We allready dipsersed zinc oxide and titanium oxide nanoparticles in ethanol using as dispersing agent sodium salt of polymetil metacrylate acid. It is possible to work also in methanol but depends on the kind of nanoparticles. Zeta potential measurments aer very useful to find the exact behaviour.

Can I ask which metal oxide you have?. I prepared already many metal oxide like (Fe3O4, CuFeO2, SnO2, SiO2, CeO2) and their nanocomposite. Some of them were dispersed effectively in aqueous solution via large biomolecules.

Hi,

maybe you can try the ligand exchange with 11-mercaptoundecanoic acid.

Other method, recently published by my group, is the fase transfer using CO2 switchable surfactants. The reference is RSC Adv., 2013,3, 4867-4871.

You can try download it in my profile.

I hope it would be useful for your work.

We allready dipsersed zinc oxide and titanium oxide nanoparticles in ethanol using as dispersing agent sodium salt of polymetil metacrylate acid. It is possible to work also in methanol but depends on the kind of nanoparticles. Zeta potential measurments aer very useful to find the exact behaviour.

may i know which metal oxide you have, and what are you looking for? because it will help us to understand. we prepared metal oxide like (Fe3O4, Cuo, ZnO , Tio2, nanocomposite. Some of them were dispersed effectively in aqueous solution,but we not try for disperse in methanol, because for Biomedical application methanol is in Toxic category,

i also agree with Radus Answer it may be possible to work also in methanol but depends on the kind of nanoparticles. Zeta potential measurments aer very useful to find the exact behaviour. But nice question & discuss. thank you

Any metal oxide nanoparticles can be attached to polyethylene glycol (PEG) polymer chains to make them aqueous soluble. See below an example

Effective PEGylation of Iron Oxide Nanoparticles for High Performance In Vivo Cancer Imaging. Advanced Functional Materials, 2011, Volume 21, Issue 8, pages 1498–1504.

iron oxide have no problem to be soluble in water or methanol and have good capping ability to PEG and other biomolecules. The question should be precise, which metal oxide she has?.

The particles that we generally work with are ZrO2, BaZrO3, HfO2 and TiO2.

Already thank you for the nice suggestions, we will try some of them in the lab. We will not use the biomolecules, because they probably will not work for methanol. Thank you Salvador for the article.

We have PEG, polyacrylic acid, polyvinylpyrollidone in the lab, so we definitely will try these ones.

Methanol, being a polar solvent (less polar than water) it works quiet well with hydrophilic oxides (in the means of dispersibilty). I think the most simple method is test the dispersability of your material in water. If there works, it will work 90% in methanol. I do not recommend capping, if you are using your material for catalytic applications (we had a lot of problems with it). Cheers,

Zsolt

Thank you for your answer Zsolt.

The particles are not used for catalytic applications, so capping is possible, but preferable short chain lengths.

it would be better to disperse NPs in ethanol, chloroform or DMF. with methanol, some characteristics of the NPs will be disappeared.

To get good dispersion of nano metal oxides for exampels TiO2 and ZnO in polar solvents like H2O and methanol, you can use this technical method :

At the first step you must Pour the solution into a baker and put it on a heater and metal oxide nano desired was add slowly with stir the solution.

Try synthesizing your nanoparticles in triethylene glycol (Cryst. Growth Des., 2012, 12 (3), pp 1469–1475)... by other side is always possible to perform the surface modification of nanoparticles with several structures (small molecules, surfactants, polimers, polyelectrolites...) that allow you to control the solubility on the different solvents.

Metal oxide nanoparticles mainly ZnO and TiO2 are well dispersed in ethanol and methanol. If you try the combination of methanol and acetone (1:1) then u will get well dispersed metal oxide nanoparticles

Yes, Metal oxide nanoparticles are dispersible in methanol as well as ethanol also. We already dispersed and make suspension for some analysis. so, you keep try for the same.

You could try to disperse your metal oxide nanoparticles in methanol using ultrasonic probe.

So metal oxide nanoparticles can be a pain to ligand exchange. You should look into NOBF4 exchanges. Essentially you strip the surface of ligands and then it is more susceptible your ligand of choice.

I have made FeOx Nanoparticles soluble in water with MUA liked Salvador says. But I have not been able to just add the MUA to the organically soluble particles and have that work. I needed NOBF4.

look for Foley and Strouse should be coming out soon with a protocal

Dear Katrien,

when you have a stable dispersion in high boiling hydrophobic solvents due to modification with adsorbed amphiphiles making the particle surface hydrophobic, it seems to me that phase transfer into methanol should be possible in one step. Dissolving a methanol soluble surfactant, ionic or nonionic, in methanol, emulsifying and then separating the emulsion, should transfer the particles into methanol due to formation of an adsorbed double layer. Know that this sounds simpler as it may work in practice, but I would try this way.

Dear all,

Could "zeta potential measurment" apply to the metal-oxide nanodispersion in "organic solvent"? such as PGMEA, toluene, or cyclohexnone?

Dear You-Ming,

measuring of zeta potential of nanodispersion in organic solvent cannot be applied. The particles are stabilized by steric stabilization. Zeta potential applies to nanoparticles stabilized by electrostatic repulsion.

 Dear bashir kayode Sodipo,

Thanks a lot.

Generally, what kind of parameter could be used for evaluating the degree of stability of nanodispersion in organic solvent?

You could measure stability directly. Separation behaviour is a classical attempt for characterization of dispersion stability. For nanoparticle dispersions analytical centrifugation is very useful. Indirectly of course one may use particle size distribution.

Dear all,

what is the best method for dispersing ZnO nanoparticles in butanol, DMF and DMA?

Using ligand exchange .. you can do so easily ..

SEE 

https://www.researchgate.net/publication/286639591_Water_dispersible_CoFe2O4_nanoparticles_with_improved_colloidal_stability_for_biomedical_applications

Article Water dispersible CoFe2O4 nanoparticles with improved colloi...

 Dear all,

Does anyone have method to disperse ZrO2 nanoparticle in toluene or water?

ZrO2 nanoparticles are well dispersible in water. Problem is when you start with highly aggregated/agglomerated particles, which are then much larger than nano.

You can directly synthesise ZnO within methanol with or without modification.

Article Synthesis and testing of ZnO nanoparticles for photo-initiat...

Sir Titus Sobish, SnO2 nps always make a good solution in water. How can I dispersed them in ethanol or organic solvents. I tried to use oleic acid but oleic acid itself can't dissolve in water.

it is practically insoluble in water.

' How can I dispersed them in ethanol or organic solvents. I tried to use oleic acid but oleic acid itself can't dissolve in water.' ???

Plasma coating or reaction with ligands can change dispersibility and stability of dispersions. Both approaches are not my expertise.