High-yield nanosized (Si)AlPO-41 using ethanol polarity equalization and co-templating synthesis approach

Nanoscale ◽  
2015 ◽  
Vol 7 (13) ◽  
pp. 5787-5793 ◽  
Author(s):  
Gerardo Majano ◽  
Kolio Raltchev ◽  
Aurelie Vicente ◽  
Svetlana Mintova
Keyword(s):  
High Yield ◽  
Nanometer Scale ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Synthesis Approach ◽  
Templating Synthesis

Control of the crystallite dimensions of the microporous aluminophosphate AlPO-41 (AFO-type framework structure), and the Si-containing analogue SAPO-41, was attained down to the nanometer scale under stable hydrothermal conditions in the presence of ethanol and a co-template.

scholarly journals Additive-Enhanced Exfoliation for High-Yield 2D Materials Production

Nanomaterials ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 601
Author(s):  
Dinh-Tuan Nguyen ◽  
Hsiang-An Ting ◽  
Yen-Hsun Su ◽  
Mario Hofmann ◽  
Ya-Ping Hsieh
Keyword(s):  
Large Scale ◽  
2D Materials ◽  
Transition Metal Dichalcogenides ◽  
Spectroscopic Characterization ◽  
High Yield ◽  
Nanometer Scale ◽  
Efficient Production ◽  
Device Performance ◽  
Metal Dichalcogenides ◽  
Scale Deposition

The success of van-der-Waals electronics, which combine large-scale-deposition capabilities with high device performance, relies on the efficient production of suitable 2D materials. Shear exfoliation of 2D materials’ flakes from bulk sources can generate 2D materials with low amounts of defects, but the production yield has been limited below industry requirements. Here, we introduce additive-assisted exfoliation (AAE) as an approach to significantly increase the efficiency of shear exfoliation and produce an exfoliation yield of 30%. By introducing micrometer-sized particles that do not exfoliate, the gap between rotor and stator was dynamically reduced to increase the achievable shear rate. This enhancement was applied to WS2 and MoS2 production, which represent two of the most promising 2D transition-metal dichalcogenides. Spectroscopic characterization and cascade centrifugation reveal a consistent and significant increase in 2D material concentrations across all thickness ranges. Thus, the produced WS2 films exhibit high thickness uniformity in the nanometer-scale and can open up new routes for 2D materials production towards future applications.

scholarly journals Epimerization-free C-term Activation of Peptide Fragments by Ball-Milling

2020 ◽  
Author(s):  
Yves Yeboue ◽  
Marion Jean ◽  
Gilles Subra ◽  
Jean Martinez ◽  
Frédéric Lamaty ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ball Milling ◽  
High Yield ◽  
Coupling Agents ◽  
Peptide Fragment ◽  
Peptide Fragments ◽  
Solution Synthesis ◽  
High Yields ◽  
Synthesis Approach ◽  
Yield And Purity

Ball-milling enabled to perform [2+1], [2+2], and [2+3] peptide couplings with high yields and, if any, very low epimerization. Very good results were obtained with peptide fragments containing highly epimerization-prone and/or highly hindered amino acids at C-term such as phenylglycine, cysteine and valine. Ball-milling was clearly identified as the key element to obtain both high yield and purity along with low epimerization. Indeed, the ball-milling conditions proved to be superior to the classical solution synthesis approach on a various array of widely used coupling agents. These results open avenues for the development of highly efficient, convergent and flexible peptide synthesis strategies based on peptide fragment couplings mediated by ball-milling.

scholarly journals Epimerization-free C-term Activation of Peptide Fragments by Ball-Milling

2020 ◽  
Author(s):  
Yves Yeboue ◽  
Marion Jean ◽  
Gilles Subra ◽  
Jean Martinez ◽  
Frédéric Lamaty ◽  
...  
Keyword(s):  
Amino Acids ◽  
Ball Milling ◽  
High Yield ◽  
Coupling Agents ◽  
Peptide Fragment ◽  
Peptide Fragments ◽  
Solution Synthesis ◽  
High Yields ◽  
Synthesis Approach ◽  
Yield And Purity

Ball-milling enabled to perform [2+1], [2+2], and [2+3] peptide couplings with high yields and, if any, very low epimerization. Very good results were obtained with peptide fragments containing highly epimerization-prone and/or highly hindered amino acids at C-term such as phenylglycine, cysteine and valine. Ball-milling was clearly identified as the key element to obtain both high yield and purity along with low epimerization. Indeed, the ball-milling conditions proved to be superior to the classical solution synthesis approach on a various array of widely used coupling agents. These results open avenues for the development of highly efficient, convergent and flexible peptide synthesis strategies based on peptide fragment couplings mediated by ball-milling.

scholarly journals A new form of NaMnAsO4

2019 ◽  
Vol 75 (7) ◽  
pp. 969-971
Author(s):  
Matthias Weil ◽  
Théo Veyer
Keyword(s):  
Crystal Structure ◽  
Manganese Oxide ◽  
Trigonal Bipyramid ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Coordination Numbers ◽  
Distorted Octahedral Coordination ◽  
Sodium Cations ◽  
Distorted Octahedral ◽  
New Form

A new form of NaMnAsO4, sodium manganese(II) orthoarsenate, has been obtained under hydrothermal conditions, and is referred to as the β-polymorph. In contrast to the previously reported orthorhombic α-polymorph that crystallizes in the olivine-type of structure and has one manganese(II) cation in a distorted octahedral coordination, the current β-polymorph contains two manganese(II) cations in [5]-coordination, intermediate between a square-pyramid and a trigonal bipyramid. In the crystal structure of β-NaMnAsO4, four [MnO5] polyhedra are linked through vertex- and edge-sharing into finite {Mn4O16} units strung into rows parallel to [100]. These units are linked through two distinct orthoarsenate groups into a framework structure with channels propagating parallel to the manganese oxide rows. Both unique sodium cations are situated inside the channels and exhibit coordination numbers of six and seven. β-NaMnAsO4 is isotypic with one form of NaCoPO4 and with NaCuAsO4.

scholarly journals Crystal structure of dimanganese(II) zinc bis[orthophosphate(V)] monohydrate

2015 ◽  
Vol 71 (2) ◽  
pp. 154-156 ◽  
Author(s):  
Ghaleb Alhakmi ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Transition Metal ◽  
Hydrogen Bonds ◽  
Title Compound ◽  
The Other ◽  
Water Molecules ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Metal Phosphates

The title compound, Mn2Zn(PO4)2·H2O, was obtained under hydrothermal conditions. The structure is isotypic with other transition metal phosphates of the typeM3−xM′x(PO4)2·H2O, but shows no statistical disorder of the three metallic sites. The principal building units are distorted [MnO6] and [MnO5(H2O)] octahedra, a distorted [ZnO5] square pyramid and two regular PO4tetrahedra. The connection of the polyhedra leads to a framework structure. Two types of layers parallel to (-101) can be distinguished in this framework. One layer contains [Zn2O8] dimers linked to PO4tetrahedraviacommon edges. The other layer is more corrugated and contains [Mn2O8(H2O)2] dimers and [MnO6] octahedra linked together by common edges. The PO4tetrahedra link the two types of layers into a framework structure with channels parallel to [101]. The H atoms of the water molecules point into the channels and form O—H...O hydrogen bonds (one of which is bifurcated) with framework O atoms across the channels.

High-Yield Preparation of Titanium Dioxide Nanostructures by Hydrothermal Conditions

2009 ◽  
Vol 9 (2) ◽  
pp. 1103-1107 ◽  
Author(s):  
Juan Vasquez ◽  
Harold Lozano ◽  
Vladimir Lavayen ◽  
Mónica Lira-Cantú ◽  
Pedro Gómez-Romero ◽  
...  
Keyword(s):  
Titanium Dioxide ◽  
High Yield ◽  
Hydrothermal Conditions

scholarly journals Crystal structure of magnesium copper(II) bis[orthophosphate(V)] monohydrate

2015 ◽  
Vol 71 (1) ◽  
pp. 55-57 ◽  
Author(s):  
Jamal Khmiyas ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Single Crystals ◽  
Water Molecules ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
The Third ◽  
Hydrogen Bonding Interactions

Single crystals of magnesium copper(II) bis[orthophosphate(V)] monohydrate, Mg1.65Cu1.35(PO4)2·H2O, were grown under hydrothermal conditions. The crystal structure is formed by three types of cationic sites and by two unique (PO4)3−anions. One site is occupied by Cu2+, the second site by Mg2+and the third site by a mixture of the two cations with an Mg2+:Cu2+occupancy ratio of 0.657 (3):0.343 (3). The structure is built up from more or less distorted [MgO6] and [(Mg/Cu)O5(H2O)] octahedra, [CuO5] square-pyramids and regular PO4tetrahedra, leading to a framework structure. Within this framework, two types of layers parallel to (-101) can be distinguished. The first layer is formed by [Cu2O8] dimers linked to PO4tetrahedraviacommon edges. The second, more corrugated layer results from the linkage between [(Cu/Mg)2O8(H2O)2] dimers and [MgO6] octahedra by common edges. The PO4units link the two types of layers, leaving space for channels parallel [101], into which the H atoms of the water molecules protrude. The latter are involved in O—H...O hydrogen-bonding interactions (one bifurcated) with framework O atoms across the channels.

scholarly journals Crystal structure of poly[bis(μ2-5-hydroxynicotinato-κ2N:O3)zinc]

2015 ◽  
Vol 71 (2) ◽  
pp. m23-m23
Author(s):  
Wen-Bing Wang ◽  
Shan-Shan Xu ◽  
Hong-Ji Chen
Keyword(s):  
Crystal Packing ◽  
Three Dimensional ◽  
Zinc Nitrate ◽  
Tetrahedral Coordination ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Intermolecular Hydrogen Bonds ◽  
Coordination Environment ◽  
Hydroxy Groups ◽  
Distorted Tetrahedral Coordination

The title coordination polymer, [Zn(C6H4NO3)2]n, was prepared under hydrothermal conditions by the reaction of zinc nitrate with 5-hydroxynicotinic acid in the presence of malonic acid. In the structure, the ZnIIion is coordinated by two carboxylate O atoms and two pyridine N atoms of four 5-hydroxynicotinate ligands in a distorted tetrahedral coordination environment. The μ2-bridging mode of each anion leads to the formation of a three-dimensional framework structure. Intermolecular hydrogen bonds between the hydroxy groups of one anion and the non-coordinating carboxylate O atoms of neighbouring anions consolidate the crystal packing.

scholarly journals Crystal structure of SrCo4(OH)(PO4)3, a new hydroxyphosphate

2020 ◽  
Vol 76 (7) ◽  
pp. 1022-1026
Author(s):  
Fatima-Zahra Cherif ◽  
Mhamed Taibi ◽  
Ali Boukhari ◽  
Jilali Aride ◽  
Abderrazzak Assani ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Infrared Spectroscopy ◽  
Hydrogen Bonds ◽  
Single Crystals ◽  
Title Compound ◽  
Crystal Packing ◽  
Framework Structure ◽  
Hydrothermal Conditions

Single crystals of strontium tetracobalt tris(orthophosphate) hydroxide, SrCo4(OH)(PO4)3, were grown serendipitously under hydrothermal conditions at 473 K. The crystal structure consists of undulating chains of edge-sharing [CoO6] octahedra that are linked into (010) layers by common vertices between chains. Adjacent layers are linked along [010] into a framework structure by tetrahedral [CoO4] units and by PO4 tetrahedra. The framework delimits channels extending along [100] in which the eleven-coordinate strontium cations are situated. Bifurcated O—H...O hydrogen bonds of weak strengths consolidate the crystal packing. The title compound was also characterized by infrared spectroscopy.

scholarly journals A triclinic polymorph of dicadmium divanadate(V)

2013 ◽  
Vol 69 (11) ◽  
pp. i79-i79 ◽  
Author(s):  
Ahmed Ould Saleck ◽  
Abderrazzak Assani ◽  
Mohamed Saadi ◽  
Lahcen El Ammari
Keyword(s):  
Crystal Structure ◽  
Title Compound ◽  
Three Dimensional ◽  
Framework Structure ◽  
Hydrothermal Conditions ◽  
Coordination Environment ◽  
Coordination Numbers ◽  
Monoclinic Form ◽  
Triclinic Symmetry

The title compound, Cd2V2O7, was obtained under hydrothermal conditions. Different from the known monoclinic form, the new polymorph of Cd2V2O7has triclinic symmetry and is isotypic with Ca2V2O7. The building units of the crystal structure are two Cd2+cations, with coordination numbers of six and seven, and two V atoms with a tetrahedral and a significantly distorted trigonal–pyramidal coordination environment, respectively. Two VO5pyramids share an edge and each pyramid is connected to one VO4tetrahedronviaa corner atom, forming an isolated V4O148−anion. These anions are arranged in sheets parallel to (-211) and are linked through the Cd2+cations into a three-dimensional framework structure.

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