347
light Control Films, Coatings, and sheets
There are many methods for producing thin films, coatings, or
sheets that exploit the unique light properties of nanomaterials that
are useful in relation to light transmission and control. Many of
these methods rely on physical vapor deposition (PVD) and chemical vapor deposition (CVD) techniques that can deposit many types
of nanomaterials on substrates in layered or oriented ways (see
Chapter 8). Deposition processes can be used on many types of
substrates, but various kinds of glasses and polymeric films are commonly used. Other types of processes are in common use as well.
Many of these synthesis processes can be controlled with the objecFigure 9.34
Films. Angle dependence of colors and effect of
strain. (a) Influence of particle size and viewing
angle on color. (b) Angle-dependent film. (c) A
flexible colloidal single crystal (2 × 2 cm elastic
single crystal with 60° multilayer edges). (d)
Influence of strain with flexible crystalline films on
color (percentage stretching). (All images courtesy
of BASF.)
(a)
(b)
(c)
Perpendicular
Horizontal
Illumination angle
(d)
0%
28%
14%
39%
60%
Light and Optical Environments