scholarly journals Tuning the Morphology in the Nanoscale of NH4CN Polymers Synthesized by Microwave Radiation: A Comparative Study

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 57
Author(s):  
Cristina Pérez-Fernández ◽  
Pilar Valles ◽  
Elena González-Toril ◽  
Eva Mateo-Martí ◽  
José Luis de la Fuente ◽  
...  
Keyword(s):  
Soft Matter ◽  
Compositional Data ◽  
Low Cost ◽  
Reaction Times ◽  
Principal Component ◽  
Simultaneous Thermal Analysis ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
Thermal Methods ◽  
Macromolecular Systems

A systematic study is presented to explore the NH4CN polymerization induced by microwave (MW) radiation, keeping in mind the recent growing interest in these polymers in material science. Thus, a first approach through two series, varying the reaction times and the temperatures between 130 and 205 °C, was conducted. As a relevant outcome, using particular reaction conditions, polymer conversions similar to those obtained by means of conventional thermal methods were achieved, with the advantage of a very significant reduction of the reaction times. The structural properties of the end products were evaluated using compositional data, spectroscopic measurements, simultaneous thermal analysis (STA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). As a result, based on the principal component analysis (PCA) from the main experimental results collected, practically only the crystallographic features and the morphologies in the nanoscale were affected by the MW-driven polymerization conditions with respect to those obtained by classical syntheses. Therefore, MW radiation allows us to tune the morphology, size and shape of the particles from the bidimensional C=N networks which are characteristic of the NH4CN polymers by an easy, fast, low-cost and green-solvent production. These new insights make these macromolecular systems attractive for exploration in current soft-matter science.

scholarly journals Natural Mordenite from Spain as Pozzolana

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1220
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo A. Martín ◽  
Isabel Díaz
Keyword(s):  
Mechanical Test ◽  
Low Cost ◽  
Principal Component ◽  
Test Results ◽  
Mechanical Compression ◽  
San Jose ◽  
X Ray Diffraction ◽  
Pozzolanic Cement ◽  
Natural Clinoptilolite ◽  
Potential Use

This work deals with anomalous concentrations of natural mordenite in the southeast of Spain. The X-ray diffraction (XRD) and scanning electron microscopy (SEM) studies evidenced that the samples contain mainly monomineral zeolitic phase of mordenite (70% to 74%), usually accompanied by smectite (montmorillonite), the principal component of bentonite. A study of the applicability of these zeolites is presented to establish the potential use as pozzolanic cements. For comparative purposes, synthetic commercial mordenite is also characterized and tested. The initial mixtures were prepared using cement and mordenite at a 75:25 ratio. Chemical analysis and a pozzolanicity test showed the high pozzolanic character. These mixtures were further added to sand and water, yielding the cement specimens to be used as concrete. Mechanical test results showed that the mechanical compression at 7 and 28 days fall into the range of 19.23 to 43.05 MegaPascals (MPa) for the cement specimens built with natural mordenites. The obtained results fall in the same range of cement specimens prepared with natural clinoptilolite, using mixtures within the European requirement for commercial concretes. Thus, these results and the low cost of natural mordenite of San José de los Escullos deposit supports the potential use of natural mordenite as pozzolanic cement.

scholarly journals Polystyrene-supported aluminum chloride as an efficient and reusable catalyst for condensation of indole with various carbonyl compounds

2010 ◽  
Vol 75 (4) ◽  
pp. 423-431 ◽  
Author(s):  
Bahman Tamami ◽  
Nasrolahi Shirazi ◽  
Parvanak Borujeni
Keyword(s):  
Aluminum Chloride ◽  
Carbonyl Compounds ◽  
Low Cost ◽  
Reaction Times ◽  
Reusable Catalyst ◽  
Reaction Conditions ◽  
Crosslinked Polystyrene ◽  
Aldehydes And Ketones ◽  
Polymeric Catalyst ◽  
Work Up

Crosslinked polystyrene-supported aluminum chloride (Ps-AlCl3) is a stable, recyclable and environmental friendly heterogeneous catalyst for the condensation of indole with aldehydes and ketones to afford bis-indolylmethanes. In addition, (Ps-AlCl3) shows satisfactory selectivity in the reaction of mixtures of an aldehyde and a ketone with indole. Although AlCl3 is a water sensitive, corrosive and environmentally harmful compound, Ps-AlCl3 is a stable and water-tolerant species. The mild reaction conditions, short reaction times, easy work-up, high to excellent yields, chemoselectivity, reuse of the catalyst for at least ten times without significant change in its catalytic activity, low cost, and easy preparation and handling of the polymeric catalyst are obvious advantages of the present method.

scholarly journals Influence of Wood-Based Biomass Ash Admixing on the Structural, Mechanical, Hygric, and Thermal Properties of Air Lime Mortars

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2227 ◽  
Author(s):  
Milena Pavlíková ◽  
Lucie Zemanová ◽  
Jaroslav Pokorný ◽  
Martina Záleská ◽  
Ondřej Jankovský ◽  
...  
Keyword(s):  
Building Materials ◽  
Mechanical Test ◽  
Low Cost ◽  
Simultaneous Thermal Analysis ◽  
Fluorescence Analysis ◽  
X Ray Diffraction ◽  
Biomass Ash ◽  
X Ray ◽  
Binder Ratio ◽  
Active Admixture

Mechanically-activated wood-based biomass ash (WBA) was studied as a potential active admixture for design of a novel lime-pozzolan-based mortar for renovation purposes. The replacement ratio of lime hydrate in a mortar mix composition was 5%, 10%, and 15% by mass. The water/binder ratio and the sand/binder ratio were kept constant for all examined mortar mixes. Both binder constituents were characterized by their powder density, specific density, BET (Brunauer–Emmett–Teller), and Blaine specific surfaces. Their chemical composition was measured by X-ray fluorescence analysis (XRF) and mineralogical analysis was performed using X-ray diffraction (XRD). Morphology of WBA was investigated by scanning electron microscopy (SEM) and element mapping was performed using an energy dispersive spectroscopy (EDS) analyzer. The pozzolanic activity of WBA was tested by the Chapelle test and assessment of the Portlandite content used simultaneous thermal analysis (STA). For the hardened mortar samples, a complete set of structural, mechanical, hygric, and thermal parameters was experimentally determined. The mortars with WBA admixing yielded similar or better functional properties than those obtained for traditional pure lime-based plaster, pointing to their presumed application as rendering and walling renovation mortars. As the Chapelle test, STA, and mechanical test proved high pozzolanity of WBA, it was classified as an alternative eco-efficient low-cost pozzolan for use in lime blend-based building materials. The savings in CO2 emissions and energy by the use of WBA as a partial lime hydrate substitute in mortar composition were also highly appreciated with respect to the sustainability of the construction industry.

Regio- and Diastereoselective Synthesis of Novel Polycyclic Pyrrolo[2,1-a]isoquinolines Bearing Indeno[1,2-b]quinoxaline Moieties by a Three-Component [3+2]-Cycloaddition Reaction

Synlett ◽  
2019 ◽  
Vol 31 (03) ◽  
pp. 267-271 ◽  
Author(s):  
Firouz Matloubi Moghaddam ◽  
Atiyeh Moafi ◽  
Behzad Jafari ◽  
Alexander Vilinger ◽  
Peter Langer
Keyword(s):  
Cycloaddition Reaction ◽  
Reaction Times ◽  
Dipolar Cycloaddition ◽  
Diastereoselective Synthesis ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
One Pot ◽  
Three Component Reaction ◽  
Relative Stereochemistry ◽  
High Yields

A regio- and diastereoselective synthesis of 2,3-dihydro-10b′H-spiro[indeno[1,2-b]quinoxaline-11,1′-pyrrolo[2,1-a]isoquinoline]-2′,3′-diylbis(phenylmethanone) derivatives containing four contiguous chiral stereocenters was achieved through 1,3-dipolar cycloaddition of isoquinolinium N-ylides in a one-pot three-component reaction. The desired products were obtained in short reaction times and in moderate to high yields (up to 92%) under relatively mild reaction conditions. The structure and relative stereochemistry of the desired product was confirmed by X-ray diffraction analysis.

A Novel and Facile Synthesis of Thiopyrimidines and O-Glucosides

2019 ◽  
Vol 4 (2) ◽  
pp. 65-69
Author(s):  
Rajendra Krushnaji Wanare
Keyword(s):  
Low Cost ◽  
Reaction Times ◽  
Alcoholic Solution ◽  
Mass Spectral Data ◽  
Reaction Conditions ◽  
Mass Spectral ◽  
Antibacterial And Antifungal Activities ◽  
Ft Ir ◽  
Antibacterial And Antifungal ◽  
Subsequent Deacetylation

Reaction of 3-methyl-5-(3'-aryl prop-2'-enoyl)-1,2-benzisoxazole (1a-j) with thiourea and alcoholic solution of KOH afforded 3-methyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (2a-j). Oxidation of products 2a-j using alkaline KMnO4 solution produces 5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylic acids (3a-j). Condensation of products 3a-j with 2,3,4,6-tetra-Oacetyl-α-D-glucopyranosyl bromide (TAGBr), the glucosylating agent synthesized 3-(2,3,4,6-tetra-O-acetyl-3-acetyl-β-D-glucopyranosyl)-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazoles (4a-j). Subsequent deacetylation of compounds 4a-j were carried out with CH3ONa furnishes β-Dglucopyranosyl-5-(4'-aryl-2'-thiopyrimidin-6'-yl)-1,2-benzisoxazole-3-carboxylates (5a-j). All the synthesized compounds were analyzed by elemental analysis (C, H and N), FT-IR, 1H NMR and mass spectral data. Most of the prepared compounds were analyzed their antibacterial and antifungal activities by cup-plate method. The present approach offers several advantages such as shorter reaction times, cleaner reactions, good yields, low-cost reagent and mild reaction conditions.

scholarly journals Development of Biodegradable Agar-Agar/Gelatin-Based Superabsorbent Hydrogel as an Efficient Moisture-Retaining Agent

Biomolecules ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 939 ◽  
Author(s):  
Jyoti Chaudhary ◽  
Sourbh Thakur ◽  
Minaxi Sharma ◽  
Vijai Kumar Gupta ◽  
Vijay Kumar Thakur
Keyword(s):  
Low Cost ◽  
X Ray Diffraction ◽  
Natural Polymers ◽  
Reaction Conditions ◽  
Superabsorbent Hydrogel ◽  
X Ray ◽  
Microwave Assisted ◽  
Water Swelling ◽  
Water Holding ◽  
Scanning Electron

Downgrading in the yield of crop is due to the inadequate availability of water. The way out for this trouble is to construct synthetic resources dependent on natural polymers with great water absorption and preservation limits. The present study investigated the design of agar-agar (Agr) and gelatin (GE) copolymerized methyl acrylate (MA) and acrylic acid (AA) hydrogel (Agr/GE-co-MA/AA) as a soil conditioner for moisture maintenance in agriculture. Agr/GE-co-MA/AA hydrogel was prepared by utilizing microwave-assisted green synthesis following the most suitable reaction conditions to obtain a remarkable water swelling percentage. The fabricated Agr/GE-co-MA/AA hydrogel was investigated through field emission scanning electron microscopy (FESEM), fourier transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD). The water holding capacity of the soil and sand was examined by mixing Agr/GE-co-MA/AA hydrogel with soil and sand. The result demonstrates that the water holding time extended from 10 to 30 days for soil and 6 to 10 days for sand by using Agr/GE-co-MA/AA hydrogel. This synthesized biodegradable, low-cost and non-toxic Agr/GE-co-MA/AA hydrogel shows novelty as soil water maintaining material for irrigation in agriculture.

scholarly journals 1, 3, 5-Tris (2-hydroxyethyl) Isocyanurate Functionalized SBA-15 (THEIC-SBA-15): as a Novel Heterogeneous Nano-Catalyst for the One-Pot Three-Component Synthesis of Tetrahydrobenzo [b] Pyrans in Water

2020 ◽  
Vol 10 (6) ◽  
pp. 6706-6717
Keyword(s):  
Electron Microscopy ◽  
Low Cost ◽  
Ethyl Cyanoacetate ◽  
Reaction Times ◽  
Hexagonal Structure ◽  
Reaction Conditions ◽  
One Pot ◽  
Transition Electron Microscopy ◽  
Nano Catalyst ◽  
The One

1, 3, 5-Tris (2-hydroxyethyl) isocyanurate functionalized SBA-15 is used as a novel, highly efficient, and recyclable heterogeneous nano-catalyst for the one-pot 3-component synthesis of tetrahydro benzo [b] pyran derivatives. These unique derivatives were synthesized through the condensation reactions of the enolizable compounds, different aldehydes, and malononitrile (or ethyl cyanoacetate) under the mild reaction conditions, in the short reaction times, and gives excellent yields in the refluxing H2O as a green solvent. The accuracy of synthesizing functionalized SBA-15 was confirmed with FT-IR spectroscopy. Then the catalyst was characterized by scanning electron microscopy (SEM), transition electron microscopy (TEM), and surface area analysis (BET). TEM images demonstrated that the synthesized catalyst had a hexagonal structure. Simplicity in the operation, rapidity, high yields, low cost, mild reaction conditions, catalyst with low loading, evading the usage of toxic change metals, stability, and the catalyst reusability are the main advantages of the proposed protocol.

Iterative Supervised Principal Component Analysis-Driven Ligand Design for Regioselective Ti-Catalyzed Pyrrole Synthesis

2020 ◽  
Author(s):  
Xin Yi See ◽  
Benjamin Reiner ◽  
Xuelan Wen ◽  
T. Alexander Wheeler ◽  
Channing Klein ◽  
...  
Keyword(s):  
Principal Component Analysis ◽  
De Novo ◽  
Principal Component ◽  
Component Analysis ◽  
Catalyst Design ◽  
Data Driven ◽  
Initial Reaction ◽  
Training Set ◽  
Reaction Conditions ◽  
Component Loadings

<div> <div> <div> <p>Herein, we describe the use of iterative supervised principal component analysis (ISPCA) in de novo catalyst design. The regioselective synthesis of 2,5-dimethyl-1,3,4-triphenyl-1H- pyrrole (C) via Ti- catalyzed formal [2+2+1] cycloaddition of phenyl propyne and azobenzene was targeted as a proof of principle. The initial reaction conditions led to an unselective mixture of all possible pyrrole regioisomers. ISPCA was conducted on a training set of catalysts, and their performance was regressed against the scores from the top three principal components. Component loadings from this PCA space along with k-means clustering were used to inform the design of new test catalysts. The selectivity of a prospective test set was predicted in silico using the ISPCA model, and only optimal candidates were synthesized and tested experimentally. This data-driven predictive-modeling workflow was iterated, and after only three generations the catalytic selectivity was improved from 0.5 (statistical mixture of products) to over 11 (> 90% C) by incorporating 2,6-dimethyl- 4-(pyrrolidin-1-yl)pyridine as a ligand. The successful development of a highly selective catalyst without resorting to long, stochastic screening processes demonstrates the inherent power of ISPCA in de novo catalyst design and should motivate the general use of ISPCA in reaction development. </p> </div> </div> </div>

Surfactant involved in Copper Sulfide Nanocrystallites Synthesis

2009 ◽  
Vol 59 (12) ◽  
Author(s):  
Claudia Maria Simonescu ◽  
Valentin Serban Teodorescu ◽  
Camelia Capatina
Keyword(s):  
Copper Sulfide ◽  
X Ray Diffraction ◽  
Reaction Parameters ◽  
Reaction Conditions ◽  
X Ray ◽  
Selected Area Electron Diffraction ◽  
Transmission Electron ◽  
Shape Of Nanoparticles ◽  
Tem Transmission Electron Microscopy ◽  
Shape And Size

This paper presents the obtaining of copper sulfide CuS (covelite) from Cu(CH3COO)2.H2O and thioacetamide (TAA) system. The reaction was conducted in presence or absence of sodium-bis(2-ethylhexyl) sulfosuccinate (Na-AOT). The effects of various reaction parameters on the size and on the shape of nanoparticles have been examined. CuS obtained was characterized by X ray diffraction, IR spectroscopy, TEM � transmission electron microscopy and SAED selected area electron diffraction. The influence of surfactant to the shape and size of CuS (covellite) nanocrystals was established. The size of the nanocrystals varied from 10-60 nm depending on the reaction conditions such as quantity of surfactant.

Synthesis of Phosphonates via Michaelis-Arbuzov Reaction

2017 ◽  
Vol 14 (6) ◽  
pp. 883-903 ◽  
Author(s):  
Boppudi Hari Babu ◽  
Gandavaram Syam Prasad ◽  
Chamarthi Naga Raju ◽  
Mandava Venkata Basaveswara Rao
Keyword(s):  
Reaction Times ◽  
Biologically Active ◽  
Fine Tuning ◽  
Arbuzov Reaction ◽  
Reaction Conditions ◽  
Solvent Type ◽  
Potential Applications ◽  
Synthetic Methodologies ◽  
Optimal Reaction ◽  
The Arbuzov Reaction

Background: Michaelis–Arbuzov reaction has played a key role for the synthesis of dialkyl or diaryl phosphonates by reacting various alkyl or aryl halides with trialkyl or triaryl phosphite. This reaction is very versatile in the formation of P-C bond from the reaction of aliphatic halides with phosphinites or phosphites to yield phosphonates, phosphinates, phosphine oxides. The Arbuzov reaction developed some methodologies, possible mechanistic pathways, selectivity, potential applications and biologically active various phosphonates. Objective: The synthesis of phosphonates via Michaelis–Arbuzov reaction with many new and fascinating methodologies were developed and disclosed in the literature, and these are explored in this review. Conclusion: This review has discussed past developments and vast potential applications of Arbuzov reaction in the synthesis of organophosphonates. As presented in this review, various synthetic methodologies were developed to prepare a large variety of phosphonates. Improvements in the reaction conditions of Lewis-acid mediated Arbuzov rearrangement as well as the development of MW-assisted Arbuzov rearrangement were discussed. Finally, to achieve high selectivities and yields, fine-tuning of reaction conditions including solvent type, temperature, and optimal reaction times to be considered.

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