Bionic technology Lab

1. Bionic technology Lab A Novel Superhydrophilic and Underwater SuperoleophobicHydrogel-Coated Mesh for Oil Water Separation ZhongxinXue , Shutao Wang , Ling Lin , Li Chen , Mingjie Liu , Lin Feng , and Lei Jiang Advanced Materials Vol. 23, 4270–4273 (2011) KUAS Chemical Engineering

2. KUAS Chemical Engineering 4 Conclusions Experimental 1 5 3 2 Abstract Introduction Bionic technology Lab Outline Results and discussion

3. KUAS Chemical Engineering Bionic technology Lab Abstract • Here,we report the fabrication of a novel superhydrophilic and underwater superoleophobichydrogel-coated mesh in an oil/water/solid three-phase system, which consists of rough nanostructuredhydrogel coatings and microscale porous metal substrates. • 在此,我們報導一種製備在油/水/固體三相的系統下超親水與在水下超疏油的水凝膠塗布之篩網，它們是由奈米結構的水凝膠與微米級孔洞的金屬基材所構成的。 • It can selectively and effectively ( > 99%) separate water from oil/water mixtures such as vegetable oil, gasoline,diesel, and even crude oil/water mixtures without any extra power. • 它可以有選擇性與有效的從油水混和物中分離出水，如:植物油、汽油、柴油、原油，而且不需要施加而外的能量。

4. KUAS Chemical Engineering Bionic technology Lab Abstract • During the separation process, the underwater superoleophobic interface with low affinity for oil drops prevents the coated mesh from fouling by oils, which makes the recycling of oil and materials easy. • 在分離的過程中，與油滴親和力低的超疏油介面可以避免被油滴汙染，這使得石油和材料易於回收。 • This novel water-removing type of material has completely opposite wettability to traditional hydrophobic and oleophilic materials and thus overcomes the easy-fouling and hard-recycling limitations in essence. • 這種新式的材料分離水之類型與傳統的疏水親油材料之潤濕性是相反的，而且克服了材料易汙染與不易重複使用的限制。

5. KUAS Chemical Engineering Bionic technology Lab Abstract • It is a new attempt to use special wettability to design next-generation materials for oil/water separation, which suggests attractive potential applications in industrial oily waste water treatments and oil spill cleanup. • 這是種新的嘗試去設計下一代特別潤濕性的油水分離材料，這會在工業含油廢水處理和石油洩漏的清理工作有潛在應用。

6. KUAS Chemical Engineering Bionic technology Lab Introduction Oil/water separation is a worldwide challenge • Industrial oily wastewater • Oil spill accidents “Oil-removing”type • Absorption • easily fouled or even blocked up by oils • secondary pollution • Not easily recyclable

7. KUAS Chemical Engineering Bionic technology Lab Introduction “Oil-removing”type’s materials (oleophilic materials) • kapok • carbon-based materials • hydrophobic aerogels • polytetrafluoroethylene (PTFE) coatingmesh • polydimethysiloxane (PDMS) coated nanowire membrane • nanoporouspolydivinylbenzene materials • crosslinked oil-absorbing polymer gels

8. KUAS Chemical Engineering Bionic technology Lab Experimental Materials: • (PAM) Polyacrylamide (Mn = 3 000 000) • (BIS) N , N -methylenebisacrylamide • (AM) acrylamide • (DEOP) 2,2’-diethoxyacetophenone 黏著劑 架橋劑 單體 光起始劑

9. KUAS Chemical Engineering Bionic technology Lab Experimental

10. KUAS Chemical Engineering Bionic technology Lab Results and discussion Diameter = 41.5 ± 2.7 μ m 300 mesh thickness = 1.2 μ m Diameter = 39.1 ± 1.9 μ m pore without hydrogel Random papillae structures Figure 1 . SEM images of (a) stainless steel mesh. (b) PAM hydrogel-coated stainless steel mesh.(c) Enlarged view of a single pore of the PAM hydrogel-coated stainless steel mesh. (d) The higher magnification image of one single wire on hydrogel-coated stainless steel mesh,

11. KUAS Chemical Engineering Bionic technology Lab Results and discussion 300 mesh Superoleophobic Figure 2. Relationship between the pore diameters of the PAM hydrogel coated mesh and the oil contact angles (DCE, 2 μL).

12. KUAS Chemical Engineering Bionic technology Lab Results and discussion oil adhesion force Figure 3. Contact angles of water droplets (CA) and 1,2-dichloroethane (OCA); oil adhesion force of 1,2-dichloroethane (OAF) on different surfaces in different systems. The diameter of the mesh is about 50μm.

13. KUAS Chemical Engineering Bionic technology Lab Results and discussion OCA= 155.3 ° ± 1.8 ° sliding angle = 2.6 ° ± 0.5 ° low oil-adhesion Figure 4. (a) Photograph of an oil droplet (DCE, 2 μ L) on the coated mesh in water with a contact angle of 155.3 ° ± 1.8 ° and ( b) sliding angle of 2.6 ° ± 0.5 ° . (c) the dynamic underwater oil-adhesion measurements ( d) Superoleophobic and low oil-adhesion properties of the coated mesh in oil/water/solid system for a selection of oils in terms of its contact angle and oil-adhesion force.

14. KUAS Chemical Engineering Bionic technology Lab Results and discussion crude oil and water (30% v/v) Figure 5. The separation process of the (a)(b) crude oil/water mixture(c)(d)vegetable oil/water mixture.

15. KUAS Chemical Engineering Bionic technology Lab Results and discussion

16. KUAS Chemical Engineering Bionic technology Lab Results and discussion oil/water/solid composite interface oil oil water Hydrogel & water hydrogel substrate substrate 被吸附的水分子會降低油滴與固體表面的接觸面積。 Figure 6. 油水分離示意圖

17. KUAS Chemical Engineering Bionic technology Lab Results and discussion oil concentration of water after separation Oil rejection coefficient (R (%)): oil concentration of the oil/water mixture Experimental intrusion pressure ( Pexp ): 油滴滲入網子所需壓力 Theoreticalintrusion pressure ( Ptheor ): hmax= 14cm Figure 7. (a) The separation efficiency of the PAM hydrogel-coated mesh for a selection of oils in terms of their oil rejection coefficient. (b) The theoretical and experimental values of intrusion pressures for a series of oils.

18. KUAS Chemical Engineering Bionic technology Lab Results and discussion = θ0:is the CA on a flat surface γ LV :is the liquid-vapor surface tension θ0:is the OCA on a flat surface • γL1L2: is the water/oil interfacial tension Figure 8. Illustration of the calculation of theoretical intrusion pressure.

19. KUAS Chemical Engineering Bionic technology Lab Conclusions • was successfully fabricated • superhydrophilic and underwater superoleophobicPAM hydrogel-coated mesh • in an mesh in an oil/water/solid three-phase system. • The as-prepared meshes • high separation effiiency • resistance to oil fouling • easy to recycle • a good oil retention barrier

20. KUAS Chemical Engineering Bionic technology Lab Conclusions • Application • industrial outlet sewer pipes • Oil fences for oil spill accidents • separation of high-viscosity oils