scholarly journals Humidity-Mediated Anisotropic Proton Conductivity through the 1D Channels of Co-MOF-74

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1263 ◽  
Author(s):  
Ali Javed ◽  
Ina Strauss ◽  
Hana Bunzen ◽  
Jürgen Caro ◽  
Michael Tiemann
Keyword(s):  
Relative Humidity ◽  
Proton Conductivity ◽  
Solvothermal Synthesis ◽  
Electrical Potential ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Proton Mobility ◽  
Structure And Morphology ◽  
Ir And Raman ◽  
Scanning Electron

Large Co-MOF-74 crystals of a few hundred micrometers were prepared by solvothermal synthesis, and their structure and morphology were characterized by scanning electron microscopy (SEM), IR, and Raman spectroscopy. The hydrothermal stability of the material up to 60 °C at 93% relative humidity was verified by temperature-dependent XRD. Proton conductivity was studied by impedance spectroscopy, using a single crystal. By varying the relative humidity (70–95%), temperature (21–60 °C), and orientation of the crystal relative to the electrical potential, it was found that proton conduction occurs predominantly through the linear, unidirectional (1D) micropore channels of Co-MOF-74, and that water molecules inside the channels are responsible for the proton mobility by a Grotthuss-type mechanism.

Solvothemal Synthesis and Characterization of α-MnS Micronsized Architectures

2012 ◽  
Vol 486 ◽  
pp. 309-312
Author(s):  
Rong Wu ◽  
Le Tian Tao ◽  
Ji Kang Jian
Keyword(s):  
Electron Microscopy ◽  
Mixed Solvent ◽  
Volume Ratio ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
X Ray ◽  
Structure And Morphology ◽  
Scanning Electron

Mixed solvent of ethylenediamine (EDA) and ethylene glycol (EG) using MnCl4H2O, and (NH2)2CS as precursors was used to synthesize α-MnS micronsized architectures. Optimal α-MnS crystals were successfully grown from a mixed solvent of EDA:EG with a volume ratio of 1:1, reaction temperature of 140-180 °C and maintained for 6h. X-ray diffraction (XRD), scanning electron microscopy (SEM) was employed to characterize the structure and morphology of the product. The results show that the morphologies of α-MnS are found to be temperature dependent.

Solvothermal Synthesis of CuInS2 Porous Microspheres

2010 ◽  
Vol 663-665 ◽  
pp. 1150-1153
Author(s):  
Han Mei Hu ◽  
Chong Hai Deng
Keyword(s):  
Crystal Structure ◽  
Electron Microscopy ◽  
Solvothermal Synthesis ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
Porous Microspheres ◽  
Structure And Morphology ◽  
Transmission Electron ◽  
Scanning Electron

The porous hierarchical spherical CuInS2 microsturctures have been successfully fabricated through one-pot solvothermal technique. The crystal structure and morphology of the as-synthesized products are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results reveal that the shells of CuInS2 microspheres are composed of nanosheets or nanoparticles. The possible formation mechanism of CuInS2 porous microspheres is simply discussed.

High proton conductivity in a nickel(ii) complex and its hybrid membrane

2019 ◽  
Vol 48 (6) ◽  
pp. 2190-2196 ◽  
Author(s):  
Shuai-Liang Yang ◽  
Yue-Ying Yuan ◽  
Fei Ren ◽  
Chen-Xi Zhang ◽  
Qing-Lun Wang
Keyword(s):  
Hydrogen Bond ◽  
Proton Conductivity ◽  
Hybrid Membrane ◽  
Water Molecules ◽  
Hybrid Membranes ◽  
High Proton Conductivity ◽  
High Proton ◽  
Hydrogen Bond Networks

A novel 2D nickel(ii) complex (1) has been successfully synthesized using a 2,2′-bipyridyl, polycarboxylsulfonate ligand H4SBTC and Ni2+ ions. Owing to the presence of abundant water molecules, hydrogen bond networks and other protons, 1 and its hybrid membranes demonstrate high proton conductivity.

scholarly journals Hyaluronan orders water molecules in its nanoscale extended hydration shells

2021 ◽  
Vol 7 (10) ◽  
pp. eabf2558
Author(s):  
J. Dedic ◽  
H. I. Okur ◽  
S. Roke
Keyword(s):  
Second Harmonic ◽  
Hydration Shell ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Flexible Chain ◽  
Optical Modeling ◽  
Hydration Shells ◽  
Second Harmonic Scattering ◽  
Nuclear Quantum Effects ◽  
Extracellular Environment

Hyaluronan (HA) is an anionic, highly hydrated bio-polyelectrolyte found in the extracellular environment, like the synovial fluid between joints. We explore the extended hydration shell structure of HA in water using femtosecond elastic second-harmonic scattering (fs-ESHS). HA enhances orientational water-water correlations. Angle-resolved fs-ESHS measurements and nonlinear optical modeling show that HA behaves like a flexible chain surrounded by extended shells of orientationally correlated water. We describe several ways to determine the concentration-dependent size and shape of a polyelectrolyte in water, using the amount of water oriented by the polyelectrolyte charges as a contrast agent. The spatial extent of the hydration shell is determined via temperature-dependent measurements and can reach up to 475 nm, corresponding to a length of 1600 water molecules. A strong isotope effect, stemming from nuclear quantum effects, is observed when light water (H2O) is replaced by heavy water (D2O), amounting to a factor of 4.3 in the scattered SH intensity.

scholarly journals Solid-Phase “Self-Hydrolysis” of [Zn(NH3)4MoO4@2H2O] Involving Enclathrated Water—An Easy Route to a Layered Basic Ammonium Zinc Molybdate Coordination Polymer

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4022
Author(s):  
Kende Attila Béres ◽  
István E. Sajó ◽  
György Lendvay ◽  
László Trif ◽  
Vladimir M. Petruševski ◽  
...  
Keyword(s):  
Coordination Polymer ◽  
Solid Phase ◽  
Water Molecules ◽  
Temperature Dependent ◽  
Dynamic Interactions ◽  
Ammonia Release ◽  
Successive Substitution ◽  
Red Dye ◽  
Hydrolysis Of ◽  
Zinc Molybdate

An aerial humidity-induced solid-phase hydrolytic transformation of the [Zn(NH3)4]MoO4@2H2O (compound 1@2H2O) with the formation of [(NH4)xH(1−x)Zn(OH)(MoO4)]n (x = 0.92–0.94) coordination polymer (formally NH4Zn(OH)MoO4, compound 2) is described. Based on the isostructural relationship, the powder XRD indicates that the crystal lattice of compound 1@2H2O contains a hydrogen-bonded network of tetraamminezinc (2+) and molybdate (2−) ions, and there are cavities (O4N4(μ-H12) cube) occupied by the two water molecules, which stabilize the crystal structure. Several observations indicate that the water molecules have no fixed positions in the lattice voids; instead, the cavity provides a neighborhood similar to those in clathrates. The @ symbol in the notation is intended to emphasize that the H2O in this compound is enclathrated rather than being water of crystallization. Yet, signs of temperature-dependent dynamic interactions with the wall of the cages can be detected, and 1@2H2O easily releases its water content even on standing and yields compound 2. Surprisingly, hydrolysis products of 1 were observed even in the absence of aerial humidity, which suggests a unique solid-phase quasi-intramolecular hydrolysis. A mechanism involving successive substitution of the ammonia ligands by water molecules and ammonia release is proposed. An ESR study of the Cu-doped compound 2 (2#dotCu) showed that this complex consists of two different Cu2+(Zn2+) environments in the polymeric structure. Thermal decomposition of compounds 1 and 2 results in ZnMoO4 with similar specific surface area and morphology. The ZnMoO4 samples prepared from compounds 1 and 2 and compound 2 in itself are active photocatalysts in the degradation of Congo Red dye. IR, Raman, and UV studies on compounds 1@2H2O and 2 are discussed in detail.

Inorganic salt hydrates and zeolites composites studies for thermochemical heat storage

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Ata Ur Rehman ◽  
Muhammad Zahir Shah ◽  
Shehla Rasheed ◽  
Wasim Afzal ◽  
Muhammad Arsalan ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Water Sorption ◽  
Inorganic Salt ◽  
Heat Storage ◽  
Water Molecules ◽  
Thermochemical Heat Storage ◽  
Dehydration Enthalpy ◽  
Salt Hydrates ◽  
Heat Storage Materials ◽  
Pure Salt

Abstract Salt hydrates (MgSO4 and ZnSO4) impregnated in zeolites, offer a variety of improvements, mostly providing a large surface area for salt hydrates and water molecules. A composite of 5 and 10% of salt contents were prepared as heat storage materials. The study’s finding showed that dehydration enthalpy of MgSO4 (1817 J g−1) and ZnSO4 (1586 J g−1) were 10 and 15% improved than pure salt hydrates by making composites. During the hydration process of composites, the water sorption is 30–37% improved and further the increasing of salt contents in composites enhances more 10% increase in the water resorption. The cyclicability of MgSO4/zeolite and ZnSO4/zeolite were 45 and 51% improved than their corresponding pure salt hydrates. The effect of humidity on the water sorption result reveals that composites of MgSO4/zeolite and ZnSO4/zeolite at 75% relative humidity (RH), the mass of water are 51 and 40% increase than 55% RH.

Solvothermal Synthesis of Bi2Se3 Hexagonal Nanosheet Crystals

2011 ◽  
Vol 236-238 ◽  
pp. 1712-1716 ◽  
Author(s):  
Hai Tao Liu ◽  
Jun Dai ◽  
Jia Jia Zhang ◽  
Wei Dong Xiang
Keyword(s):  
Electron Microscope ◽  
Solvothermal Synthesis ◽  
Solvothermal Method ◽  
Raw Materials ◽  
X Ray Diffraction ◽  
Uniform Size ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Scanning Electron

Bismuth selenide (Bi2Se3) hexagonal nanosheet crystals with uniform size were successfully prepared via a solvothermal method at 160°C for 22 h using bismuth trichloride(BiCl3) and selenium powder(Se) as raw materials, sodium bisulfite(NaHSO3) as a reducing agent, diethylene glycol(DEG) as solvent, and ammonia as pH regulator. Various techniques such as X-ray diffraction (XRD), field-emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), and selected area electron diffraction (SAED) were used to characterize the obtained products. Results show that the as-synthesized samples are pure Bi2Se3 hexagonal nanosheet crystals. A possible growth mechanism for Bi2Se3 hexagonal nanosheet crystals is also discussed based on the experiment.

Characteristic of a Novel Composite Inorganic Polymer Coagulant-PAZF Prepared from Industrial Wastes

2014 ◽  
Vol 977 ◽  
pp. 82-85
Author(s):  
Ming Li ◽  
Yan Zhen Yu ◽  
Juan Ting Wang
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Complex Compounds ◽  
Industrial Wastes ◽  
X Ray Diffraction ◽  
X Ray ◽  
Structure And Morphology ◽  
Coagulation Performance ◽  
Composite Coagulant ◽  
Scanning Electron

A new composite coagulant polymeric aluminum zinc ferric (PAZF) was synthesized from industrial wastes. The structure and morphology of the coagulant was characterized by X-ray Diffraction (XRD), Infrared Spectroscopy (IR) and Scanning Electron Microscopy (SEM) and the coagulation performances were evaluated by dyeing-printing wastewater treatment. The results show that new complex compounds are formed in PAZF. Compared with poly aluminum chloride (PAC), the contents of ionic polymerized bonds and the cross-copolymerization among Fe (III), Al (III) and Zn (II) hydroxyl polymerized bonds are increase obviously, and the surface morphology of PAZF presents a net-like structure with the longer molecular chain. Coagulation experiments indicate that PAZF exhibits better coagulation performance in removing turbidity, COD and chromaticity.

scholarly journals Structure and Morphology Properties of Nanoparticle Hematite Pigment from Lathe Waste

2021 ◽  
Vol 13 (1) ◽  
pp. 21
Author(s):  
Lilik Miftahul Khoiroh ◽  
Asmaul Dwi Ayu Sholekah ◽  
Eny Yulianti
Keyword(s):  
Electron Microscopy ◽  
Scanning Electron Microscopy ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Crystallinity Degree ◽  
X Ray ◽  
Structure And Morphology ◽  
Calcination Method ◽  
Scanning Electron ◽  
Color Reader

Hematite coated PEG was synthesized by the sonication-calcination method. A variation of Na2CO3 is investigated to know the effect on structure and morphology. Characterization of samples are using X-ray fluorescence, X-ray diffraction, Scanning electron microscopy, and color reader techniques. XRF data showed that iron is the highest element in the precursor. The X-ray diffraction data confirm that Fe(OH)3, α-FeOOH, and Fe3O4 established at the sonication stage are then transformed into the α-Fe2O3 phase after calcination. The X-ray diffraction data also was found that α-Fe2O3 at 0.5 M formed with the highest crystallinity degree. The scanning electron microscopy showed that the particle's shape is spherical, bar-shaped, and aggregate. However, the distribution of particles is not uniform and still displays agglomeration. The Color reader shows the highest degree of lightness obtained is at 1 M variation.

scholarly journals ELECTRO-OSMOTIC FRACTIONATION OF HYDROGEN ISOTOPES IN ELECTROLYTIC SOLUTIONS USING COMPOSITE PROTON-PERMEABLE MEMBRANES

2021 ◽  
pp. 11-16
Author(s):  
O. Pushkar'ov ◽  
A. Zubko ◽  
I. Sevruk ◽  
V. Dolin
Keyword(s):  
Hydrogen Bonds ◽  
Proton Conductivity ◽  
Tritiated Water ◽  
High Mobility ◽  
Hydrogen Isotopes ◽  
Water Molecules ◽  
Proton Conducting ◽  
Partial Dissociation ◽  
Surface Modified ◽  
Conducting Membranes

Based on the analysis of the features of electroosmotic processes that are implemented in proton-conducting membranes, the possibility of fractioning hydrogen isotopes in electrolytes formed using tritiated water (HTO) is estimated. The interaction of the solution with the membranes in their channels leads to polarization and partial dissociation of the electrolyte molecules. In water molecules, when protium is replaced by a heavy isotope of hydrogen, the energy of breaking of hydrogen bonds increases and the process of their dissociation proceeds predominantly according to the scheme: HTO ↔ H+ + TO—. A part of the released protons can join water molecules to form the H3O+ ion. H3O+ and TO— ions are more mobile than other singly charged ions. The main characteristic that determines the suitability of electroosmotic membranes to the fractionation of hydrogen isotopes is proton conductivity. The released protons have anomalously high mobility due to their small size, tunnel and relay movement through hydrogen bonds between adjacent polar groups in the channels of the proton-conducting membranes. To ensure high proton conductivity in the pores and channels of the membranes, modifying substances are fixed, which contain the groups: –ОН- , –NH2, –NH, –SH, –COOH, –SO3H, acid salts and oxides, containing surface proton-conducting groups. To create proton-conducting membranes, it is possible to use surface-modified β-alumina (β-Al2O3(H3O+)) and protonated (H3O+) montmorillonite with ionic conductivity (5х103 – 4х104 Ohm х cm–1). The most effective are surface modifiers with negatively charged sulfonic groups. The imposition of an external electric field leads to the movement of ions in the electrolyte, which leads to a redistribution of the isotope ratio in the near-anode and cathode spaces.

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