靜電紡絲技術之相關應用

靜電紡絲技術在各領域擁有相當多元的應用，舉凡能源、過濾、環保及

被受到矚目的生醫領域等。由此可知，靜電紡絲是具有相當潛力的技術。

以下將提出靜電紡絲技術在各領域相關之應用文獻。

2012 年，C. Wang 等人提出利用氧化石墨烯(Graphene oxide, GO)分散在 PVA 溶液裡，接著將此高分子混合溶液利用電紡絲技術，噴出具有 GO 與 PVA 的複合奈米纖維，圖 2-12 即為 GO 與 PVA 複合纖維之 SEM 圖【36】。 此外，圖 2-13 為針對複合纖維進行拉曼光譜檢測(Raman spectroscopy)的結 果，比較熱處理前後複合纖維與純 PVA 纖維之光譜分析，可發現在熱處理 過後可減少 PVA 所產生之峰值，亦表示 PVA 可藉由熱處理而碳化。此外，

研究結果指出加入很少量約 0.02%的 GO，就可提升奈米纖維的拉伸強度 42 倍，並且透過氫氣熱處理後可以得到多孔的 3D 結構，如圖 2-14 所示【36】。

Figure 2-12 (a-b) SEM images of GO/PVA nanofibers fabricated by electrospinning. (c-d) TEM images of GO/PVA nanofibers.【36】

Figure 2-13 Raman spectra obtained from GO, PVA, and GO/PVA nanofibers.【36】

Figure 2-14 SEM images of calcined nanofibers, (a-b) under 500 ^oC in N2, (c-d) 500 ^oC in H2.【36】

2008 年，D. Zhang 等人提出一種電紡絲技術新穎的應用方法【37】，藉

大量溶劑的蒸氣釋出導致纖維黏在一起，造成圖案定義的序度降低。而在溶 劑部份，隨著溶劑 DMF/THF 的比例改變，THF 增加會影響圖案定義的規則 性，當 THF 含量越高時，會使圖案越來越不明顯。THF 介電係數為 7.4、

DMF 介電係數為 36.7 ，若 THF 增加就會降低整體介電係數，因而降低纖 維的表面電荷，造成庫侖作用力減少，纖維即趨向隨機沉積，造成圖案化效 果降低【37】。

Figure 2-15 (a) Schematic illustration of collecting process using a cylindrical collector with equally spaced circular protrusions (es, electrospinning process; pc, patterned collector). (b) A fibrous tube with patterned architectures (scale bar = 5 mm). (c) Magnified image of part (b) (scale bar = 200 m).【37】

Figure 2-16 A fibrous tube with four different patterns on one tube. (a) Schematic illustration of one patterned collector with four different patterns and the relevant fibrous tube (pc: patterned collector. ft: fibrous tube. cs1 to 4: 4 different sides of the collector. ts1 to 4: four different sides of the obtained tube). (b) Optical image of fibrous tube as illustrated in (a). (c) The image of unfolded tube as shown in (b). (d-g) High magnification images of 4 different sides of (c), which shows different patterned architectures.【37】

Figure 2-17 (a) Influence of voltage on patterned architectures (v, voltage). (b) Influence of feeding rate on patterned architectures (FD, feeding rate). (c) Influence of volume ratio of solvents (DMF/THF) on patterned architectures (VR, volume ratio; D, DMF; T, THF). (scale bar = 100 m).【37】

靜電紡絲技術逐漸應用於透明導電電極上，由於目前標準的透明電極製 聚氟化二乙烯(Polyvinylidene fluoride, PVDF)奈米纖維上，由於 PVDF 是化 學穩定性極佳之材料，因此於電漿環境中並不會使材料產生破壞，最後透過

若沉積 50 nm 片電阻值為 908 ，若沉積 200 nm 片電阻率則為 432 ，由此 NFs are used as templates for sputtering Pt at 30 mA current in Ar atmosphere, and (c) the four-probe method was used in sheet resistance measurements.

Transfer printing of Pt-coated NWs onto flexible rubber substrates. (d) Pt-coated NWs are transfer printed onto flexible PDMS rubber. (e) PDMS is used to cover the top surface and encapsulate the entire device. (f) The bendable and transparent electrode consists of Pt-coated NWs fully packaged with PDMS.【38】

Figure 2-19 Digital photos of a series of NW transparent electrodes with different fiber densities and electrospinning times of (a) 7 min, (b) 5 min, (c) 3 min, (d) 1 min and (e) no fiber, respectively. All samples are sputtered Pt for 12 min. Each sample has a size of 2 cm × 2.5 cm. The right column shows corresponding optical images. (f) SEM (scanning electron microscope) picture of one Pt-coated NW, which indicates conformal deposition and smooth coating of Pt. (g) SEM photo of the close-up view in (a). (h) I-V curve of Pt-coated NW thin film with a transparency of almost 80%. The performance of sheet resistance and transmittance is comparable to that of other electrospun metal fibers produced via the high temperature processing route.【38】

Figure 2-20 (a) Transmittance spectrum of pattern-transferred, Pt-coated NWs with different sheet resistances and ITO on glass. (b) Performance comparison of our transparent Pt-coated NW network with a CNT network, graphene thin film, ITO electrode, Cu grid, sputtered Cu film with thickness of 50 nm, and sputtered Pt film with thickness of 50 nm and 200 nm, respectively.【38】

Figure 2-21 (a) The transparent electrodes based on pattern-transferred, Pt-coated NW electrodes show exceptional flexibilities compared with sputtered Pt films on PDMS substrates. (b) An optical image of Pt-sputtered film on PDMS after bending to a 3 mm radius clearly shows that the Pt sputtered film cleaves with innumerable microcracks of 3–4 m spacing in the bending direction. (c) An optical image of a Pt-coated NW network after bending to a 3 mm radius indicates the Pt-coated NWs are structurally maintained and electrically intact. (d) Pt-coated NW electrodes show much smaller changes in terms of sheet resistance change upon stretching with 12.5% and 25% strain.【38】

2006 年，Y. Zhu 等人利用靜電紡絲技術製作複合聚苯胺/聚苯乙烯之超 疏水抗腐蝕薄膜【39】，此薄膜耐酸鹼之有效範圍，從極酸至極鹼以及強氧 化劑皆可有效抵抗。圖 2-22 即為所製作出之複合纖維形貌，可發現纖維並 非均勻，由於 PANi 的摻入，會使得紡出之纖維具有紡垂狀；由圖 2-23 可發 現該纖維膜在 0-14 的 pH 值，都可保持優異之接觸角及穩定導電性，亦表示 此複合纖維薄膜擁有優異抗酸鹼能力。

Figure 2-22 (a) SEM image of an electrospun PANi/PS composite film with lotus-leaf-like structure prepared from a 3.72 wt.-% PS:ABSA/DMF solution. (b) Magnified view of a single sub-microsphere from. (c-d) Atomic force microscopy images of the electrospun PANi/PS composite film.【39】

Figue 2-23 (a) The relationship between pH and the contact angle (CA) on a PANi/PS composite film prepared from 3.72 wt. % PS solution. (b) The relationship between pH and conductivity of a PANI/PS composite film prepared from a solution of 3.72 wt. % PS. (c) The shape of a 1 mol L^-1 ammonium persulfate solution droplet on a PANi/PS composite film, with a CA of about 161.3°. (d) The shapes of water droplets on a flat PANi/PS film with a CA of about 0°. 【39】