Optimisation of Metallic Nanoshell Suspensions for Radiation Experiments
Yasitha L. Hewakuruppu, Leonid A. Dombrovsky, Victoria Timchenko, Guan H. Yeoh, Xuchuan C. Jiang and Robert A. Taylor
The use of metallic nanoshells as thermal carriers in applications such as in tumor hyperthermia and solar energy harvesting can be specifically attributed to the uniqueness of their optical properties. This paper presents a theoretical modelling approach (based on Mie theory) to optimise the optical properties of nanoshells for these applications. To check that this approach works for real (non-uniform) nanoshell samples, this model is validated by comparison with experimental data. To demonstrate this approach, this paper describes the process used to obtain a specific gold and silver nanofluid for a pump-probe radiation experiment. Owing to the nature of the proposed experiment, the resulting water-based nanofluid consists of two types of nanoshells, one which effectively absorbs the pump’s radiation while the other scatters the probe’s radiation. Thus, the optimum nanofluid contains gold/silica nanoshells of 37.6 nm core radius and 2.4 nm shell thickness (for absorbing the pump radiation) and silver/silica nanoshells of 10.8 nm core radius and 49.2 nm shell thickness (for scattering the probe radiation). The proposed nanofluid design procedure, however, represents a general approach that can be adopted to design nanofluids for other optical experiments and applications.
Keywords: Nanoshells, Nanofluids, Mie theory, Plasmon resonance, Nanoparticle mediated tumor therapy, Radiative heat transfer