for synthesizing silver-silica nanoparticles by sol-gel method , i have probem with it .
Please see the following article. I hope this will fulfill your requirement...
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I have on my master. You can see details in this article: Article Organically modified silica (ORMOSIL) bearing imidazolium – ...
Lin Sun Himanshu Mishra Anna Paula Azevedo De Carvalho
Infact i would like to synthesize mesopororous silica-silver janus nano particles in free-alcohol system. To the best of my knowledge, during the process of synthesis, after adding TEOS to the solution of silver sol and CTAB , by passing 10 minutes , i can not see the white precipitation which is demonstrative of forming silica .Also, i extended the time of reaction too, but i did not make any difference apparently .
10 min is a very fast reaction when it is caralysed FOR EXAMPLE, IN A IONIC LIQUID mEDIUM rEACTION. Traditionaly the sOL-GEL silica particle even in alcohol or water medium take at least 4 hour to turn from a solution into a white dispersion. I suggest you wait more than 10 minites.
Sorry, i mean into a white coloidal dispersion. In the case other cases you can have a gel; it depends the morphology, TYPE, sYSE you whant and so on.
I have experience about synthesising silica sol-gel, but never add silver particles to the sol-gel.
Xinshu Zou in my protocol i have to add TEOS to the ctab and Ag nanoparticle solutin ,then stirr under temperature of 40 C for 10 minutes. i wonder if silica nanoparticles form or not? because i cant observe white precipitation at all .infact, i dont wanto synthesise core-shell structure ,but i want to synthe
size janus nanoparticles .
In my opinion, the silica nanoparticle dispersed in the solution like sol. If you see white precipitation at the solution bottom, that you maybe synthesis the micrometer silica particle already.
What is the pH of your Ag-CTAB solution before adding TEOS? You don’t report a catalyst in your protocol. If your solution is pH neutral, TEOS hydrolysis and condensation rate constants are extremely slow.
What solvent are u using? Water, ethanol, or other (even mixtures) have been used for synthesis of silica particles. You can find lots of good and even recent papers to tune particle size. Temperature, stirring rate (laminar or hydrodynamic flow), pH, molar concentrations and addition rate of TEOS will all determine your final outcome and PDI. I don’t have experience using an Ag-sol-gel, but I really wonder how you will control the Janus aspect in this one-pot synthesis... I guess you end up with core-shell instead since even small additions of TEOS will “uniformly” coat the existing Ag particles since they have no preference for only half of the Ag particle...
The wax-Pickering emulsion technique could give you Janus properties. If you have Ag- particles with CTAB in the matrix, they should segregate to the interface upon mixing with hot, liquid wax. You can then coat the exposed side with a small amount of TEOS when the wax hardens.
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