全國中小學科展

化學

空間震盪與擴散

筆者將K?Cr?O?置於明膠溶液中煮沸,加入AgNO?水溶液,使之造成空間震盪反應。產生Liesegang ring。並且在研究空間震盪的過程中,筆者在研究過程中同時發展出一個程式,可以完成空間震盪實驗完成之後,由其震盪條紋的時空關係,得知ksp與擴散係數。或者可以在已知ksp和擴散係數的條件之下,預測出空間震盪實驗完成時的情形。We put K?Cr?O? into glutin, boiling it. After it concretizes, add AgNO? aqua into the glutin of K?Cr?O?. It is made to be space oscillation reaction with the Liesegang rings. And when we research for the process of space oscillation, we develop a program which can know the Ksp or diffusing coefficient after finising an experiment in Lablratory. Or we can predict the statement after the experiment on the condition of the Ksp and diffusing coefficient.

親愛的,我把汽油”變硬”了!

汽油給人的第一印象想必就是危險易燃,並且很容易揮發,在運輸及保存上有許多缺點,最簡單來說,汽油的高揮發性造成能源的散失、汽油的易燃性則造成了許多意外。而萌生研究製成汽油固態燃料的念頭。

鋅電極低污染性金屬浸鍍處理對銀鋅電池的影響

Because the electrolyte solution used in an alkaline battery is a concentrated KOH solution, the zinc electrode in such a battery undergoes both a charging reaction and a corrosive reaction with the alkaline solution. The corrosive reaction not only reduces the lifetime of the battery but also produces hydrogen, which can cause the battery to explode and burn. Most of the zinc alkaline batteries currently on the market use mercury plating on the zinc electrode to increase its resistance to corrosion. To reduce corrosion of the zinc electrode in an alkaline battery and to avoid the use of toxic mercury, this study aimed to design a device to measure the quantity of hydrogen gas produced during the charging of a zinc-silver battery. We plated the zinc electrode with the immersion electroless plating method, using several different kinds of low-polluting anticorrosive additives(metallic compounds such as lead, tin, and indium)instead of mercury. We also used the vacuum immersion electroless plating method and added zincate ion into electrolyte solution to reduce further the quantity of hydrogen produced. The results of the experiment revealed that either a 10:1 or 100:1 ratio of lead to tin under optimal conditions will yield much better results than mercury.鹼性電池中使用的電解質溶液為濃氫氧化鉀溶液,因此電池中的鋅極除了放電反應之外,也會與濃鹼溶液中發生腐蝕反應。鋅極的腐蝕作用不僅會降低電池放電壽命,而且所產生的氫氣更可能使電池發生爆裂燃燒的危險。目前市面上所售之含鋅鹼性電池,大多是用鋅極鍍「汞」作為鋅極抗腐蝕的方法。為了改善銀鋅鹼性電池中鋅極在放電時的腐蝕效應,以及減少其所產生的氫氣量,本實驗設計了一動態放電裝置,可用於檢測銀鋅電池的放電電壓、放電時間與鋅極腐蝕反應的氫氣生成量。本研究藉由浸鍍其他低污染性金屬溶液 (鉛、錫、銦的化合物)來取代不環保的鍍汞製程,並進一步設計抽真空的浸鍍裝置,以及電解質溶液採用含有ZnO22-的KOH溶液,有效的降低電池中氫氣生成量。最後綜合所有優良條件,以鋅極採用真空浸鍍(Pb:Sn)為(10:1)及(100:1)的條件,此舉非常有效地提高電池中鋅極抗腐蝕性。此項製程所使用的Pb、Sn污染性質遠遠低於目前工業上所使用的汞製程污染,而且製程成本也遠遠低於Hg製程成本。

滾球之謎

在一次課外進行的示範實驗中,化學老師用玻棒將KNO3的飽和溶液塗在白紙上上,以吹風機把水吹乾後,以線香去點塗過KNO3的地方,會發現火星會沿著塗過KNO3的軌跡燃燒,示範後,我們實際操作,發現KCIO3也有這種特質,於是有人嘗試以KNO3加上KCIO3的溶液進行實驗,意外的發現在實驗進行時,軌跡之前端會出現小小的球(爆燃),邊滾邊燒,且球中有一些氣體,為得知這是什麼,於是設計,進行以下的實驗。

嗜甲烷菌對丙烯催化模式之比較-溶解型與微粒體型甲烷單氧化酵素

在嗜甲烷菌中,甲烷與甲醇間的轉化是由甲烷單氧化酵素來進行。目前已知有兩種型態\r 的甲烷單氧化酵素,一種是溶解型甲烷單氧化酵素,存在於較低銅離子濃度之水溶液環境中﹔\r 另外一種為微粒體甲烷單氧化酵素,鑲嵌在細胞內質膜上,表現於較高的銅離子濃度環境下。\r 除了本身的天然基質-甲烷之外,其他種類之簡單烷烯類化合物,甚至芳香族化合物,均可\r 作為此酵素催化的基質。其中,甲烷單氧化酵素將丙烯轉化成環氧丙烯與甲烷轉化成甲醇的\r 催化活性非常接近,因此丙烯普遍被用來作為酵素活性測量的基質。為了直接測量它們的活\r 性,我們設計出一種方法,可以讓我們直接利用氣相色層分析儀,來偵測細胞的催化反應過\r 程。基於異丁烷在甲烷單氧化酵素幾乎不存在任何活性,故我們將其作為內標準氣體,並藉\r 由丙烯在氣相色層分析儀中吸收訊號的遞減來偵測細胞的催化活性。在多樣性的動力學實驗\r 中,我們發現以sMMO 為催化酵素時,丙烯的轉化是依據一級動力學反應趨勢而減少。相對\r 的,以pMMO 為催化酵素時,丙烯的減少趨勢則是依據零級動力學反應模式進行。在比較完\r Pipes 緩衝液、上清液蛋白質及內質膜蛋白質溶液之丙烯吸附量測試結果後,我們發現內質膜\r 蛋白可吸附的丙烯分子相對於其它兩種溶液是最多的。依據Michaelis-Menten 動力學理論,\r 可得到以下結論﹕丙烯的轉化在sMMO 中是以基質受限的催化形式進行,而在pMMO 中則\r 已達到最佳的催化速率。\r \r In methanotrophs, the oxidation of methane to methanol is catalyzed by methane\r monooxygenase. There are two distinct forms of the enzyme associated with different gene\r products. One is the soluble methane monooxygenase (sMMO) expressed in the cytosolic portion\r of the cell and grown under copper-limiting growth conditions. The other enzyme is the\r particulate methane monooxygenase (pMMO), a membrane-associated protein that is expressed\r under high copper-to-biomass ratios. In addition to the natural substrates of methane gas,\r simple aliphatic alkanes, alkenes, or even aromatic compounds could be used as the substrates of\r the methane monooxygenase. In those gaseous simple alkenes and alkanes, propylene converted\r to propylene oxide by methane monooxygenase has been considered as popularly use for enzymatic\r activity determination because of its comparable activity to the methane gas. To measure the\r catalytic behavior of the methanotroph directly, we design a method to choose isobutane as the\r internal standard because of the negligible activity in the methane monooxygenase. The catalytic\r activity can be simply inferred from the decrease of the gaseous propylene signals in the GC\r chromatograms by generating the liquefied epoxides mediated by MMO within the methanotrophic\r bacteria. Under various kinetics measurements, when we incubate the methanotroph grown under\r copper-limiting concentrations, we observed the diminishment of propylene follow a first-order\r kinetic behavior with the over-expression of soluble methane monooxygenase. However, the\r growth of bacteria under 40 M presents the zero-order kinetic trend with the bulk expression of\r pMMO. After the quantification of the dissolved propylene in the deionized water, soluble\r proteins solution as well as membrane proteins solution, we observe the membrane proteins could\r adsorb more propylene molecules in comparison with the other solution mixtures. By considering\r Michaelis-Menten kinetics, we conclude the propylene conversion in sMMO is under substrate\r limiting catalysis whereas the pMMO has attended the optimized velocity of propylene conversion.

均相沉澱法製備CZA 觸媒之探討

本研究以均相沉澱法合成多成分的銅鋅鋁觸媒系統,並嘗試克服傳統共沉澱法的不均勻性且提高比表面積,過程中我們利用改變尿素濃度、水添加量、反應溫度與時間等四種變因成功合成出具有高活性的銅鋅鋁觸媒。研究得知最佳的合成條件為尿素3M 並添加三倍體積的水,在95°C 下反應2 小時。與傳統觸媒相比,均相反應合成的銅鋅鋁觸媒除了有較小的粒徑外,其還原溫度也較低,顯示較佳的觸媒活性。而在250°C 甲醇重組的製氫反應條件下,均相反應合成的銅鋅鋁觸媒也有較高的甲醇轉化效率、氫氣產生率以及CO2 的選擇率,而添加鈰與鋯可更進一步使觸媒活性再提升。未來除可利用此合成方法合成均勻性佳的多成份材料,亦可應用此高效能觸媒進行甲醇重組反應以產生氫氣提供燃料電池使用。; Multi-composition Cu-Zn-Al catalyst system was synthesized by homogeneous precipitation method. This method was anticipated to improve the homogeneity of metal mixing and to increase the surface area of catalyst derived by conventional co-precipitation method. In the research, we successfully synthesized Cu-Zn-Al catalyst with high activity by adjusting four experimental parameters -- urea concentration, water amount, reaction temperature and reaction time. The better catalyst can be obtained under urea concentration of 3M diluted by 3 times water, and the kinetics conditions of 95°C and 2h. Compared with the co-precipitation method, homogeneous precipitation method derived Cu-Zn-Al catalyst performed higher methanol conversion, hydrogen production rate and CO2selectivity under methanol reforming reaction at 250°C. Modifying the support by addition of Ce and Zr might further improve the activity of the catalyst. In the future, not only can this method apply on synthesizing other multi-composition materials with high homogeneity, but also the high performance catalyst can be used to do methanol reforming reaction in order to supply hydrogen on fuel cell.

聚苯胺製備改良及其在防蝕應用研究

導電高分子在各面之應用非常廣泛,其中聚苯胺因價格便宜,製作簡便,使其應用潛力更為突出。聚苯胺在鐵系及非鐵系金屬之防蝕能力已被證實,但由於聚苯胺與金屬之附著力不良使其應用受到限制。本文以提高聚苯胺在有機溶劑中溶解度以達到和金屬有效附著增加其防蝕能力為主,而奈米粒子所具有的表面效應、小尺寸效應及宏觀量子隧道效應,可為研究目標之一。但由於高分子奈米微粒之製備仍屬有限,故仍在研究中。 \r The development and application of the conducting polymer poly-aniline is getting\r prosperous and popular. The capability of poly-aniline in corrosion protection has\r been proved. But due to the adhesion of poly-aniline on the metal is poor, the applications\r are restricted. In this paper, the authors utilized how advance the solubility of\r poly-aniline in organic solution to modify the adhesion of poly-aniline on the metal\r in order to improve the effect of the corrosion protection of poly-aniline in ferrous\r metal. And the nanoparticles have the special effects such as the surface effect,\r the small size effect and the macro-quantum channeling effect. It can be an object\r for research.

含環胺-亞胺雙牙配基及其鎳錯合物的合成、結構鑑定,及烯烴催化聚合反應

本研究合成含環形胺—亞胺雙牙配基鎳金屬催化劑,用以催化烯烴聚合反應。將2-甲基丙醛經由溴化、胺化及亞胺化的步驟合成含胺—亞胺的雙牙配基,Et2NCMe2CH=N(2,6-iPr2C6H3) (3a)、(c-C4H8)N- CMe2CH=NPh (3b)、RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d)。再將配基和Ni(DME)Br2 (DME = 1,2- 二甲烷氧基乙烷) 反應, 形成鎳金屬錯合物Ni [Et2NCMe2CH=N(2,6-iPr2C6H3)]Br2 (4a)、Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d),並作結構鑑定。其中3b、3c、3d、4c、4d 均為合成的新化合物,4d 獲得X 光單晶繞射結構。 以合成之鎳錯合物作為催化劑,催化乙烯或降冰片烯(C7H10)的聚合反應,探討反應活性和高分子產物的性質。與含相同碳數的錯合物比較,在胺基具環形取代基的錯合物對乙烯的催化活性較佳,聚乙烯產物分子量較高,分子量分布範圍狹窄;其對降冰片烯的催化活性略遜於非環形者。同為環形取代基時,六環較五環者對乙烯的催化活性較差,但對降冰片烯的催化活性較佳。顯示乙烯聚合與降冰片烯聚合有不同的反應決定步驟。催化劑及配基的設計的確可以操控聚合反應及其高分子產物的性質。 The synthesis of α-amino aldeimines Et2NCMe2CH=N(2,6-iPr2C6H3) (3a), (c-C4H8)NC Me2CH=NPh (3b), RNCMe2CH=N(2,6-Me2C6H3) (R = c-C4H8 3c,c-C5H10 3d), as well as the nickel complexes Ni [Et2NCMe2C- H=N(2,6-iPr2C6H3)]Br2 (4a), Ni[RNCMe2CH=N (2,6-Me2C6H3)]Br2 (R = c-C4H8 4c,c-C5H10 4d) has been succeeded. Their structures were mainly determi ned by spectroscopy or elemental analysis. The complex 4d was characterized by X-ray crysta llographic analysis. It shows that the nickel complex has distorted tetrahedral configuration. The catalytic reactions of ethylene or norbornene polymerization using the newly synthesized nickel complexes are studied. All catalyts show high activity toward studied olefin polymerization. Comparing the data of the catalytic ethylene polymerization for complex 4c with those of its isomer complex 4a, the former is found to results in higher activity as well as the larger molecular weight of the PE products with the narrower dispersity. On the contrary, 4c shows lower activity in the reactions of norbornene polymerization than 4a. For the cyclic amine derivatives, 4c of five-membered amino group shows better catalytic activity toward ethylene polymerization than 4d of six-membered amino group. But 4d gives better perfomance for norbornene polymerization than 4c. Such results indicate that the processes of ethylene and norbornene polymerization might have different rate-determining steps. These study confirms that the design of ligand and catalyst are crucial with respect to the control of the catalytic olefin polymerization and the properties of the polymeric products.

分子篩包覆奈米銀製作與應用

本實驗合成之奈米銀粒子產物分為水溶液與固態形式。奈米銀粒子水溶液態製造方法以多芽基之檸檬酸根離子當保護劑,再以NaBH4 還原生成奈米銀粒子。而固態形式之奈米銀粒子是先以四級銨鹽界面活性劑當保護劑,經過NaBH4 還原生成奈米銀粒子水溶液後,再用二氧化矽包覆奈米銀粒子,藉由高溫燒去保護劑,得到含奈米銀粒子之二氧化矽分子篩材料。 將含奈米銀粒子之二氧化矽分子篩材料產物浸在純水中,除了不會改變水溶液性質外,又能以分子篩通透的特性,讓奈米銀漸進地釋放出銀離子,而達到長效性抗菌效果。 至於具抗菌性棉衫或濾網的製作,則採直接浸泡在奈米銀粒子水溶液中的方法,使奈米銀粒子吸附於上,針對上述實驗非常成功,洗滌超過十次且放置時間長達一個月以上,其抗菌效果仍佳,表示此簡易法製成的棉衫或濾網具有長效性的抗菌功效,為本研究重大突破。 奈米銀粒子對環境的影響是利用黑殼蝦來測試,控制適當奈米銀粒子濃度,使黑殼蝦能生存,亦可達到水中殺菌的效果。本實驗為首次針對奈米銀粒子對環境影響的測試並獲得重大的成果。;In this study, two Ag nanoparticles samples including Ag nanoparticles in aqueous solution and in solid form were prepared. The Ag nanoparticles aqueous solution readily obtained from reduction of AgNO3 aqueous solution with NaBH4solution in the presence of the sodium citrate as protecting agent. To prepare the Ag nanoparticles@porous silica sample, cationic alkyltrimethylammonium surfactant was used as the protecting agent of Ag nanoparticles and template of the porous silica. The Ag nanoparticles@porous silica was synthesized via reduction by NaBH4, silicification in silicate solution and calcination for the removal of surfactant. When adding the Ag nanoparticles@porous silica, the property of the aqueous solution was not changed. In addition, the Ag+ ion was gradually released from the accessible silica matrix to achieve a long-lasting effect on anti-bacteria. To prepare anti-bacteria clothes and sieves, these objects were soaked in Ag nanoparticles aqueous solution. The Ag nanoparticles were spontaneously absorbed into the clothes and sieves. The anti-bacteria efficiency of the Ag-nanoparticles containing clothes and sieves still remains even after ten-time washing and a period of time longer than one month. These worthy results indicate that this synthetic method provides a simple way to prepare the long-lasting Ag-nanoparticles containing clothes and sieves for anti-bacteria application. To investigate the influence of the Ag nanoparticles on the environment, shrimps are used as testing objects. With a well control on the Ag nanoparticles concentration, the shrimps survived well and the bacteria content was reduced. It is the first time to have testing result about the effect of the Ag nanoparticles on the environment. Thus, this is the most remarkable achievement in our experiments.

光觸媒結合分子篩-去團聚及光催化效果探討

二氧化鈦是光觸媒中最常被使用的,雖然合成方法很多,但如何提升其產量及分解效果,一直是學界及業界的熱門議題。\r 在此篇報告中,我們發展出一種新的方法來製造二氧化鈦,利用控制合成時溶液的pH值、使用幾丁質當作新的保護劑,並且改變加熱的溫度和時間來得到二氧化鈦奈米顆粒。在降解實驗中亞甲藍光的分解反應速率級數為一級,降解亞甲藍液的半生期在2.9~7.0分鐘,比一般文獻的數十分至數小時以上的速度高出許多。\r 另外,在幾丁質未燒去的實驗中,我們發現亞甲籃分子會被吸附在幾丁質的表面上但不被分解,燒去幾丁質時奈米粒子又無法完全分散,為解決這一個問題,我們使用了分子篩,分子篩可以吸附許多有機物質,再加上其為具有許多中/微孔構造的鋁矽酸鹽礦物,奈米粒子可以分散在其表面而不生團聚;在光降解的實驗中發現光觸媒結合分子篩後可大幅提高染料的分解效果,在短短一分鐘之內便將亞甲藍分解掉一半以上!\r 這個實驗提供了很好的方法,可以快速有效的合成二氧化鈦奈米顆粒,作為光觸媒使用。我們相信這個方法可以推廣到其他有機汙染物質,以降低工業進步後對地球環境所造成之污染危害。