Ian Wark Research Institute
ARC Special Research Centre
ARC Special Research Centre
Research Area: Polymer science, nanomaterials, hybrid
materials
Supervisors:
A/Prof Naba Dutta
and
Prof Namita Roy
Choudhury
Description: The estimated annual cost of corrosion worldwide
has been estimated to be nearly $300 billion per year. Aside from the
cost in dollars, corrosion is a serious problem that directly and
definitely contributes to the depletion of natural resources. The
proposed project aims to address the need for environmentally friendly
high performance protective coating for active metals such as the carbon
steels used in highly aggressive marine environment. Corrosion does not
occur in dry air and the rate of corrosion is dormant between 30-35%
relative humidity, the critical level being 45%, above which the rate of
corrosion accelerates. The majority of metallic materials, particularly
active metals such as carbon steel on exposure to such environmental
conditions during their applications deteriorate and fail prematurely.
Such items may become corroded over relatively short period of time in
salt water environment.
Silicate and phosphate based coatings are most frequently used as
ceramic anti-corrosion coatings, which are effective, chemically inert,
hard and thermally stable. However, their usages are limited by their
brittleness, higher processing temperature and the presence of
micro-cracks and defects. On the other hand organic coatings can be
easily formulated and can form a dense coating with better elastic
properties. But polymer coatings are often mechanically weak, display
inadequate wetting and adhesion properties to the substrate and poor
resistance to heat. To overcome the limitations new class of hybrid
coatings is to be developed using molecular level combination of organic
and inorganic components. These hybrid coatings have enormous potential
due to the flexibility in chemical approach and ability to tailor the
system to specific needs. However, in such systems the resulting
nanostructure, degree of organization and the ultimate properties
achieved not only depend on the chemical nature of the components used,
but also on the nature, extent and accessibility of the inner interfaces
that controls the synergy between the two components. This proposal
represents a novel concept for designing high stiffness and high
toughness polymeric anti-corrosion coating based on hybrids containing
cross-linkable functional groups as the base material. Nano-structured
material engineering approach will be employed to create designed
interface to open up the possibility of significant enhancement of the
macroscopic properties, which is almost impossible or difficult to
achieve by traditional methods. We will examine how the tailoring of the
surface structure on a nanometer scale can dramatically alter the
macroscopic properties of a coatings including film strength modulus and
delamination rate. We will also attempt to introduce bio-inspired
self-healing character to the hybrid coating, which will enable the
coating to repair itself on failure without external intervention to
prevent corrosion of the underlying substrate.
The detail characteristics of the coating in nano, micro and macro
levels will be evaluated using a wide range of microscopic,
spectroscopic and diffraction techniques. The phase behaviour, flow
property, film properties, cure characteristics, barrier properties and
mechanical behaviour of the films will be evaluated in detail.
Viscoelastic behaviour, films, stability and environmental aging
behaviour of the coating will also be evaluated to establish
structure-property-performance relationship. Different electrochemical
experiment in the laboratory including potentiodynamic polarization
methods, electrochemical impedance spectroscopy (EIS), scanning Kelvin
probe, SKP and in the field samples will be employed for detail
evaluation of corrosion characteristics of the film and predict its long
term survival.
Funding: An ARC-Linkage grant application to the Australian
research Council (ARC) is currently being assessed. International
students should apply for an International Postgraduate Research
Scholarship (IPRS) and a UniSA President's Scholarship (UPS). To be
eligible for UPS, applicants must have a supervisor willing to nominate
them for consideration. Australian students should apply for an
Australian Postgraduate Award (APA) and a UniSA Australian Postgraduate
Research Award (USAPRA).
