Theatin van Leeuwen

There is a DLS method, which measures the hydrodynamic size of nanoparticles using the Brownian motion of nanoparticles. There is the TEM method, which measures the size of nanoparticles. The hydrodynamic size of nanoparticles is always larger due to the fact that the charged particle is surrounded by solvent (water) molecules and significantly interacts with the ion.

For laboratory work, you can take the instructions to the DLS and measure the size of a nanoparticle in a polar and non-polar solvent.

One way to try and understand what could happen is as follows: A neutral particle is made up of charged particles anyway. Water has an electrical dipole moment so it's the coupling between this dipole moment and the particle that matters. A neutral particle can only couple to the dipole moment of water through its dipole moment (if it doesn't vanish, as well-in which case it's the quadrupole moment that matters); an electrically charged particle can couple to the individual constituents of the dipole-it can deform the dipoles. So it can lose energy more easily and therefore one might say that it will be slower than a neutral particle that can't lose energy as easily, since it interacts less strongly with water molecules.

I also recommend DLS method

Stam Nicolis so would this also be the same principle for molecules? I was thinking more along the lines of simple molecules like NaCl or sugar or larger drug molecules.

Apologies I probably confused everyone by saying 'particles' when I meant 'molecules' as my research is nanoparticle focused...(oops).

Yes, of course.

Thanks :)

If falling freely under a local gravity, both the identical types of particles would move with the common terminal velocity; else, there may be disparities due to unlike gravito-electrostatic force coupling