UV-radiation-induced formation of gold nanoparticles in a three-dimensional polymer matrix

The possibility of generation of a surface plasmon resonance by gold nanoparticles in a 3D network polymer matrix upon irradiation of a liquid acrylic composition containing a dissolved Au³⁺ salt is demonstrated for the first time. UV-irradiation of the solution simultaneously causes gold photoreduction to Au⁰ and acrylate photopolymerization. The possibility of preparing transparent colorless films that, when heated or exposed to light, give rise to a visible-spectrum absorption band belonging to a plasmon resonance of metal nanoparticles is demonstrated. The intensity and position of the plasmon resonance band depend on the parameters of the 3D polymer network, chemical structure of the oligomer, type of the support, and conditions of formation of Au⁰ particles. The formation of reduced gold nanoparticles responsible for the plasmon resonance band occurs more effectively in low-density networks with a large interchain length and containing oligomer block capable of complexation with the metal. The formation of nanoparticles is affected by the chlorine-containing products of the reduction of the gold salt.