官能化聚苯胺薄膜之彈性、摩潤以及結構性質關聯性之研究

Investigation of the Correlations between Elastic, Tribological, and Structural Properties in Functionalized Polyaniline Thin Films

江晞賢(Chiang Hsi-Hsien)

指導教授 ： 邱顯智

國立臺灣師範大學/理學院/物理學系/碩士(2021年)

https://doi.org/10.6345/NTNU202100771

摘要

我們利用了原子力顯微鏡研究「正丁硫醇官能化的聚苯胺」，針對聚苯胺薄膜的分子排列有序程度與其彈性模量和摩擦特性的關係進行探討。我們使用攪拌聚苯胺溶液的方式來控制聚苯胺薄膜之分子排列的有序程度，並每攪拌24小時抽取出聚苯胺溶液滴製在基板上以製成聚苯胺薄膜以供研究。聚苯胺長鏈分子在溶液中很容易自我糾纏成團，而攪拌時溶液中所產生的剪切力則可以將自我糾纏的聚苯胺分子拉展開來。因此，在我們滴製聚苯胺薄膜樣品的過程中，已伸展開的長鏈聚苯胺分子便更能在溶劑揮發的時候，自行排列成有秩序的結構。我們也利用了「X光繞射」和「掃描電子顯微鏡」確認了聚苯胺薄膜的分子排列結構，並確定了聚苯胺薄膜在攪拌時間為72小時的時候，具有最有秩序的分子排列結構。隨後，我們使用原子力顯微鏡的「峰值力定量奈米力學應用模式」和「側向力顯微術」測量了聚苯胺薄膜的表面形貌、彈性模量、吸附力變化以及樣品與探針間的動摩擦係數。我們發現，分子排列結構越有秩序的聚苯胺薄膜，其彈性模量越大且動摩擦係數越小。這是因為彈性模量較大的聚苯胺薄膜，其分子排列結構較為緻密，因此當原子力顯微鏡的探針施壓在其表面時所產生的形變程度便較小、對探針所產生的能量耗散也較小，進而導致側向力顯微術測量出較小的動摩擦係數。反之，彈性模量較小也就是較軟的聚苯胺薄膜，其所被測量出的動摩擦係數則較大。綜觀所究，我們成功證實可以利用「調整攪拌時間」的方式控制聚苯胺薄膜結構分子排列的有序程度，進而調控聚苯胺薄膜的彈性及摩擦性質。

關鍵字

原子力顯微鏡 ； 正丁硫醇官能化聚苯胺 ； 摩擦係數 ； 彈性模量

並列摘要

We studied the influence of structural order on the elastic and the frictional properties on the butylthio-functionalized polyaniline (PAni-SBu) thin films by atomic force microscopy (AFM). To manipulate the structural order of the films, the PAni-SBu powers were dissolved into N-Methyl-2-pyrrolidone solvent and stirred continuously. The PAni-SBu thin films were fabricated by the drop-cast method approximately every 24 hours. Because of the mechanical stirring, the highly coiled polymer chains of PAni can be stretched in the solution. Therefore, when drop-cast on a substrate surface, the PAni-SBu chains may self-assemble into more ordered structures when solvents evaporate. By using X-ray diffraction and scanning electron microscopy, we found that the structural order of PAni-SBu thin films strongly depends on the solution stirring time. However, beyond an optimal stirring time, the structure of the film becomes disordered again because of the oxidation of polymer chains resulting from the prolonged stir in ambient conditions. By using AFM-based techniques, we found that both the out-of-plane elastic moduli and the friction coefficients of the films highly depend on the solution stirring time used prior to the film fabrication. While the polymer films that have higher structural order exhibit larger film elasticity and smaller friction coefficient, the films possess more disordered structure were found to be softer and have larger friction coefficients. Our results demonstrate that it is possible to control the degree of structure order of PAni-SBu thin films by mechanical stirring of polymer solution, and then manipulate the elastic and frictional properties of the films.

並列關鍵字

Atomic force microscopy ； Butylthio-functionalized polyaniline ； Friction coefficient ； Elasticity modulus

參考文獻

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