Mechanical Property Evaluation of Electrodeposited Nanocrystalline Metals by Micro-testing

Electrodeposition is a very important technology in the fabrication of micro-components for micro-electro-mechanical systems (MEMS) or integrated circuits. Evaluations of the materials used in these devices as 3D components should be conducted using micro-sized specimens due to the sample size effect on the practical use of the components. Nanocrystalline metals could be deposited using an electrodeposition method with supercritical CO2 emulsion. Our experiment on the micro-specimens provides information on micro-mechanical testing of electrodeposited metals including the effect of sample size, grain size, and anisotropic structures on mechanical properties. In this chapter, recent studies on crystal growth in electrodeposition of metals and its evaluation using micron-sized testing will be presented

Crystal Growth by Electrodeposition with Supercritical Carbon Dioxide Emulsion

葉黃素為護眼保健食品的重要成分，屬於脂溶性營養素，因此限制了保健食品之應用。本研究目的為開發水溶性較高的葉黃素酯，以提升在保健食品之實用性。首先將廠商提供的原料進行超音波攪拌萃取葉黃素酯，溶劑為正己烷、丙酮及四氫呋喃，溶固比為 80，萃取時間為 60 分鐘，結果顯示四氫呋喃萃出物含有 25.3 % 葉黃素。將四氫呋喃萃出物進行甲醇-正己烷(1:1, v/v)的液液萃取，可將葉黃素提純至 44.7 %，但水中溶離率幾近於零。再將提純之材料加入 β - 環狀糊精(β-cyclodextrin, β-CD)進行超臨界二氧化碳抗溶結晶(supercritical carbon dioxide antisolvent, SAS)，產製易溶水的葉黃素酯包覆物。在固定溫度 55 ºC、抗溶時間 10 min、進料流速 0.5 ml/min 下、探討乳化劑種類 (Tween 20、Tween 80)、乳化劑含量(15 %、25 %)、攪拌時間(0.5、2、4、6 hr) 、壓力(120、140 bar)、提純材料和 β- 環狀糊精之進料量比(Wext/Wβ-CD) (0.5、1、2)對包覆物之總產率、葉黃素濃度、包覆率、回收率以及溶離率的影響。結果顯示乳化劑以 25% tween 80、攪拌時間 4 hr、壓力 140 bar、 Wext/Wβ-CD 0.5 可得較佳之包覆效率 77.9 % 、回收率 43.6 % 及溶離率 30.6 %，沉澱物總產率 69.0% 、葉黃素濃度 94.1 mg/g。因此固定上述條件，以應答曲面實驗設計(response surface methodology, RSM)之中心混成方法(central composite design, CCD)尋找 SAS操作溫度(45、55、65 ºC)及乳化劑含量(15、25、35 %)之最適條件。RSM 預測溫度 57.3 ºC及乳化劑含量 33.6 %時，可得包覆效率 68.8 %、回收率 43.3 % 及溶離率 31.4 %，沉澱物總產率 71.7 %、葉黃素濃度 89.2 mg/g。以 SAS 技術進行 β- CD及乳化劑包覆富含葉黃素酯之萃出物可提升其水中溶離度約 31%。包覆後之產物水溶性明顯增加，可提升葉黃素酯在保健食品之應用性。Lutein is an important component of health food for protecting the eyes. However, its applications in actual health supplements are rather limited as the substance is a fat soluble nutrient and has very low water solubility. This study aimed to develop a form of lutein ester with improved water solubility to enhance its applications in health supplements. Raw materials provided by the supplier first underwent ultrasonic stirring to extract lutein ester using hexane, acetone, and tetrahydrofuran (THF) at a solvent-to-solid ratio (SSR) of 80 with an extraction time of 60 minutes. Results found that the THF extract provided 25.3% of lutein. The THF extract was then subject to liquid-liquid extraction using a methanol / hexane (1:1, v/v) solvent to further raise lutein purity to 44.7%. However, the solubility of hexane-extract in water was still very close to zero. β-cyclodextrin (β-CD) was then added to the purified material in the supercritical carbon dioxide antisolvent (SAS) process to generate an encapsulated lutein ester with improved water solubility. The process was carried out under a fixed temperature of 55ºC, time of 10 min, and feed flow rate of 0.5 mL/min. Total yield (TY) of the encapsulated material, lutein ester concentration (Clut), encapsulation efficiency (EE), recovery (R), and dissolution rate (RD) were investigated under different emulsifiers (Tween 20 and Tween 80), emulsifier concentrations (15 % and 25 %), stirring times (0.5, 2, 4, and 6 hr), pressures (120 and 140 bar), and feed ratios of the extracted material and β-cyclodextrin (Wext/Wβ-CD) (0.5, 1, and 2). Results showed that the experimental conditions of 25 % of Tween 80 as emulsifier, 4-hr stirring time, 140 bar, and Wext/Wβ-CD of 0.5 gave better results of 77.9% EE, 43.6% R, 30.6% DR, 69.0% TY, and 94.1 mg/g Clut. A response surface methodology (RSM) experiment with central composite design (CCD) was then employed using the aforementioned conditions to identify the optimal SAS temperature (45, 55, and 65ºC) and emulsifier concentration (15, 25, and 35 %). Results of the RSM experiment predicted an optimal condition of 58oC for the temperature and emulsifier concentration of 33.6 %, which would provide the following: 68.8% EE, 43.3% R, 31.0% DR,71.7% TY, and 89.2 mg/g Clut. Using SAS for β-CD with emulsifier encapsulation of extracts rich in lutein ester would help improve dissolution rate in water about 31%. Water solubility was significantly increased for the encapsulated product, improving the applicability of lutein ester in health foods.摘要 i Abstract iii 縮寫表 v 目錄 vi 表目錄 viii 圖目錄 ix 附表目錄. x 第一章 緒論 1 1-1 研究動機 1 1-2 研究目的與規劃 2 第二章 文獻回顧 4 2-1類胡蘿蔔素簡介 4 2-2葉黃素簡介 5 2-2-1 葉黃素及葉黃素酯結構 5 2-2-2葉黃素特性 6 2-3 乳化劑介紹 7 2-4 環糊精介紹 8 2-5 超臨界二氧化碳的技術與應用 11 第三章 實驗材料與方法 15 3-1 原料與材料製備 15 3-2 試劑與藥品 16 3-2-1 氣體 16 3-2-2 藥品 16 3-2-3標準 18 3-3 實驗設備 19 3-3-1 超音波攪拌萃取設備 19 3-3-2 超臨界抗溶結晶設備 20 3-3-3高效能液相層析儀(HPLC)24 3-3-4 場發射掃描式電子顯微鏡 25 3-3-5動態光散射粒徑分析儀 25 3-3-6 其他設備 25 3-4 實驗方法與步驟 26 3-4-1 葉黃素定量 26 3-4-2超音波攪拌萃取葉黃素酯 32 3-4-3 液液萃取葉黃素酯 31 3-4-4 溶解度實驗 32 3-4-5 超臨界抗溶沉澱過程 33 3-4-6 溶離率實驗36 3-5 粒徑分析37 3-6電子顯微鏡(SEM)分析37 第四章 結果與討論 38 4-1超音波萃取 38 4-2液液萃取 41 4-3葉黃素酯液液萃取萃出物與 β-CD 在溶劑的溶解度實驗 45 4-4 SAS包覆液液萃出物的預實驗 45 4-4-1 包覆物及乳化劑的影響 45 4-4-2 攪拌時間以及乳化劑種類的影響 45 4-4-3 乳化劑的影響 46 4-4-4進料量比(Wext/Wβ-cd)的影響 46 4-4-5 壓力(P)的影響 47 4-5 應答曲面設計SAS 實驗 49 4-5-1溶離率(DR)應答分析值 53 4-5-2葉黃素濃度(Clut)應答分析值 53 4-5-3總產率(TY)應答分析值 53 4-5-4包覆率(EE)應答分析值 54 4-5-5回收率(R)應答分析值 55 4-5-6 RSM的預測值與實驗值比較 55 4-6 粒徑分析 58 4-7 電子顯微鏡(SEM)分析 59 第五章 結論 62 參考文獻 68   表目錄 表一、各種化學物質的臨界壓力、溫度和密度 13 表二、HPLC定量葉黃素之檢量線 29 表三、超音波攪拌萃取金盞草萃出物 40 表四、液液萃取 42 表五、溶解度實驗 44 表六、超臨界二氧化碳抗溶沉澱葉黃素酯萃出物預實驗 48 表七、超臨界二氧化碳抗溶沉澱之應答曲面設計實驗數據 50 表八、應答曲面實驗設計的預測值與實驗值比較 57 圖目錄 圖一、實驗流程圖 3 圖二、葉黃素及葉黃素酯結構 5 圖三、三種環狀糊精示意圖 9 圖四、超臨界二氧化碳相圖與臨界點相變圖 12 圖五、二氧化碳的密度-壓力的相圖 12 圖六、原料包裝以及原料 15 圖七、超臨界抗溶沉澱實驗設備圖 23 圖八、HPLC 圖譜 30 圖九、SAS 包覆程序之Tween 80進料量與抗溶溫度應答曲面圖 52 圖十、葉黃素酯萃出物與 β-CD 共沉澱物之粒徑分佈 58 圖十一、金盞草萃出物及液液萃出物 SEM圖 60 圖十二、不同條件下 SAS 沉澱物之 SEM 圖 61 附表目錄 附表一、SAS 溶離率(DR)的變方分析與回歸方程式 63 附表二、SAS 葉黃素濃度(Clut)的變方分析與回歸方程式 64 附表三、SAS 包覆物之總產率(TY)的變方分析與回歸方程式 65 附表四、SAS包覆率(EE)的變方分析與回歸方程式 66 附表五、SAS 回收率(R)的變方分析與回歸方程式 6

Nanoscale Cu Wiring by Electrodeposition in Supercritical Carbon Dioxide Emulsified Electrolyte

Novel electrodeposition (ED) techniques utilizing supercritical carbon dioxide (scCO2) emulsions (SCE) are introduced. ScCO2 has low surface tension and high compatibility with hydrogen. Thus, this method is applied in fine Cu wiring to allow the complete filling of Cu into nanoscale confined space. The electrochemical reactions are carried out in emulsions composed of an aqueous electrolyte, scCO2, and surfactants. Three aspects in fine Cu wiring will be introduced, which are the dissolution of the Cu seed layer in the SCE, the gap-filling capability of the ED-SCE, and the contamination in the plated Cu. At first, the dissolution of the Cu seed layer in the SCE was observed. In order to prevent the dissolution of the Cu seed layer, the addition of Cu particles into the SCE was found to be effective. The electrolyte containing the SCE and the Cu particles is named scCO2 suspension (SCS). The gap-filling capability was evaluated using test element groups (TEGs) with patterns of vias with a diameter of 70 nm and an aspect ratio of 5. Many defects were observed in the vias filled using the conventional electrodeposition (CONV) method. On the other hand, defect-free fillings were obtained by the ED-SCS method. Because of the high-pressure environment needed to form the scCO2, the reaction cells are usually batch-type high-pressure vessels. In order to improve the feasibility of the ED-SCS technique, a continuous-flow reaction system is also proposed and examined using a round-type large-area TEG with a diameter of 300 mm. Complete fillings were obtained for vias with a diameter of 60 nm and an aspect ratio of 5 on the large-area TEG. This result was in good agreement with that of the batch-type reaction system and demonstrated the successful application of the continuous-flow system with ED-SCS

Single-photon generation from a nitrogen impurity center in GaAs

We have demonstrated single-photon emission from a nitrogen luminescence center in GaAs. An inhomogeneously broadened luminescence band formed by localized centers was observed in the spectral range from 1480 meV to 1510 meV at 5 K in nitrogen delta-doped GaAs. Optical properties of the individual centers were investigated by steady-state and time-resolved micro photoluminescence. We have found that a bright luminescence center emits single photons with a radiative lifetime of 650 ps, which is much shorter than the lifetime of NN pairs in previous reports

Induction and Enhancement of Cardiac Cell Differentiation from Mouse and Human Induced Pluripotent Stem Cells with Cyclosporin-A

Induced pluripotent stem cells (iPSCs) are novel stem cells derived from adult mouse and human tissues by reprogramming. Elucidation of mechanisms and exploration of efficient methods for their differentiation to functional cardiomyocytes are essential for developing cardiac cell models and future regenerative therapies. We previously established a novel mouse embryonic stem cell (ESC) and iPSC differentiation system in which cardiovascular cells can be systematically induced from Flk1+ common progenitor cells, and identified highly cardiogenic progenitors as Flk1+/CXCR4+/VE-cadherin− (FCV) cells. We have also reported that cyclosporin-A (CSA) drastically increases FCV progenitor and cardiomyocyte induction from mouse ESCs. Here, we combined these technologies and extended them to mouse and human iPSCs. Co-culture of purified mouse iPSC-derived Flk1+ cells with OP9 stroma cells induced cardiomyocyte differentiation whilst addition of CSA to Flk1+ cells dramatically increased both cardiomyocyte and FCV progenitor cell differentiation. Spontaneously beating colonies were obtained from human iPSCs by co-culture with END-2 visceral endoderm-like cells. Appearance of beating colonies from human iPSCs was increased approximately 4.3 times by addition of CSA at mesoderm stage. CSA-expanded human iPSC-derived cardiomyocytes showed various cardiac marker expressions, synchronized calcium transients, cardiomyocyte-like action potentials, pharmacological reactions, and ultra-structural features as cardiomyocytes. These results provide a technological basis to obtain functional cardiomyocytes from iPSCs