This lecture will provide an overview of our work on amphiphilic polymer conetworks (APCN) [1] during the past twenty-five years, with emphasis on the last five years, on their formation,
characterization and modeling. APCNs comprise covalently cross-linked hydrophilic and hydrophobic segments, and are consequently capable of microphase separating upon transfer into a selective solvent like water [2]. Thus, these materials represent the network analogs to surfactants. While currently evaluated in various emerging applications in biomedicine and technology, with a notable example in the latter area that of their use as matrices for gel or solid polymer electrolytes in re-chargeable batteries,
APCNs are credited with a major real-market application, with global annual sales totaling 10 billion US dollars. This is their use as silicone hydrogel soft contact lenses, in which the carefully selected hydrophilic and hydrophobic segments, as well as their microphase separated morphology, impart to the lens important properties related to eye comfort and oxygenation [3].

Our latest APCNs are carefully formed by end-linking well-defined polymer segments involving, in most cases, an amphiphilic block copolymer or a hydrophobic homopolymer, and a hydrophilic four- armed linker [4,5]. Dynamic covalent acylhydrazone links are employed so as to allow APCN self- healing and recycling, thereby extending materials service life and reducing environmental footprint [6].

Characterization of the self-assembled structures, via scattering, and the mechanical properties in water identifies the APCNs with the largest domain sizes, longest-range ordering and greatest extensibility, providing various choices to the applications engineer to select among materials with a broad spectrum of attributes. These experimental results on morphology and mechanical properties are complemented by and compared to the results of thermodynamic modeling and dissipative particle dynamics simulations [7].

We expect that our work will lay the foundation for the design and development of next-generation APCNs

1. C. S. Patrickios, Ed., Amphiphilic Polymer Co-Networks: Synthesis, Properties, Modelling and Applications; Royal Society of Chemistry, Cambridge, UK, 2020.
2. C. S. Patrickios and K. Matyjaszewski, Amphiphilic Polymer Co-networks: Thirty-Two Years Old and Growing Stronger – A Perspective, Polym. Int. 2021, 70, 10-13.
3. P. C. Nicolson and J. Vogt, Soft Contact Lens Polymers: An Evolution, Biomaterials 2001, 22, 3273- 3283
4. D. E. Apostolides, C. S. Patrickios, M. Simon, M. Gradzielski, A. Blanazs, C. Mussault, A. Marcellan, N. Alexander and C. Wesdemiotis, Model Dynamic Covalent Thermoresponsive Amphiphilic Polymer Co-networks Based on Acylhydrazone End-linked Tetronic T904 Star Block Copolymers, Polym. Chem. 2023, 14, 201-211.
5. 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, Near-model Amphiphilic Polymer Conetworks Based on Four-arm Stars of Poly(vinylidene fluoride) and Poly(ethylene glycol): Synthesis and Characterization, Macromolecules 2018, 51, 2476-2488.
6. D. E. Apostolides and C. S. Patrickios, Dynamic Covalent Polymer Hydrogels and Organogels Crosslinked through Acylhydrazone Bonds: Synthesis, Characterization and Applications, Polym. Int. 2018, 67, 627-649.
7. D. G. Tsalikis, M. Ciobanu, C. S. Patrickios and Y. Higuchi, Model Amphiphilic Polymer Conetworks in the Bulk: Dissipative Particle Dynamics Simulations of Their Self-assembly and Mechanical Properties, (favorably) reviewed in Macromolecules, 1 August 2023

Costas S. Patrickios is a professor at the Department of Chemistry, University of Cyprus. He obtained his PhD from Massachusetts Institute of Technology, Cambridge, MA, USA in Chemical and Biochemical Engineering in 1993. He has since held several positions, first as a Post-doctoral researcher in the Department of Chemical Engineering at Massachusetts Institute of Technology (1993) and then as an EPSRC Post-doctoral fellow in the Department of Chemistry (1994-1996) at the University of Sussex, UK. Following a lectureship at UMIST Manchester, UK (1996-1997), he joined the University of Cyprus first as an Assistant Professor (1996), an Associate Professor (1998) and in 2007 was promoted to full Professor, a position which he currently holds. He has also been serving as the Chairman of the Polymer Networks Group (PNG) since 2019.

PNG is an international organization, established in Europe (France, Germany, US, & Czech Republic) in 1976, aiming to promote, through biannual meetings, the science and technology of polymer networks.

                    

The SimEA project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No. 810660