本研究係利用二十烷、水及界面活性劑調製並以機械力攪拌、乳化成內含相變化材料(Phase Change Material, PCM)的奈米微粒懸浮乳液；另以尿素與甲醛調配成所謂尿素甲醛樹酯，進而將兩者混合製成以二十烷為核心，尿素甲醛樹酯為外殼的相變化材料次微米膠囊懸浮液。並針對核心材料與外殼材料劑量一定時，不同製程(界面活性劑之比例、乳化時間與包覆時間不同)之次微米膠囊懸浮液之相關性質，諸如粒徑、介面電位、熔點、凝固點、殼厚及過冷度等進行實驗量測探討。實驗結果顯示，次微米膠囊之粒徑受界面活性劑多寡與乳化時間之影響；而PCM乳化懸浮液則是在加了界面活性劑後，始能達到奈米尺寸。添加與二十烷重量百分比為4︰1的界面活性劑並施以二十小時的超音波乳化後，次微米膠囊的粒徑有顯著的下降，最小可達約300 nm，並在黏度及熱傳導係數方面有所改善。

In the present study, a mixture of PCM (Phase Change Material) suspension, emulsified from n-Eicosane, water, and the surfactant, and the so-called “Urea- Formaldehyde resin (U-F resin)” pre-polymer of mixture dispersed with urea and formaldehyde has been prepared. Then blend two to n-Eicosane as the core, U-F resin for the shell of a Sub-Micro-Encapsulated Phase Change Material suspension. And for the core material and shell material for a certain dose, different process (the ratio of surfactants, emulsifying time and covered different periods of time) of sub-micro-encapsulated PCM suspension of the related properties, such as particle size, zeta potential, melting/freezing points, shell thickness, coating rate and supercooling point, are then investigated experimentally. The results, capsules’ size by the amount of emulsifying surfactant time effect; and PCM emulsified suspension is the addition of surfactants before we achieve the nanometer size. Add 5 g (core material：surfactant = 4:1 ) of surfactant and imposed 20 hours of ultrasound emulsification, the size of capsules with significant improvement, the minimum size of about 300 nm, and the viscosity and thermal conductivity also have been improved.

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