Voltammetry of alkylated colloids

timmyeatchips

Can anyone point me towards some background reading on how to go about using voltammetry to determine energy levels in semiconductor nanoparticles that are held in colloidal suspension by an alkyl (probably undecyl) monolayer - will this hydrophobic envelope pose problems in terms of getting electron transfer to occur at the electrodes?

chem_tr

Hello, I see that you are an advanced chemistry-related guy. Nice to see you here. I think some phase transfer catalyst or micellar structire will help this hydrophobic envelope be in the solution with no harmful effects.

I have little knowledge about voltammetry, but since charged particles are affected, it has something to do with zeta potentials, etc. If you tell me the principle behind this, maybe I can be of more help. Or just wait for the other members.

timmyeatchips

I'm simply trying to reduce / oxidise the particles in contact with the working electrode, driven by an external potential, in the hope of being able to determine the potentials at which the first oxidation/reduction occurs and therefore be able to calculate the HOMO-LUMO energy gap.
The analysis will be carried out in organic solvent. My main concern is that the alkyl layer may prevent electrical contact between the silicon core of the particles and the electrodes

chem_tr

Well, since "equivalent dissolves equivalent", your hydrophobic tail will be solvatized by relatively minor amounts of organic solvent (cf. water, a.k.a. hydratation). If the alkyl layer is a normal alkane with no branches, then these hydrophobic tails will tend to stay outside of the silicon cores, I presume. So they may slow the process down, but not necessarily block.

Regards