化學

The highly water-absorbing polymers were prepared by the reaction of acrylic acid as a graft\r monomer and natural starch (eg. rice starch, sticky rice starch or corn starch) as the backbone\r using water hydrogen peroxide and vitamin C as solvent, initiator and catalyst, respectively. The\r reaction was carried out by mixing of starch in distilling water and stirring at 60-70 ℃ for 3\r hours and then cooled to 30℃ Acrylic acid was added and the pH was adjusted to 6-9 by the\r addition of limestone powder. To the stirred mixture were then added hydrogen peroxide (30%\r v/v) and vitamin C and continued stirring for 3 hours until the solution became viscous The\r viscous solution was neutralized with potassium hydroxide (30%v/v) to give the pH for 6.5-7\r and allowed to cool to room temperature overnight. The resulting solution was spread on\r winnowing baskets and allowed to dry under the sun to yield a continuous absorbent polymer\r film. The absorbent polymer film was ground and yield of white powder, The above procedure\r was repeated by using another types of starch. The ability of starch slurry to swell on heating, by\r absorption of water, is it’s most important practical property. Rice starch has very low swelling\r capacity in aqueous media compare with sticky rice starch and corn starch. The capacities of\r water-absorbing polymer were tested by placing polymer powder in the beaker and adding of\r water until it swell and cannot absorb more water. The polymers were found to be an excellent\r water absorbent, which absorbed water about 248, 245 and 167 times in weight of polymer for\r corn starch, sticky rice starch and rice starch, respectively. The water retention was calculated by\r measuring the amount of water releasing after every week for 10 weeks. They have also good\r water retention capacity. The swollen polymers were mixed with soil in ratio 1:3 and the\r increasing water holding capacity of soils which promotes more efficient plant growth in pot were\r test. It was found that the soil could be absorbed water for 10 weeks. It is possible to use highly\r water-absorbing polymers from natural starch in agriculture because they are low in cost and the\r polysaccharide main portion of the product is biodegradable

自組薄膜(SAMs, self-assembled monolayers)乃是具有特定官能基的化合物在不需外力作用 下自動吸附到基質表面上而自行排列成有自序規則之結構。SAMs技術因製備容易且穩定，在 應用上深具潛力。目前此方法中，以硫醇接在Au上的研究最為廣泛。本作品希望藉著SAMs 方法將硫醇分子吸附於鐵片或其他金屬表面上，以達成防鏽與抗酸目的。我們分別透過接觸 角量測研究正十二硫醇在鐵片上形成分子薄膜的可能性；利用酸與金屬產生氣體的速率研究 分子薄膜抗酸蝕的情況；測試分子薄膜的耐熱性；根據鐵片生銹時pH值變化、重量變化與[Fe2+] 含量差異來探究分子薄膜能否防鏽；最後找出適合形成分子薄膜的濃度與溫度效應。由實驗 結果我們發現SAMs薄膜確實能吸附於鐵(及鎳、銅、鋅等金屬)的表面上並增加抗酸與防鏽蝕 能力，薄膜對熱的穩定性極佳，35℃時結合效果較佳，而濃度的提高有助於SAMs的效用。 Self-assembled monolayers(SAMs) are elements which have specific functions.SAMs,ordered molecular aggregates can automatically adhere to the surface of substrate without any force.The applcation of SAMs’technique has high potential not only because ther are easy to make but also because they are stable.Exposing molecules such as alkyl thiols to an Au(0) surface is now in widespread use. In this work,we apply the thiols chemisorb onto the Fe or other metal surface to make it rust-resistant and acid-resistant.We study the following issues to find the appropriate conditions of forming monolayers in varying concentration and temperture: I. The possibility of forming n-dodecanthiol molecular monolayers on Fe surface by measuring the contact angles. II. The ability of antiacid corrodibility by comparing the rates of producing gas from acid and metal. III. The heat-resistant of molecular monolayers. IV. Whether it’s antirust by detecting the changes of pH,weight,and the concentrations of Fe2+ during the iron rust. According to the results,we conclude SAMs do adhere to the surface of Fe(and other matal like Ni,Cu,Zn), which increases the ability of antiacid and antirust.Besides they are stable to heat, have good combining effect at 35℃, and it is beneficial to the effect of SAMs through raising their concentration.

In order to facilitate a paradigm shift from traditional high volume chemical experiments to an environmentally friendly microdose experiment; I had to innovate and overcome a lot of difficulties. After six generations of experiment design I successfully reduced the volume of the combined reactants to a single drop. I utilized many recycled components to build my apparatus including a vintage computer, a simple CD disk, optical sensors and a transistor from a common computer mouse. By using a CCD monitor with an external camera feed, the single drop chemical reaction can be observed in real time and a recording of the event can be made. I chose the focus of the experiment to be the reaction of sodium thiosulfate and hydrochloric acid to create a colloidal solution of sulfonium nanoparticles. By employing a custom-made transparency target to achieve a higher precision of measurement I have also conducted deeper research into the reaction order and the rate constants. 為了將傳統高劑量的化學實驗順利的推向顯微液滴的化學實驗上，今年我們更是創新突破了很多困難的關卡。 儀器設計由第一代減量研究到第六代的減量設計，目前已能成功的運用報廢的光碟片、報廢的電腦、報廢滑鼠內的感光二極體元件及電晶體來自製設計出兩反應物各一滴溶液做自動偵測反應的記錄。透過顯微鏡加裝的CCD電子螢幕目視觀看、拍成電子影片檔由電腦播放的目標。 因此，我選定了硫代硫酸鈉溶液和鹽酸溶液反應可產生硫奈米微粒的膠態溶液作為實驗的主軸及設計可較精確定量的投影片載液面，我們也企圖對其反應速率式的級數及反應速率常數做更深入的探討。

In this research we derived heating effects on anti-oxidation by optical rotation analyses. A simple and accurate Polarimeter was devised with polar screens, laser, and photo resistor; the laser was used for light source, and the photo resistor for detection. Four kind of fruits, Hyloceeus polyrhizus, California plum, kiwi and tomato were experimented by heating them in boiling water and microwave oven. Their optical rotations versus time duration were calculated. Then we used ABTS/ the H2O2/HRP analysis system from Arnao's research to obtain the heating effects on anti-oxidation by calculating the vitamin C densities versus lag time. We found that there was a tendency of increased anti-oxidation at the beginning by heating, but decreased afterwards. Better oxidation was achieved by using microwave for Hyloceeus polyrhizus, by using boiling water for kiwi and tomato, and by using both methods for California plum. The same tendency was also found in the optical rotation analyses. Therefore we successfully developed a new method to measure the antioxidant activities by the optical rotation. We can also apply this method to simulate the fruit digestion process in the stomach, which let us understand further about anti-oxidation ( or optical rotation ) versus time. 本研究利用偏振片、雷射光為光源、光敏電阻為偵測器，組裝成一個簡易且精確的旋光度計。 我們利用此旋光度計對奇異果、火龍果、聖女蕃茄、加州李子四種水果以微波、水煮及油浴三種方式來處理，求出水果的旋光度與熱處理時間的關係。再藉由Arnao 研究的ABTS/ H2O2/HRP 分析系統，以不同濃度的維生素C與延遲時間畫圖作為標準曲線來測量總抗氧化活性，並比較熱處理後抗氧化活性的變化趨勢。 透過本研究可以了解不同熱處理方式對四種水果之抗氧化活性初期皆有增加的趨勢，但隨著時間增長則抗氧化活性降低。其中奇異果與聖女蕃茄用油浴，火龍果用微波處理，加州李子則是用任何熱處理方式均可得較佳的抗氧化活性，而熱處理後在旋光度測量上也有相同的趨勢。因為此兩種方法有一致的反應趨勢，所以證明我們成功地開發出一種可以利用旋光度來測定抗氧化的新方法。 最後，應用本方法進一步模擬水果在胃部裡的消化，讓我們更可以了解在整個消化的過程中抗氧化活性(旋光度)隨時間變化的情形。

目前市面上缺乏簡單而精準的過氧化氫檢測法，我們參考Fenton Reaction 中，鐵離子對過氧化氫分解的催化模式，利用鐵、鈷、鎳、錳、鋅分子篩，測試他們催化過氧化氫分解反應的效率，從成本、毒性、活化能的多方考量下，選擇以分子篩來固定金屬催化離子，作為我們後續實驗的研究主軸。實驗的初步，我們選擇過氧化氫作為自由基，並著重於過氧化氫的分解反應。利用濃差電池的原理，設計出一套濃度檢測系統，由分子篩作為電極。鑒於粉末狀的分子篩容易流失，我們製備出陶土鐵分子篩，以陶土固定分子篩，並以此作為電極，搭配白金絲，透過能士特方程式，測出過氧化氫的濃度，且藉由電路調控放大倍率，可以直接控制檢測範圍。從實驗結果得知，鐵分子篩在處理過氧化氫的時候，不會有鐵離子溶出的現象，且其催化性在酸性液中可以維持，能不斷的使用，長時間來看，分子篩相當有經濟與環境保護上的價值。We attempted to provide a system for quickly determining the concentration of free radicals. The existing methods or techniques are inefficient or need expensive equipment, therefore, an inexpensive system is being sought for. As a preliminary study, we focused on the decomposition of hydrogen peroxide. Taking the Fenton reaction as reference, we designed a measuring system. This system includes a catalyst containing Fe or Pt ions for catalyzing hydrogen peroxide decomposition reaction. The Fe- and Pt-zeolite were prepared to hold Fe and Pt ions to avoid losing. Because the electrically induced potential would decrease with the decrease in the concentration of hydrogen peroxide, we could measure the concentration of hydrogen peroxide by monitoring the electrical potential. We determined the initial concentration of hydrogen peroxide in water from the initial electrical potential measured through the equation obtained from the calibration line. The practicability of this system has been assured after a series of experiments. We will further develop the technique for measuring other free radicals. We anticipate that this technique will be further developed for measuring other free radicals. Although there are several problems and limitations to be solved and conquered, one thing is for sure: this system is an environment-friendly and cost-effective facility for determining the concentration of free radicals in an aqueous solution.

洗潔劑分散系泡膜的變化十分有趣，是否能用吹泡法比較表面張力大小？沾黏在立體的框上會怎麼樣？能否由框上薄膜面積大小討論界面劑的化學性質呢？

目前市面上可以轉換顏色的物品大多可是經由物理變化所控制的，而以化學發光的產品，往往都只能有單一顏色，例如螢光棒，當它被製造出來時，就註定了本身就帶某種顏色，難道光的顏色無法經由某些特殊反應讓其在不同顏色間轉換嗎 ?

由於低廉成本、無毒及其他原因，由二氧化鈦、有機染料及電解液所製造的光敏有機太陽能電池(DSC)被預測即將成為一種大規模廣泛流行的太陽能電池。本實驗比較合成染料(像紅汞和疊氮離子)及成本較低且無毒的天然植物染料用於太陽能電池的效能。有些天然植物染料的效能大於合成染料的效能，像是紫色高麗菜、地瓜……等。在研製太陽能電池的過程中, 本研究利用自製的幾丁質燒結出的奈米顆粒成效極佳，不但粒徑大小符合，在燒結的過程中也不需經過物理研磨及介面活性劑的輔助，並且在低溫下即可燒結，並由BET 和SEM 測得幾丁質燒結的TiO2 的孔隙度大於標準燒結的TiO2 的孔隙度，因此本實驗決定利用去乙醯化之幾丁質扮演太陽能電池的二種角色:介面活性劑及保護劑。在本實驗中，部分的電池效能不盡理想，或許是因為所有的太陽電池樣本均使用相同的電解液(I3-)。要找到每種太陽能電池最適合的電解液則需要更多的研究。Because of the desirable features of low cost, non-toxin, and other reasons a dye-sensitized nanostructured solar cell (DSC) composed of nanocrystalline TiO2, organic dyes and electroiytes is expected to be in prevalent use. This study compared the differences in the functioning of different dyes in the solar cells, specifically those between the synthetic dyes, such as Merchrochronate and Polypyridyl complexes of ruthenium (N3-), and dyes made of natural plants which cost less and are not toxic. Some natural dyes, such as purple cabbage, sweet potato, etc, were found to have better efficiency than the synthetic dyes. The study makes use of self-made chitin to sinter nano particles, and the result is excellent. First, the particle radius meets the size requirements. Second, in the process of sintering nano particles, no physical pulverizing or surfactant assistance was needed. Third, the nano particles can be sintered at a low temperature. Fourth, from BET and SEM measurements, the degree of aperture of TiO2 sintered with chitin is superior to that sintered with Triton X-100. For these reasons, the de-acetylated chitin was chosen to serve as surfactant assistance and protector in the solar cells in this study. The study also found that some solar cells were not efficient enough. Maybe it is because all the samples of solar cells in this study were produced with the same electrolyte (I3-). Further study is needed to figure out the most suitable electrolytes for each solar cell.

Our aim to attend this science fair is to design an instrument that can plat and measure the mass at the same time. In hope of designing a simple, accurate and convenient apparatus, we created an electronic circuit to display our original idea. In the process of constant improvements, we finally accomplished a “Super Mass Plating Gauge”, which can be easily and widely utilized in school teaching. The production of microbalance and the arrangement of electric circuit are the most significant parts in our research. The major components of the “Super Mass Plating Gauge” include a straw, metal clips and our creativity—the well-arranged electric circuit. The idea of microbalance originated from the Internet, but we advanced it by numerous experiments. First, we attached a steel cord to one side of the cathode in the electricity supplier. Next, we fixed the other side to the negative plate. And then, on the end of the negative plate, we tied a metal clip with the metal that will be plated. Eventually a new “plating gauge” was invented. By doing so, we could use this instrument to make our experiments. Our experimental goal is to research how different kinds of metal, time, electrode and voltage can affect the reduced mass on the cathode. We made use of such metal as copper, zinc and silver to carry out the experiments. In the end, by analyzing the results, we concluded a plating formula that can be applied to metal plating. 我們做此科展的目的，是要設計一個可以邊電鍍、邊測量質量的儀器，我們希望這個儀器是簡便、精確、且線路簡單，並且能推廣到教學的器材。經過我們不斷改良，終於完成了「便利質量電鍍器」 。 其中製作微量天秤和線路的配置方法，是本研究的重要部分。微量天秤的主要結構是吸管、鱷魚夾、及線路。微量天秤的構想，是參考以前的科展作品並加以改良，可精準測量到0.00010g，而裡面的線路，則是我們的創意（如圖一） 。只要把電源供應器的正極，接上左右任一鋼條，負極接到容器另一端，並加上一個鱷魚夾，夾上被鍍物，便是一個可邊電鍍，邊測量質量的儀器了！如此一來，我們就能以此儀器來作我們以下的實驗。 我們實驗目的在探討電鍍時不同金屬、不同時間、電極大小及電壓，對正極金屬片所減少質量的影響。 最後，我們推導出一個有關電鍍時正極金屬片質量變化量的實驗公式。為此，我們也要做許多次、許多種的實驗，來驗證我們的公式是否正確，並以我們所學的理論來推論。