壹、新型脫鎂葉綠素輔助甲醇分解 貳、探討駐極體製作為粒子加速器之可行性 參、新型能源收集方法:自動上鏈機構

1.New Pheophytin-assisted Methanol Decomposition 2.A Possible Electret Charge Accelerator 3.New Energy Harvesting Method: Self-winding Mechanism

賴玟柄(Wen-Bing Lai)

指導教授 ： 廖重賓

國立虎尾科技大學/電機資訊學院/光電與材料科技研究所/碩士(2015年)

摘要

壹、新型脫鎂葉綠素輔助甲醇分解
甲醇是一種具高能量密度、在許多環境下都保持液態的物質。以其為燃料的電池不需要像間接式電池般必須經過複雜的汽化產生氫氣的過程。一般，甲醇分解依賴鉑(Pt)或釕(Ru)作為催化劑，其中Pt效率較高，但是甲醇氧化過程中未完全氧化的含碳中間產物會殘留在Pt催化劑表面上(在酸性電解液中，可能以Pt=C=O吸附形態存在)，因而阻礙後續甲醇分子的吸附，導致Pt催化活性的降低，此即CO毒化(poisoning)效應。本研究以脫鎂葉綠素(pheophytin)進行甲醇分解。以簡單的化學電池結構實驗，使用不鏽鋼(stainless steel)作為負極、碳(carbon)棒作為正極、鹽酸(HCl)水溶液作為電解液，再以脫鎂葉綠素塗佈在負極後加入甲醇(CH3OH)。經測量放電曲線，發現可以得到可觀的電能。

貳、探討駐極體製作為粒子加速器之可行性
粒子加速器(particle accelerator)的應用很廣泛，即使日常生活中也常見到粒子加速器的應用，例如用於電視的陰極射線管及X-ray等設施，在各個科學領域更能看到它的應用。通常將帶電荷粒子加速到高能要耗費很多的外加能量，然而，駐極體(electret)是一種自身帶有電場的物體。本研究試圖以完全被動之駐極體取代高壓電源產生電場。首先以目前較為普及、但只帶弱電場之的鈦酸鋇(barium titanate, BaTiO3)進行CASTEP量子計算模擬其可行性。鈦酸鋇在絕對零度時晶格呈現三角晶系，自發極化軸方向為[111]，在室溫下呈現四方晶系，自發極化軸方向為[001]，自發極化強度Ps(saturated polarization)=26×10-2 C/m2。經使用Matlab計算在巨觀下鈦酸鋇晶體(2cm×16cm)的外部電場形狀與電場強度，外部電場呈現所需之連續性、電場強度約1000 V/m。初步研究顯示，利用鈦酸鋇晶體、不外加能量，欲將一個電子加速至50 keV需要約60公尺長的鈦酸鋇晶體結構。

參、新型能源收集方法:自動上鏈機構
本研究試圖產出一種受到震動後能長期持續充電的裝置。亦即，利用發條使機械能轉換為電能，包含一個上鏈擺陀、兩組磁鐵與線圈、發條裝置。實際上，其為利用上鏈擺陀將機械能儲存在發條裝置。第一組磁鐵位於上鏈擺陀，並且隨著上鏈擺陀運動與第一組線圈互相作用產生電流。第二組磁鐵藉由傳動齒輪連接於發條裝置，當發條裝置釋放機械能時，經由傳動齒輪帶動與第二組線圈互相作用產生電流。
發電裝置藉由至少兩磁性元件作為轉子進行發電，可以提升發電效能。另外，利用位於上鍊擺陀上之磁性元件來發電之方式，可以減少所需零件的數量，具有節省空間及降低成本之優點。機構擺陀與齒輪組件使用3D列印技術製作，使用銣鐵硼磁鐵尺寸為直徑D = 15mm、厚 = 2.5mm、1個直徑D =16mm、厚 = 5mm的線圈，整體機構體積54cm3輸出功率為7.71mW。使用精密齒輪可將機構體積縮小到18 cm3得到相同的輸出功率。

關鍵字

脫鎂葉綠素 ； 直接甲醇燃料電池 ； 粒子加速器 ； 駐極體 ； 鈦酸鋇 ； 自動上鍊 ； 震盪發電

並列摘要

1.New Pheophytin-assisted Methanol Decomposition
Methanol is a liquid chemical of high energy density under a variety of environments. Fuel cells using it as the fuel (i.e., DMFC, direct methanol fuel cell) do not require the extra labor of generating hydrogen gas for use as fuel as do in all indirect fuel cells. Normally, methanol decomposition relies on platinum (Pt) or ruthenium (Ru), especially the former, as the catalyst. However, in the methanol oxidation process, some generated carbon-containing chemicals (likely in the form of Pt=C=O) tend to settle on the surface of platinum and downgrade its functionality. This undesirable effect is normally termed “the poisoning of Pt.”
In this study, pheophytin was employed to replace Pt or Ru in the methanol decomposition. Simple chemical cell structure experiments were set up, using stainless steel and carbon bars as the negative and positive electrodes, respectively, and hydrochloric acid as the electrolyte, with the negative electrode further coated with pheophytin, the injected methanol was observed to decompose and generate noticeable current.

2. A Possible Electret Charge Accelerator
Particle accelerators have been applied extensive in many fields, ranging from home applicances (such as the electron guns within TVs) to high-end scientific projects. Normally, it takes external energy to drive charged particles to the desired speed. However, electret is something with its own electric field. This research attempted to align electrets in the way that such a continuous electric field could be established for the acceleration purposes. To examine the feasibility in the first place, the readily available but weak-field electrets, barium titanate (BaTiO3), was chosen for the 1st-principle CASTEP quantum simulations. It is now known that barium titanate exhibits triangular crystal lattice at absolute zero temperature. However, under room temperature, the lattice becomes orthorhombic, with the saturated polarization being about 26×10-2 C/m2 and in the [001] direction. Then, Matlab simulations indicated that a continuous electric field of about 1000 V/m could be erected using barium titanate, even though the cost of driving an electron to 50 keV would mean a 60 m long such passive accelerator.

3. New Energy Harvesting Method:Self-winding Mechanism
An energy-harvesting device was attempted and created in which the device was designed to remain charging even after the cease of external excitation. This was made possible by adopting the same principle pure mechanical watch has been based upon for the past few decades.
In the engaged experiment, the oscillator hammer and gear assembly were designed and made using 3D printing machine. With NdFeB magnet of the size diameter = 15mm, thickness = 2.5mm, and coil of the size: diameter = 16mm, thickness = 5mm, the output power of 7.71 mW was obtained. Using more precise machine tooling, this device can shrink to 18 cm3 in volume while offering the same output power.

並列關鍵字

pheophytin ； DMFC ； accelerator ； electret ； barium titanate ； self-winding ； energy harvesting

參考文獻

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