"Mdel amphiphilic polymer conetworks comprising star polymers..." Costas S. Patrickios

Model Amphiphilic Polymer Conetworks Comprising Star Polymers End-linked via Dynamic Covalent Acylhydrazone Bonds

Costas S. Patrickios Department of Chemistry, University of Cyprus

This lecture will provide an overview of our work on the development of robust [1], self-healable [1,2] and self-assembling [3] amphiphilic polymer conetworks via the use of model building blocks interconnected through chemically reversible cross-links. The building blocks are pairs of four-arm star polymers comprising arms of precise length and composition, with the one partner end-functionalized with (four) aldehyde groups and the other end-functionalized with (four) acylhydrazide groups, and whose combination would lead to the formation of dynamic covalent acylhydrazone cross-links (also resulting in gelation), potentially conferring upon the formed gels the properties of self-healing, reversibility, recyclability and injectability. The well-defined structure of the constituting star polymer building blocks secures conetwork homogeneity and enhancement of the mechanical properties, in addition to the capability of deriving accurate structure-property relationships. Amphiphilicity is introduced into the conetworks in two different ways : first, by the combination of two different types of four-arm star homopolymers, a hydrophilic and a hydrophobic, and, second, by the use of amphiphilic star block copolymers. Network amphiphilicity leads to self-assembly in aqueous media, with the formed hydrophobic domains offering themselves for solubilization of hydrophobic species (drugs for delivery or environmental pollutants for sequestration), but also providing a means for mechanical energy dissipation, thereby further enhancing the mechanical properties of the system. In addition to synthesis, we will provide the results from the characterization of the swelling, rheological, mechanical, dynamic and self-assembling properties of these model amphiphilic polymer conetworks, and also their potential use as gel polymer electrolytes by their loading with an ionic liquid.

References
1. D. E. Apostolides, T. Sakai and C. S. Patrickios, Macromolecules 2017, 50, 2155 – 2164.
2. D. E. Apostolides and C. S. Patrickios, Polym. Int. 2018, 67, 627 – 649.
3. D. E. Apostolides, C. S. Patrickios, T. Sakai, M. Guerre, G. Lopez, B. Améduri, V. Ladmiral, M. Simon, M. Gradzielski, D. Clemens, C. Krumm, J. C. Tiller, B. Ernould and J.-F. Gohy, Macromolecules 2018, 51, 2476 – 2488.