聚苯胺/超疏水有機金屬骨架複合材料及超疏水盤狀液晶之合成、鑑定與性質研究及其在金屬防蝕上的應用

Synthesis,Characterization and Property Studies of Polyaniline/Superhydrophobic MOF Composite Material and Superhydrophobic Discotic Liquid Crystal Materials for Corrosion Protection Applications

黃偉傑(Wei-Chieh Huang)

指導教授 ： 葉瑞銘

中原大學/理學院/化學研究所/碩士(2018年)

https://doi.org/10.6840/cycu201800477

摘要

本碩士論文的研究主軸主要為新型防蝕塗料的研發，內容分為兩個部分:（一）聚苯胺/超疏水有機金屬骨架複合塗料的製備、鑑定及防蝕應用；（二）超疏水盤狀液晶材料之合成、鑑定與防蝕應用。
首先，第一部分是利用電活性聚苯胺做為防蝕塗料基材，添加入少量（1-5 %）新型具超疏水性質的有機金屬骨架（Metal-Organic Frameworks, MOFs）粉體，以形成一系列有機無機複合材料，並進一步將其應用在金屬防蝕的塗料上，利用電化學量測並確認複合塗料的防蝕量化效果。 基本上，利用過硫酸銨為氧化劑進行氧化聚合以合成電活性聚苯胺。 接著，以傅立葉紅外光譜儀（FT-IR）鑑定聚苯胺之特徵官能基; 以電化學循環伏安法證實聚苯胺具有可逆的氧化還原能力。 接著，將聚苯胺粉末溶解在NMP溶劑中，再添加特定量的超疏水無機MOFs（ZrTZ-68）粉體至聚苯胺溶液中以形成懸浮複合溶液，進一步將溶液塗佈於冷軋鋼片上，進行加熱以有效移除有機溶劑NMP，即可獲得複合材料塗層。 所合成之複合材料初步以掃描式電子顯微鏡（Scanning Electron Microscope, SEM）鑑定其表面樣貌，並透過能量色散X-射線光譜（EDX）證實ZrTZ-68在聚苯胺溶液中之分散性良好，且從表面接觸角可觀察到聚苯胺，添加5 % ZrTZ-68-C18後接觸角可由87.4°上升至113.2°，共上升25.8°，並利用表面疏水性與MOFs粉體在塗層中可延長氧氣滲透路徑，透過氣體滲透測試可觀察到聚苯胺，添加5 % ZrTZ-68-C18後氧氣滲透量可由3.412 barrer下降至1.358 barrer。 最後也利用電化學儀器對複合塗層進行防腐蝕測試，從接觸角、塔伏曲線、電化學阻抗、氣體滲透測試，證實複合塗料之防蝕能力。 研究中更進一步探討添加不同比例之ZrTZ-68，對於防腐蝕能力之影響，由實驗結果得知，當ZrTZ-68添加量為5 %時，防蝕能力最佳。
第二部分是以少於十個步驟的過程合成出一系列C1、C3及C6對稱的奈米石墨烯（Nanographene）分子，利用不對稱雙苯炔烴（Diarylalkynes），將其進行三環化（Cyclotrimerization）反應後會得到兩種區域異構物，再分別進行氧化環化去氫反應得到兩個低對稱的盤狀液晶，結構主體是以六苯并蔻（HBC）為主，並針對物理及化學性質進行討論。 將其上述三者對稱性液晶製備成抗腐蝕塗料，塗佈於冷軋鋼片上，經由室溫固化後，即可得到盤狀液晶膜材。 透過接觸角（CA）、交流阻抗測試（EIS）可知化合物1具有較佳疏水性（143.9°）與高電阻（186.7kΩ/cm2），並且將盤狀液晶膜材浸泡於不同pH值之溶液環境中，因盤狀液晶具有優異的疏水性（Hydrophobic）與自癒性質（Self-healing），使得盤狀液晶穩定性高。

關鍵字

聚苯胺 ； 有機金屬骨架 ； 防腐蝕 ； 超疏水 ； 盤狀液晶

並列摘要

This dissertation mainly focused on two research parts：
（1）preparation and characterization of composite materials containing polyaniline/super-hydrophobic MOFs and applied in anticorrosive coatings；（2）Synthesis, characterization and property studied of super-hydrophobic discotic liquid crystal materials.
For the first part of dissertation, polyaniline（PANI）was synthesized by oxidative polymerization of aniline monomers with ammonium persulfate as oxidant. Moreover, the PANI/MOFs composites were prepared by performing the oxidative polymerization of aniline monomers in the presence of suitable amount of as-prepared super-hydrophobic MOFs materials. The as-prepared materials were subsequently characterized by FT-IR spectroscopy. Redox capability of as-prepared materials was investigated upon ITO electrode by performing the electrochemical cyclic voltammetry studies. The dispersion capability of super-hydrophobic MOFs in PANI was observed by scanning electron microscope （SEM） and energy-dispersive X-ray（EDX）. Furthermore, the surface wettability of as-prepared PANI and corresponding composite coatings was investigated by contact angle（CA）of water droplets. It should be noted that the incorporation of super-hydrophobic MOFs in PANI coating may effectively increase the CA of water droplets on the surface of corresponding coatings, and super-hydrophobic MOFs provides surface hydrophobicity and extended oxygen permeation pathways to block oxygen permeation.
The as-prepared materials were then dissolved in NMP, followed by casting onto the cold rolled steel（CRS）electrode in fume hood at operational temperature of 120 C for 12 hours to get rid of the solvent. The corrosion protection of CRS electrode coated with PANI or corresponding composites were determined by standard electrochemical corrosion measurements. It should be noted that the introduction of 1 wt-% of superhydrophobic MOFs into PANI coating may significantly enhance the corrosion protection of polymer coating based on a series of electrochemical corrosion measurements. Moreover, increasing the loading（e.g., 3 wt-%）of super-hydrophobic MOFs incorporated in PANI may further promote the anticirrosion performance upon CRS electrode.
For the second part of dissertation, a series of high and low symmetry hexa-peri-hexabenzocoronene derivatives, compounds 1–3, was successfully synthesized and applied for corrosion resistance on iron surfaces. In particular, compound 1 exhibited excellent anti-corrosion behavior, as demonstrated by electrochemical impedance spectroscopy（EIS）and contact angle（CA）measurements. A high resistance of 186.7 kΩ/cm2 and excellent hydrophobicity （CA ∼143.9°） with brine solution were obtained. The discotic columnar liquid crystals（DCLCs）coating on the iron surface provide protection under various environments, including exposure to air and solutions with different pH values. This characteristic is attributed to the excellent hydrophobicity and self-healing properties of discotic columnar liquid crystals.

並列關鍵字

Polyaniline ； Metal-Organic Frameworks ； Anti-corrosion ； Discotic Liquid Crystal

參考文獻

（一）聚苯胺/超疏水有機金屬骨架複合材料防腐蝕塗料的應用性

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