):  
H. Mori ◽  
Y. Murata ◽  
H. Yoneyama ◽  
H. Fujita
Keyword(s):  
Aqueous Solution ◽  
Iron Oxide ◽  
Fine Particles ◽  
Aqueous Suspension ◽  
Volume Ratio ◽  
Exchange Capacity ◽  
Nano Composites ◽  
Pillared Montmorillonite ◽  
Topographic Features ◽  
Transmission Electron

Recently, a new sort of nano-composites has been prepared by incorporating such fine particles as metal oxide microcrystallites and organic polymers into the interlayer space of montmorillonite. Owing to their extremely large specific surface area, the nano-composites are finding wide application[1∼3]. However, the topographic features of the microstructures have not been elucidated as yet In the present work, the microstructures of iron oxide-pillared montmorillonite have been investigated by high-resolution transmission electron microscopy.Iron oxide-pillared montmorillonite was prepared through the procedure essentially the same as that reported by Yamanaka et al. Firstly, 0.125 M aqueous solution of trinuclear acetato-hydroxo iron(III) nitrate, [Fe3(OCOCH3)7 OH.2H2O]NO3, was prepared and then the solution was mixed with an aqueous suspension of 1 wt% clay by continuously stirring at 308 K. The final volume ratio of the latter aqueous solution to the former was 0.4. The clay used was sodium montmorillonite (Kunimine Industrial Co.), having a cation exchange capacity of 100 mequiv/100g. The montmorillonite in the mixed suspension was then centrifuged, followed by washing with deionized water. The washed samples were spread on glass plates, air dried, and then annealed at 673 K for 72 ks in air. The resultant film products were approximately 20 μm in thickness and brown in color.

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.

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