有別於傳統的油-水分離方法，利用材料表面特殊濕潤性質，可望達成開發高效率、省能源、快速且簡易的新穎油-水分離程序的目標。本研究以聚酯纖維紡織品及三聚氰胺泡綿為基材，進行超疏水/超親油的表面修飾處理，進而分別做為分層 (stratified)及乳化 (emulsified)的油-水混合物的分離介質。表面修飾浸鍍溶液共有三種:分別是偏氟乙烯六氟丙烯共聚物 (PVDF-HFP)與1H, 1H, 2H, 2H-全氟癸基三乙氧基矽烷 (FAS-17)、正辛基三乙氧基矽烷 (AS)、及疏水改質的二氧化矽奈米粒子 (HM-SiO2)等混合的溶液。表面的濕潤特性，則由靜態接觸角及傾斜角的測量鑑定，並且依照表面對水之黏著模式區分為: Cassie, Meta及Wenzel等三種型態。此外，也訂定三個油-水分離的指標:分離效率、分離速率及分離選擇率，用以評估分離膜及吸收綿的油-水分離效能。
實驗結果顯示，聚酯纖維紡織品經由PVDF-HFP/FAS-17=1/0.5及PVDF-HFP/HM-SiO2=1/x (x=0.5, 0.8)浸鍍改質後，三種表面皆呈現疏水/親油性質。前者及x=0.8的表面為Wenzel黏著型態，x=0.5的表面則為Meta黏著型態。三者應用於甲苯-水分層混合物的分離，效率皆高達98%以上。三聚氰胺泡綿經由PVDF-HFP/AS=1/0.5及PVDF-HFP/HM-SiO2=1/x (x=0.4, 0.5)浸鍍改質後，表面也呈現疏水/親油性質。前者及x=0.4的表面為Wenzel黏著型態， x=0.5則為Meta黏著型態。三者應用於甲苯在水中(O/W)乳液的分離，效率皆高達97%以上。
對於分層油-水混合物分離速率及選擇率的影響因素，分離速率受黏著型態影響較小，主要是受到分離膜孔徑的影響。含奈米粒子的浸鍍液使得分離膜孔徑變小，導致分離速率較低。選擇率則不受表面黏著型態及分離膜孔徑的影響。至於乳化油-水混合物的分離，分離速率會受表面黏著型態影響。Wenzel黏著型態的吸收綿，與水有較好的接觸，使得包覆在水裡的油滴得以快速的被吸收，分離速率較大，選擇率則變低。Meta黏著型態的吸收綿，則是分離速率變小，選擇率則較高。而吸收綿的孔徑亦會影響分離速率，含奈米粒子的浸鍍液使得吸收綿孔徑變小，導致分離速率較低。選擇率則受吸收綿孔徑的影響較小。

Different from traditional methods, oil-water separation based on the materials with special wettability is strongly advocated. In this work, polyester fabric and melamine sponge were used as the substrates for surface modifications with the aims to separate stratified and emulsified, respectively, oil-water mixtures. Hydrophobic/oleophilic surface properties were achieved by dipping the substrates in three kinds of solutions including: PVDF-HFP/FAS-17, PVDF-HFP/AS, and PVDF-HFP/HM-SiO2 mixtures with various ratios. Static and sliding contact angles were measured and wetting behavior was classified into Wenzel, Meta, and Cassie modes. Furthermore, separation efficiency, rate, and selectivity were proposed as three indices to evaluate the separation performance.
Experimental results of stratified toluene-water mixture separation revealed that higher than 98% efficiencies exhibited by fabric separation membranes treated with PVDF-HFP/FAS-17=1/0.5 and PVDF-HFP/HM-SiO2=1/x (x=0.3, 0.5, 0.8). Membrane pore size reduced by the deposition of HM-SiO2 nanoparticles has stronger effect on separation rate than the membrane wetting mode. Pore size and wetting mode of membrane, however, have little effect on separation selectivity.
For separation of toluene-in-water emulsion, higher than 97% efficiencies were exhibited by melamine sponge treated with PVDF-HFP/AS=1/0.5 and PVDF-HFP/HM-SiO2=1/x (x=0.4, 0.5, 2). Separation rate is affected by pore size of sponge and wetting mode of surface. Higher separation rates were exhibited by sponge surfaces with Wenzel wetting mode than Meta mode. Smaller pore size of sponge also leads to a smaller separation rate. Separation selectivity is affected more by surface wetting mode than pore size.
Keywords: Superhydrophobic/superoleophilic surface; Polyester separation membrane; Melamine absorption sponge; Oil-water separation; Surface wetting mode.

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