The Surface of Colloidal Nanoparticles Revealed by Vibrational Sum Frequency Scattering Spectroscopy

13 October 2023, Version 1
This content is a preprint and has not undergone peer review at the time of posting.


Solvation shells strongly influence the interfacial chemistry of colloidal systems, from the activity of proteins to the colloidal stability and catalysis of nanoparticles. Despite their fundamental and practical importance, solvation shells remain largely undetected by spectroscopy. Here, we apply for the first-time vibrational sum frequency scattering spectroscopy (VSFSS)—an interface-specific technique—to colloidal nanocrystals, with porous metal–organic frameworks (MOFs) as a case study. Due to the porous nature of the solvent-particle boundary, MOF particles challenge conventional models of colloidal and interfacial chemistry. Spectra indicate the presence of ordered solvation shells and spontaneous ordering within the MOF. VSFSS also applies to colloidal TiO2 and other common nanoparticles, revealing solvation shells with distinct spectral features that arise from the specific surface chemistry of each material. These findings explain the unexpected colloidal stability of MOF colloids, while providing a roadmap for applying VSFSS to wide-ranging colloidal nanocrystals in general.


sum-frequency generation
metal-organic framework
solvation shell
colloidal stability


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.