| Summary: | 碩士 === 長庚大學 === 化工與材料工程研究所 === 91 === Abstract
Polyaniline (PAn) is currently considered to have high potentiality toward practical applications due to its cheap, good environmental stability and protonation with a protonic acid. However, it is very difficult to be dissolved in common organic solvents owing to its inherent rigid backbone. Thus, the aim of this research is to study the mechanism of PAn by react with 2,2'-azobis-isobutyronitrile (AIBN) and acrylonitrile (AN) in dimethylsulfide (DMSO) solution, and to investigate structure of the polymers. The tools used for the studied are ultraviolet-visible spectroscopy (UV-Vis), infrared spectroscopy (IR), X-ray diffractometer (XRD), differential scanning calorimeter (DSC), thermogravimetric analyzer (TGA), and cyclic voltammogram.
In the solution test, it was found that PAn/AN polymer could be dissolved in high polarity solvent. For IR spectra, all the absorption bands at 2247 cm-1 of C≣N stretching vibration of PAN, and at 3325 cm-1 of N-H stretching vibration of PAn, shifted toward low frequency. These results indicate the presence of hydrogen-bond interactions of PAn added with AN. For PAn/AN DMSO solution, two absorption peaks exist at 330 nm (π-π* transition of the benzenoid ring) and 615 nm (excition absorption of the quinoid ring), but the absorbance of imine peak decreases and shifts toward higher energy in comparison with that of PAn. It is due to the thermal dissociation of DMSO into proton, which will attack imine form of PAn to amine form, causing the decreasing of imine structure. XRD results indicate pure PAN has crystal structure. The composite of blend PAn/PAN of 1/10 still has crystal structure, regardless of the addition of PAn. From the blend structure become regardless and imine peak shift to higher energy shown that have part compatibility between PAn and PAN blends in the amorphous phase. In cyclic voltammogram analysis, we find SYN 1/10 and all kinds of blends have electroactivity. SYN 1/10 and blend composites show a higher potential for the first redox process in comparison to that of polyaniline, which is due to the steric effects. SYN 1/10 shows a lower potential for the second redox process by 100 scans in comparison to that of polyaniline. The second redox process of blend composites is the same as polyaniline. The PAN、SYN 1/10 and blend 1/10 were immobilized with protein containing amine group, which were confirmed by Scan Array 4100.
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