The synthesized of polyaniline nano-materials and uesd to sensor

• Main Authors: Yi-Cang Lai, 賴奕蒼
• Other Authors: Sze-Ming Yang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/05220097905847293246

碩士 === 國立中央大學 === 化學工程與材料工程研究所 === 96 === There are two parts in this thesis: firstly, we fabricate ordered anodic alumina membranes(AAO) with uniform pore diameters of 50 nm, 30 nm, 20 nm and 15nm by two-step anodizing process. Then, we synthesize polyaniline nanotubes/wires by electrochemical method within the holes of the AAO membrane. SEM and TEM were used to observe the morphology of the polyaniline nanotubes/wires. FT-IR spectra and CV show that the product synthesized in the channels of AAO membranes is polyaniline. Different structures of polyaniline nanotubes and wires are tested as sensor materials for detecting NO2. The sensitivities of polyaniline nanotubes are higher than nanofibers because of the larger surface area of polyaniline nanotubes. For polyaniline nanotubes, when the tube diameters are between 200nm and 50nm, the sensitivity increases while decreasing diameters of the tube. Since the smaller nanotubes have larger surface area per unit weight. But when the tube diameters are smaller than 30nm, the sensitivity lowered while decreasing diameter. Additionally, polyaniline materials were immersed in HAuCl4 solution, gold was deposited on polyaniline. EDX was used to check the presence of gold and mapping was used to obtain the distribution of gold. The polyaniline/gold sensor has better sensitivity than polyaniline sensor because gold help the transference of electrons. We choose DBSA instead of HCl as dopant, the reproducibility of the sensor is greatly enhanced. Secondly, the Pt electrodes for glucose sensor are modified with polianiline and polianiline-metal (palladium, silver, gold). The result shows that both the sensitivity and reproducibility decrease in following order : metal-polyaniline electrode＞polyaniline electrode＞unmodified electrode. Comparisons of the metal-polyaniline electrodes show that silver-polyaniline has the highest current, gold-polyaniline has the best reproducibility, and palladium –polyaniline has the best sensitivity.