鎳金屬殼層披覆正十八烷微膠囊之製備與研究

Preparation of Nickel-Coated n-Octadecane Microcapsules

鍾曉旻(Hsiao-Min Chung)

指導教授 ： 段葉芳

國立臺北科技大學/工程學院/化學工程研究所/碩士(2010年)

https://doi.org/10.6841/NTUT.2010.00531

摘要

本研究探討鎳金屬披覆正十八烷微膠囊之製備條件，對製得產物觀察其表面形貌、粒徑大小、熱穩定性。研究討論分為兩個部分：
第一部分是採用原位聚合法製備出壁材為尿素甲醛樹脂殼層之正十八烷微膠囊，製備條件如：正十八烷與尿素甲醛預聚物的比例、反應溫度、縮合反應的 pH 值、界面活性劑量與分散劑的濃度，並嘗試於預聚物溶液中添加 NaCl，所得產物利用 SEM、DSC、FTIR 進行分析，觀察微膠囊的表面形貌、粒徑大小、包覆率、產量及產率之間的影響。
第二部分為製備披覆鎳金屬外殼之正十八烷微膠囊，首先進行敏化與活化處理披覆一層鈀錫金屬外殼，並利用鈀原子催化鎳生成。文中探討改變敏化與活化時間及敏化液與活化液的添加量對鈀原子披覆於微膠囊表面之相對含量影響，而後進行無電鍍鎳反應，改變鍍鎳的條件如：鍍鎳液的添加量、鍍鎳的時間及敏化/活化處理次數進行無電鍍鎳反應，並使用 SEM、XRF 與 TGA 進行產物分析，比較各種操作條件對鎳金屬披覆於微膠囊表面之相對含量影響。
由實驗結果得知製備正十八烷微膠囊時，提高正十八烷的比例，可以增加正十八烷的包覆率，微膠囊粒徑也隨之增大，藉由適當比例的界面活性劑與分散劑，可以提高反應系統的穩定度，製得微膠囊粒徑可縮減為 3.2µm，產量為 10.88g，包覆率為 33.52%。製備鈀金屬進行敏化與活化處理時，添加 4.8mL 敏化液進行敏化處理 10 分鐘與添加 4.8mL 活化液進行活化處理 20 分鐘，可披覆鈀原子相對含量達到 11.4wt% ，隨後進行無電鍍鎳反應，由於還原劑是使用次磷酸鈉進行無電鍍鎳反應，所得的鎳層為含磷 1~10wt% 的鎳磷合金，隨著延長鍍鎳時間至 20 分鐘與增加鍍鎳液的添加量為 10 mL 時，鎳金屬披覆於正十八烷微膠囊表面的相對含量增至 98.6wt%，5wt% 熱重損失溫度提高為 235.17℃，因此鈀金屬或鎳金屬殼層披覆正十八烷微膠囊，可以增加殼的機械強度，並可提高微膠囊的熱穩定性。

關鍵字

微膠囊 ； 無電鍍 ； 相變材料 ； 尿素甲醛樹脂

並列摘要

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.

並列關鍵字

Microcapsule ； Electroless Plating ； Phase Change Material

參考文獻

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