Hello everyone,
I have some problems about producing ordered-magnetic silica core/shell nanoparticles. I attached a file what I have done also I added the references that I used to synthesis.
I tried different protocols but still i could not obtain monodisperse and ordered core/shell nanoparticles. I observed aggregated NPs as well as worm-shape NPs. I kept the samples in an ultrasonic water bath for 1 hour before TEM analysis. Furthermore, I could not see the silica shell clearly in TEM analysis, even if the nanoparticles were well dispersed in water.
Does anyone have idea why I have shapeless NPs and what is the crux of getting core/shell NPs?
Thank you in advance!
After obtaining the nanoparticles in reverse micelles, verify their size on TEM. Maybe they have already been aggregated before adding TEOS, i.e. before getting the shell. Magnetic particles you apparently get from hydroxide. Perhaps you badly calcined it when you received the oxide.
After obtaining the nanoparticles in reverse micelles, verify their size on TEM. Maybe they have already been aggregated before adding TEOS, i.e. before getting the shell. Magnetic particles you apparently get from hydroxide. Perhaps you badly calcined it when you received the oxide.
thank you to respond,
I prepared Fe3O4 by thermal decomposition method and obtained small and monodisperse NPs as you can see in the picture that I shared. in the method i used toluene, I applied sonication for 1 hour to disperse all NPs in the solution of tolune/ethanol/water.
Do you think it is not enough to disperse of NPs or should I reduce the amount of NPs?
Also in the method used CTAB, I also applied sonication to disperse all NPs in the CTAB solution but still I saw worm-shaped NPs. I will get images from CTAB-coated NPs. If the problem is on this step, what should I do in the next?
Magnetic nanoparticles are good. Cover them with silicon according to the TEOS procedure after washing. Such techniques are described in the literature.
Hello. Try coating with using TEOS. Below I attached two articles that can help you.
Article Controlled surface functionalization of silica-coated magnet...
Article Producing ultra-thin silica coatings on iron-oxide nanoparti...
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