Journal of Encapsulation and Adsorption Sciences, 2012, 2, 69-78
http://dx.doi.org/10.4236/jeas.2012.24010 Published Online December 2012 (http://www.SciRP.org/journal/jeas)
Dispersion and Performance Properties of Carbon
Nanotubes (CNTs) Based Polymer Composites: A Review
Bhagwan F. Jogi, Mayur Sawant, Madan Kulkarni, Prakash K. Brahmankar
Department of Mechanical Engineering, Dr. Babasaheb Ambedkar Technological University,
Lonere, India
Email: bfjogi@dbatu.ac.in, bfjogi@yahoo.com
Received August 5, 2012; revised September 23, 2012; accepted October 17, 2012
ABSTRACT
Carbon nanotubes (CNTs) based polymer composites have variety of engineering applications (electromagnetic shield-
ing, antistatic coatings, high-strength low-density corrosion-resistant components, lightweight energy storage and many
more); due to their excellent mechanical, electrical, chemical, magnetic, etc. properties. In the polymer nanocomposites
CNTs are dispersed in the polymeric matrix. However the dispersion may be uniform or may not be uniform. The big-
gest challenge is the effective dispersion of individual CNTs in the polymer matrices, as CNTs tends to form clusters
and bundles due to strong van der Waals’ forces of attraction. The aggregated structure continue until physical (Me-
chanical) or chemical modification (Encapsulation/surface modification) of CNTs. Few modification methods such as
vigorous mixing of the polymers damages CNTs structure, and may hinder their properties. But these problems can be
overcome by mechanical or chemical modification of CNTs surfaces. In the chemical modification, the modifier or the
long tail surfactant may encapsulate and/or partially wrap the CNTs surfaces. In this review, recent work on CNTs
based polymer nanocomposite is carried out with few modifiers/encapsulating agents. Incorporation of CNTs in poly-
mer matrix changes the performance properties such as tensile strength, tensile modulus, elongation at break, toughness,
Dynamic mechanical thermal analysis (DMTA), etc. The phase morphology of the composite materials throws light on
the properties of CNTs based polymer nanocomposite. Moreover phase morphology may be directly correlated with the
behavior of the material, hence reviewed here through transmission electron microscopy (TEM) and scanning electron
microscopy (SEM). Furthermore review is also carried out on the non-isothermal crystallization (DSC) and rheology of
CNTs polymer nanocomposite.
Keywords: Carbon Nanotubes (CNTs); Encapsulation/Surface Modification; Transmission Electron Microscopy
(TEM); Mechanical Properties; Crystallization
1. Introduction
Carbon nanotubes (CNTs) based polymer matrices cre-
ates a class of novel materials (nanocomposites) exhibit-
ing superior mechanical, thermal, electrical and barrier
properties suitable to replace many existing materials for
engineering applications. In this context, use of CNTs in
polymer matrices has gained considerable attention in the
scientific and industrial community due to the possibility
to utilize the unique (mechanical, thermal and electrical)
properties of CNTs [1-4]. CNTs based polymer nano-
composites possess high stiffness, high strength and good
electrical conductivity at relatively low concentrations of
CNTs [5-8].
Various studies involving on single wall carbon nano-
tubes (SWNTs) and multiwall carbon nanotubes
(MWNTs) have shown that, CNTs can have high
modulus and strength levels in the range 200 - 1000 GPa
and 200 - 900 MPa respectively [2,4]. Other studies
shows that, CNTs have unique electrical properties, ca-
pable of acting as metallic-like conductors or having
characteristics of a semiconductor depending upon the
distortion or “chirality” of graphite lattice [3,9,10]. In
addition, CNTs have very large aspect ratios, as high as
100 - 1000 [2]. These special properties make CNTs as
excellent candidate for high strength and electrically con-
ductive polymer nanocomposite applications. Electronics
and automotive are the two major areas in which CNTs
used as filler material in polymer composites. Electronic
applications, particularly in the semiconductor field,
CNTs are used to dissipate unwanted static charge
buildup. This dissipative effect is achieved by thoroughly
dispersed CNTs in a given polymer matrix, where CNTs
form an interconnecting conductive pathway for charge
to flow [2,11]. In conductive polymer composites, con-
ductive compounds need very low fibril loading less than
2 wt% to achieve electrostatic dissipation, compared to ~
8 - 20 wt% for carbon black based compounds [6]. In the
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