Work

Polymer, Water, and Salt Partitioning in Complex Coacervates Characterized by Femtosecond Stimulated Raman Microscopy

Year: 2025

Type: article

Abstract: Complex coacervates can form through liquid–liquid phase separation in aqueous solutions containing oppositely charged macromolecules. This process results in macromolecule‐rich droplets (coacervate phase) coexisting with a macromolecule‐depleted supernatant phase. Here, femtosecond stimulated Raman microscopy (FSRM) is introduced as a tool to rapidly analyze both the supernatant and coacervate phases of complex coacervates. The well‐known polyelectrolyte pair poly(diallyldimethylammonium chloride) and poly(4‐styrenesulfonate) is investigated. Coacervate formation is induced by the addition of KBr and NH4SCN as a Raman‐active salt. For both salts, the partitioning of polymer and water between the coacervate droplets and the supernatant phase is quantified. For the Raman‐active salt NH4SCN, its partitioning between phases was also monitored. NH4SCN was found to be enriched in the coacervate phase, as confirmed by FTIR spectroscopy. Overall, FSRM proves to be a valuable tool for collecting new data on coacervate composition requiring only low sample volumes and simple sample preparation, while offering convenient data acquisition.

Source: Chemistry - Methods

DOI: 10.1002/cmtd.202500005

Authors: Francisco van Riel Neto, Carolin Borbeck, Torben Henning Saatkamp, Maxine Kenny, Stephan Schmidt, Peter Gilch

Institutions: Heinrich Heine University Düsseldorf, University of Freiburg

Language: English

Topic: Electrostatics and Colloid Interactions

Subfield: Physical and Theoretical Chemistry

Field: Chemistry

Domain: Physical Sciences

Open Access status: gold

Estimated APC paid: $2,750

Funder: Deutsche Forschungsgemeinschaft