Effect of Surfactants and Nanoparticle Materials on the Stability and Properties of CuO-Water and Fe3O4-Water Nanofluids

2020 ◽  
Author(s):  
Nikhil S. Mane ◽  
Vadiraj Hemadri
Keyword(s):  
Thermal Properties ◽  
Zeta Potential ◽  
Hydrodynamic Characteristics ◽  
Ammonium Bromide ◽  
Lauryl Sulfate ◽  
Improved Performance ◽  
Cetyl Trimethyl Ammonium ◽  
Surfactant Material ◽  
The Stability ◽  
Nanoparticle Material

Abstract The arguments in favor of using nanofluids in thermal applications have been increasing substantially for the last few decades. Nanofluids provide improved performance in heat transfer processes in comparison to their base fluids as a result of their superior thermal properties. Even though nanofluids exhibit better thermal properties, their usage has been limited due to their stability issues. The stability of the nanofluid greatly affects its thermal properties over a period of time. The stability and thermal properties of nanofluids can be affected by parameters like surfactants used and their concentrations, and also on the nanomaterial used in the nanofluid. In this study, surfactant material and nanoparticle material are selected as process variables and for each variable two levels are selected. For surfactant material, Sodium Lauryl Sulfate (SLS) and Cetyl Trimethyl Ammonium Bromide (CTAB) are selected. Surfactant concentration ratios are taken as 1:2 for CuO and 1:4 for Fe3O4 material. Four nanofluid samples are prepared with 0.1% weight of nanoparticles and their stability and properties are studied. The feasibility of turbidity as an indicator for stability is also explored in this work. The results show that the zeta potential and hydrodynamic characteristics are largely dependent on the surfactant material. Both surfactants show good stability of nanofluids. In-line with earlier observations, it is also observed that the nanoparticle material has a dominant effect on the thermal conductivity of the nanofluids. Comparing the turbidity of the nanofluids to the zeta potential, it is observed that the turbidity measurement gives first-hand information about the stability of nanofluids and can act as an index for stability. But still, more exploration is necessary for this field so a quantitive relation can be established between turbidity and zeta potential of different nanofluid materials and concentrations.

Use of Detergents in the Analysis of Fibrous Feeds. I. Preparation of Fiber Residues of Low Nitrogen Content

1963 ◽  
Vol 46 (5) ◽  
pp. 825-829 ◽  
Author(s):  
P J Vax Soest
Keyword(s):  
Nitrogen Content ◽  
Sodium Lauryl Sulfate ◽  
Dry Matter ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Alkaline Solutions ◽  
Ammonium Bromide ◽  
Lauryl Sulfate ◽  
Cetyl Trimethyl Ammonium ◽  
Low Nitrogen ◽  
Nonionic Detergents

Abstract Anionic, cationic, and nonionic detergents in different buffering media were examined for their capacity to dissolve nitrogenous constituents in forage dry matter, in the interest of preparing fiber of a low nitrogen content. Of the combinations examined, cetyl trimethyl ammonium bromide in strongly acid solution and sodium lauryl sulfate in slightly alkaline solutions appeared most effective.

Use of Detergents in the Analysis of Fibrous Feeds. I. Preparation of Fiber Residues of Low Nitrogen Content

1990 ◽  
Vol 73 (4) ◽  
pp. 487-491 ◽  
Author(s):  
P J Van Soest
Keyword(s):  
Nitrogen Content ◽  
Sodium Lauryl Sulfate ◽  
Dry Matter ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Alkaline Solutions ◽  
Ammonium Bromide ◽  
Lauryl Sulfate ◽  
Cetyl Trimethyl Ammonium ◽  
Low Nitrogen ◽  
Nonionic Detergents

Abstract Anionic, cationic, and nonionic detergents in different buffering media were examined for their capacity to dissolve nitrogenous constituents in forage dry matter, in the interest of preparing fiber of a low nitrogen content. Of the combinations examined, cetyl trimethyl ammonium bromide in strongly acid solution and sodium lauryl sulfate in slightly alkaline solutions appeared most effective.

Spontaneous Formation of CTAB/SDBS Vesicles

2014 ◽  
Vol 953-954 ◽  
pp. 1230-1233 ◽  
Author(s):  
Lin Lin Cui ◽  
Li Juan Fu
Keyword(s):  
Cetyl Trimethyl Ammonium Bromide ◽  
Sodium Dodecyl ◽  
Sodium Dodecyl Benzene Sulfonate ◽  
Ammonium Bromide ◽  
Complex Formulation ◽  
Structure And Morphology ◽  
Spontaneous Formation ◽  
Dodecyl Benzene Sulfonate ◽  
Cetyl Trimethyl Ammonium ◽  
The Stability

Cetyl trimethyl ammonium bromide/sodium dodecyl benzene sulfonate (CTAB/SDBS) complex formulation of scale effect on the spontaneous formation of vesicles and the influence of different factors on the stability of vesicles were discussed, structure and morphology of vesicles were observed.

Spontaneous Formation of CTAB/SLS Vesicles

2014 ◽  
Vol 953-954 ◽  
pp. 1234-1237
Author(s):  
Lin Lin Cui
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Scale Effect ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Sodium Dodecyl ◽  
Ammonium Bromide ◽  
Complex Formulation ◽  
Structure And Morphology ◽  
Spontaneous Formation ◽  
Cetyl Trimethyl Ammonium ◽  
The Stability

Cetyl trimethyl ammonium bromide/sodium dodecyl sulfate (CTAB/SLS) complex formulation of scale effect on the spontaneous formation of vesicles and the influence of different factors on the stability of vesicles were discussed, structure and morphology of vesicles were observed.

Gum arabic helps prepare better lacey polymer films for specimen support in electron microscopy

1993 ◽  
Vol 51 ◽  
pp. 240-241
Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare
Keyword(s):  
Electron Microscopy ◽  
Polymer Films ◽  
Gum Arabic ◽  
Complete Removal ◽  
Ammonium Bromide ◽  
Release Agent ◽  
Astigmatism Correction ◽  
Long Time ◽  
Micro Holes ◽  
Cetyl Trimethyl Ammonium

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.

An Experimental Investigation on Thermal Conductivity and Viscosity of Graphene doped CNTs /TiO2 Nanofluid

2020 ◽  
Vol 17 (3) ◽  
Author(s):  
A.M. Zetty Akhtar ◽  
M.M. Rahman ◽  
K. Kadirgama ◽  
M.A. Maleque
Keyword(s):  
Thermal Conductivity ◽  
Zeta Potential ◽  
Base Fluid ◽  
Minimum Quantity Lubrication ◽  
Cutting Fluid ◽  
Cutting Zone ◽  
Observation Method ◽  
The Stability ◽  
The Relationship ◽  
Zeta Potential Analysis

This paper presents the findings of the stability, thermal conductivity and viscosity of CNTs (doped with 10 wt% graphene)- TiO2 hybrid nanofluids under various concentrations. While the usage of cutting fluid in machining operation is necessary for removing the heat generated at the cutting zone, the excessive use of it could lead to environmental and health issue to the operators. Therefore, the minimum quantity lubrication (MQL) to replace the conventional flooding was introduced. The MQL method minimises the usage of cutting fluid as a step to achieve a cleaner environment and sustainable machining. However, the low thermal conductivity of the base fluid in the MQL system caused the insufficient removal of heat generated in the cutting zone. Addition of nanoparticles to the base fluid was then introduced to enhance the performance of cutting fluids. The ethylene glycol used as the base fluid, titanium dioxide (TiO2) and carbon nanotubes (CNTs) nanoparticle mixed to produce nanofluids with concentrations of 0.02 to 0.1 wt.% with an interval of 0.02 wt%. The mixing ratio of TiO2: CNTs was 90:10 and ratio of SDBS (surfactant): CNTs was 10:1. The stability of nanofluid checked using observation method and zeta potential analysis. The thermal conductivity and viscosity of suspension were measured at a temperature range between 30˚C to 70˚C (with increment of 10˚C) to determine the relationship between concentration and temperature on nanofluid’s thermal physical properties. Based on the results obtained, zeta potential value for nanofluid range from -50 to -70 mV indicates a good stability of the suspension. Thermal conductivity of nanofluid increases as an increase of temperature and enhancement ratio is within the range of 1.51 to 4.53 compared to the base fluid. Meanwhile, the viscosity of nanofluid shows decrements with an increase of the temperature remarks significant advantage in pumping power. The developed nanofluid in this study found to be stable with enhanced thermal conductivity and decrease in viscosity, which at once make it possible to be use as nanolubricant in machining operation.

scholarly journals Preparation of Porous Hydroxyapatite Using Cetyl Trimethyl Ammonium Bromide as Surfactant for the Removal of Lead Ions from Aquatic Solutions

Polymers ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1617
Author(s):  
Silviu-Adrian Predoi ◽  
Carmen Steluta Ciobanu ◽  
Mikael Motelica-Heino ◽  
Mariana Carmen Chifiriuc ◽  
Monica Luminita Badea ◽  
...  
Keyword(s):  
Cetyl Trimethyl Ammonium Bromide ◽  
Morphological Changes ◽  
Low Cost ◽  
Lead Ions ◽  
Ammonium Bromide ◽  
Porous Hydroxyapatite ◽  
X Ray ◽  
Composition And Structure ◽  
Cetyl Trimethyl Ammonium ◽  
Co Precipitation

In the present study, a new low-cost bioceramic nanocomposite based on porous hydroxyapatite (HAp) and cetyl trimethyl ammonium bromide (CTAB) as surfactant was successfully obtained by a simple chemical co-precipitation. The composition and structure of the HAp-CTAB were characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), scanning electron microscope (SEM) equipped with an energy dispersive X-ray (EDX) spectrometer, and N2 adsorption/desorption analysis. The capacity of HAp-CTAB nanocomposites to remove the lead ions from aqueous solutions was studied by adsorption batch experiments and proved by Langmuir and Freundlich models. The Pb2+ removal efficiency of HAp-CTAB biocomposite was also confirmed by non-destructive ultrasound studies. The cytotoxicity assays showed that the HAp-CTAB nanocomposites did not induce any significant morphological changes of HeLa cells after 24 h of incubation or other toxic effects. Taken together, our results suggests that the obtained porous HAp-CTAB powder could be used for the decontamination of water polluted with heavy metals, such as Pb2+.

scholarly journals The Effect of pH and Storage Temperature on the Stability of Emulsions Stabilized by Rapeseed Proteins

Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1657
Author(s):  
Karolina Östbring ◽  
María Matos ◽  
Ali Marefati ◽  
Cecilia Ahlström ◽  
Gemma Gutiérrez
Keyword(s):  
Zeta Potential ◽  
Storage Temperature ◽  
Emulsion Stability ◽  
Press Cake ◽  
Strong Impact ◽  
Soy Lecithin ◽  
Rapeseed Protein ◽  
Rapeseed Proteins ◽  
Precipitation Ph ◽  
The Stability

Rapeseed press cake (RPC), the by-product of rapeseed oil production, contains proteins with emulsifying properties, which can be used in food applications. Proteins from industrially produced RPC were extracted at pH 10.5 and precipitated at pH 3 (RPP3) and 6.5 (RPP6.5). Emulsions were formulated at three different pHs (pH 3, 4.5, and 6) with soy lecithin as control, and were stored for six months at either 4 °C or 30 °C. Zeta potential and droplet size distribution were analyzed prior to incubation, and emulsion stability was assessed over time by a Turbiscan instrument. Soy lecithin had significantly larger zeta potential (−49 mV to 66 mV) than rapeseed protein (−19 mV to 20 mV). Rapeseed protein stabilized emulsions with smaller droplets at pH close to neutral, whereas soy lecithin was more efficient at lower pHs. Emulsions stabilized by rapeseed protein had higher stability during storage compared to emulsions prepared by soy lecithin. Precipitation pH during the protein extraction process had a strong impact on the emulsion stability. RPP3 stabilized emulsions with higher stability in pHs close to neutral, whereas the opposite was found for RPP6.5, which stabilized more stable emulsions in acidic conditions. Rapeseed proteins recovered from cold-pressed RPC could be a suitable natural emulsifier and precipitation pH can be used to monitor the stability in emulsions with different pHs.

Influence of Different Dispersants on the Dispersion Property of Nano-Aluminium Powders

2011 ◽  
Vol 71-78 ◽  
pp. 122-125 ◽  
Author(s):  
Ling Li Song ◽  
Ren Yuan Zhang ◽  
Ling Bo Mao ◽  
Wen Jie Zhu ◽  
Miao Yan Zheng
Keyword(s):  
Sodium Dodecyl Sulfate ◽  
Ultrasonic Vibration ◽  
Cetyl Trimethyl Ammonium Bromide ◽  
Sodium Dodecyl ◽  
Dispersion Property ◽  
Ammonium Bromide ◽  
Aluminum Powders ◽  
Ultrasonic Time ◽  
Dodecyl Sulfate ◽  
Cetyl Trimethyl Ammonium

The influences of dispersant type, supersonic time and concentration on the dispersion property of the nano-aluminium powders in glycol water were systematically studied by using Sodium dodecyl sulfate (SDS)，cetyl trimethyl ammonium bromide (CTAB) and sodium hexa metah posphate（SHMP）as dispersants. During the first stage of the experiments, influences of dispersant type and ultrasonic time with these dispersants were evaluated. The next stage of the study was focused on SHMP concentration. The influence of SHMP concentration was assessed. The results show that with the increasing of ultrasonic time, the dispersion property of nano-aluminum powders first increases and then decreases, and SHMP is the best one. The excellent dispersing condition on the dispersion property of nano-aluminium is: 5g/L SHMP and 50 min ultrasonic vibration.

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