- 學位論文
光聚合法製備仿生超疏水聚甲基丙烯酸甲酯/二氧化矽奈米複合材及其在防腐蝕之應用研究
Photosynthesis of PMMA-SiO2 hybrid materials with biomimetic surface structure for corrosion protection applications
摘要
本論文首次成功以光固化的方式製備出PMMA/SiO2之有機/無機混成複合防蝕塗料，並利用「SiO2裸露堆疊」與「仿生結構的複製」的製作技術來製備出具新穎且先進的超疏水防蝕塗料。 本次研究首先以矽酸乙酯(TEOS)與3-(三甲氧基甲矽烷基)丙基丙烯酸酯(MSMA)進行鹼催化「溶膠-凝膠法」製備出表面具有乙烯基改質的二氧化矽（Vinyl- modified silica； VMS）顆粒，為實驗添加之二氧化矽，並利用傅利葉轉換紅外線光譜儀（FT-IR）、29Si 魔角固態核磁共振分析與13C 交叉極化魔角固態核磁共振，來進行結構確認。並利用轉印的方式複製新鮮千年芋(Xanthosoma sagittifolium)的表面結構，得到仿生聚二甲基矽氧烷（PDMS）模板。 接著將改質二氧化矽與甲基丙烯酸甲酯（MMA）利用2-苄基-2-(二甲基氨基)-4'-嗎啉基苯基丁酮做為光起始劑，混合均勻即為「聚甲基丙烯酸甲酯/二氧化矽複合防蝕塗料」，將上述塗料塗佈於冷軋鋼（CRS）上，再以壓印的方式將冷軋鋼壓於PDMS模板上方，以波長365nm之UV燈在距離10公分的狀態下，照射60分鐘進行光聚合反應，成功轉印製備出仿生聚甲基丙烯酸甲酯/二氧化矽超疏水表面，將其利用掃描式電子顯微鏡（Scanning Electron Microscope, SEM）做表面型態鑑定，發現表面有許多微米尺度的乳凸(Pillar)，以及許多奈米尺度的皺褶(Valley)，與新鮮千年芋葉面表面結構相符，證實成功複製千年芋表面微結構，除仿生微結構外可透過SEM發現複合材表面具有SiO2的裸露堆疊，進一步利用原子力顯微鏡 (Atomic Force Microscope, AFM)鑑定，可發現因為SiO2的裸露堆疊其表面粗糙度有11%的提升，且聚甲基丙烯酸甲酯/二氧化矽塗層表面的接觸角 (Contact Angle) 因仿生結構與SiO2¬的裸露，從89∘大幅上升至163∘，並利用循環伏特安培儀（Cyclic voltammetry, CV）與交流阻抗模組(Impedance)探討其防蝕能力。研究結果顯示:仿生結構與改質二氧化矽顆粒的表面堆疊可有效提升水滴的接觸角約80∘，此大幅提升之接觸角可提升材料作為防腐蝕塗層之排水性，而水能溶解部分氧氣，因此塗層亦會具有排氧性，而氧氣是金屬腐蝕之元兇，因此，此仿生複合材料塗層推測應具有有效的金屬防腐蝕效果，電化學防蝕量測的結果亦證實了此結果。
並列摘要
In this dissertation, UV-curing technique was used to develop eco-friendly corrosion inhibitors of PMMA/silica composite (PSC) with bioinspired Xanthosoma sagittifolium leaf-like, superhydrophobic surface. Surface morphology of as-synthesized hydrophobic PMMA (HP) and superhydrophobic PSC (SPSC) coatings was found to show lots of micro-scaled mastoids, each decorated with many nano-scaled wrinkles was investigated systematically by scanning electron microscopy (SEM). The contact angle of water droplet on sample surface was found to be increased from 81∘ (PMMA) and 103∘(PSC) surface to of 148∘(HP) and 163∘(SPSC) surface. It should be noted that SPSC coating was found to reveal advanced corrosion protection effect on CRS electrode as compared to that of neat PMMA, PSC and HP coatings based on series of electrochemical corrosion measurements in 3.5 wt % NaCl electrolyte. Enhancement of corrosion protection of SPSC coatings on CRS electrode could be explained by the following two theories: (1) The approximate superhydrophobicity repelled the moisture and further reduced the water/corrosive media adsorption on the PMMA surface, preventing the underlying metals from corrosion attack, (2) the silica nanoparticles onto the small papillary hills of bioinspired structure which to enhance the surface hydrophobicity to superhydrophobic degree, leading the better anticorrosion effect.