2007 Graduate Catalog and 2006 Annual R & D Report - Sirindhorn ...

2007 Graduate Catalog and 2006 Annual R & D Report
Sirindhorn International Institute of Technology (SIIT)
Both linear and nonlinear optical properties of
ferroelectrics can also be studied in the framework of
this phenomenological theory by introducing Landau-
Khalatnikov equations to model the dynamical
interaction of a ferroelectric material with an incident
electromagnetic beam. The resonance frequency of
ferroelectrics is in the infrared; linear far infrared
spectroscopy can be used as a probe of the thin-film
properties of ferroelectrics. Many interesting nonlinear
effects can also arise. Important applications in this
area are terrahertz wave devices, tunable infrared
sources, and parametric amplifiers.
Nanotechnology and Nanoscience
This is currently one of the most exciting areas of
research, with great promise for future technologies.
The programme of research of interest is to model
nanoscale structures and from there start to model
and propose devices that exploit the properties of
these structures. The key point about the nanoscale
is that quantum properties become much more
apparent than at larger scales. This means that the
technology and devices of the future will become
increasingly linked to basic physics. Therefore it is
essential to study the physics of these structures and
devices. A variety of theoretical and computational
techniques, such as density function theory,
molecular dynamics and Monte Carlo simulation, are
available to study the quantum properties. Single
processor computers can be used for some problems,
whereas for more computationally intensive problems
a cluster of computers can be employed for parallel
processing.
Dr. Pakorn Opaprakasit
Assistant Professor
B.Sc. (1 st Class Honors) in Chemistry, Chiang Mai University, Thailand.
M.S. in Materials Science and Engineering (Polymer Option), the Pennsylvania State University,
Pennsylvania, USA.
Ph.D. in Materials Science and Engineering, the Pennsylvania State University, Pennsylvania, USA.
Areas of Specialization: Infrared spectroscopy, Rapid prototyping, Natural rubber,
Biocompatible/biodegradable polymers, Lactide-based polyesters, Coal/fossil fuels, Biodiesel.
Research Interests:
Properties Enhancement of Polylactide and
Natural Rubber for Multicolor Articles Rapid
Prototyping
The work is aiming to enhance properties of
polylactide and natural rubber, and to setup a
processing methodology to manufacture multicolor
articles from the two economically significant raw
materials of Thailand. Rapid prototyping (RP) is
employed to reduce design and development time by
fabricating parts layer-by-layer. Natural rubber is
used in latex form, while polylactide is applied in
powder form. Various properties of these materials
are modified to be used in the RP process. Mixing
behavior of colorants and base materials (polylactide
and natural rubber) is also investigated to develop an
in-process technique of producing colored parts.
Thermal Properties and Degradation of
Polylactide
Polylactic acid or polylactides (PLA) are well known
as a biodegradable and biocompatible thermoplastic
and are of interest in various medical applications.
Their enzymatic degradability and mechanical
properties, which are comparable to those of PE and
PS, have also attracted interest in using these
degradable polymers as packaging materials. Most
importantly, the monomer constituents of these
polymers can be derived from agricultural resources
such as carbohydrates. A racemic crystal structure or
stereocomplex can be achieved by mixing two
polylactides with opposite configurations: poly L-
lactide (L-PLA) and poly D-lactide (D-PLA). This
stereocomplex, in turn, shows a higher melting
temperature than that of its homopolymer counterpart.
Accordingly, this stereocomplex has been used as a
potential high performance biodegradable material.
Current research is focused on the mechanism and
dynamics of crystallization and degradation
processes of these polylactides and their
stereocomplex.
Conventional and Two-Dimensional FTIR
Spectroscopy
Infrared spectroscopy is a fundamental analytical
technique that is widely used in material
characterization. Recently, an advanced
methodology, two-dimensional infrared spectroscopy
(2D-FTIR) has been developed as a novel data
analysis and presentation technique. This technique
has provided notable advantages over conventional
FTIR. For example, an improvement in band
resolution, simplicity in band assignment, and
determination of relative order of responses of
specific functional groups to external perturbation,
have been achieved. The 2D-FTIR has been applied
to study effects of mechanical and electrical
perturbations on the structural transition of
PVDF/TrFE/CTFE piezoelectric polymer, and
investigate crystallization of biodegradable polymer or
polylactide.
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