Browse
Submit Data
Databases
API
Help

Dataset Information

49 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Microwave-Assisted Vacuum Synthesis of TiO₂ Nanocrystalline Powders in One-Pot, One-Step Procedure.

ABSTRACT: A new method for fast and simple synthesis of crystalline TiO₂ nanoparticles with photocatalytic activity was developed by carrying out a classic sol-gel reaction directly under vacuum. The use of microwaves for fast heating of the reaction medium further reduces synthesis times. When the solvent is completely removed by vacuum, the product is obtained in the form of a powder that can be easily redispersed in water to yield a stable nanoparticle suspension, exhibiting a comparable photocatalytic activity with respect to a commercial product. The present methodology can, therefore, be considered a process intensification procedure for the production of nanotitania.

SUBMITTER: Paradisi E

PROVIDER: S-EPMC8746694 | biostudies-literature | 2021 Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Microwave-Assisted Vacuum Synthesis of TiO<sub>2</sub> Nanocrystalline Powders in One-Pot, One-Step Procedure.

Paradisi Enrico E Rosa Roberto R Baldi Giovanni G Dami Valentina V Cioni Andrea A Lorenzi Giada G Leonelli Cristina C

Nanomaterials (Basel, Switzerland) 20211231 1

A new method for fast and simple synthesis of crystalline TiO<sub>2</sub> nanoparticles with photocatalytic activity was developed by carrying out a classic sol-gel reaction directly under vacuum. The use of microwaves for fast heating of the reaction medium further reduces synthesis times. When the solvent is completely removed by vacuum, the product is obtained in the form of a powder that can be easily redispersed in water to yield a stable nanoparticle suspension, exhibiting a comparable pho ...[more]

PMID: 35010100

Similar Datasets

Microwave assisted, sequential two-step, one-pot synthesis of novel imidazo[1,2-a]pyrimidine containing tri/tetrasubstituted imidazole derivatives.

Project description:A series of novel imidazo[1,2- a ]pyrimidine containing tri/tetrasubstituted imidazole derivatives (1-10) has been synthesized via sequential two-step, one-pot, multicomponent reaction using imidazo[1,2- a ]pyrimidine-2-carbaldehyde, benzil, primary amines, and ammonium acetate catalyzed by p -toluenesulfonic acid under microwave-assisted conditions. The results showed that target compounds can be obtained from a wide range of primary amines bearing different functional groups with moderate to good yields (46%-80%) under optimum reaction conditions. This method provides a green protocol for imidazo[1,2- a ]pyrimidine containing tri/tetrasubstituted imidazole derivatives due to ethyl alcohol as a green solvent, microwave irradiation as a greener heating method and one-pot multicomponent reaction as a green technique. The synthesized compounds have been elucidated using various spectroscopic tools such as FT-IR, 1H NMR, 13 C NMR, and MS.

| S-EPMC7925308 | biostudies-literature

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water.

Project description:The hydantoin scaffold is renowned for its wide-ranging biological activities, including antibacterial, antiviral, anticancer, anti-inflammatory, and anticonvulsant effects. In this study, we present an innovative, sustainable approach to synthesizing hydantoins (H2a-j) directly from amino acids. This method employs a column chromatography-free, two-step, one-pot microwave-assisted synthesis that delivers hydantoins in yields ranging from 34% to 89%. The protocol demonstrates exceptional functional group tolerance, accommodating phenyl, aliphatic, phenol, alcohol, heterocyclic, and sulfide groups. This scalable, rapid, and eco-friendly strategy offers a promising avenue for the efficient synthesis of hydantoins, aligning with green chemistry principles and expanding the accessibility of these bioactive compounds for pharmaceutical applications.

| S-EPMC11912639 | biostudies-literature

A novel one-pot and one-step microwave-assisted cyclization-methylation reaction of amino alcohols and acetylated derivatives with dimethyl carbonate and TBAC.

Project description:A simple and efficient microwave-assisted methodology for the synthesis of 4-substituted-3-methyl-1,3-oxazolidin-2-ones from amino alcohols catalyzed by a ionic liquid was developed. This novel one-pot and one-step cyclization-methylation reaction represents an easier and faster method than any other reported protocols that can be used to obtain the desired products in good yields and high purity. Applying microwave irradiation at 130°C in the presence of TBAC, dimethyl carbonate acts simultaneously as carbonylating and methylating agent and surprisingly promotes an in situ basic trans esterification when a N-acetylated amino alcohol is used as starting material. Furthermore, dimethyl carbonate worked better than diethyl carbonate in performing this reaction.

| S-EPMC4322309 | biostudies-literature

Microwave-Assisted, One-Pot Synthesis of Doxycycline under Heterogeneous Catalysis in Water.

Project description:The selective synthesis of active pharmaceutical molecules is a challenging issue, particularly when attempting to make the reactions even more sustainable. The present work focuses on the microwave-assisted hydrogenolysis of oxytetracycline to selectively produce α-doxycycline. Although the combination of microwave irradiation and a heterogeneous rhodium catalyst provided good conversions, the selective synthesis of active α-doxycycline was only achieved when an oxytetracycline-cyclodextrin complex was used as the starting material, giving the desired product at 34.0% yield in a one-step reaction under very mild conditions.

| S-EPMC8466421 | biostudies-literature

A green metal-free "one-pot" microwave assisted synthesis of 1,4-dihydrochromene triazoles.

Project description:The synthesis of several 4-aryl-1,4-dihydrochromene-triazoles was achieved via a metal-free "one-pot" procedure using PEG400 as the sole solvent in an eco-friendly process. Using microwave irradiation, the triazole derivatives were obtained in good yields and short reaction times starting from readily accessible building blocks.

| S-EPMC8695595 | biostudies-literature

Microwave assisted one-pot green synthesis of cinnoline derivatives inside natural sporopollenin microcapsules.

Project description:We present a green and efficient approach for the synthesis of novel cinnoline derivatives inside natural Lycopodium clavatum sporopollenin (LCS) microcapsules via a one-pot microwave (MW) assisted reaction for the first time. We also propose the concept that the robust micrometre-sized sporopollenin microcapsules can act as MW microreactors. We demonstrate the feasibility of this concept by in situ synthesising 8-hydroxy-7-nitro-6-(3-nitrophenyl)-3-oxo-2-(p-tolyl)-2,3,5,6-tetrahydrocinnoline-4-carbonitrile inside the LCS microcapsules via a microwave (MW) assisted reaction of ethyl 5-cyano-4-methyl-6-oxo-1-(p-tolyl)-1,6-dihydropyridazine-3-carboxylate with 1-nitro-2-phenylethylene in the presence of piperidine as a base at 100 °C for 20 minutes. The LCS microparticles are extensively characterised before and after the MW induced reaction using several techniques. The formation of the cinnoline compound inside the LCS microcapsules is confirmed by laser scanning confocal microscopy (LSCM), X-ray diffraction (XRD) and fourier-transform infrared spectroscopy (FTIR) analyses. Using liquid chromatography-mass spectrometry (LCMS) analyses, we show that the structural integrity of the cinnoline compound, recovered from the cinnoline loaded (cinn-loaded) LCS, is preserved. The pure cinnoline is found to show promising optical properties with two λ max absorption peaks at 310 and 610 nm. Both the pure cinnoline and cinn-loaded LCS show promising antibacterial activity against Pseudomonas aeruginosa (Gram-negative) and Bacillus cereus (Gram-negative) human pathogenic bacterial strains. The successful MW induced reaction of the prominent cinnoline derivative inside the biocompatible LCS microreactors can open up intriguing applications in materials and pharmaceutical sciences.

| S-EPMC9081757 | biostudies-literature

Synthesis of Substituted Benzaldehydes via a Two-Step, One-Pot Reduction/Cross-Coupling Procedure.

Project description:The synthesis of functionalized (benz)aldehydes, via a two-step, one-pot procedure, is presented. The method employs a stable aluminum hemiaminal as a tetrahedral intermediate, protecting a latent aldehyde, making it suitable for subsequent cross-coupling with (strong nucleophilic) organometallic reagents, leading to a variety of alkyl and aryl substituted benzaldehydes. This very fast methodology also facilitates the effective synthesis of a 11C radiolabeled aldehyde. Aluminum-ate complexes enable transmetalation of alkyl fragments onto palladium and subsequent cross-coupling.

| S-EPMC6558639 | biostudies-literature

Microwave-assisted one-step synthesis of water-soluble manganese-carbon nanodot clusters.

Project description:Using metal coordination to assemble carbon nanodots (CND) into clusters can enhance their photophysical properties for applications in sensing and biomedicine. Water-soluble clusters of CNDs are prepared by one-step microwave synthesis starting from ethylenediaminetetraacetic acid, ethylenediamine and MnCl2·4H2O as precursors. Transmission electron microscopy and powder X-Ray diffraction techniques indicate that the resulting clusters form spherical particles of 150 nm constituted by amorphous CNDs joined together with Mn ions in a laminar crystalline structure. The nanomaterial assemblies show remarkable fluorescence quantum yields (0.17-0.20) and magnetic resonance imaging capability (r1 = 2.3-3.8 mM-1.s-1). In addition, they can be stabilized in aqueous solutions by phosphate ligands, providing a promising dual imaging platform for use in biological systems.

| S-EPMC10447561 | biostudies-literature

Deformation-Thermal Co-Induced Ferromagnetism of Austenite Nanocrystalline FeCoCr Powders for Strong Microwave Absorption.

Project description:Nanocrystalline soft magnetic alloy powders are promising microwave absorbents since they can work at diverse frequencies and are stable in harsh environments. However, when the alloy powders are in austenite phase, they are out of the screen for microwave absorbents due to their paramagnetic nature. In this work, we reported a strategy to enable strong microwave absorption in nanocrystalline austenite FeCoCr powders by deformation-thermal co-induced ferromagnetism via attritor ball milling and subsequent heat treatment. Results showed that significant austenite-to-martensite transformation in the FeCoCr powders was achieved during ball milling, along with the increase in shape anisotropy from spherical to flaky. The saturation magnetization followed parabolic kinetics during ball milling and rose from 1.43 to 109.92 emu/g after milling for 4 h, while it exhibited a rapid increase to 181.58 emu/g after subsequent heat treatment at 500 °C. A considerable increase in complex permeability and hence magnetic loss capability was obtained. With appropriate modulation of complex permittivity, the resultant absorbents showed a reflection loss of below -6 dB over 8~18 GHz at thickness of 1 mm and superior stability at 300 °C. Our strategy can broaden the material selection for microwave absorbents by involving Fe-based austenite alloys and simply recover the ferromagnetism of industrial products made without proper control of the crystalline phase.

| S-EPMC9268570 | biostudies-literature

Microwave-Assisted Sequential One-Pot Synthesis of 8-Substituted Pyrazolo[1,5-a][1,3,5]triazines.

Project description:This paper reports a convenient sequential one-pot approach for the synthesis of an array of 14 pyrazolo[1,5-a][1,3,5]triazines, substituted in C8 by halogen (Br), various functions (CN and CO2Et) and alkyl or (het)aryl groups. This study confirms the interest of combining the efficient heating obtained under dielectric microwave heating and the achievement of sequential one-pot reactions, avoiding the tedious work-up and purification of intermediate compounds, achieving sustainable synthesis processes. Considering usual conventional methods, this microwave protocol is featured by advantages in terms of yields, reaction times, and convenient gram scale synthesis.

| S-EPMC8230123 | biostudies-literature