| AVS 57th International Symposium & Exhibition | |
| Nanometer-scale Science and Technology | Tuesday Sessions |
| Session NS-TuP |
| Session: | Nanometer-Scale Science and Technology Poster Session |
| Presenter: | E. Yilmaz, Bilkent University, Turkey |
| Authors: | E. Yilmaz, Bilkent University, Turkey S. Suzer, Bilkent University, Turkey |
| Correspondent: | Click to Email |
Polymer-nanoparticles are technologically important composite systems, gaining increasing interest from many different fields of science in the last decade. Many procedures were introduced for synthesis of gold and other metallic NPs in solution and their integration to polymer films afterwards. But a more efficient approach is to synthesize nanoparticles directly inside the polymer matrix. Irradiation of polymer-metal precursor mixtures with energetic light is a practical method for this purpose. In this study, we present in-situ synthesis of gold nanoparticles within poly(methylmethacrylate) (PMMA) films by UV irradiation.
An advantage of synthesizing gold NPs within polymer films is the opportunity of photo-patterning. Films having patterns made of regions with and without gold NPs can be produced, using masks designed to cut off the UV radiation at desired places. Such patterned films were investigated with secondary electron microscope (SEM) and dark regions between irradiated regions and masked regions were observed. These dark regions are speculated to be “ion free regions”, where gold ions diffuse through irradiated regions during UV irradiation. These regions of about 10 μm width, suggests a very large distance for gold ions to diffuse through a rigid matrix like PMMA, which is very interesting. Supporting evidence for the existence and the properties of these regions was obtained from fluorescence studies with Rhodamine 6G molecule and x-ray electron spectroscopy (XPS). In XPS the gold content gradient shows, the border of the irradiated region contains more gold than the middle of the irradiated region which supports the diffusion of gold ions from masked regions through the irradiated regions.
Additionally, the electrical properties of PMMA with and without gold nanoparticles were investigated using XPS, while applying external bias to PMMA films with and without gold nanoparticles to probe the charging properties of the films. We observe an enhancement of conductivity of PMMA films containing gold nanoparticles.