Preparation of Nickel-Coated n-Octadecane Microcapsules

• Main Authors: Hsiao-Min Chung, 鍾曉旻
• Other Authors: 段葉芳
• Format: Others
• Language: zh-TW
• Published: 2010
• Online Access: http://ndltd.ncl.edu.tw/handle/aggq5u

碩士 === 國立臺北科技大學 === 化學工程研究所 === 98 === In this study, n-octadecane microcapsules with polymer shell were prepared using in-situ polymerization, then nickel were coated onto the microcapsules to prepare Ni-coated n-octadecane microcapsules. The ratio of n-octadecane and pre-polymer, reaction temperature, pH, the concentration of surfactant and dispersant were investigated, and also tried to involve NaCl into the prepolymer solution. The products were analysed using SEM, DSC and FTIR, then discussed the relationship between the particle size and its morphology, core/shell ratio, enclosed amount and yield. When preparing metal-coated microcapsules, a Pd-Sn shell were prepared through sensitization and activation reaction before Ni deposition. The coating of Pd atom then catalyzed the deposition of Ni. In this part, the amount of nickel plating solution and reaction time were investigated. The relative Ni content of products from each condition were analyzed and compared by XRF, TGA and SEM. The results showed that the enclosed amount and particle size of microcapsules were increased with the amount added of n-octadecane. The particle size was decreased with suitable concentrations of surfactant and dispersant. The resulting particle sizes of microcapsules could be reduced to 3.2μm with enclosed amount of 33.52% and yield of 10.88g. In the treatment of sensitization and activation in Pd-plating process, 10 minutes of sensitization with 4.8mL sensitizing reagent and 20 minutes of activation with 4.8mL activating reagent resulted in 11.4wt% of relative Pd content. During the reaction of electroless nickel plating, sodium hypophosphite was used as the reducing agent. Therefore, there is 1~10wt% of phosphorous in the Ni-coating layer of the microcapsule. The amount of nickel deposition increased to 98.6wt% with 20 minutes of reaction time and 10mL of nickel plating reagent added, and the 5% weight loss temperature were also increased to 235.17℃. Therefore, the thermal stability and mechanical strength were inhanced after nickel coating process.