Ligand Charge Density: PEG-COOH vs. PEG-OH

[GGdog0818]

I want to exchange my Au-citrate nanoparticle with two kinds of ligands :PEG-COOH and PEG-OH.
Which one is suppose to have more anionic charge density.

 

[Hyo X]

The carboxylic acid is more acidic than the alcohol. I vote COOH more anionic.

How are you doing the phase transfer? i have done some phase transfer on citrate capped nanoparticles.

 

[Alkim]

I agree with Hyo X but don't forget to consider pH and PEG's molecular weight!