Nanoparticles of Pd: Synthesis by Microwave-Solvothermal Method and Optical Properties

2008 ◽  
Vol 8 (8) ◽  
pp. 3930-3935 ◽  
Author(s):  
Dongsheng Li ◽  
Sridhar Komarneni
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Pd Nanoparticles ◽  
Absorption Bands ◽  
Reaction Conditions ◽  
Transmission Electron ◽  
Vis Spectroscopy ◽  
Particle Size And Morphology ◽  
Particle Size And Shape ◽  
Size And Morphology

Well-dispersed Pd nanoparticles were synthesized by microwave-assisted solvothermal technique using methanol and ethanol. Particle size and morphology were controlled mainly by the reaction temperature. Particle size of Pd nanoparticles was controlled in the range of 2 to 11 nm by manipulating the reaction conditions. The Pd nanoparticles were characterized by transmission electron microscopy for particle size and shape and UV-Vis spectroscopy for optical properties. UV-Vis spectra showed that synthesized Pd nanoparticles stabilized with PVP had absorption bands at around 280 to 290 nm.

Synthesis of Pt Nanoparticles and Nanorods by Microwave-assisted Solvothermal Technique

2006 ◽  
Vol 61 (12) ◽  
pp. 1566-1572 ◽  
Author(s):  
Dongsheng Li ◽  
Sridhar Komarneni
Keyword(s):  
Particle Size ◽  
Pt Nanoparticles ◽  
Transmission Electron Microscopy Image ◽  
Molar Ratio ◽  
Reaction Conditions ◽  
Microwave Assisted ◽  
Metal Sources ◽  
Transmission Electron ◽  
Particle Size And Morphology ◽  
Size And Morphology

Platinum nanoparticles and nanorods were synthesized by microwave-assisted solvothermal techniques. Changing the reaction conditions controlled particle size and morphology. The effects of the reaction conditions, such as the molar ratio of the polyvinylpyrrolidone (PVP) repeating unit to the metal sources, the concentration of metal sources, the reaction temperature, and the presence of distilled water were investigated. Nanoparticles of Pt were approximately 3 nm in size. Produced nanoparticles and nanorods were characterized by transmission electron microscopy. Image JTM software was used to calculate the particle size and size distribution.

scholarly journals Colloidal Probes of PNIPAM-Grafted SiO2 in Studying the Microrheology of Thermally Sensitive Microgel Suspensions

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Jing Shang ◽  
Ruonan Gao ◽  
Fu Su ◽  
Huaguang Wang ◽  
Dan Zhu
Keyword(s):  
Phase Transition ◽  
Particle Size ◽  
Depletion Effect ◽  
Transmission Electron ◽  
Particle Size And Morphology ◽  
Complex Rheology ◽  
Colloidal Probes ◽  
Size And Morphology ◽  
Collapsed States ◽  
Good Probe

The complex rheology and the phase behavior of thermally sensitive poly(N-isopropylacrylamide) (PNIPAM) microgels have been investigated in both the swollen and collapsed states by using microrheology. To avoid the interactions between the tracer probes and the PNIPAM microgels, such as the adsorption or the depletion effect, the probes of silica (SiO2) particles have been grafted with PNIPAM chains (SiO2-PNIPAM) and characterized with Fourier transform infrared spectroscopy (FTIR). The successful preparation of SiO2-PNIPAM has also been proved by the investigation of the particle size and morphology with dynamic light scattering (DLS) and transmission electron microscope (TEM) below and beyond the phase transition temperature of PNIPAM. The microrheology of the PNIPAM microgel suspension has been investigated by using the prepared SiO2-PNIPAM particles as microrheological probes, and the results show that the diffusive coefficient of the probes in the swollen state is one-fifth of that in the collapsed state, and the viscosity of the PNIPAM microgel suspension in the swollen state is four times higher than that in the collapsed state, indicating SiO2-PNIPAM is a good probe in the microrheological study of PNIPAM microgel suspensions.

Synthesis of Calcium Carbonate from Calcium Chlorine Solution Using Homogeneous Precipitation Method

2005 ◽  
Vol 486-487 ◽  
pp. 542-545 ◽  
Author(s):  
Kyung Nam Kim ◽  
Dae Yong Shin ◽  
Se Gu Son ◽  
Yong Do Kim
Keyword(s):  
Particle Size ◽  
Calcium Carbonate ◽  
Precipitation Method ◽  
Homogeneous Precipitation ◽  
Reaction Conditions ◽  
Homogeneous Precipitation Method ◽  
Reaction Solution ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Hydrolysis Of

Calcium carbonate(CaCO3) was synthesized from aqueous CaCl2 solution, using the homogeneous precipitation technique, which uses the hydrolysis of urea. The effects of reaction conditions on the morphology of CaCO3 were examined at 50-90°C. Particle size of CaCO3 decreases, as the concentrations of urea and [Ca2+] are increased. Calcite is produced more, as the concentration of [Ca2+] is increased. Method to stir the reaction solution affects significantly the particle size and morphology of CaCO3. Uniform needle-like aragonite particles were obtained, when left at 90°C for 4hours without stirring.

Synthesis of Tin Oxide (SnO2) by the Oxalate Route: Effects of Addition Method and Ageing

2007 ◽  
Vol 561-565 ◽  
pp. 973-976 ◽  
Author(s):  
H. Taib ◽  
Charles C. Sorrell
Keyword(s):  
Particle Size ◽  
Tin Oxide ◽  
Collision Frequency ◽  
Atmospheric Moisture ◽  
Addition Method ◽  
Diffusion Distance ◽  
Chloride Dihydrate ◽  
Particle Size And Morphology ◽  
Particle Size And Shape ◽  
Size And Morphology

Aqueous solutions of tin (II) chloride dihydrate and oxalic acid dihydrate (both 0.04 M) were prepared and mixed by (1) dropwise addition and (2) instantaneous addition, with both involving addition of the latter to the former. Following filtering, washing, and drying, the precipitates were calcined and ground. The particle size and morphology of uncalcined and calcined tin oxalate were examined by electron microscopy and laser diffraction. The method of addition was important in that it influenced both the particle size and shape of tin oxalate. This resulted from the time effect of the ionic collision frequency and the proximity effect of the diffusion distance. As expected, ageing was important in that it caused grain growth and reduction of surface area of the tin oxalate. Although there appeared to be an effect of the method of addition on agglomeration of the tin oxide, this was a result of adsorption of atmospheric moisture, which depended on the relative humidity of the environment during grinding.

Preparation and Characterization of Ag, Au and Ti Metal Nanoparticles Colloids by Pulsed Laser Ablation in Liquids

2011 ◽  
Vol 415-417 ◽  
pp. 648-651 ◽  
Author(s):  
Bing Xu ◽  
Ren Guo Song ◽  
Chao Wang
Keyword(s):  
Particle Size ◽  
Laser Ablation ◽  
Metal Nanoparticles ◽  
Pulsed Laser ◽  
Pulsed Laser Ablation ◽  
Average Diameter ◽  
Transmission Electron ◽  
Particle Size And Morphology ◽  
Size And Morphology

Ag, Au and Ti metal nanoparticles colloids have been prepared by pulsed laser ablation in various liquids. The particle size and morphology of the obtained nanoparticles colloids were characterized by transmission electron microscopy (TEM), the average diameter and its distribution were analyzed by Image-ProPlus software. The results showed that the Au nanoparticles were of the best characterization, the average diameter was the smallest (D=8.79 nm), and also, the distribution of particle size was the narrowest (=17.5 nm) and the morphologies were more homogeneous.

Direct manipulation of particle size and morphology of ordered mesoporous silica by flow synthesis

RSC Advances ◽  
2015 ◽  
Vol 5 (18) ◽  
pp. 13331-13340 ◽  
Author(s):  
T. N. Ng ◽  
X. Q. Chen ◽  
K. L. Yeung
Keyword(s):  
Particle Size ◽  
Mesoporous Silica ◽  
Hollow Spheres ◽  
Ordered Mesoporous Silica ◽  
Direct Manipulation ◽  
Flow Synthesis ◽  
Precise Control ◽  
Ordered Mesoporous ◽  
Particle Size And Morphology ◽  
Size And Morphology

Flow-synthesis of mesoporous silica allows deliberate and precise control over the size and shapes and enables the preparation of complex microstructures (i.e., hollow spheres).

Composition, particle size, and near-infrared irradiation effects on optical properties of Au–Au2S nanoparticles

2008 ◽  
Vol 23 (1) ◽  
pp. 281-293 ◽  
Author(s):  
Mei Chee Tan ◽  
Jackie Y. Ying ◽  
Gan Moog Chow
Keyword(s):  
Particle Size ◽  
Optical Properties ◽  
Thermal Effects ◽  
Near Infrared ◽  
Sodium Sulfide ◽  
Irradiation Effects ◽  
Absorption Bands ◽  
Molar Ratios ◽  
Nir Absorption ◽  
Structure And Microstructure

Near-infrared (NIR)-absorbing nanoparticles synthesized by the reduction of tetrachloroauric acid (HAuCl4) using sodium sulfide (Na2S) exhibited absorption bands at ∼530 nm and at the NIR region of 650−1100 nm. A detailed study on the structure and microstructure of as-synthesized nanoparticles was reported previously. The as-synthesized nanoparticles were found to consist of amorphous AuxS (x = ∼2), mostly well mixed within crystalline Au. In this work, the optical properties were tailored by varying the precursor molar ratios of HAuCl4 and Na2S. In addition, a detailed study of composition and particle-size effects on the optical properties was discussed. The change of polarizability by the introduction of S in the form of AuxS (x = ∼2) had a significant effect on NIR absorption. Also, it was found in this work that exposure of these particles to NIR irradiation using a Nd:YAG laser resulted in loss of the NIR absorption band. Thermal effects generated during NIR irradiation had led to microstructural changes that modified the optical properties of particles.

scholarly journals Dehumidified Air-Assisted Spray-Drying of Cloudy Beetroot Juice at Low Temperature

2021 ◽  
Vol 11 (14) ◽  
pp. 6578
Author(s):  
Aleksandra Jedlińska ◽  
Alicja Barańska ◽  
Dorota Witrowa-Rajchert ◽  
Ewa Ostrowska-Ligęza ◽  
Katarzyna Samborska
Keyword(s):  
Particle Size ◽  
Physicochemical Properties ◽  
Spray Drying ◽  
Low Temperatures ◽  
Beetroot Juice ◽  
Particle Size And Morphology ◽  
Size And Morphology ◽  
Tapped Density ◽  
Lower Loss ◽  
Better Than

This paper discusses the physicochemical properties of powders obtained by spray drying of cloudy beetroot juice, using dehumidified air in variants with or without carriers. The inlet air temperature was 130 °C or 90 °C, and the addition of the carriers was at a ratio of juice to carrier solids of 3:2. In the obtained powders, the following physicochemical properties were determined: water content and water activity, apparent density, loose and tapped density, porosity, flowability, particle size and morphology, and the content and retention of betalains. It was possible to dry cloudy beetroot juice without the use of carriers at low temperatures (90 or 130 °C). The 100% beetroot powders were characterized by satisfactory physicochemical properties, often better than those with carriers (including lower hygroscopicity and higher color saturation and yield). A lower loss of betalains was found for the powders with the addition of carriers. The best process yields were obtained for the powder without carriers at 130 °C and 90 °C.

Synthesis and Characterization of Calcium Tartrate Dihydrate Nanoparticles

2015 ◽  
Vol 14 (04) ◽  
pp. 1550013 ◽  
Author(s):  
Urvisha Tarpara ◽  
Poorvesh Vyas ◽  
Mihir J. Joshi
Keyword(s):  
Average Crystallite Size ◽  
Powder Xrd ◽  
Xrd Pattern ◽  
Crystalline Materials ◽  
Transmission Electron ◽  
Calcium Tartrate ◽  
Particle Size And Morphology ◽  
Wet Chemical ◽  
Size And Morphology

Calcium tartrate finds various applications. In the present study, calcium tartrate nanoparticles were synthesized by wet chemical method using surfactant mediated approach. The powder XRD pattern revealed the typical broadening of peaks indicating the nanostructured nature. The average crystallite size was calculated by applying the Scherrer's formula to powder XRD pattern and was found in the range of 22.8–23.9 nm. The particle size and morphology of the synthesized nanoparticles was confirmed by using transmission electron microscopy (TEM). FTIR spectroscopy was used to confirm the presence of various functional groups. From TGA, it was found that calcium tartrate nanoparticles remained stable up to 120°C and were having two water molecules associated with them. The results are compared with the bulk crystalline materials available in the literature.

Synthesis and Properties of (Bi0.5Na0.5)TiO3 Powders by Hydrothermal Method

2007 ◽  
Vol 336-338 ◽  
pp. 140-142
Author(s):  
Jun Jie Hao ◽  
Xiao Hui Wang ◽  
Shi Yun Lin ◽  
Long Tu Li
Keyword(s):  
Particle Size ◽  
Hydrothermal Method ◽  
Single Phase ◽  
Piezoelectric Ceramics ◽  
Treatment Temperature ◽  
Lead Free ◽  
Excellent Candidate ◽  
Traditionally Prepared ◽  
Particle Size And Morphology ◽  
Size And Morphology

Na0.5Bi0.5TiO3 (NBT) is considered to be an excellent candidate for lead-free piezoelectric ceramics. In this study, we propose a hydrothermal method for the preparation of single phase NBT powder at relatively low treatment-temperature. The particle size and morphology of the synthesized powders were examined by SEM. The powders were further pressed into disk and sintered at 1120°C/2h in air, and its properties and microstructure were compared with traditionally prepared samples.

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