本研究將前驅溶液填入針筒，透過幫浦推動針筒使針頭尖端產生液滴，液滴滴落後撞擊玻璃瓶中矽油，蒐集完成後加熱進行反應，建立液滴輔助合成金屬有機框架的操作平台。以傳統溶劑熱法合成金屬有機框架PCN-222，可得到約20微米大小的柱狀結晶，而利用液滴輔助合成在適當的條件下能夠有效限制PCN-222的結晶長度在4~5微米。
研究結果顯示，透過針頭輔助可生成15~200 μm的液滴，體積流率為0.06~0.60 ml/min。其中，撞擊高度和體積流率對PCN-222結晶的影響較不顯著；而使用直徑較小的24G(0.55 mm)針頭相較直徑較大的19G(1.1 mm)針頭，可以得到較平滑且較多的柱狀結晶。同時縮短反應時間並比較兩種合成方式的差異，在傳統批次合成中，隨反應時間調降至8小時，結晶長度有明顯縮短至6.5 μm，但結晶變得較破碎；而針頭產生液滴輔助合成，結晶長度有隨反應時間下降而縮短，較不顯著，約落在4~5 μm。根據BET分析的結果以及SEM拍攝下觀察到的結晶型態，利用液滴輔助合成PCN-222可以在反應時間縮短為12小時的情況下，得到與傳統批次合成48小時的比表面積結果相近，為2441 m2/g。

In this study, a droplet-assisted method for synthesis of metal-organic framework was established. For conventional synthesis of PCN-222, the columnar crystal with the size of about 20 μm was obtained. However, under appropriate conditions, the crystal length of PCN-222 was decreased to 4~5 μm via the droplet-assisted method. The results showed that the impact height and volume flow rate did not influence crystallization of PCN-222 while using the syringe needle with a smaller diameter led to smoother and more columnar crystals compared to the syringe needle with a larger diameter. For the conventional batch synthesis, the crystal length was significantly affected by the reaction time and it was decreased to 6.5 μm as the reaction time was reduced to 8 h. On the other hand, the crystal length was not affected by the reaction time when applying the droplet-assisted method, which was about 4~5 μm. Based on the results of BET analysis and the crystal morphology, the specific surface area of PCN-222 synthesized by droplet-assisted method at reduced reaction time was comparable to that synthesized through conventional bath process, which is 2441 m2/g.

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