Civil Engineering Reference
In-Depth Information
1 7
Bacterial Cellulose and Its Multifunctional
Composites: Synthesis and Properties
V . h
iruvengadam* and Satish Vitta*
Department of Metallurgical Engineering and Materials Science, Indian Institute of Technology
Bombay, Mumbai, India
Abstract
Bacterial cellulose (BC) is an extremely pure form of cellulose and hence has high mechanical
strength compared to plant cellulose. It also has a nanoporous reticulate structure formed by the
i bers. h e high strength coupled with the porous structure makes BC an ideal host material to
incorporate a wide variety of materials to realize a range of functionalities. h ese materials range
in size from microns to nanometers and thus of er high l exibility to synthesize multifunctional
composites. h is chapter discusses composites made using BC in combination with a range of
materials suitable for application in modern electronic technologies such as l exible conductors,
magnets and displays.
Keywords:
Bacterial cellulose , composite , magnetic materials , catalyst , fuel cell , optical device ,
electrically conducting material
17.1
Introduction
In 1886, Adrin J. Brown accidentally found a jelly-like white translucent fermented
product while working on chemical actions of bacterium aceti. h is translucent jelly
was referred to as “Vinegar plant” or “Mother” and was commonly used for vinegar
production in Europe. h rough chemical reactivity and elemental analysis, the jelly
that grew on acidii ed red-wine or beer wort was ascertained to be similar to plant cel-
lulose with molecular formula C
6
H
10
O
5
[1-3]. Since the fermented product was chemi-
cally identical to plant cellulose but originated from bacterial source, it was named as
bacterial cellulose (BC).
Similar to plant cellulose, the molecular structure of BC has been found to be made
of β-1-4 glucopyranose molecules covalently connected by acetal functions between
C1 and C4 carbon atoms as shown in Figure 17.1a. In order to accommodate the bond
angle of acetal functions, every second glucose molecule is rotated in plane by 180°. As
a result of this rotation two adjacent structural units constitute a basic repeating unit
