仿生表面結構及活化生質碳材之導入對聚苯胺應用在硫化氫氣體感測元件之性能提升的探討

本論文之研究主軸，是以導電高分子「聚苯胺」為主要基材，透過兩種方式: (1) 改變聚苯胺表面型態及 (2) 添加活化生質碳材於聚苯胺中，來研究此兩種方式對此材料於應用氣體感測元件效能之提升成效。論文的第一部份研究之核心精神以結合「仿生」的概念為主，透過聚二甲基矽氧烷 (PDMS) 之軟模板轉印技術，複製了天然的千年芋葉片的表面微結構，製備出具備葉面微奈米複合「乳凸」結構之聚苯胺薄膜，預期可提升原本聚苯胺塗層之表面積，之後並將其塗覆於「指叉式電極」的表面，來研究「仿生結構的導入」是否能有效改善聚苯胺之氣體感測元件效能。第二部分研究之核心精神以導入「活化生質碳材」為主，透過使用廢棄之椰子殼材料進行高溫碳化及活化處理後，製備出高比表面積之活化碳材並適量添加於聚苯胺中，來研究「活化生質碳材的導入」是否能有效改善聚苯胺之氣體感測元件效能。在材料合成方面，本研究論文以過硫酸銨為氧化劑，對苯胺單體進行「原位氧化聚合法」來合成聚苯胺，並以1H-NMR光譜, FT-IR光譜及GPC進行聚苯胺之結構鑑定，並以循環伏安儀(CV)及紫外可見(UV-VIS)光譜儀進行材料性質之鑑定，確認所合成聚苯胺具有「可逆氧化還原」及「可逆摻雜」的物理性質。另一方面，選擇利用「轉印千年芋葉片」及「添加活化生質碳材」兩種方式來提升聚苯胺在氣體感測元件上的應用。「千年芋之仿生結構的導入」(第一部分): 透過PDMS軟模板轉印技術，將「天然」千年芋葉片的表面結構進行轉印，藉此得到「人造」具仿生結構之聚苯胺薄膜，並利用掃描式電子式顯微鏡 (SEM) 及水滴接觸角 (WCA) 進行「表面微結構型態」及「表面親疏水性質」的觀察。在性質鑑定方面，利用CV及UV-VIS光譜檢測具仿生結構之聚苯胺薄膜，確保「千年芋之仿生結構的導入」可有效提升聚苯胺之「可逆氧化還原」及「可逆摻雜」性質。「活化生質碳材的導入」(第二部分): 首先將廢棄之椰子殼進行高溫碳化得到椰子殼碳粉(CC)，然後透過化學活化法，利用ZnCl2對CC進行活化，得到活化的碳材(AC)。所製備之CC 及AC利用BET檢測碳材之孔洞大小及表面積，利用Raman光譜進行碳材之結構鑑定，利用SEM進行碳材之表面型態觀察。後續將適量的CC及AC添加入聚苯胺，之後利用CV及UV-VIS光譜進行聚苯胺複合塗料之「可逆氧化還原」及「可逆摻雜」性質的檢測。確保「活化生質碳材的導入」可有效提升聚苯胺之「可逆氧化還原」及「可逆摻雜」性質。第一部分所合成之材料以等面積的方式黏附於鍍有ITO指叉式電極（inter-digitated electrode, IDE）的表面上，膜厚度約為 28 µm, 做為後續氣體感測元件樣品。第二部分之樣品將其溶於NMP溶劑中，經過旋轉塗佈機將其塗佈於ITO-IDE表面上，膜厚度約為 100 nm, 接著在所建構的硫化氫氣體感測系統中進行氣體感測元件的量測。本研究論文中氣體感測的基本測試項目有如下四項：（a）靈敏度（Sensitivity）; （b）氣體選擇性（Selectivity）; （c）穩定性（Stability）及（d）重複性（Repeatability）。在室溫下，藉由在不同環境相對濕度下(60 %RH 與80 %RH) 之氣體進行量測比較。由研究的結果明白地顯示: 千年芋仿生結構的導入，可增強聚苯胺之氣體感測靈敏度~ 200%。此外，3wt-%的AC導入聚苯胺中，可增強聚苯胺之氣體感測靈敏度~ 300%。綜而言之，本研究所研究的兩種方式: (1) 「千年芋仿生結構的導入」及 (2)「活化生質碳材的導入」皆能有效大幅改善聚苯胺之氣體感測元件的執行效能。

關鍵字

聚苯胺；仿生；千年芋葉；生質碳；碳化；活化；硫化氫；氣體感測

並列摘要

The main research focus on this thesis is to use the conductive polymer "polyaniline (PANI)" as the main substrate. There are two approaches: method (1) changing the surface morphology of PANI and method (2) adding activated biomass carbon materials to the PANI. The effect of these two methods on improving the performance of PANI in the application of gas sensing is studied. The core spirit of the research in the first part of the thesis is based on the concept of " biomimetic ". Through the soft template transfer technology of polydimethylsiloxane (PDMS), the surface microstructure of the natural Xanthosoma sagittifolium leaves is replicated. A PANI film with a leaf-surface micro-/nano-scaled hierarchical structure was prepared, which is expected to increase the surface area of the original PANI coating, followed by coating on the surface of "inter-digited electrode" to study the effect of "biomimetic" structure of coating on gas sensing performance. The core spirit of the second part of the research is to study the gas sensing effect of introduce "activated biomass carbon materials" into PANI . After high-temperature carbonization and activation treatment of waste coconut shells, activated carbon (AC) with high specific surface area were prepared and added to PANI in a suitable amount, followed by studying the gas sensing performance of carbon-based PANI composites with different loading of raw carbon and activated carbon. In terms of materials synthesis, this research uses ammonium persulfate as oxidant to synthesize PANI by "in-situ oxidative polymerization" of aniline monomer, and uses 1H-NMR spectrum, FT-IR spectrum and GPC to identify the structure of PANI. The material properties were identified by cyclic voltammetry (CV) and ultraviolet-visible (UV-VIS) spectrometers, and it was confirmed that the synthesized PANI had the physical properties of "reversible redox" and "reversible doping". On the other hand, two methods of " Xanthosoma sagittifolium leaves" and "adding activated biomass carbon materials" were chosen to enhance the application of PANI in gas sensing devices. "Introduction of the biomimetic structure of the Xanthosoma sagittifolium " (Part 1): The surface structure of "natural" Xanthosoma sagittifolium leaves was transferred through the PDMS soft template transfer technology to obtain an "artificial" PANI film with a biomimetic structure. The "surface morphology" and "surface wettability" was observed by scanning electron microscope (SEM) and water droplet contact angle (WCA). In terms of property identification, the use of CV and UV-VIS spectroscopy to detect PANI films with biomimetic structures ensures that the "introduction of the biomimetic structure of Xanthosoma sagittifolium leaves" can effectively enhance the "reversible redox" and "reversible doping" properties of PANI. "Introduction of activated biomass carbon materials" (Part 2): First, the waste coconut shells are carbonized at high temperature to obtain coconut shell carbon powder (CC), and then through chemical activation method, CC is activated with ZnCl2 to obtain activated carbon materials (AC). The prepared CC and AC were tested by BET for the pore size and surface area of the as-prepared carbon materials, Raman spectroscopy was used to identify the structure of the carbon materials, and SEM was used to observe the surface morphology of the carbon materials. Subsequently, an appropriate amount of CC and AC were added to the PANI, and then the "reversible redox" and "reversible doping/de-doping" properties of the PANI composite coating were detected by CV and UV-VIS spectroscopy. Ensure that the "introduction of activated biomass carbon materials" can effectively improve the "reversible redox" and "reversible doping/de-doping" properties of PANI. Materials synthesized in the first part was adhered to the inter-digitated electrode (IDE) coated with ITO in an equal area, and the film thickness was ca. about 28 µm, which was used as a sample of the subsequent gas sensing device. The second part of the sample was dissolved in NMP solvent, and coated on the surface of ITO-IDE through a spin coater with a film thickness of about 100 nm, and then the gas was processed in the constructed hydrogen sulfide gas sensing system. The basic test items for gas sensing in this research paper were given as follows: (a) Sensitivity; (b) Selectivity; (c) Stability and (d) Repeatability ). At room temperature, measurements were made with gases at different ambient relative humidity (60 %RH and 80 %RH). The results of the study clearly show that the introduction of biomimetic structure of Xanthosoma sagittifolium can enhance the gas sensing sensitivity of PANI by ~200%. In addition, the introduction of 3 wt% AC into PANI can enhance the gas sensing sensitivity of PANI by ~300%. In conclusion, the two methods studied in this study: (1) "Introduction of biomimetic structure of Xanthosoma sagittifolium " and (2) "Introduction of activated bio-carbon materials" can effectively and greatly improve the gas sensing device of PANI performance.

並列關鍵字

Polyaniline ； Biomimetic ； Xanthosoma Violaceum Schott leaf ； Biomass Carbon ； Coconut Shell ； Carbonization ； Activation ； Hydrogen Sulfide ； Gas Sensing

參考文獻

[1] Terms and Definitions in Industrial-Process Measurement and Control, International Electrotechnical Committee, 1982.

Google Scholar

[2] I. Lundström, M. S. Shivaraman, C. M. Svensson, J. Appl. Phys, 1975, 46, 3876.

Google Scholar

[3] S. Middelhoek, D. J. W. Noorlag, Sensors and Actuators B. 1981, 2, 29.

Google Scholar

[4] M. Mada, “Fundamentals of Microfabrication”, CRC Press, 1997.

Google Scholar

[5] W. Gopel, T. A. Jones, M. Kleitz, J. Lundstrom, T. Seiyama, Chemical and Biochemical Sensors, 1991.

Google Scholar

主題瀏覽