Eur. Phys. J. B (2013) 86: 150
https://doi.org/10.1140/epjb/e2013-31055-y

Regular Article

Optical properties of a metalo-dielectric nanocomposite: small gold spherical nanoparticles in a cylindrical di-block copolymer

¹ Department of Physics, Shahid Bahonar University, 76169-133 Kerman, Iran
² Department of Physics, Sharif University of Technology, 11365-11155 Tehran, Iran
³ CNR SPIN and Dipartimento di Scienze Fisiche, Facoltà di Ingegneria, Università di Napoli Federico II, P.le Tecchio 80, 80125 Napoli, Italy

^a e-mail: Askari.s.ali@gmail.com
^b e-mail: gpepe@na.infn.it

Received: 13 November 2012
Received in final form: 15 January 2013
Published online: 10 April 2013

Abstract

In this paper, the well-known effective medium approximation (EMA) and coupled dipole approximation (CDA) methods are employed to study the optical properties of a metal nanoparticle-block copolymer (MNP-BCP) nanocomposite. This approach is applied to study a system consisting of small gold spherical nanoparticles randomly distributed in the cylindrical micelles of a di-BCP. At first, the EMA method is used to obtain the effective dielectric function of a semi-metallic cylinder. Then, the extinction spectrum of the hexagonal 2D-array of semi-metallic cylinders is obtained by the CDA method. This procedure makes it possible to study simultaneously both the electromagnetic extinction of MNPs and incident light scattering from the 2D-array of polymeric cylinders. This work investigates the effect of different parameters such as filling fraction of MNPs, inter-cylinder distances, polarization and direction of the incident light and the difference between the refractive indices of the BCP blocks on the optical properties of the MNP-BCP nanocomposite system.