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Chunliu FANG |
Ph.D.
Student 2008-2012
NUS Graduate School for Integrative Sciences and Engineering
(NGS)
CONTACT
EDUCATION
M.S., Chemistry, University of Science and Technology
of China, 2008
RESEARCH
INTEREST |
My research
interest is to develop a high performance alternative proton
exchange membrane (PEM).
In a direct
methanol fuel cell (DMFC) system, the role of a PEM is to allow the
transfer of protons from anode to cathode while preventing
significant diffusion of methanol. A typical PEM is composed of two
components, namely, hydrophilic and hydrophobic moieties. The former
usually contains sulfonic acid groups and contributes to water
adsorption and proton transport, while the latter maintains
mechanical strength and dimensional stability of membranes. It is
widely accepted that the PEM microstructure plays an important role
in affecting the final transport properties. For example, the proton
transport in a PEM is to pass through some connective hydrophilic
channels, which form from the microphase separation between the
hydrophilic and hydrophobic moieties.
In order to
achieve a controllable microstructure, it requires a better
understanding of the factors that affect membrane microstructure and
critical PEM properties (e.g., proton conductivity, methanol
permeability, water uptake, dimensional stability, and etc.).
Among the alternative PEMs, the semi-interpenetrating polymer
network (SIPN) is an attractive structure. It is a special class of
polymer composites where one or more linear (or branched) polymers
percolate molecularly into a network of other polymers. In
comparison with simple polymer blends or cross-linked PEMs, SIPNs
have the potential of offering a better control on the
microstructure and the properties of the resultant materials. Through
tuning the temperature and composition of the reaction mixture,
especially the proportion of the dispersed phase, the SIPNs can
developed a microphase co-continuous morphology which realizes the
maximum connection of hydrophilic domains. In addition, the
interlocking mechanism of SIPNs can lead to imposed miscibility
between incompatible constituents and the enhancement of mechanical
properties. In our work, we systematically studied the effect of
cross-linkers on the microstructure and PEM properties of SIPN
membranes. The aim of our study is to gain a better understanding of
structure-property relationship and hence control and optimization
of the SIPN PEM properties. So far, good performance PEMs have been
prepared by our group.
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