Influence of SDBS on Stability of Copper Nano-Suspensions

2007 ◽  
Author(s):  
Xinfang Li ◽  
Dongsheng Zhu ◽  
Gang Chen ◽  
Xianju Wang
Keyword(s):  
Heat Transfer ◽  
Zeta Potential ◽  
Cu Nanoparticles ◽  
Transfer Enhancement ◽  
Sodium Dodecylbenzenesulfonate ◽  
Absolute Value ◽  
Ph Values ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

Dispersion and stability of Cu nano-suspensions with dispersant is the important base for the study of rheology and heat transfer enhancement of the suspensions. This paper presented a procedure for preparing a nanofluid which was a suspension consisting of nanophase powders and a base liquids. By means of the procedure, Cu-H2O nanofluids with and without dispersant were prepared, whose sedimentation photographs were given to illustrate the stability and evenness of suspension with dispersant. Dispersion and stability of Cu nanoparticles in water were studied under different pH values and the concentration of sodium dodecylbenzenesulfonate (SDBS) dispersant by the method of zeta potential, absorbency and sedimentation photographs. The results show that zeta potential has very corresponding relation with absorbency, and the higher absolute value of zeta potential and absorbency are, the better dispersion and stability in system is. The absolute value of zeta potential and absorbency are higher at pH 9.5. SDBS can significantly increase the absolute value of the zeta potential of the particle surfaces by electrostatic repulsions, which leads to the enhancement of the stability of the Cu suspensions. The optimizing concentration for SDBS in the 0.1% copper nano-suspensions is 0.07%, which has the best disperse results.

Surface Modification of Nano-Copper and its Dispersive Behavior in Water

2008 ◽  
Vol 373-374 ◽  
pp. 670-673
Author(s):  
X.J. Wang ◽  
Dong Sheng Zhu ◽  
X.F. Li ◽  
Nan Wang
Keyword(s):  
Particle Size ◽  
Surface Modification ◽  
Zeta Potential ◽  
Cu Nanoparticles ◽  
Sodium Dodecylbenzenesulfonate ◽  
Absolute Value ◽  
Ph Values ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

In this paper, by measurement of zeta potential and particle size the surface modification of Cu nanoparticles in water was investigated at different pH values and different concentration of sodium dodecylbenzenesulfonate (SDBS) dispersant. The results show that the absolute value of zeta potential has very corresponding relation with particle size, and that the higher the absolute value of zeta potential and the smaller of the particle size are, the better dispersion and stability of copper nano-suspensions system is. It is also found that SDBS can significantly affect the value of zeta potential and particle size by electrostatic repulsions, which lead to the enhancement of the stability of the Cu suspensions, and the optimizing concentration for SDBS in 0.1% copper nano-suspensions is 0.07%, which have the best disperse results.

Investigation on Dispersive Behavior of TiO2-H2O Nanofluids

2013 ◽  
Vol 468 ◽  
pp. 49-52
Author(s):  
Xian Ju Wang ◽  
Xin Fang Li ◽  
Zhen Zhang Li ◽  
Fang Lin
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Zeta Potential ◽  
Mass Fraction ◽  
Sodium Dodecyl ◽  
Absolute Value ◽  
Dodecyl Sulfate ◽  
The Absolute ◽  
The Stability ◽  
Electrostatic Repulsions

This paper investigated the effects of different pH and dispersant concentration on the dispersion of TiO2 H2O by the measuring zeta potential and absorbency. The results show that the absolute value of zeta potential and the absorbency are higher at pH8-10. Sodium dodecyl sulfate (SDS) can significantly increase the absolute value of zeta potential of particle surfaces by electrostatic repulsions, which leads to the enhancement of the stability for TiO2 nanosuspensions. 0.1%(Mass fraction) TiO2 nanosuspensions has the best dispersion at the SDS optimizing concentration 0.045 %. The results also show the zeta potential has good corresponding relation with absorbency, and the higher absolute value of zeta potential and the absorbency are, the better dispersion and stability in system is.

Effect of Modified Sludge on the Particles Flocculation and Slurry Stability in the Co-slurry of Sludge and Petroleum Coke

2017 ◽  
Vol 15 (3) ◽  
Author(s):  
Meng Liu ◽  
Xiaobin Zhang ◽  
Liang Zhao
Keyword(s):  
Energy Consumption ◽  
Zeta Potential ◽  
Petroleum Coke ◽  
Reflectance Measurement ◽  
Absolute Value ◽  
Calculation Results ◽  
The Absolute ◽  
The Stability ◽  
Shearing Energy ◽  
Slurry Stability

Abstract Sewage sludge modified by Ca(OH)2 and Fe2(SO4)3 were used as make the slurry with petroleum coke, and changes in the size distribution and a total number of particles in the slurry were determined by Focused Beam Reflectance Measurement (FBRM) to explore the particles flocculation mechanism. In addition, the structural strength of petroleum coke sludge slurry (PCSS) was calculated by two mathematic models to illustrate the how the sludge improves the stability of PCSS. The results indicated that the absolute value of the Zeta potential of PCSS increased with the sludge addition and that PCSS stability improved. However, the absolute value of the Zeta potential decreased and the stability declined after the sludge was modified by Fe2(SO4)3 and Ca(OH)2. Petroleum coke particles were wrapped by sludge flocs, and small particles flocculated during their co-slurry process to form a spatial network structure, effectively prevented the settlement of petroleum coke particles and ultimately improved the stability of slurry. The calculation results obtained by the two mathematic models reveal that the shearing energy consumption per-unit-quality of PCSS using raw sludge is twice or thrice than that of PCWS. However, energy consumption was reduced after the sludge was modified by Fe2(SO4)3.

Stability and Enhancement of Boiling in Microchannels

2011 ◽  
Author(s):  
A. E. Bergles
Keyword(s):  
Heat Transfer ◽  
Heat Flux ◽  
Critical Heat Flux ◽  
High Heat ◽  
Heat Fluxes ◽  
Transfer Enhancement ◽  
The Past ◽  
The Stability ◽  
Saturated Boiling ◽  
Microelectronic Components

During the past 20 years, there has been intense worldwide interest in microchannel heat exchangers, particularly for cooling of microelectronic components. Saturated boiling of the coolant is usually indicated in order to accommodate high heat fluxes and to have uniformity of temperature. However, boiling is accompanied by several instabilities, the most severe of which can sharply limit the maximum, or critical, heat flux. These stability phenomena are reviewed, and recent studies will be discussed. Elevation of the critical heat flux will be discussed within the context of heat transfer enhancement. Means to improve the stability of boiling and the enhancement of boiling heat transfer, in general, are discussed.

Investigation on the Effect of an Divalent Electrolyte on the Flocculation of SDBS with Al3+

2012 ◽  
Vol 610-613 ◽  
pp. 163-168
Author(s):  
Jie Yan ◽  
Dong Wang ◽  
Fei Fei Yang ◽  
Dong Mei Yao
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Zeta Potential ◽  
Anionic Surfactant ◽  
Potential Surface ◽  
Sodium Dodecylbenzenesulfonate ◽  
Molar Ratios ◽  
Ph Values ◽  
Average Size

The effect of an divalent electrolyte Ca2+ on the flocculation of two different concentrations of anionic surfactant Sodium Dodecylbenzenesulfonate (SDBS) with Al3+ has been investigated at different molar ratios Al3+ to SDBS at 298.15 K. The results showed that the flocculation characteristics of 0.01 mol•L-1 SDBS (above the critical micelle concentration CMC) and 0.001 mol•L-1 SDBS (below the CMC) were obviously different with an increase of dosages of Al3+. The z-average size of flocculate of 0.01 mol•L-1 SDBS with Al3+ decreased particularly with the pre-addition of Ca2+，It suggested the formation of the complexion Ca(SDBS)2. At optimization flocculation areas at 298.15K, pH values were all around 3.5 in the flocculation systems SDBS/Al3+ and Ca2+/SDBS/Al3+ whether the SDBS concentration above or below the CMC. The pre-addition of Ca2+ slightly affected other flocculation parameters of SDBS/Al3+ systems such as zeta potential, surface tension, conductivity and pH.

Heat transfer enhancement using different shapes of Cu nanoparticles in the flow of water based nanofluid

2020 ◽  
Vol 95 (5) ◽  
pp. 055209 ◽  
Author(s):  
Salman Saleem ◽  
Muhammad Qasim ◽  
Aisha Alderremy ◽  
Saima Noreen
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Enhancement ◽  
Cu Nanoparticles ◽  
Transfer Enhancement ◽  
Water Based ◽  
Different Shapes

Effect of Aminosulphonate Based Superplasticizer on the Properties of Slag Pastes

2013 ◽  
Vol 864-867 ◽  
pp. 755-758
Author(s):  
Qun Pan ◽  
Cong Li Shi ◽  
Bin Zhu
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Absolute Value ◽  
As Adsorption ◽  
The Absolute ◽  
Over Time

This study indicates how aminosulphonate (AS) based superplasticizer affects the properties of slag pastes activated by NaOH, such as adsorption, zeta potential and mini slump. It was concluded that the adsorption of superplasticizer on slag pastes depended directly on the dosage of the superplasticizer and the retarder. Slag particles grounded with the retarder YP-3 adsorbed 1.53 times of superplasticizer AS as much as pure slag particles at 1.5% mass of the slag, and the absolute value increment of the zeta potential of the slag paste suspension containing the retarder YP-3 is 15.20mV, compared with 9.81mV in the system without YP-3. Besides, the Slag pastes activated by NaOH containing the retarder YP-3 show better rheological properties and lower fluidity loss over time.

Thermal Performance of Automobile Radiator Using Carbon Nanotube-Water Nanofluid—Experimental Study

2014 ◽  
Vol 6 (4) ◽  
Author(s):  
Sandesh S. Chougule ◽  
S. K. Sahu
Keyword(s):  
Heat Transfer ◽  
Nusselt Number ◽  
Carbon Nanotube ◽  
Ph Value ◽  
Removal Rate ◽  
Synthesis Method ◽  
Heat Removal ◽  
Nanoparticle Concentration ◽  
Transfer Enhancement ◽  
Ph Values

In the present study, the convective heat transfer enhancement of carbon nanotube (CNT)-water nanofluid has been studied experimentally inside an automobile radiator. Heat removal rate of the coolant flowing through the automobile radiators is of great importance for the optimization of fuel consumption. In this study, four different concentrations of nanofluids in the range of 0.15–1 vol. % were prepared with the addition of CNT nanoparticles into water. The CNT nanocoolants are synthesized by functionalization (FCNT) and surface treatment (SCNT) method. The effects of various parameters, namely synthesis method, variation in pH values and nanoparticle concentration on the Nusselt number are examined through the experimental investigation. Results demonstrate that both nanocoolants exhibit enormous change Nusselt number compared with water. The results of functionalized CNT nanocoolant with 5.5 pH exhibits better performance compared to the nanocoolant with pH value of 6.5 and 9. The surface treated CNT nanocoolant exhibits the deterioration in heat transfer performance. In addition, Nusselt number found to increase with the increase in the nanoparticle concentration and nanofluid velocity.

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