Facile one-step coating of thiol-ene polyHIPE with polydopamine, gold and palladium nanoparticles

Porous emulsion-templated polymers (polyHIPEs) exhibit highly interconnected porosity and specific surface area, making them attractive for applications in tissue engineering, catalysis, water remediation, and energy storage. Noble metal nanoparticles, such as gold (AuNPs) and palladium nanoparticles (PdNPs), are widely used for their catalytic, electronic, and biomedical properties. However, conventional methods for incorporating these nanoparticles into polyHIPEs often require toxic reducing agents, multi-step procedures, and offer limited control over nanoparticle distribution. In this study, we report a facile one-step approach for preparing polydopamine (PDA)-coated polyHIPEs functionalised with AuNPs and PdNPs under mild basic conditions at room temperature. PDA serves as both a reducing agent and an adhesive layer, enabling uniform nanoparticle deposition while preventing aggregation. The process was conducted with four different concentrations of Au and Pd precursors, allowing controlled variation in nanoparticle density. The resulting material demonstrated high stability, well-distributed nanoparticles, and structural properties suitable for potential applications, in catalysis, sensing devices and tissue engineering. This environmentally friendly strategy provides a simple and scalable method for functionalizing porous polymers with noble metal nanoparticles, expanding the scope of polyHIPE-based materials for sustainable and biomedical applications. • Highly porous polyHIPE materials decorated with gold or palladium nanoparticles are produced in a simple one-pot method • Dopamine polymerisation in the presence of the polyHIPE both coats the surface with polydopamine and, simultaneously, reduces gold or palladium salts, depositing metallic nanoparticles evenly upon the internal surfaces of the porous material • The process is simple, cost effective and enhances the sustainability of the coating process due to the reduced number of steps and ambient reaction conditions.