One-pot Microwave Synthesis Research Articles

One-pot microwave synthesis of NiO/MnO2 composite as a high-performance electrode material for supercapacitors

A facile and energy efficient microwave synthesis of NiO/MnO2 composite is presented in this study. The NiO nanoparticles (∼30 nm) and composite of NiO nanoparticles with nano-particle MnO2 were grown on the surface of graphite. The morphologies and electrochemical performance of NiO@graphite and NiO/MnO2@graphite composite were tested and compared. The SEM results showed that addition of MnO2 prevented the agglomeration of NiO nanoparticles. The electrochemical results of NiO/MnO2@graphite has demonstrated better performance than NiO@graphite, with higher specific capacitance of 102.78 mAh g−1 at 1 A g−1 and superior cycling stability with specific capacitance retention of 140% over more than 1500 cycles. The excellent electrochemical performance of NiO/MnO2@graphite makes it suitable for electrode material of supercapacitors.

Rapid fabrication of TiO2@carboxymethyl cellulose coatings capable of shielding UV, antifog and delaying support aging

Agricultural plastic films capable of shielding UV, filtering visible light and antifog are important to prolong their life and protect safeties of agriculturists and crops. In this work, high stable and small size TiO2@polymer nanoparticles (NPs) were prepared by an efficient one-pot microwave synthesis using titanic sulfate as Ti resource, carboxymethyl cellulose sodium (CMC) as complexing agent and stabilizer. The TiO2@CMC NPs obtained were then utilized to fabricate poly(ethylene imine) (PEI)/TiO2@CMC coatings on the surface of polypropylene films by a layer-by-layer assembly technique. The TiO2@CMC NPs show rapid deposition rate because small, spherical and anion-rich TiO2@CMC NPs possess large specific surface area and fast diffusion rate. More importantly, property experiments confirm that (PEI/TiO2@CMC)*15 coatings can not only effectively shield UV rays, filter visible light and prevent fogging but also delay the aging of their supports.

One-Pot Microwave Synthesis of Water-Dispersible, High Fluorescence Silicon Nanoparticles and Their Imaging Applications in Vitro and in Vivo.

Silicon nanoparticles (SiNPs) have been reported to be synthesized by microwave-assisted methods under high pressure. However, there is still a lack of knowledge about the synthesis of SiNPs via microwave-assisted methods under normal pressure. Here we developed a new, facile, one-pot microwave-assisted method for the synthesis SiNPs (∼4.2 nm) with excellent water solubility under normal pressure by employing glycerol as the solvent. Furthermore, glycerol might be responsible for the photoluminescence quantum yield (PLQY) value up to 47% for the resultant SiNPs. The use of organic solvent could afford less nanoparticle surface defects compared with those prepared in aqueous solution, thus improving the fluorescent efficiency. The as-prepared SiNPs simultaneously featured bright blue-green fluorescence, long lifetime (∼12.8 ns), obvious up-conversion luminescence originating from two-photon absorption, superbly strong photostability, and favorable low toxicity. As a satisfactory probe, the as-synthesized SiNPs were successfully applied in fluorescence imaging of human cervical carcinoma cell lines (HeLa) and zebrafish.

Rapid microwave-assisted synthesis of sub-30 nm lipid nanoparticles

HypothesisAccessing the phase inversion temperature by microwave heating may enable the rapid synthesis of small lipid nanoparticles. ExperimentsNanoparticle formulations consisted of surfactants Brij 78 and Vitamin E TPGS, and trilaurin, trimyristin, or miglyol 812 as nanoparticle lipid cores. Each formulation was placed in water and heated by microwave irradiation at temperatures ranging from 65°C to 245°C. We observed a phase inversion temperature (PIT) for these formulations based on a dramatic decrease in particle Z-average diameters. Subsequently, nanoparticles were manufactured above and below the PIT and studied for (a) stability toward dilution, (b) stability over time, (c) fabrication as a function of reaction time, and (d) transmittance of lipid nanoparticle dispersions. FindingsLipid-based nanoparticles with distinct sizes down to 20–30nm and low polydispersity could be attained by a simple, one-pot microwave synthesis. This was carried out by accessing the phase inversion temperature using microwave heating. Nanoparticles could be synthesized in just one minute and select compositions demonstrated high stability. The notable stability of these particles may be explained by the combination of van der Waals interactions and steric repulsion. 20–30nm nanoparticles were found to be optically transparent.

Ligand Passivated Core–Shell FePt@Co Nanomagnets Exhibiting Enhanced Energy Product

A one-pot microwave synthesis of Fe 0.65 Pt 0.35 @Co allows systematic growth of the soft-magnet Co shell (0.6 nm to 2.7 nm thick) around the hard-magnet Fe 0.65 Pt 0.35 core (5 nm in diameter). Controlled growth leads to a four-fold enhancement in energy product of the core-shell assembly as compared to the energy product of bare Fe 0.65 Pt 0.35 cores. The simultaneous enhancement of coercivity and saturation moment reflects the onset of theoretically predicted exchange spring behavior. The demonstration of nanoscale exchange-spring magnets will result in improved high-performance magnet design for energy applications.

One-Dimensional Fluorescent Silicon Nanorods Featuring Ultrahigh Photostability, Favorable Biocompatibility, and Excitation Wavelength-Dependent Emission Spectra.

We herein report a kind of one-dimensional biocompatible fluorescent silicon nanorods (SiNRs) with tunable lengths ranging ∼100-250 nm, which can be facilely prepared through one-pot microwave synthesis. In addition to the strong fluorescence (quantum yield value: ∼15%) and negligible toxicity, the resultant SiNRs exhibit excitation wavelength-dependent photoluminescence whose maximum emission wavelength ranges from ∼450 to ∼600 nm under serial excitation wavelengths from 390 to 560 nm, providing feasibility for multicolor biological imaging. More significantly, the SiNRs are ultrahighly photostable, preserving strong and nearly unchanged fluorescence under 400 min high-power UV irradiation, which is in sharp contrast to severe fluorescence quenching of organic dyes (e.g., FITC) or II-VI quantum dots (QDs) (e.g., CdTe QDs and CdSe/ZnS QDs) within 15 or 160 min UV treatment under the same experiment conditions, respectively. Taking advantage of these attractive merits, we further exploit the SiNRs as a novel type of color converters for the construction of white light-emitting diodes (LED), which is the first proof-of-concept demonstration of LED device fabricated using the one-dimensional fluorescent silicon nanostructures.

One-Pot Microwave Synthesis of Pyrimido[4,5-b]quinoline and its C- and S-Glycosides with Anti-Inflammatory and Anticancer Activities

One-Pot Microwave Synthesis of Pyrimido[4,5-b]quinoline and its C- and S-Glycosides with Anti-Inflammatory and Anticancer Activities

Rapid microwave synthesis of white light emitting magic sized nano clusters of CdSe: role of oleic acid

A rapid green one-pot microwave synthesis of magic sized nano clusters of CdSe is presented using cycloalkeno-1,2,3-selenadiazoles as the Se source. The role of oleic acid in the cluster formation is discussed, which emit white light when illuminated with 365 nm light.

Microwave-assisted synthesis of anisotropic gold nanocrystals in polymer matrix and their catalytic activities

We report a facile and fast one-pot microwave (MW) synthesis of gold nanotriangle, nanobranches and nanorod. Gold salt is reduced to gold nanoparticles by ethylene glycol/polyethylene glycol in the presence of hydroxypropyl methyl cellulose. Morphology of the nanocrystals can be tailored by varying the amount of capping agents, reducing agent and the MW irradiation time. Synthesised nanoparticles are characterised by ultraviolet–visible (UV–Vis), transmission electron microscopic and X-ray diffraction spectroscopy study. The key requirement for producing the gold triangle and gold nanorod of higher aspect ratio is the adequate MW heating time. The photocatalytic activity of gold nanocrystals is investigated by monitoring the photochemical reduction of 2,4,6-trinitrophenol (TNP) in the presence of excess NaBH4. The reaction is first order with respect to the concentration of TNP. It has been observed that the catalytic efficiency of rod-like gold nanocrystals is higher than the other gold nanocrystals.

Cr-MIL-101 encapsulated Keggin phosphotungstic acid as active nanomaterial for catalysing the alcoholysis of styrene oxide

Mesoporous chromium-based terephthalate metal–organic framework (MIL-101) encapsulated Keggin phosphotungstic acid (HPW) [MIL-101(HPW)] was demonstrated to be an active heterogeneous catalyst for selective catalysis of the ring opening reaction of styrene oxide with methanol, achieving 99% yield of 2-methoxy-2-phenylethanol in 20 minutes at 40 °C. Similar MIL-101 samples prepared using one-pot microwave synthesis in the absence of HPW or in the presence of hydrofluoric acid (HF) were less active. The impact of fluoride and HPW polyanion incorporation on the acidity of MIL-101 was investigated by the in situ infrared spectroscopy technique using CO as a probe molecule. Additional hydroxyl groups and Lewis acid sites are present in MIL-101(HPW) explaining the observed superior catalytic performance in styrene oxide methanolysis.

One-pot microwave synthesis of tertiary phosphine sulfides directly from aromatic alkenes, elemental phosphorus and sulfur in KOH–DMSO system

Aromatic alkenes (vinylbenzene, 1-(tert-butyl)-4-vinylbenzene, 1-chloro-4-vinylbenzene) react with red phosphorus and elemental sulfur in the superbasic system KOH–DMSO(H2O) under microwave irradiation (600 W, 6–8 min, Ar) in the presence of hydroquinone to afford tris(2-phenylethyl)-, tris[2-(4-tBu-phenyl)ethyl]- and tris[2-(4-Cl-phenyl)ethyl]phosphine sulfides in 53%, 38% and 42% yield, respectively.

One-Pot Microwave Synthesis of Water-Dispersible, Ultraphoto- and pH-Stable, and Highly Fluorescent Silicon Quantum Dots

Fluorescent silicon quantum dots (SiQDs) are facilely prepared via one-pot microwave-assisted synthesis. The as-prepared SiQDs feature excellent aqueous dispersibility, robust photo- and pH-stability, strong fluorescence, and favorable biocompatibility. Experiments show the SiQDs are superbly suitable for long-term immunofluorescent cellular imaging. Our results provide a new and invaluable methodology for large-scale synthesis of high-quality SiQDs, which are promising for various optoelectronic and biological applications.