In situ monitoring of block copolymer self-assembly via solvent exchange through controlled dialysis with light and neutron scattering detection

27 March 2023, Version 2
This content is a preprint and has not undergone peer review at the time of posting.


Solution self-assembly of amphiphilic block copolymers (BCs) is typically performed by solvent to water exchange. However, BC assemblies are often trapped in metastable states depending on the mixing conditions, such as the magni-tude and rate of water addition. BC self-assembly can be performed under near thermodynamic control by dialysis which accounts for a slow and gradual water addition. In this communication we report the use of a specifically de-signed dialysis cell to continuously monitor by dynamic light scattering and small-angle neutron scattering the mor-phological changes of PDMS-b-PEG BCs during THF to water exchange. The complete phase diagrams of near-equilibrium structures can then be established. Spherical micelles first form before evolving to rod-like micelles and vesicles, decreasing the total developed interfacial area of self-assembled structures in response to increasing interfacial energy as the water content increases. The dialysis kinetics can be tailored to the time scale of BC self-assembly by modifying the membrane pore size, which is of interest to study the interplay between thermodynamics and kinetics in self-assembly pathways.


block copolymers
In situ dialysis
Light and Neutron Scattering

Supplementary materials

Supporting file
Materials & Methods


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.