Effect of “corona-core” structuring of poly(1-vinyl-1,2,4-triazole)–poly(acrylic acid)-Ag(I) interpolymer complexes on the radiation-induced preparation and stability of silver nanoparticles

Interpolymer complexes (IPC) of water-soluble polymers can be promising matrices for the synthesis of metal colloids. In this work, silver nanoparticles were obtained via radiation-induced reduction (under X-ray irradiation) of complexes based on poly (1-vinyl-1,2,4-triazole) (PVT) and poly (acrylic acid) (PAA) containing Ag+ ions. Particular attention was paid to the role of the supramolecular structure in the formation of nanoparticles. Combined dynamic light scattering and electrophoretic mobility measurements have revealed that, in pH range 5.5–7, micro-scale aggregates of the initial PVT-PAA-Ag(I) IPC transform into nano-sized particles consisting of a PVT-Ag(I) core electrostatically stabilized by PAA loops and tails forming a corona. It was explicitly demonstrated for the first time that such transformation of IPC aggregates can significantly enhance the efficiency of AgNPs formation. In particular, using UV-VIS spectroscopy and transmission electron microscopy, we have shown that at pH 7.0 the core of the “corona-like” form of the PVT-PAA-Ag(I) complex ensures the radiation-induced generation of AgNPs with a narrow size distribution due to the strong affinity of triazole groups to the metal surface. At the same time, the localization of the excessive negatively charged carboxylate groups in the outer part of the complex provides a long-term colloidal stability of the prepared AgNPs.