TRIBOLOGICAL CHARACTERISTICS, ELECTRICAL PROPERTIES

1. TRIBOLOGICAL CHARACTERISTICS,
ELECTRICAL PROPERTIES
SETHULAKSHMI KV
II MSc BPS
CBPST,KOCHI

2. TRIBOLOGICAL CHARACTERISTICS
Wear resistance
Coefficient of friction
Lubricating properties

9. ELECTRICAL PROPERTIES
 Dieletric strength
 Dielectric constant
 Dissipation factor
 Surface and Volume resistivity
 Arc resistance
 Comparative tracking index

31. Polycarbazole Nanocomposites with Conducting Metal
Oxides for Transparent Electrode Applications
 The preparation and characterization of conducting polycarbazole (PCz)
hybrid films with a colorless transparency are described. They were prepared by
the vacuum evaporation of tin, aluminum, or gallium onto anion-doped green-
colored PCz films, or by applying gallium to the films, followed by their
exposure to ambient air.
 The resultant hybrid films consisting of an undoped PCz backbone and metal
compounds exhibited good transparencies (90−95% at a wavelength of 550
nm). The hybrid films have a specific cross-sectional structure in which the
small regions of the metal compounds are dispersed in the PCz backbone. The
hybridization reaction was mechanistically explained on the basis of the
combination of a metal corrosion reaction and polymer dedoping reaction,
which was successfully supported by the chemical analyses of the hybrid films.
 The electric conductivities of the hybrid films, measured by a four-point-probe
method, ranged from 2.2 × 10−4 to 6.0 × 10−3 S cm−1, which are considered to be
the lowest limit because the use of the hybrid films as an electrochemical
electrode reveals that a network of conductive paths is preferentially formed in
the film thickness direction rather than in the in-plane direction.

33. Nanocomposites
 Inorganic nanoparticles of different nature and size can be combined with the
conducting polymers, giving rise to a host of nanocomposites with interesting physical
properties and important application potential. Such nanocomposites have been
discussed in this review, throwing light on their synthesis techniques, properties, and
applications.
 A large variety of nanoparticles have been chosen in this respect with inclusion
techniques utilizing both chemical and electrochemical routes. The nature of the
association between the components can be studied from TEM pictures.
 upon the synthesis techniques and the characteristics of the inorganic materials,
ultimate properties of the resulting composite are controlled. In this way, the exceptional
colloidal stability of different silica sols have been utilized to form stable PPy-silica and
PAn-silica nanocomposite colloids. Similarly the magnetic susceptibility of γ-Fe2O3, the
elctrochromic property of WO3, and the catalytic activity of Pd, Pt, etc. metals have been
successfully combined with existing electrical conductivity of conducting polymers in the
hybrid nanocomposite materials. Functional groups viz. −NH2 and −COOH have also
been added to the composite particles and all these combinations and modifications have
improved the applicability of conducting polymers in different fields, e.g., electrodes of
batteries, display devices, immunodiagnostic assay, etc

35. properties of multiwalled carbon
nanotubes/glass-ceramic nanocomposites
 In the present investigation the electrical
resistivity of CNT/glass composites was measured
and it was demonstrated that higher electrical
conductivity values were obtained compared to
previous similar materials fabricated by
conventional powder processing.

36. Enhanced Thermoelectric Performance of Single-Walled
Carbon Nanotubes/Polyaniline Hybrid Nanocomposites
 Hybrid nanocomposites containing carbon nanotubes (CNTs) and
ordered polyaniline (PANI) have been prepared through an in situ
polymerization reaction using a single-walled nanotube (SWNT) as
template and aniline as reactant.
 TEM, SEM, XRD, and Raman analyses show that the polyaniline grew
along the surface of CNTs forming an ordered chain structure during
the SWNT-directed polymerization process.
 The SWNT/PANI nanocomposites show both higher electrical
conductivity and Seebeck coefficient as compared to pure PANI, which
could be attributed to the enhanced carrier mobility in the ordered
chain structures of the PANI. The maximum electrical conductivity and
Seebeck coefficient of composites reach 1.25 × 104 S m−1 and 40 μV K−1,
respectively, and the maximum power factor is up to 2 × 10−5 W m−1 K−2,
more than 2 orders of magnitude higher than the pure polyaniline.
 Highly ordered chain structure is a novel and effective way for
improving the thermoelectric properties of conducting polymers.