| Summary: | 碩士 === 國立交通大學 === 應用化學研究所 === 98 === (Part 1) This manuscript describes the preparation of polytriazole/clay nanocomposites through in situ polymerization of PTA, using click chemistry, in the presence of a propargyl-modified clay. The clay layers became exfoliated and dispersed well in the PTA matrix, thereby improving the thermal and mechanical properties of the clay. This approach can be extended to combine propargyl-modified clays with other azide- and alkyne-containing polymers.
Among various types of proton exchange membranes(PEMs) for fuel cells, several nonfluorinated polymeric materials are attracting more attention as alternatives to perfluorinated polymer membranes.The nonfluorinated PEMs can achieve high proton conductivities by introducing high extent of sulfonic acid groups, but tend to deteriorate the mechanical strength and permeability of PEMs simultaneously. The aggregation of conductive sites will cause these PEMs highly swollen or dissolved in aqueous/alcoholic solutions. The development of more efficient membranes with improved proton conductivity and reduced methanol crossover without detrimentally mechanical and chemical stabilities remains an important challenge.
(Part 2) Sulfonated polytriazole-clay (SPTA-clay) nanocomposites have been successfully prepared by in situ polymerization of SPTA using click chemistry in the presence of propargyl-functionality modified clay. The clay layers were found to be exfoliated and well dispersed in the SPTA matrix which resulted in improvement of thermal stability, echanical strength, methanol permeatbility, water retention, ion channel size, and ionic cluster distribution by the incorporation of a small amount of clay (SPTA 1 and 3). The SPTA-clay nanocomposite membranes by incorporating a small amount of clay in SPTA matrix possess higher selectivity defined as ratio of proton conductivity to methanol permeability, therefore, it had potential usage of a proton exchange membrane (PEM) for direct methanol fuel cells (DMFCs).
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