Environmental Friendship Synthesis of Ultra-Fine Silver Particles for Electromagnetic Shielding Materials

2012 ◽  
Vol 189 ◽  
pp. 97-100
Author(s):  
Ming Shan Yang ◽  
Lin Kai Li
Keyword(s):  
Particle Size ◽  
Ionic Liquid ◽  
Uniform Distribution ◽  
Room Temperature ◽  
Silver Powder ◽  
Synthesis Method ◽  
Ethanol Solution ◽  
Electromagnetic Shielding ◽  
Silver Particles ◽  
Step Method

A room-temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4), was synthesized with two-step method, and putting p-benzenediol and AgNO3 ethanol solution into [bmim]BF4, ultra-fine silver powder were prepared successfully in this paper. The effects of the temperature and material mol ratio of AgNO3 and p-benzenediol on the shape of products were studied. The products were characterized by XRD, SEM, IR and TEM. The results showed that the particle size of silver was much smaller and in the range of nanometers, and had narrowly, uniform distribution, which indicates that the synthesis method using ionic liquid, is the better “green” and “environment friendship” method to prepare ultra-fine silver powder for electromagnetic shielding.

Green Preparation of Ultra-Fine Silver Particles in Ionic Liquid

2012 ◽  
Vol 190-191 ◽  
pp. 491-495
Author(s):  
Ming Shan Yang ◽  
Ying Quan ◽  
Wen Tang ◽  
Lin Kai Li
Keyword(s):  
Particle Size ◽  
Ionic Liquid ◽  
Room Temperature ◽  
Silver Powder ◽  
Synthesis Method ◽  
Ethanol Solution ◽  
Silver Particles ◽  
Step Method ◽  
Environment Friendly ◽  
H Nmr

A room-temperature ionic liquid, 1-n-butyl-3-methylimidazolium tetrafluoroborate([bmim]BF4), was synthesized with two-step method and its structure was characterized by IR, H-NMR. Putting p-benzenediol and AgNO3 ethanol solution into [bmim] BF4, ultra-fine silver powder were prepared successfully in this paper. The effects of the temperature and material mol ratio of AgNO3 and p-benzenediol on the shape of products were studied. The products were characterized by XRD, SEM, IR and TEM. The results showed that the particle size of silver was much smaller and in the range of nanometers, and had narrowly, uniform distribution, which indicates that the synthesis method using ionic liquid, is the better “green” and “environment friendly” method to prepare ultra-fine silver powder.

Hydrothermal Synthesis of CoFe2O4 Nanoparticles and their Magnetic Properties

2013 ◽  
Vol 821-822 ◽  
pp. 1358-1361 ◽  
Author(s):  
Fan Zhang ◽  
Rui Liang Su ◽  
Li Zhi Shi ◽  
Yang Liu ◽  
Yan Na Chen ◽  
...  
Keyword(s):  
Particle Size ◽  
Magnetic Properties ◽  
Room Temperature ◽  
Magnetic Measurements ◽  
Spinel Ferrite ◽  
Synthesis Method ◽  
Ferrite Nanoparticles ◽  
Particle Sizes ◽  
Naoh Solution ◽  
20 Nm

CoFe2O4 (CFO) nanoparticles was synthesized by a simple hydrothermal method using NaOH solution as a mineralizer at 200 °C for 4 h. It was found that CFO particle sizes decreased firstly and then increased with the increasing of NaOH concentration, and had a minumum value about 10-20 nm when selected 4 mol/L NaOH solution, indicating the NaOH concentration played an important role in controlling the particle size of CFO powders. The room temperature magnetic measurements showed that the saturation magnetization value was 48 emu/g, which is less than the bulk value. The synthesis method is possible to be a general approach for the preparation of other spinel ferrite nanoparticles.

scholarly journals Efficient Oxidative Desulfurization of Model Oil at Room Temperature with Ionic Liquid as Extraction Solvent

KIMIKA ◽  
2013 ◽  
Vol 24 (1) ◽  
pp. 2-7
Author(s):  
Harold Henrison C. Chiu ◽  
Susan D. Arco ◽  
Zhang Chun Ping ◽  
Nelson R. Villarante
Keyword(s):  
Ionic Liquid ◽  
Ionic Liquids ◽  
Chain Length ◽  
Room Temperature ◽  
Extraction Efficiency ◽  
Oxidative Desulfurization ◽  
Alkyl Substituent ◽  
Step Method ◽  
Extraction Solvent ◽  
Model Oil

The oxidative desulfurization of model oil (hexane solution of thiophene) was carried out at room temperature in a two-step method involving: 1) the acetic acid catalyzed oxidation of thiophene with hydrogen peroxide and 2) the subsequent extraction of the oxidized products with  three  1-alkyl-3-methylimidazolium  bromide  [RMIM]Br  ionic  liquids  of  varying  alkyl substituent R chain length  (R: C2, C4,  C6) and with acetonitrile as control. For purposes of comparison,  a  non-oxidative  extractive  desulfurization  of  model  oil  with  the  above  ionic liquid and with acetonitrile was also performed.  The thiophene extraction efficiencies of the ionic liquids and that of the control in both the oxidative and non-oxidative procedures were determined  by  means  of  gas  chromatography.  The  ionic  liquid  of  the  shortest  alkyl substituent chain length (R: C2), [EMIM] Br exhibited the highest extraction efficiency in the oxidative desulfurization of the model  oil; the extraction efficiency of [EMIM] Br was also observed  to  exceed  that  of  acetonitrile.  In  general,  the  oxidative  desulfurization  with  the above [RMIM]Br’s is apparently a more efficient method of thiophene removal from the model oil as compared to a non-oxidative procedure with the same extraction solvents. The extraction efficiency of [RMIM]Br’s was observed to decrease with the lengthening of the alkyl  substituent  chain.  The  same  trend  is  observed  in  the  non-oxidative  extractive desulfurization of the model oil. Recyclability analysis of [EMIM]Br showed that [EMIM]Br can be recycled thrice with no significant decrease in extraction efficiency.

EPD of Metallic Silver Particles: Problems and Solutions

2006 ◽  
Vol 314 ◽  
pp. 95-100 ◽  
Author(s):  
Martin Zarbov ◽  
David Brandon ◽  
Leah Gal-Or ◽  
Nissim Cohen
Keyword(s):  
Particle Size ◽  
Size Distribution ◽  
Silver Powder ◽  
High Viscosity ◽  
Metallic Silver ◽  
Silver Particles ◽  
Counter Electrodes ◽  
Present Contribution ◽  
Low Dielectric ◽  
Key Factor

Cerel has devoted the past several years to the development of prototype microcomponents for the electronics industry based on EPD processing. The present contribution summarizes some problems Cerel has experienced in the integration of EPD for metallic silver particles into a viable production process. In particular, the parameters that need to be controlled due to the metallic nature of the silver particles have been analyzed. Selection of a metallic silver powder suitable for EPD is the key factor. An appropriate particle size and shape, as well as a controlled size distribution, significantly improves the green density of the deposit. Metallic silver particles in a suspension tend to aggregate, especially when exposed to an electric field. This leads to premature sedimentation, as well as low green densities for the electrophoretic deposit. The following factors were found to contribute significantly to preventing premature sedimentation: • The replacement of pure silver by palladium-coated silver particles. • Dispersion preparation in a high viscosity medium of low dielectric constant. • The presence of steric, electrosteric and ceramic oxide additives in the siver powder dispersion. Finally, control of the solids loading and particle size distribution in the suspension, and the geometrical design of the EPD cell, including the counter-electrodes, were also shown to be important for the successful electrophoretic deposition of silver particles in the commercial production of micro-components by EPD.

Preparation of Highly Crystallized Yttrium Oxysulfide Suspension via a Novel Colloidal Processing

2016 ◽  
Vol 16 (4) ◽  
pp. 3951-3955 ◽  
Author(s):  
Hong Wang ◽  
Tao Jiang ◽  
Ming-Ming Xing ◽  
Yao Fu ◽  
Yong Peng ◽  
...  
Keyword(s):  
High Temperature ◽  
Solid State ◽  
Solid State Reaction ◽  
Colloidal Particles ◽  
Synthesis Method ◽  
Acid Leaching ◽  
Ethanol Solution ◽  
Colloidal Processing ◽  
Step Method ◽  
Leaching Process

High-crystallized Y2O2S suspension was synthesized by a novel two-step method of high temperature solid-state reaction and subsequent colloidal processing. The synthesis method proposed in this study retains all advantages of the high temperature solid-state reaction method. The obtained data agrees with that of the PDF card, which indicates the product is pure Y2O2S crystals. The results show that the prepared Y2O2S particles are highly crystallized without any significant defects. The fine smooth particles were almost regular, exhibiting an approximately subspherical shape. Quantitative image analysis of particles suggests a mean particle size of 120±34 nm. That is to say, the yttrium oxysulfide colloid prepared by this method have a very narrow size distribution. The obtained ethanol suspension shows Tyndall effect when irradiated with laser of wavelength 532 nm. In addition, the particles exhibit excellent dispersibility in ethanol solution. This is rarely observed for the covalent compounds, which generally present poor dispersibility in solution. As is known to all, the state of the dispersion depends on the acid leaching process. The acid leaching process facilitates the adsorption of ethanol molecules on the surface of the particles. The electrostatic repulsive force among colloidal particles will improve their rheological properties and dispersibility in solution. In this study, the particles can be dispersed well in ethanol after acid leaching. The method proposed in this study can be extended for the preparation of mono-dispersed oxysulfide nanophosphors and may provide an efficient way for the preparation of stable covalent compound dispersions.

scholarly journals Single step electrodeposition process using ionic liquid to grow highly luminescent silicon/rare earth (Er, Tb) thin films with tunable composition

RSC Advances ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 3789-3797 ◽  
Author(s):  
Shibin Thomas ◽  
Jeremy Mallet ◽  
Hervé Rinnert ◽  
Michael Molinari
Keyword(s):  
Thin Films ◽  
Ionic Liquid ◽  
Rare Earth ◽  
Room Temperature ◽  
Single Step ◽  
Room Temperature Ionic Liquid ◽  
Step Method ◽  
Electrodeposition Process ◽  
One Step

A one-step method for the electrodeposition of silicon–erbium (Si/Er) and silicon–terbium (Si/Tb) thin films using room temperature ionic liquid (RTIL) has been successfully developed.

Preparation and Characterization of a Novel Room Temperature Dicationic Ionic Liquid and its Application in the Synthesis of Xanthenediones Under Solvent-Free Conditions

2018 ◽  
Vol 21 (8) ◽  
pp. 602-608 ◽  
Author(s):  
Zainab Ehsani-Nasab ◽  
Ali Ezabadi
Keyword(s):  
Ionic Liquid ◽  
Room Temperature ◽  
Reaction Times ◽  
Significant Loss ◽  
Solvent Free ◽  
Acidity Function ◽  
Efficient Catalyst ◽  
Solvent Free Conditions ◽  
Hammett Acidity Function ◽  
Dicationic Ionic Liquid

Aim and Objective: In the present work, 1, 1’-sulfinyldiethylammonium bis (hydrogen sulfate) as a novel room temperature dicationic ionic liquid was synthesized and used as a catalyst for xanthenediones synthesis. Material and Method: The dicationic ionic liquid has been synthesized using ethylamine and thionyl chloride as precursors. Then, by the reaction of [(EtNH2)2SO]Cl2 with H2SO4, [(EtNH2)2SO][HSO4]2 was prepared and after that, it was characterized by FT-IR, 1H NMR, 13C NMR as well as Hammett acidity function. This dicationic ionic liquid was used as a catalyst for the synthesis of xanthenediones via condensation of structurally diverse aldehydes and dimedone under solvent-free conditions. The progress of the reaction was monitored by thin layer chromatography (ethyl acetate/n-hexane = 3/7). Results: An efficient solvent-free method for the synthesis of xanthenediones has been developed in the presence of [(EtNH2)2SO][HSO4]2 as a powerful catalyst with high to excellent yields, and short reaction times. Additionally, recycling studies have demonstrated that the dicationic ionic liquid can be readily recovered and reused at least four times without significant loss of its catalytic activity. Conclusion: This new dicationic ionic liquid can act as a highly efficient catalyst for xanthenediones synthesis under solvent-free conditions.

Positive Role of Synthesis Method and Hard Template on the Catalytic Performance of SAPO-34 in Methanol to Olefin Reaction.

2020 ◽  
Vol 23 ◽  
Author(s):  
Sajjad Rimaz ◽  
Reza Katal
Keyword(s):  
Particle Size ◽  
Synthesis Method ◽  
Catalytic Performance ◽  
Hard Template ◽  
Structure Directing Agent ◽  
Positive Role ◽  
Methanol To Olefin ◽  
Dg Method ◽  
Synthesis Procedure

: In the present study, SAPO-34 particles were synthesized using hydrothermal (HT) and dry gel (DG) conversion methods in the presence of diethyl amine (DEA) as an organic structure directing agent (SDA). Carbon nanotubes (CNT) were used as hard template in the synthesis procedure to introduce transport pores into the structures of the synthesized samples. The synthesized samples were characterized with different methods to reveal effects of synthesis method and using hard template on their structure and catalytic performance in methanol to olefin reaction (MTO). DG conversion method results in smaller particle size in comparison with hydrothermal method, resulting in enhancing catalytic performance. On the other side, using CNT in the synthesis procedure with DG method results in more reduction in particle size and formation of hierarchical structure which drastically improves catalytic performance.

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