| Summary: | 碩士 === 國立高雄應用科技大學 === 化學工程與材料工程系博碩士班 === 102 === Polyaniline(PANI)/ferrite(Fe3O4)/graphite nanocomposites were successfully prepared by emulsion polymerization of aniline in the presence of Fe3O4 with dodecylbenzenesulfonic acid(DBSA) as surfactant. The obtained polymers were mixed with graphite and carboxyl-terminated butadiene acrylonitrile(CTBN) resin, then coated on the substrate of polyimide membrane which owns poor shielding effectiveness. The ratios of PANI-Fe3O4 and graphite in the nanocomposites were adjusted to find out the optimum one for the best conducting, magnetic and electromagnetic shielding properties, respectively, at the same time, to explore the effect of the nanocomposites on the electromagnetic interference(EMI) shielding effectiveness(SE).
Morphology and properties were illustrated via XRD, UV-vis-NIR, FE-SEM, and cryo-TEM, respectively. The Fe3O4 nanoparticles were uniformly distributed on the surface of the fibrous PANI as already confirmed from Mapping micrograms. The Fe ratio in the PANI-Fe3O4 nanocomposites was obtained from the EDS spectrum and the SQUID patterns, demonstrating the superparamagnetic properties of PANI-Fe3O4.
Furthermore, shielding effectiveness(SE) of the nanocomposites containing Fe3O4 and graphite was studied using a microwave vector network analyzer(VNA) in the range 0.01 to 5GHz. The shielding measurements revealed that EMI SE of PANI-2Fe3O4/Graphite/CTBN nanocomposites with volume ratio of 10/40/50 and film thickness close to 60μm were 19dB, which means nearly 99% of the incident electromagnetic wave were shielded due to the cooperation effect of PANI, Fe3O4, and graphite, which can improve the EMI SE. As a result, polyaniline nanocomposites with Fe3O4 and graphite could be good candidates for lightweight and EMI shielding materials.
|
|---|
