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Bionic technology Lab

Bionic technology Lab. Studies on Oil / Water Separation Membranes via Electrospinning. Advisor ： Ping- Szu Tsai Speaker ： Jeng -Yi Wu Date : 2012 . 07.04. KUAS Chemical Engineering. KUAS Chemical Engineering. 3. Conclusions. Experimental. 4. 2. 1. Introduction.

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Bionic technology Lab

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  1. Bionic technology Lab Studies on Oil / Water Separation Membranes via Electrospinning Advisor ： Ping-Szu Tsai Speaker ： Jeng-Yi Wu Date : 2012 . 07.04 KUAS Chemical Engineering

  2. KUAS Chemical Engineering 3 Conclusions Experimental 4 2 1 Introduction Bionic technology Lab Outline Results and discussion

  3. KUAS Chemical Engineering Bionic technology Lab Introduction- Lotus effect • Hierarchical structure • Low surface energy material 10μm wax 100nm http://nanotechweb.org/cws/article/tech/21936/1/0504031

  4. KUAS Chemical Engineering θ θ θ Bionic technology Lab Introduction- Wetting property 5˚<θ<90˚ Hydrophilic θ<5˚ Superhydrophilic θ>150˚ Superhydrophobic 90˚<θ <150˚ Hydrophobic Smooth substrate with hydrophilic material Roughness substrate with hydrophilic material Smooth substrate with hydrophobic material Roughness substrate with hydrophobic material

  5. KUAS Chemical Engineering Bionic technology Lab Introduction (液滴適用於平坦表面) • Young’s equation • γLV cosθ =γSV –γSL • (液滴適用於完全潤濕固體) • Wenzel’s equation • Cassie and Baxter equation (液滴適用於粗糙固體表面)

  6. KUAS Chemical Engineering Bionic technology Lab Introduction low surface free energy high surface free energy Figure 1. Illustration of the relationships between the four kinds of fundamental superwetting/antiwetting properties (in blue boxes) and the further special surface superwetting/antiwetting functions (in yellow boxes) that are obtained by combining either two of the fundamental properties. Herein, the double arrow indicates coexistence of the two properties, and the reversible arrow indicates switching of the two properties.

  7. KUAS Chemical Engineering Bionic technology Lab Review • PTFE emulsion coating on stainless-steel mesh • Micro/nano structure • Superhydrophobic→pore diameters 50~200 μm (Jiang et al., Angew. Chem. Int. Ed., 2004)

  8. KUAS Chemical Engineering Bionic technology Lab Review • (Yang et al., Surface & Coatings Technology, 2011) • A series of functional silica films on stainless steel meshes are fabricated by • simple sol–gel process. • surface modification by perfluorooctyltriethoxysilane . • this is potential to be used in intelligent oil/water separating device.

  9. KUAS Chemical Engineering Bionic technology Lab Review • The TPU electrospun mat with bead-on-string morphologies. • The TPU electrospun film presented superhydrophobic trait after treatment with hydrophobic nanosilicas • Mat displays both superhydrophobicity and superoleophilicity • It can be useful for separating mixtures of oil and water (Wang et al., Materials Letters 2011)

  10. KUAS Chemical Engineering Bionic technology Lab Review Sun等人製備出具有熱反應型的Poly(N-isopropylacrylamide) (PNIPAAm)聚合物，其臨界溶解溫度（LCST）約32 -33°C，如圖一(a)(b)所示，當升溫高於LCST時，PNIPAAm聚合物表面的官能基會由原先裸露親水的部分改變成為裸露出疏水的部分，進而改變機材表面的親疏水性質，因此當基材由25°C上升到40°C，表面的水滴接觸角會由0°上升到149.3°(Sun et al., 2004)。 (a)經由熱親疏水轉換之示意圖，(b)水滴在不同溫度基材上之接觸角圖(左)25°C(右)40°C(Sun et al., 2004)。

  11. KUAS Chemical Engineering Bionic technology Lab Review Feng等人觀察到運用各種方法所製備的粗糙氧化鋅奈米薄膜，經過UV光照射後讓原本具有超疏水性質的氧化鋅奈米薄膜轉變為超親水的性質，再將薄膜存放在黑暗中一段時間後又能回復為超疏水的特性，如圖二所示。會有光轉換的原因為氧化鋅為光觸媒，經過UV光的照射後會使表面產生親水的氫氧官能基(-OH group)。 水滴的形狀在奈米氧化鋅薄膜上照光前(左)後(右)。 (Feng et al., 2004)

  12. KUAS Chemical Engineering Bionic technology Lab Review 平坦的PTFE接觸角大約為108°，Han等人將PTFE由0%單軸拉伸至190%，發現PTFE表面性性質由疏水(WCA=108°)變成超疏水性質(WCA=165°)，接觸角會有如此劇烈變化的原因是在拉伸的過程中PTFE結晶度改變以致表面的特性轉為超疏水，但此材料的親疏水轉換是不可逆的。隨後Zhang等人對彈性聚酰胺膜做雙軸延伸，如圖三所示。當伸長率大於120%時彈性聚酰胺膜表面的性質將由超疏水轉為超親水，釋放應力後彈性聚酰胺膜表面又變回原本的超疏水性質，並且過了多次的轉變後還保有原還超疏水的性質。 • 超疏水與超親水間的彈性轉換(a)雙軸延伸之前WCA為151.2° (b)雙軸延伸120%之後WCA為0°(c)可逆的超疏水/超親水轉換薄膜經過多次的拉伸與釋放應力。(Zhang et al., 2005) 。

  13. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  14. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  15. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  16. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  17. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  18. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  19. KUAS Chemical Engineering Bionic technology Lab Review 平坦 • 超疏

  20. KUAS Chemical Engineering Bionic technology Lab Motiving 傳統油水分離技術: • 重力沉降、吸附、氣浮、過濾、生化反應、超音波法等。 缺點: • 佔地面積大、耗時、分離效率低、需要添加化學藥劑、費用高等。

  21. KUAS Chemical Engineering Bionic technology Lab Motiving 油水分離膜: • 利用超疏水與超親油網膜的表面來分離油水混合物。 優點: • 分離過程無耗能 • 可重複使用

  22. KUAS Chemical Engineering Bionic technology Lab Motiving • 在不鏽鋼網上組裝階層式結構的粒子 • 粒子推疊出的結構，有崩塌的疑慮 • 水滴有可能穿過薄膜 • 以靜電紡絲法製備油水分離膜 • 纖維結構比較不會有崩塌的疑慮 • 利用毛細現象來分離油水混合物，水滴不易穿透薄膜

  23. KUAS Chemical Engineering Bionic technology Lab Motiving • 探討變數 • 二氧化矽粒子清潔對矽烷改質的影響。 • 靜電紡絲的TPU濃度、收集時間與組裝疏水奈米粒子後對纖維膜之疏水性及親油性影響。

  24. KUAS Chemical Engineering Bionic technology Lab Experimental-Material ( ) n

  25. KUAS Chemical Engineering Bionic technology Lab Experimental 圖一、奈米二氧化矽清潔流程圖

  26. KUAS Chemical Engineering Bionic technology Lab 圖二、奈米二氧化矽疏水改質流程圖

  27. KUAS Chemical Engineering Bionic technology Lab 圖三、製備油水分離膜流程圖

  28. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 表一、不同清潔方式二氧化矽矽烷改質前後粒徑分布

  29. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 圖四、二氧化矽酸化反應式 (顏銓佑, 2004)

  30. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 圖五、矽烷改質反應機制示意圖

  31. KUAS Chemical Engineering Bionic technology Lab Results & Discussion -CH3 ,–CH2 Wavenumber (cm-1) 圖六、不同清潔方式二氧化矽改質前後FTIR圖

  32. KUAS Chemical Engineering Bionic technology Lab Results & Discussion Silica M-300 ℃ M-HCl M-ethanol 圖七、不同清潔方式二氧化矽改質前後疏水測試圖

  33. KUAS Chemical Engineering Bionic technology Lab Results & Discussion (b) (a) 圖八、 (a)5 wt% 與(b)8 wt% TPU纖維膜表面結構圖

  34. KUAS Chemical Engineering (a) (b) Bionic technology Lab 5 WT% Increase collection time (d) (c) 8 WT% 圖九、不同收集時間之靜電紡絲纖維膜POM圖

  35. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 表二、平板TPU與壓錠疏水改質粒子表面接觸角

  36. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 表三、 5 wt%與 8 wt% TPU薄膜靜態接觸角

  37. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 圖十、正十四烷於TPU纖維膜上到達0°所需時間圖

  38. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 圖十一、油水分離膜表面潤濕性(a)水滴接觸角為 158.6° (b)正十四烷接觸角為 0°

  39. KUAS Chemical Engineering (b) Bionic technology Lab 5 WT% Increase collection time (c) (d) 8 WT% 圖十二、不同收集時間之油水分離膜POM圖

  40. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 圖十三、正十四烷於油水分離膜上到達0°所需時間圖

  41. KUAS Chemical Engineering Bionic technology Lab Results & Discussion 染色後的水 沙拉油 染色後的水 沙拉油 圖十四、油水分離膜分離油水混合物

  42. KUAS Chemical Engineering Bionic technology Lab Conclusions • 三種清潔粒子的程序: • 乙醇清洗與300℃鍛燒的粒子無法提升改質的效果。 • 經過鹽酸清洗的粒子改質後有良好的疏水性質。 • POM觀察薄膜表面: • TPU的濃度增加 • 纖維結構:串珠結構→纖維的結構。 • 薄膜上的孔洞變大 • 收集的時間增加→薄膜上的孔洞漸漸變小。

  43. KUAS Chemical Engineering Bionic technology Lab Conclusions • 薄膜的潤濕性: • TPU濃度的增加 • 串珠結構(Wenzelstate) → 纖維結構(Cassiestate)，提升疏水性。 • 孔洞變大→毛細現象減弱，親油性降低。 • 收集的時間增加 • 單一粗糙尺寸→疏水性不變。 • 孔洞變小→ 增強毛細現象，親油性提升。 • 組裝疏水奈米粒子後 • 超疏水的特性， • 提升親油性。

  44. KUAS Chemical Engineering Bionic technology Lab Conclusions • 油水分離膜: • 可以有效率的分離油水混合物。 Thankyou for your attention !

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