Preparation of Silica Nanoparticles Using Silica-Rich Filtrate from Potassium-Rich Rock

2010 ◽  
Vol 160-162 ◽  
pp. 1372-1377
Author(s):  
Cong Cong Yin ◽  
Hong Bin Qi ◽  
Xiao Chao Chen ◽  
Zhi Hui Wang
Keyword(s):  
Silica Nanoparticles ◽  
Raw Materials ◽  
Average Particle Size ◽  
Chemical Precipitation ◽  
Precipitation Process ◽  
Average Particle ◽  
Dispersion Method ◽  
Ultrasonic Dispersion ◽  
Uniform Size ◽  
Size Of Particles

The silicon-rich filtrate which was obtained from the desilication solution of potassium-rich rock was used as raw materials to prepare nanometer sillica and ultrasonic dispersion method was applied to the chemical precipitation process. A detailed study was carried out on the effect of filtrate concentration, surfactant dosage, reaction temperature, calcinations temperature, ultrasonic dispersion on size of silica nanoparticles. The basic properties and size of particles were characterized by means of FE-SEM, TEM, XRD, TGA and FTIR. The results obtained in the study indicated that monodisperse and uniform-size silica nanoparticles were prepared using ultrasonication by chemical precipitation process and the average particle size was 50 nm.

scholarly journals Influence of Glass Powder Size Sorting on Properties of Composite Systems

2016 ◽  
Vol 47 (1) ◽  
pp. 25-31
Author(s):  
K. Dědičová ◽  
P. Valášek
Keyword(s):  
Glass Powder ◽  
Adhesive Bonding ◽  
Raw Materials ◽  
Average Particle Size ◽  
Polymeric Materials ◽  
Average Particle ◽  
Powder Size ◽  
Size Sorting ◽  
Powder Particles ◽  
Size Of Particles

Abstract Glass powder ranks among the secondary raw materials, which can be used in the interaction with polymeric materials. In the present experiment the polymeric/epoxy particle composite with different sizes of glass powder particles is described. Such utilization of recyclable materials is environmental-friendly and should be preferred. The size of particles forming the filler of the described composites is one of the key characteristics affecting the mechanical properties. Due to the properties of the systems filled with glass powder, these materials can potentially be used in agriculture (renovations, adhesive bonding, cementing, etc.). In the experiment, glass powder was dimensionally sorted through sieves. Three fractions of glass powder with particles size of 0−30, 30−50, and 50−90 μm were created and utilized, the average particle size being 18.7, 38.7, and 72.6 μm, respectively. The interaction of the 18.7 μm particles did not lead to a statistically significant decrease of shear strength values in the interval 0−20 vol.%. The presence of glass powder, however, in all cases decreased tensile strength.

Preparation of the Silica Micro-Spheres by Chemical Precipitation Process

2012 ◽  
Vol 602-604 ◽  
pp. 259-264 ◽  
Author(s):  
Bin Wen ◽  
Chun Qing Huo ◽  
Cong Hao Li ◽  
Long Zhang
Keyword(s):  
Ethyl Acetate ◽  
Sodium Silicate ◽  
Average Particle Size ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Chemical Precipitation ◽  
Precipitation Process ◽  
Average Particle ◽  
Optimum Reaction ◽  
Addition Amount

Silica micro-spheres were prepared from sodium silicate at room temperature with ethyl acetate as the precipitant. The effect of process parameters on the yield and the morphology of SiO2 powders was systematically investigated and the optimum reaction condition was confirmed as follows: the concentration of sodium silicate was 0.6 mol/L, the total addition amount of the blend surfactants of PEG-1000 and sodium dodecyl benzene sulfonate (SDBS) was 2.1% and the blend ratio was 20:1, the addition amount of ethanol and ethyl acetate were 5.0% and 8.0%, respectively, the stirring rate was 600 rpm and the reaction time was 4.0 hours. The average particle size was 400 nm and the yield was 93.8% .The product was characterized by scanning electron microscope, Infrared Spectroscopy, and X-ray powder diffraction.

Preparation BiTaO4 by Precipitation Method and its Visible-Light Photocatalytic Activity

2012 ◽  
Vol 178-181 ◽  
pp. 535-538
Author(s):  
Jing Jiao Zhang ◽  
Pei Song Tang
Keyword(s):  
Photocatalytic Activity ◽  
Visible Light ◽  
Diffuse Reflectance Spectroscopy ◽  
Raw Materials ◽  
Average Particle Size ◽  
Precipitation Method ◽  
Precipitation Process ◽  
Average Particle ◽  
X Ray Diffraction ◽  
Uv Visible

The single phase BiTaO4was synthesized using Ta2O5and Bi(NO3)3as main raw materials by precipitation process. The products were characterized by thermogravimetry and differential thermal analysis (TG-DTA), powder X-ray diffraction (XRD), scanning electron microscopy (SEM) and UV-visible diffuse reflectance spectroscopy (DRS). The results show that BiTaO4was triclinic crystal with average particle size 100nm, and a band gap of about 2.77 eV. The photocatalytic experiment of BiTaO4shows the good photocatalytic activity for the decomposition of methylene blue under visible-light irradiation.

Mesoporous Silica Nanoparticles of Hydroxyurea: Potential

2020 ◽  
Vol 10 ◽  
Author(s):  
Kumar Nishchaya ◽  
Swatantra K.S. Kushwaha ◽  
Awani Kumar Rai
Keyword(s):  
Drug Release ◽  
Silica Nanoparticles ◽  
Mesoporous Silica Nanoparticles ◽  
Release Kinetics ◽  
Average Particle Size ◽  
Silica Nanoparticle ◽  
Average Particle ◽  
Independent Variables ◽  
Lower Temperature

Background: Present malignant cancer medicines has the advancement of magnetic nanoparticles as delivery carriers to magnetically accumulate anticancer medication in malignant growth tissue. Aim: In the present investigation, a silica nanoparticles (MSNs) stacked with hydroxyurea were combined and was optimized for dependent and independent variables. Method: In this study, microporous silica nanoparticle stacked with neoplastic medication had been prepared through emulsification followed with solvent evaporation method. Prepared MSNs were optimized for dependent and independent variables. Different formulations were prepared with varying ratio of polymer, lipid and surfactant which affects drug release and kinetics of drug release pattern. The obtained MSNs were identified by FTIR, SEM, drug entrapment, in-vitro drug release, drug release kinetics study, stability testing in order to investigate the nanoparticle characteristics. Results: The percentage drug entrapment of the drug for the formulations F1, F2, F3, was found to be 27.78%, 65.52% and 48.26%. The average particle size for F2 formulation was found to be 520 nm through SEM. The cumulative drug release for the formulations F1, F2, F3 was found to be 64.17%, 71.82% and 32.68%. The formulations were found to be stable which gives controlled drug delivery for 6 hours. Conclusion: From the stability studies data it can be culminated that formulations are most stable when stored at lower temperature or in refrigerator i.e. 5˚C ± 3˚C. It can be concluded that MSN’s loaded with hydroxyurea is a promising approach towards the management of cancer due to its sustained release and less side effects.

scholarly journals Hydrothermal synthesis of tetragonal barium titanate nanopowders under moderate conditions

2021 ◽  
Vol 15 (2) ◽  
pp. 179-183
Author(s):  
Huaxing Meng ◽  
Zhiwu Chen ◽  
Zhenya Lu ◽  
Xin Wang ◽  
Xiaoyi Fu
Keyword(s):  
Barium Titanate ◽  
Average Particle Size ◽  
Ammonia Solution ◽  
Average Particle ◽  
Titanium Hydroxide ◽  
X Ray Diffraction ◽  
Hydrothermal Route ◽  
Uniform Size ◽  
Dominant Structure ◽  
Hydrolysis Of

Monodispersed tetragonal barium titanate (BaTiO3) nanopowders were synthesized by a convenient hydrothermal route at a low temperature of 200?C in only 24 h. The key point of this method is to promote the generation of ultrafine titanium hydroxide precipitation precursors with the help of absolute ethyl alcohol and ammonia solution during the hydrolysis of Ti(OC4H9)4. The results of X-ray diffraction and Raman spectra show that the as-prepared BaTiO3 nanopowders possess tetragonal-dominant structure. The synthesized tetragonal BaTiO3 nanopowders exhibit relatively uniform size and good dispersity, with the average particle size of 96.1 nm and a tetragonality of 1.0073, which enable broad application prospects in the field of multilayer ceramic capacitors.

Lead Free Paste with under 3um Solder Particles for Fine Pitch C4 bumping and pre-coating solder applications

2013 ◽  
Vol 2013 (DPC) ◽  
pp. 000862-000889
Author(s):  
Hironori Uno ◽  
Masayuki Ishikawa ◽  
Akihiro Masuda ◽  
Hiroki Muraoka ◽  
Kanji Kuba
Keyword(s):  
Chemical Reduction ◽  
Average Particle Size ◽  
Average Particle ◽  
Solder Paste ◽  
Chemical Reduction Method ◽  
Property Evaluation ◽  
Fine Pitch ◽  
Solder Bumps ◽  
Size Of Particles ◽  
Average Size

The work to be detailed in this paper is our development of 96.5mass%Sn-3.0mass%Ag-0.5mass%Cu fine solder particles with an average particle size of under 3um (D50), using a chemical reduction method. An evaluation was conducted on the properties of the particles. The average size of particles appeared to be under 3um with a higher yield compared to particles using the conventional gas atomization method. The melting temperature of fine solder particles using this method was its eutectic temperature, which is same as using the gas–atomized particles. 120um pitch solder bumps from the solder paste using the above mentioned fine solder particles were created on the substrate. As a result of property evaluation, it was turned out that the solder paste created a superior printing shape and coplanarity compared to the conventional paste with gas-atomized particles. In order to investigate the superior printing property generated by the paste with fine solder particles, the rheology of the paste was evaluated.It was verified that the anisotropic shape of particles has contributed to prevent the printed paste from slumping, which has resulted in the improvement of printed shape. It also shows that the filling characteristic of the paste was improved by the smaller particles and the better coplanarity was observed. The importance of finer solder particles for finer pitch assembly will be presented.

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.

Preparation and Particle Size Characterization of Cu Nanoparticles Prepared by Anodic Arc Plasma

2010 ◽  
Vol 92 ◽  
pp. 163-169
Author(s):  
Hong Xia Qiao ◽  
Zhi Qiang Wei ◽  
Ming Ru Zhou ◽  
Zhong Mao He
Keyword(s):  
Crystal Structure ◽  
Particle Size ◽  
Specific Surface ◽  
Size Distribution ◽  
Surface Area ◽  
Specific Surface Area ◽  
Average Particle Size ◽  
Spherical Shape ◽  
Average Particle ◽  
Uniform Size

Copper nanoparticles were successfully prepared in large scales by means of anodic arc discharging plasma method in inert atmosphere. The particle size, specific surface area, crystal structure and morphology of the samples were characterized by X-ray diffraction (XRD), BET equation, transmission electron microscopy (TEM) and the corresponding selected area electron diffraction (SAED). The experiment results indicate that the crystal structure of the samples is fcc structure as same as that of the bulk materials. The specific surface area is is 11 m2/g, with the particle size distribution ranging from 30 to 90 nm, the average particle size about 67nm obtained from TEM and confirmed from XRD and BET results. The nanoparticles have uniform size, higher purity, narrow size distribution and spherical shape can be prepared by this convenient and effective method.

Heterophase ceramics in the Hf–Si–Mo–B system obtained by a combination of SHS and hot pressing methods

2019 ◽  
pp. 36-46
Author(s):  
Yu. S. Pogozhev ◽  
M. V. Lemesheva ◽  
A. Yu. Potanin ◽  
S. I. Rupasov ◽  
V. I. Vershinnikov ◽  
...  
Keyword(s):  
Hot Pressing ◽  
Raw Materials ◽  
Average Particle Size ◽  
High Hardness ◽  
Maximum Size ◽  
Composite Ceramic ◽  
Thermal Reduction ◽  
High Mass ◽  
Average Particle ◽  
Chemical Homogeneity

The paper focuses on obtaining heterophase powder ceramics and consolidated ceramics based on borides and silicides of hafnium and molybdenum by combining the methods of self-propagating high-temperature synthesis (SHS) and hot pressing (HP). Composite ceramic SHS powders HfB2–HfSi2–MoSi2 were obtained according to the scheme of magnesium-thermal reduction from oxide raw materials where the combustion wave is characterized by temperatures of 1750–2119 K and high mass combustion rates of 8,4– 9,3 g/s. The structure of synthesized SHS powders consists of relatively large MoSi2 grains up to 10 μm in size and submicron elongated HfB2 grains located mainly inside the MoSi2 grains and rounded Si precipitates. The composition with a lower concentration of boron contains a large number of polyhedral HfSi2 grains with a size of less than 10 μm. The resulting powders are characterized by an average particle size of ~6 μm with a maximum size up to 26 μm. Phase compositions of ceramics consolidated by the HP method and SHS synthesized powders are identical. The microstructure of compact samples consists of faceted HfB2 elongated grains 0,5– 10,0 μm in size, polyhedral HfSi2 and MoSi2 grains up to 8–10 μm in size and silicon interlayers. Consolidated ceramics has a high structural and chemical homogeneity, low residual porosity of 1,1–1,7 %, high hardness of 11,7–12,6 GPa and thermal conductivity of 62–87 W/(m·K).

FeCl2–CaCl2 melt volumetric reduction by calcium dissolved in calcium chloride

2018 ◽  
pp. 4-10
Author(s):  
V. V. Polyakov ◽  
A. V. Babin ◽  
V. A. Lebedev
Keyword(s):  
Iron Powder ◽  
Average Particle Size ◽  
Average Particle ◽  
Ultrasonic Dispersion ◽  
X Ray ◽  
Reduction Of Iron ◽  
Fine Iron ◽  
Three Stages ◽  
Average Size ◽  
Temperature Aging

The purpose of this study is to obtain highly dispersed powder suitable for spheroidization for further application in additive technologies. Volumetric reduction of the FeCl2–CaCl2melt by calcium dissolved in CaCl2produced fine iron powder. The process consisted of three stages: preparation of melts containing FeCl2and Ca, their mixing and high-temperature aging at 800 °C for 1 hour. At the end of the process the frozen melt was divided into upper and bottom parts. The product from the upper part had a specific surface area of 7,60 m2/g, and for the lower part it was 5,38 m2/g, Average particle size was 157 μm for the former and 124 μm for the latter. After ultrasonic dispersion, it was reduced to 26 μm and 71 μm, respectively. Quantitative X-ray phase analysis showed that the main phase of powder is metallic iron (more than 97 wt.%). Therefore, research originality is the use of volumetric, intensive reduction of iron from chloride melts by calcium dissolved in its chloride. The uniqueness of the study consists in the product obtained, i.e. the main part of reduced iron is in the melt volume as linear aggregates 40 to 600 μm in length, 10 to 50 μm in diameter that are easily broken by ultrasonic dispersion into individual crystals with an average size of 26 μm. The results of the study demonstrated the feasibility of calcium-thermal production of fine iron powder.

Sign in / Sign up

Export Citation Format

Share Document