Mechanochemical synthesis of two-dimensional aromatic polyamides

2017 ◽  
Vol 53 (54) ◽  
pp. 7481-7484 ◽  
Author(s):  
Yang Yang ◽  
Fanxing Bu ◽  
Jingjing Liu ◽  
Imran Shakir ◽  
Yuxi Xu
Keyword(s):  
Mechanochemical Synthesis ◽  
Room Temperature ◽  
Solvent Free ◽  
Two Dimensional ◽  
Aromatic Polyamides ◽  
Temperature Conditions ◽  
First Time

2D aromatic polyamides (2DAPAs) were synthesized for the first time via a facile mechanochemical route under solvent-free and room temperature conditions.

Room Temperature Solvent-Free Synthesis of Monodisperse Magnetite Nanocrystals

2006 ◽  
Vol 6 (3) ◽  
pp. 852-856 ◽  
Author(s):  
X. R. Ye ◽  
C. Daraio ◽  
C. Wang ◽  
J. B. Talbot ◽  
S. Jin
Keyword(s):  
Oleic Acid ◽  
Solid State ◽  
Large Scale ◽  
Room Temperature ◽  
Solvent Free ◽  
Two Dimensional ◽  
New Process ◽  
High Boiling Point ◽  
Magnetite Nanocrystals ◽  
Solvent Free Synthesis

We have successfully demonstrated a facile, solvent-free synthesis of highly crystalline and monodisperse Fe3O4 nanocrystallites at ambient temperature avoiding any heating. Solid state reaction of inorganic Fe(II) and Fe(III) salts with NaOH was found to produce highly crystalline Fe3O4 nanoparticles. The reaction, if carried out in the presence of surfactant such as oleic acid–oleylamine adduct, generated monodisperse Fe3O4 nanocrystals extractable directly from the reaction mixture. The extracted nanoparticles were capable of forming self-assembled, two-dimensional and uniform periodic array. The new process utilizes inexpensive and nontoxic starting materials, and does not require a use of high boiling point and toxic solvents, thus is amenable to an environmentally desirable, large-scale synthesis of nanocrystals.

scholarly journals Physical Stability and Viscoelastic Properties of Co-Amorphous Ezetimibe/Simvastatin System

2019 ◽  
Vol 12 (1) ◽  
pp. 40 ◽  
Author(s):  
Justyna Knapik-Kowalczuk ◽  
Krzysztof Chmiel ◽  
Karolina Jurkiewicz ◽  
Natália Correia ◽  
Wiesław Sawicki ◽  
...  
Keyword(s):  
Elevated Temperature ◽  
Viscoelastic Properties ◽  
Room Temperature ◽  
Physical Stability ◽  
Ternary Systems ◽  
Storage Conditions ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Conditions ◽  
First Time

The purpose of this paper is to examine the physical stability as well as viscoelastic properties of the binary amorphous ezetimibe–simvastatin system. According to our knowledge, this is the first time that such an amorphous composition is prepared and investigated. The tendency toward re-crystallization of the amorphous ezetimibe–simvastatin system, at both standard storage and elevated temperature conditions, have been studied by means of X-ray diffraction (XRD). Our investigations have revealed that simvastatin remarkably improves the physical stability of ezetimibe, despite the fact that it works as a plasticizer. Pure amorphous ezetimibe, when stored at room temperature, begins to re-crystallize after 14 days after amorphization. On the other hand, the ezetimibe-simvastatin binary mixture (at the same storage conditions) is physically stable for at least 1 year. However, the devitrification of the binary amorphous composition was observed at elevated temperature conditions (T = 373 K). Therefore, we used a third compound to hinder the re-crystallization. Finally, both the physical stability as well as viscoelastic properties of the ternary systems containing different concentrations of the latter component have been thoroughly investigated.

Rapid mechanochemical synthesis of metal–organic frameworks using exogenous organic base

2020 ◽  
Vol 49 (45) ◽  
pp. 16238-16244 ◽  
Author(s):  
Zihao Wang ◽  
Zongzhe Li ◽  
Marcus Ng ◽  
Phillip J. Milner
Keyword(s):  
Mechanochemical Synthesis ◽  
Metal Organic Frameworks ◽  
Solvent Free ◽  
Organic Base ◽  
Metal Organic ◽  
First Time ◽  
Solvent Free Synthesis

We describe the mechanochemical, solvent-free synthesis of metal–organic frameworks using liquid organic base for the first time.

scholarly journals Controlled Morphological Changes in Self-Assembled Structures Formed by Fmoc Variants of Threonine and Serine

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Self Assembly ◽  
Room Temperature ◽  
Morphological Changes ◽  
The Self ◽  
Temperature Conditions ◽  
Morphological Transitions ◽  
Concentration Changes ◽  
Higher Temperature ◽  
Self Assembled ◽  
First Time

<p>We report for the very first time the self-assembly of<a> </a>Fmoc variant 2-(9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butoxy)butanoic acid of threonine (<b>Fmoc-Thr(tbu)-OH</b>) and <a>of serine (</a><b>Fmoc-</b><b>Ser(tbu)-OH</b>. The self-assembled structure formation of Fmoc variants of threonine and serine were examined under varying concentration and temperature conditions..Our studies reveal that the self-assembled structures formed by <b>Fmoc-Thr(tbu)-OH </b>and <b>Fmoc-Ser(tbu)-OH </b>reveal morphological transitions at the supramolecular level as we alter its concentration and temperature. <b>Fmoc-Thr(tbu)-OH </b>self-assembles to sphere at lower concentration which changes to dumb-bell shapes at higher concentration under room temperature conditions. When the solution at lower concentration is heated the spheres changes to rods while the dumb bell shapes at higher concentrations change to elongated dumb-bell-rod like morphologies. <b>Fmoc-Ser(tbu)-OH </b>on<b> </b>the other hand give flower like morphologies at lower concentration which changes to long rods at higher concentration. On heating at higher temperature 70 <sup>ο</sup>C flower-like structures change to small rods while the long rods obtained at higher concentration changes to big flower-like structures. The controlled morphological changes noted in the modified single amino acids is very interesting and pave the way for the design of novel self-assembled architectures for applications in material science and nanotechnology.</p>

Solvent-free, mechanochemical syntheses of bulk trihalide perovskites and their nanoparticles

2017 ◽  
Vol 53 (21) ◽  
pp. 3046-3049 ◽  
Author(s):  
Atanu Jana ◽  
Mona Mittal ◽  
Aayushi Singla ◽  
Sameer Sapra
Keyword(s):  
Solid State ◽  
Room Temperature ◽  
Solvent Free ◽  
Solid State Reactions ◽  
First Time

For the first time, we have synthesized APbBr3 (A = Cs+/MA+/FA+, where MA+ = CH3NH3+ and FA+ = CH(NH2)2+) bulk as well as nanoparticles (NPs) by solid-state reactions at room temperature.

Solvent-free mechanochemical synthesis of alane, AlH3: effect of pressure on the reaction pathway

2014 ◽  
Vol 16 (9) ◽  
pp. 4378-4388 ◽  
Author(s):  
S. Gupta ◽  
T. Kobayashi ◽  
I. Z. Hlova ◽  
J. F. Goldston ◽  
M. Pruski ◽  
...  
Keyword(s):  
Solid State ◽  
Mechanochemical Synthesis ◽  
Room Temperature ◽  
Reaction Pathway ◽  
Gas Pressure ◽  
Solvent Free ◽  
Metallic Aluminum ◽  
Effect Of Pressure

By application of reasonably low gas pressure, formation of metallic aluminum is completely suppressed during the solid-state mechanochemical synthesis of AlH3 at room temperature.

scholarly journals Controlled Morphological Changes in Self-Assembled Structures Formed by Fmoc Variants of Threonine and Serine

2021 ◽  
Author(s):  
Vivekshinh Kshtriya ◽  
Bharti Koshti ◽  
Nidhi Gour
Keyword(s):  
Self Assembly ◽  
Room Temperature ◽  
Morphological Changes ◽  
The Self ◽  
Temperature Conditions ◽  
Morphological Transitions ◽  
Concentration Changes ◽  
Higher Temperature ◽  
Self Assembled ◽  
First Time

<p>We report for the very first time the self-assembly of<a> </a>Fmoc variant 2-(9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(tert-butoxy)butanoic acid of threonine (<b>Fmoc-Thr(tbu)-OH</b>) and <a>of serine (</a><b>Fmoc-</b><b>Ser(tbu)-OH</b>. The self-assembled structure formation of Fmoc variants of threonine and serine were examined under varying concentration and temperature conditions..Our studies reveal that the self-assembled structures formed by <b>Fmoc-Thr(tbu)-OH </b>and <b>Fmoc-Ser(tbu)-OH </b>reveal morphological transitions at the supramolecular level as we alter its concentration and temperature. <b>Fmoc-Thr(tbu)-OH </b>self-assembles to sphere at lower concentration which changes to dumb-bell shapes at higher concentration under room temperature conditions. When the solution at lower concentration is heated the spheres changes to rods while the dumb bell shapes at higher concentrations change to elongated dumb-bell-rod like morphologies. <b>Fmoc-Ser(tbu)-OH </b>on<b> </b>the other hand give flower like morphologies at lower concentration which changes to long rods at higher concentration. On heating at higher temperature 70 <sup>ο</sup>C flower-like structures change to small rods while the long rods obtained at higher concentration changes to big flower-like structures. The controlled morphological changes noted in the modified single amino acids is very interesting and pave the way for the design of novel self-assembled architectures for applications in material science and nanotechnology.</p>

Preparation and Characterization of a Novel Room Temperature Dicationic Ionic Liquid and its Application in the Synthesis of Xanthenediones Under Solvent-Free Conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Reaction Times ◽  
Significant Loss ◽  
Solvent Free ◽  
Acidity Function ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Hammett Acidity Function ◽  
Dicationic Ionic Liquid

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.

scholarly journals Mechanochemical synthesis of poly(trimethylene carbonate)s: an example of rate acceleration

2019 ◽  
Vol 15 ◽  
pp. 963-970 ◽  
Author(s):  
Sora Park ◽  
Jeung Gon Kim
Keyword(s):  
Ball Milling ◽  
Mechanochemical Synthesis ◽  
Polymeric Materials ◽  
Solvent Free ◽  
Energy Output ◽  
Polymerization Temperature ◽  
Mechanical Degradation ◽  
Trimethylene Carbonate ◽  
Rate Acceleration ◽  
Conventional Solution

Mechanochemical polymerization is a rapidly growing area and a number of polymeric materials can now be obtained through green mechanochemical synthesis. In addition to the general merits of mechanochemistry, such as being solvent-free and resulting in high conversions, we herein explore rate acceleration under ball-milling conditions while the conventional solution-state synthesis suffer from low reactivity. The solvent-free mechanochemical polymerization of trimethylene carbonate using the organocatalysts 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) and 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) are examined herein. The polymerizations under ball-milling conditions exhibited significant rate enhancements compared to polymerizations in solution. A number of milling parameters were evaluated for the ball-milling polymerization. Temperature increases due to ball collisions and exothermic energy output did not affect the polymerization rate significantly and the initial mixing speed was important for chain-length control. Liquid-assisted grinding was applied for the synthesis of high molecular weight polymers, but it failed to protect the polymer chain from mechanical degradation.

scholarly journals Influence of a Standing Wave Flow-Field on the Dynamics of a Spray Diffusion Flame

Fluids ◽  
2021 ◽  
Vol 6 (1) ◽  
pp. 27
Author(s):  
J. Barry Greenberg ◽  
David Katoshevski
Keyword(s):  
Liquid Phase ◽  
Flow Field ◽  
Standing Wave ◽  
Diffusion Flame ◽  
Stokes Number ◽  
Flame Height ◽  
Wave Flow ◽  
Two Dimensional ◽  
Governing Equations ◽  
First Time

A theoretical investigation of the influence of a standing wave flow-field on the dynamics of a laminar two-dimensional spray diffusion flame is presented for the first time. The mathematical analysis permits mild slip between the droplets and their host surroundings. For the liquid phase, the use of a small Stokes number as the perturbation parameater enables a solution of the governing equations to be developed. Influence of the standing wave flow-field on droplet grouping is described by a specially constructed modification of the vaporization Damkohler number. Instantaneous flame front shapes are found via a solution for the usual Schwab–Zeldovitch parameter. Numerical results obtained from the analytical solution uncover the strong bearing that droplet grouping, induced by the standing wave flow-field, can have on flame height, shape, and type (over- or under-ventilated) and on the existence of multiple flame fronts.

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