For the preparing of nanofluid, which one of the following methods is suitable and does not have an effect on the final stabilization of the nanofluid?
1. First we add the nanoparticles to the base fluid and then by sonication the nanoparticles get dispersed and finally the surfactant is added.
2. First the nanoparticles are added to the base fluid and then the surfactant is added and finally by sonication the nanoparticles get dispersed.
3. First the surfactant is added to the base fluid, then the nanoparticles are added and finally the sonication is applied.
Sorry to say it, the problem is poorly posed. It makes a great deal of difference what kind of particles, "base fluid", and surfactant, not to mention what your definition of "suitable" is (low-cost, high-throughput, etc.). If it were me, I would try each one in turn, and take notes on what happens.
Thanks Mr.S.Russell for your attention
my problem is related to dispersing the Al2O3 nano particle in pure ethanol(99.96%)
I purchased 3 kinds of AL2o3 from seperate INC .
kind 1 : Al2O3 - Gamma - 25 nm
kind 2 : AL2O3 - phase is unknown- 80 nm
kind 3 : aL2O3 - 40 -50 nm - Merck
I used this method for preparing the nanofluid:
First i added the 0.05% Wt nano particle in ethanol , then added 0.5% or 1 % wt a non ionic surfactant ( such Sorbitan Oleate ( span 80 ) - Tween 80 - Tritox x100 ) , then sonication( bath sonication ) is applied for 15 minute .but all of the nano particles started to sedimentate after 15 minutes. After the 1 hours, all of the particles sedimentated in botton of the test tube.
In the article with the name:" Combustion of nanofluid fuels with the addition of boron and iron particles at dilute and dense concentrations" , it is mentioned that ethanol based nano fluid has good stability for example boron (0.5% Wt - 80 nm) with ethanol remaining stabile for 4 hours without surfactant.
Or author in the other article said that the AL nano particle (with 2nm covered by thin layer of AL2O3) remains stable for 24 hours without surfactant.
In your opinion what is my problem?
Hi,Hamid. Your question is very interesting and attracive. I always add nanoparticals to base fluid and then add dispersent or surfactant followed by magnetic stiring and sonicate subsequently during my preparation. I am not sure whether the sequence change could make a difference on stability of nanofluid. If it really do, I'm afraid whether the difference could be observed.
Furthermore, I noticed researchers add SDS with concentration 200ppm in aluminum oxide/EG nanofluid and displayed better stability.Since stabilization of Span 80 is not that satisfactory, it is not suitable for aluminum oxide/EG nanofluid.
Good luck for your research.
Hamid, As Stewart Russel said, you really need to do your own study of various surfactants and concentrations, especially if you have not found any literature articles about your specific particles. Also, to reduce the time needed to compare sedimentation, instead of just letting the dispersions stand at room ambient, centrifuge for about 10-20 minutes at a suitable speed instead. You'll again need to do a few centifugation experiments to determine "suitable speed" for your specific system. (This worked well for me for optimizing the specific surfactant and concentration of nanoparticles and surfactant concentration for inorganic fullerene dispersions.)
HELLO, Al2O3 is hydrophilic no need to add surfactant....sonication is enough n this should be for limited time..
- Badges
- Science topic
- Similar topics
- Chemistry
- Nanotechnology