Biomedical Engineering Reference
In-Depth Information
3
Optical properties of ceramic nanocomposites
R. BANERJEE and J. MUKHERJEE,
Central Glass & Ceramic Research Institute, India
Abstract: Nanoscale constituents in nanocomposites possess excellent
optical properties that differ from the macroscale properties. This
chapter focuses on the optical properties of nanoscale materials
incorporated in glass and ceramics, especially transmittance, absorption,
non-linearity and luminescence. The fluorescence property of carbon
nanotube-glass composite is a new observation which has hitherto not
been studied. All these properties make them a potential material for
optical sensors, ultraviolet-infrared shielding windows and other
biological applications.
Key words: nanocomposites, glass, ceramics, optical properties.
3.1
Introduction
The term 'composite' originally arose in engineering when two or more
materials were combined in order to rectify some shortcoming of a
particularly useful component. In other words, a composite material can be
defined as a heterogeneous mixture of two or more homogeneous phases
that have been bonded together. The phases can be of essentially any
material class, including metal, polymer, ceramic, carbon. In many cases,
the dimensions of one of the phases of a composite material are small, say
between 10 nm and a few micrometers, and under these conditions that
particular phase has properties rather different from those of the same
material in the bulk form.
When the microstructural scale falls in the range of a few nanometers,
such a material is referred to as a 'nanocomposite'. In mechanical terms,
nanocomposites differ from conventional composite materials due to the
exceptionally high surface to volume ratio of the reinforcing phase and/or its
