“Colloidal” Zinc Oxide

1937 ◽  
Vol 10 (2) ◽  
pp. 309-311
Author(s):  
H. A. Curran ◽  
T. R. Dawson
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Manufacturing Industry ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Zinc Oxides ◽  
Two Samples ◽  
Good Grade

Abstract Some ten years ago, when so-called “colloidal” zinc oxides were being introduced to the rubber manufacturing industry, two samples were investigated to determine their behavior in rubber compared with ordinary good quality zinc oxide used in rubber. According to accounts published at the time, “colloidal” zinc oxide possesses an average particle size just within the limit of resolution of high-power microscopes, and an average particle diameter of 0.15 micron. In rubber it has been claimed to impart superior reinforcement, higher tensile strength, greater resistance to abrasion, and enhanced activation of organic accelerators. In the following report, samples A and B represent two samples of the same grade of “colloidal” zinc oxide, and C a good grade of regular zinc oxide.

scholarly journals Preparation of Polyetherimide Nanoparticles by a Droplet Evaporation-Assisted Thermally Induced Phase-Separation Method

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1548
Author(s):  
Peng Zhu ◽  
Huapeng Zhang ◽  
Hongwei Lu
Keyword(s):  
Particle Size ◽  
Electron Microscope ◽  
Phase Separation ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Droplet Evaporation ◽  
Average Particle ◽  
Thermally Induced Phase Separation ◽  
Thermally Induced ◽  
Pei Nanoparticles

The droplet evaporation effect on the preparation of polyetherimide (PEI) nanoparticles by thermally induced phase separation (TIPS) was studied. PEI nanoparticles were prepared in two routes. In route I, the droplet evaporation process was carried out after TIPS. In route II, the droplet evaporation and TIPS processes were carried out simultaneously. The surface tension and shape parameters of samples were measured via a drop shape analyzer. The Z-average particle diameter of PEI nanoparticles in the PEI/dimethyl sulfoxide solution (DMSO) suspension at different time points was tested by dynamic light scattering, the data from which was used to determine the TIPS time of the PEI/DMSO solution. The natural properties of the products from both routes were studied by optical microscope, scanning electron microscope and transmission electron microscope. The results show that PEI nanoparticles prepared from route II are much smaller and more uniform than that prepared from route I. Circulation flows in the droplet evaporation were indirectly proved to suppress the growth of particles. At 30 °C, PEI solid nanoparticles with 193 nm average particle size, good uniformity, good separation and good roundness were obtained. Route I is less sensitive to temperature than route II. Samples in route I were still the accumulations of micro and nanoparticles until 40 °C instead of 30 °C in route II, although the particle size distribution was not uniform. In addition, a film structure would appear instead of particles when the evaporation temperature exceeds a certain value in both routes. This work will contribute to the preparation of polymer nanoparticles with small and uniform particle size by TIPS process from preformed polymers.

Minimum Particle Diameter of the Vanadium/Iron Co-Doped Nano TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 989-994 ◽  
pp. 611-614
Author(s):  
Ling Li ◽  
Wen Ming Zhang ◽  
Hua Yan Zhang ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Ferric Nitrate ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Vanadium Iron ◽  
Co Doped

Vanadium/iron co-doped nanoTiO2 transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, ferric nitrate, ammonium metavanadate, etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, EDS, nanolaser particle size analyzer, and UV-Vis spectrophotometer. The photocatalytic properties of V/Fe doped TiO2 were studied through degrading acid 3R dye, and the results show that when the content of V/Fe was 0.5%, the degradation rate reached more than 96% under irridation for 60 min.

Gas-phase particle size distributions and lead loss during spray pyrolysis of (Bi,Pb)–Sr–Ca–Cu–O

1995 ◽  
Vol 10 (7) ◽  
pp. 1644-1652 ◽  
Author(s):  
Abhijit S. Gurav ◽  
Toivo T. Kodas ◽  
Jorma Joutsensaari ◽  
Esko I. Kauppincn ◽  
Riitta Zilliacus
Keyword(s):  
Particle Size ◽  
Spray Pyrolysis ◽  
Gas Phase ◽  
Phase Particle ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Processing Temperature ◽  
Average Particle ◽  
Size Distributions ◽  
Particle Size Distributions

Gas-phase particle size distributions and lead loss were measured during formation of (Bi,Pb)-Sr-Ca-Cu-O and pure PbO particles by spray pyrolysis at different temperatures. A differential mobility analyzer (DMA) in conjunction with a condensation particle counter (CPC) was used to monitor the gas-phase particle size distributions, and a Berner-type low-pressure impactor was used to obtain mass size distributions and size-classified samples for chemical analysis. For (Bi,Pb)-Sr-Ca-Cu-O, as the processing temperature was raised from 200 to 700 °C, the number average particle size decreased due to metal nitrate decomposition, intraparticle reactions forming mixed-metal oxides and particle densification. The geometric number mean particle diameter was 0.12 μm at 200 °C and reduced to 0.08 and 0.07 μm, respectively, at 700 and 900 °C. When the reactor temperature was raised from 700 and 800 °C to 900 °C, a large number (∼107 no./cm3) of new ultrafine particles were formed from PbO vapor released from the particles and the reactor walls. Particles made at temperatures up to 700 °C maintained their initial stoichiometry over the whole range of particle sizes monitorcd; however, those made at 800 °C and above were heavily depleted in lead in the size range 0.5–5.0 μm. The evaporative losses of lead oxide from (Bi,Pb)-Sr-Ca-Cu-O particles were compared with the losses from PbO particles to gain insight into the pathways involved in lead loss and the role of intraparticle processes in controlling it.

Use of Calixarene Host Molecules to Stabilize Quantum-confined Cadmium Sulfide Formation

1992 ◽  
Vol 272 ◽  
Author(s):  
Robin R. Chandler ◽  
Jeffery L. Coffer ◽  
C. David Gutsche ◽  
Iftikhar Alam ◽  
Hong Yang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Diameter ◽  
Spectroscopic Studies ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Absorption And Emission ◽  
Zinc Blende ◽  
High Resolution Tem ◽  
Quantum Confined ◽  
Macrocyclic Molecules

ABSTRACTWe describe here the use of calixarenes, methylene (-CH2-) linked phenolic macrocyclic molecules, to stabilize the formation of quantum-confined (Q-) CdS clusters. Specifically, we focus on the use of an amino-derivatized calixarene, para-[(dimethylamino)- methyl]calix[6]arene, to stabilize Q-CdS clusters which have been characterized by High Resolution TEM (HREM), as well as absorption and emission spectroscopies. Under typical preparative conditions, an average particle diameter of 36 Å is obtained. HREM, in combination with Selected Area Diffraction (SAD), confirms the structure of the clusters as zinc blende CdS. Spectroscopic studies using absorption and emission methods indicate that both particle size and cluster photophysics are sensitive to the ratio of CdS to calixarene.

Swelling of Latex Particles

1959 ◽  
Vol 32 (3) ◽  
pp. 814-824
Author(s):  
Maurice Morton ◽  
Samuel Kaizerman ◽  
Mary W. Altier
Keyword(s):  
Molecular Weight ◽  
Particle Size ◽  
Interfacial Energy ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Polystyrene Latex ◽  
Average Particle ◽  
Equilibrium Solubility ◽  
Latex Particles ◽  
Equilibrium Swelling

Abstract A theoretical relation has been derived for the equilibrium swelling of latex particles. The equilibrium solubility and rate of solution of solvents were measured on a series of polystyrene latex fractions of varying particle size. The solvents used were styrene, toluene, and chlorocyclohexane. It was found, as predicted by theory, that the equilibrium amount of solvent imbibed by latex particles is a direct function of the particle diameter and an inverse function of the interfacial energy at the surface of the particles. The molecular weight of the polymer has no effect on the equilibrium swelling, within the range from 100,000 to several million molecular weight units. The rate of imbibition of these solvents appears to be extremely rapid, indicating that equilibrium solubility would appear to be maintained in most polymerization reactions. The fact that a particular solvent is a “good” solvent for the polymer does not necessarily result in a greater swelling of the particles, since the solvent may show a higher interfacial energy against the aqueous phase. The soap titration method is best for determining the average particle size of a latex for purposes of predicting equilibrium swelling.

Study of Synthesis of Nanoparticulate Zinc Oxide Aiming at the Confection of Appropriated Targets for the Production of Radioisotopes

2016 ◽  
Vol 881 ◽  
pp. 485-490
Author(s):  
Nelcy D.S. Mohallem ◽  
Juliana B. da Silva ◽  
Cristiana P. Rezende
Keyword(s):  
Particle Size ◽  
Zinc Oxide ◽  
Gamma Spectroscopy ◽  
Low Cost ◽  
Average Particle Size ◽  
Average Particle ◽  
Radioisotope Production ◽  
Target Preparation ◽  
Multifunctional Material ◽  
Freeze Dried

Zinc Oxide (ZnO) is a multifunctional material, which produces radionuclides of gallium by irradiation, widely used in diagnosis and nuclear medicine. In this work, two precursors were tested as well as two routes of synthesis, with the objective of obtaining nanoparticles appropriate to the production of pellets with grain size and porosity suitable for target preparation used in the radioisotope production by irradiation. The sintered pellets obtained from zinc acetate and NH4OH, and freeze-dried presented density of 90% of the theoretical density, average particle size of 1 μm and macropore size of 500 nm. These targets generated radionuclide of gallium (67Ga and 66Ga) inside the pores, without rupture of the pellets, confirmed by gamma spectroscopy, at low cost of production.

scholarly journals Mean grain diameters from thin sections: matching the average to the problem

2017 ◽  
Vol 81 (3) ◽  
pp. 515-530 ◽  
Author(s):  
Robert S. Farr ◽  
Victoria C. Honour ◽  
Marian B. Holness
Keyword(s):  
Size Distribution ◽  
Thin Section ◽  
Continuous Process ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Spherical Particles ◽  
Average Particle ◽  
Average Particle Diameter ◽  
Thin Sections ◽  
Wide Range

AbstractIt is common practice to estimate a mean diameter for spherical or sub-spherical particles or vesicles in a rock by multiplying the average diameter of the approximately circular cross-sections visible in thin section by a factor of 1.273. This number-weighted average may be dominatedby the hard-to-measure fine tail of the size distribution, and is unlikely to be representative of the average particle diameter of greatest interest for a wide range of geological problems or processes. Average particle size can be quantified in a variety of ways, based on the mass or surfacearea of the particles, and here we provide exact relations of these different average measures to straightforward measurements possible in thin section, including an analysis of how many particles to measure to achieve a desired level of uncertainty. The use of average particle diameter isillustrated firstly with a consideration of the accumulation of olivine phenocrysts on the floor of the 135 m thick picrodolerite/crinanite unit of the Shiant Isles Main Sill. We show that the 45 m thick crystal pile on the sill floor could have formed by crystal settling within about a year.The second geological example is provided by an analysis of the sizes of exsolved Fe-rich droplets during unmixing of a basaltic melt in a suite of experimental charges. We show that the size distribution cannot be explained by sudden nucleation, followed by either Ostwald ripening or Browniancoalescence. We deduce that a continuous process of droplet nucleation during cooling is likely to have occurred.

Minimum Particle Diameter of the Sulfur-Doped Nano-TiO2 Transparent Hydrosol at Room Temperature

2014 ◽  
Vol 587-589 ◽  
pp. 788-791
Author(s):  
Ling Li ◽  
Hua Yan Zhang ◽  
Xiao Wei Li ◽  
Zi Hao Xu ◽  
Sen Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Room Temperature ◽  
Photocatalytic Performance ◽  
Raw Materials ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Synthesis Process ◽  
Average Particle ◽  
Hydrolysis Method ◽  
Particle Size Analyzer

Sulfur-doped nanoTiO2transparent hydrosol with an average particle size of 3.8 nm was synthesized by a novel complexation-controlled hydrolysis method at room temperature and atmospheric pressure by using TiCl4, thiourea, organic carboxylic acid, NH3H2O, D-sorbitol etc. as raw materials. The composition, phase structure, particle size, absorbance spectrum, and photocatalytic performance of samples were characterized by XRD, nanolaser particle size analyzer, ultraviolet-visible spectrophotometer. In addition, the influence of reaction conditions in the synthesis process was also studied. The results indicate that when nanoparticle doped with 0.5% S, and the reflux time was 15 min, the photocatalytic performance of sulfur-doped TiO2hydrosol was best.

scholarly journals Solidification characteristics of atomized AlCu4Mg1-SiC composite powders

2012 ◽  
Vol 48 (1) ◽  
pp. 73-79 ◽  
Author(s):  
R. Yamanoglu ◽  
M. Zeren ◽  
Randall German
Keyword(s):  
Particle Size ◽  
Matrix Material ◽  
Average Particle Size ◽  
Particle Diameter ◽  
Average Particle ◽  
Composite Powders ◽  
Secondary Dendrite Arm Spacing ◽  
Dendrite Arm Spacing ◽  
The Matrix ◽  
Rapidly Solidified

In this study, rapidly solidified metal matrix composite powders have been produced by PREP (Plasma rotating electrode process) atomization. AlCu4Mg1 alloy is used as the matrix material while SiC particles, with about 650 nm average particle size, are used as the reinforcement phase. The microstructural and solidification characteristics of composite particles are studied using optical and scanning electron microscope (SEM). The relationship between secondary dendrite arm spacing (SDAS) and particle diameter was examined, and these composite powders were found to have dendritic and equiaxed solidification with a fine eutectic phase. SDAS measurements using various sized particles show that secondary dendrite arm spacing slightly decreases with the decrease in particle size.

Preparation of Mesocarbon Microbeads (MCMB) from Suspensions of a Synthetic Naphthalene Isotropic Pitch

2017 ◽  
Vol 753 ◽  
pp. 231-236
Author(s):  
Sheng Juan Ji ◽  
Xiang Lin Cheng ◽  
Jian Hong Zhao ◽  
Qing Ling Bi ◽  
Liu Cheng Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Particle Diameter ◽  
Average Particle ◽  
Average Particle Diameter ◽  
X Ray ◽  
Mesocarbon Microbeads ◽  
Dispersion Degree ◽  
Isotropic Pitch ◽  
Particle Size Analyzer ◽  
Size Dispersion

A synthetic naphthalene isotropic pitch, which was manufactured with HF/BF3 acting as catalyst, was used as material to prepare mesocarbon microbeads (MCMB) through suspension method. The material pitch was dissolved in tetrahydrofuran (THF) and the pitch-THF solution is dispersed in a 2% polyvinyl alcohol aqueous solution. After THF was volatilized, the solution was cooled and then filtered to attain little pitch sphere. The pitch spheres were oxidized in 65% HNO3 solution, and the oxidized pitch spheres were carbonized up to 1000°C to get MCMB. MCMB was analyzed by scanning electron microscope (SEM), laser particle size analyzer and X ray diffractometer. The result showed that the particle size of MCMB was 2-30 μm and the average particle diameter size of D50 was 15.83 μm. The particle size distribution accords to the normal distribution, and the particle size dispersion degree was 0.7574. The effect of 65% HNO3 oxidation of the pitch sphere showed a satisfactory result. After carbonization at 1000°C, the oxidized pitch sphere exhibited a better orientation arrangement, the distance between the aromatic plane (d002) was decreased, and the thickness of the piled plane is increased.

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