Detecting Shape of Hybrid Polymer/Surfactant Micelles: Cryo-Transmission Electron Microscopy, Small-Angle Neutron Scattering and Dynamic Light Scattering Study

Authors

  • Alexander L. Kwiatkowski Physics Department, Lomonosov Moscow State University, Moscow, Russia https://orcid.org/0000-0002-0514-384X
  • Vyacheslav S. Molchanov Physics Department, Lomonosov Moscow State University, Moscow, Russia
  • Anton S. Orekhov National Research Center, Kurchatov Institute, Moscow, Russia
  • Alexander I. Kuklin Joint Institute for Nuclear Research, Dubna, Russia
  • Olga E. Philippova Physics Department, Lomonosov Moscow State University, Moscow, Russia https://orcid.org/0000-0002-1098-0255

DOI:

https://doi.org/10.31489/2959-0663/2-24-13

Keywords:

polymer/surfactant complexes, hybrid micelles, ionic surfactant, polymer-surfactant interactions, rodlike micelles, branching points, cryo-TEM, SANS, DLS

Abstract

In-depth study of shape of hybrid micelles in the micellar solutions of anionic surfactant potassium oleate, containing hydrophobic polymer poly(4-vinylpyridine) (P4VP) was conducted via cryo-transmission electron microscopy (cryo-TEM), small-angle neutron scattering (SANS) and dynamic-light scattering of visible light (DLS). Direct visualization of the solutions with cryo-TEM evidenced the coexistence of polymer-free spherical micelles and branched rodlike hybrid micelles with mean length of 200 nm and radius of 2 nm, governed by contour length of solubilized P4VP and length of hydrophobic “tail” of potassium oleate, respectively. The formation of branches in the hybrid micelles was explained by attaching the thermodynamically unfavorable end-caps of micelles to their polymer-loaded cylindrical fragments. By SANS it was shown that the cylindrical local shape and the radius of the micelles are independent of the concentration of embedded P4VP. Relaxation processes in the solutions were investigated with DLS. Three relaxation modes were observed for hybrid micelles, similar to polymer-free wormlike micelles. Fast and medium relaxation modes were attributed to diffusion of entangled micellar chains and their segments, respectively. The slow mode was related to electrostatic repulsion between similarly charged hybrid micelles.

Spherical polymer-free micelles imaged with cryo-TEM

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Published

2024-06-27

How to Cite

Kwiatkowski, A., Molchanov, V. S., Orekhov, A. S., Kuklin, A. I., & Philippova, O. E. (2024). Detecting Shape of Hybrid Polymer/Surfactant Micelles: Cryo-Transmission Electron Microscopy, Small-Angle Neutron Scattering and Dynamic Light Scattering Study. EURASIAN JOURNAL OF CHEMISTRY, 29(2 (114), 54–60. https://doi.org/10.31489/2959-0663/2-24-13

Issue

Vol. 29 No. 2 (114) (2024): Eurasian Journal of Chemistry

Section

PHYSICAL AND ANALYTICAL CHEMISTRY

License

Copyright (c) 2024 Alexander L. Kwiatkowski, Vyacheslav S. Molchanov, Anton S. Orekhov, Alexander I. Kuklin, Olga E. Philippova

Creative Commons License

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.

Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License (CC BY-NC-ND 4.0) that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.