you can try with DMF under ultrasonication

Muhammad Salik Qureshi

You can try but you will fail, IMHO. Carry out a Stokes' Law calculation to determine the size of your settling particles. You'll find that they're in the micron (not nano) size region and there's a billion times difference here:

'The micron scale is volumetrically 109 times larger than the nanoscale. Confusing microtechnology with molecular technology is like confusing an elephant with a ladybug' K Eric Drexler quoted in Ed Regis Nano: the emerging science of nanotechnology' Little, Brown and Company, 1st Edition pp 207 - 208 (1995)

In IPA virtually all the ultrasound energy is used in boiling and volatilizing the liquid and disintegrating the sonication tip. See, for example (registration required):

Ultrasound, cavitation, and the singing kettle

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W130619UltrasoundCavitationSingingKettle.html

The important point is that drying your particles will aggregate them as sure as night follows day... You cannot recover the original dispersed phase as you cannot recover drained marshes by adding water. The key is never to dry them...

Two quotations from those greater than I:

Rudy Rucker: 'I think dry nanotechnology is probably a dead-end' Transhumanity magazine (August 2002)

Jim Adair: If the particles are agglomerated and sub-micron it may be impossible to adequately disperse the particles…… The energy barrier to redispersion is greater if the particles have been dried. Therefore the primary particles must remain dispersed in water….’‘

J H Adair, E. Suvaci, J Sindel, “Surface and Colloid Chemistry” Encyclopedia of materials: Science and Technology pp 8996 - 9006 Elsevier Science Ltd. 2001 ISBN 0-08-0431526

See (registration required):

Dispersion and nanotechnology

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W190528DispNanoMat

Adhesion and cohesion

https://www.malvernpanalytical.com/en/learn/events-and-training/webinars/W180725AdhesionCohesion

Finally, how to do what you want? Make your colloidal dispersion from a bottom-up process and never dry the resulting colloid/sol.

Muhammad Salik Qureshi

A route forward is attached.

You can also buy the product:

https://www.fishersci.com/shop/products/tin-iv-oxide-15-h-sub-2-sub-o-colloidal-dispersion/AA4459236