| Summary: | 碩士 === 國立成功大學 === 化學工程學系碩博士班 === 92 === The polyacrylonitrile fiber(PAN fiber) was modified by hydroxylamine solution to form polyacryloamidoxime fiber (PAAm fiber). FT-IR was used to analyze the modified condition of PAAm fiber, and then, element analyzer(EA) was used to measure the modification rate of PAAm fiber. Amount of silver ions chelated by the PAAm fiber could be determined by Atomic absorption(AA) spectrophotometer. Chelated silver ions of the PAAm fiber were reduced via chemical reduction method to form PAAm-Ag nanocomposite fiber in this study. The average particle size on the PAAm-Ag fiber which observed by SEM was in the range of 23nm and 30nm which could be controlled by different pH values and reducing temperatures.
In addition, the mechanism of growing nanoparticles on polymer membrane was observed by the UV-vis absorbance. TEM and SEM could determine the distribution of particle sizes on the surface and inside the polymer membrane. UV-vis absorbance near 350nm was appeared in the initial stage of different reducing condition, but no any nanoparticles appeared in this stage after TEM measurement. Thus, the absorbance was due to the formation of silver clusters, not silver nanoparticles. The average particle size increased and the size distribution became narrowed in low pH value. Particle size inside polymer membrane was from 4.9nm to 6.2nm, and there was a 425nm absorption peak. When the pH value of reaction aqueous is controlled at basic, it caused the nanoparticles to aggregate. Furthermore, as the reducing temperature increased to 60℃, the double distribution of the nanoparticles would be appeared. The mechanism of growing nanoparticles in other reducing conditions will also discussed in my research.
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