Ag Nanoparticle-Poly(acrylic acid) Composite Film with Dynamic Plasmonic Properties

Poly(acrylic acid) (PAA) thin films with embedded Ag nanoparticles (AgNPs) prepared by UV photoreduction exhibited cyclically changeable optical absorbance properties during variation of ambient aqueous medium. The observed phenomenon is due to conformational changes in the polymer matrix which leads to variation in the 3D configuration of the AgNPs ensemble. Reversible variation of the distance between nanoparticles during swelling and shrinking processes within the PAA matrix changes the optical parameters of these plasmonic metamaterials and can be considered a useful feature for optoelectronic devices and sensors. The finite-difference time-domain method was used for modelling of light extinction of developed matrix structures in their swollen and shrunken states.