臺灣博碩士論文加值系統

我們觀察膠體奈米金粒子沉積於表面接有矽烷的矽基板上之行為，探討不同的pH值對奈米金粒子在矽基板上覆蓋率比值的影響。
我們利用浸泡法使奈米金粒子(直徑=18 nm)沉積在APTMS-矽基板上形成次單層(submonolayer)薄膜，當浸泡的時間逐漸增加時，APTMS-矽基板表面所吸附的奈米金粒子也隨之增加，當時間足夠長時，基板上吸附的顆數趨近穩定值時，則稱之為飽和顆數，而時間與吸附顆數曲線會呈現出指數衰減函數(exponential decay function)的關係。
我們藉由添加HCl和NaOH溶液來調整pH值，添加HCl溶液時，pH值隨之降低，矽基板上的飽和顆數逐漸增加，因為氫離子減弱了奈米金粒子表面的電荷，而使粒子間的距離變近，所以飽和顆數逐漸增加；當加入NaOH溶液時，pH值逐漸上升，矽基板上的飽和顆數隨之降低，主要是因為APTMS-矽基板表面需要氫離子作用才能轉變為正電荷藉以吸附表面帶負電荷的奈米金粒子，所以pH值越高，膠體金溶液裡的氫離子越少，則APTMS-矽基板上所吸附的奈米金粒子越少。
我們從SEM圖上的取得奈米金粒子的分佈座標，接著用Radial Distribution Function和Shortest Distance方法估算出此實驗中奈米金粒子上靜電荷的有效斥力距離約為6 ～ 8 nm，我們將奈米金粒子的半徑加上靜電荷的有效斥力距離，估算出有效覆蓋面積比值約0.7，此數值低於ordered close packing (0.9069) 和random close packing (0.82 ± 0.02)，此結果顯示了利用靜電力吸附奈米金粒子於矽基板上的行為是random loose packing。
我們將次單層薄膜浸泡在不同碳數的硫醇中，硫醇跟金有強鍵結力，可以取代奈米金粒子表面上的檸檬酸根。而實驗結果顯示鍵結碳數較多的硫醇金粒子有較低的移動率，主要是因為碳數多的硫醇碳鏈比較長，所以接在奈米金粒子表面上的量會比較少，表面電荷降低的量較少，相反的，碳數較少時，粒子移動率較高，且實驗結果顯示出，當浸泡在六碳單硫醇時，粒子容易形成網路連結導通現象。

We studied the coverages of gold colloidal nanoparticles deposited on organosilanized silicon substrates for different pH values of gold colloids. The gold nanoparticle submonolayer films were formed by deposition of gold nanoparticles (diameter=18 nm) on (3-Aminopropyl)-trimethoxysilan (APTMS) covered substrates. When the deposition time increases, the number of adsorbed gold nanoparticles increases. If the time is long enough, the nanoparticle adsorption becomes saturated. The time-adsorption curve shows exponential decay behavior.
We used HCl and NaOH solution to adjust the pH value of gold colloids. When pH value is small, the saturation number of adsorbed nanoparticles increases. It is because the surface charge of nanoparticles reduced and the distance between nanoparticles becomes shorter, On the other hand, when NaOH solution is added, the pH value increases and the concentration of hydrogen ions reduces. Because APTMS-silicon surface needs hydrogen ions providing positive charges to attract negative charges of gold nanoparticles, the number of nanoparticles on silicon surface decreases.
We got the positions of nanoparticles from SEM pictures, and used Radial Distribution Function and Shortest Distance methods to estimate that the effective repulsive distance of the charged gold nanoparticles is 6～8 nm. By adding the radius of nanoparticles to the effective repulsive distance, we estimate that the effective coverage is about 0.7. The value is lower than that of the ordered close packing (0.9069) and the random close packing (0.82 ± 0.02). The results show that the adsorption of nanoparticles on silicon substrate is random loose packing.
The sub-monolayer films were immersed in thiols which have different carbon number. Because gold and thiol have strongth bonding, thiol can replace the citrate on the surface of gold nanoparticles. The experimental results show that the nanoparticles binding with long carbon chain thiols have lower mobility, because the long carbon chain thiols can replace the less amount of citrate on the surface of nanoparticles. It causes that the surface charge has less change and the nanoparticles have lower mobility.
The experimental results show that for the films which were immersed in six-carbon thiol, the particles easily form a network pattern.

目 錄
中文摘要…………………………………………………………Ι
Abstract……………………………………………………ΙΙ
致謝………………………………………………………………ΙΙΙ
目錄………………………………………………………………IV
圖目錄…………………………………………………………VI
表目錄………………………………………………………… VII
第一章 簡介
1.1 奈米技術………………………………………………………………1
1.2 奈米金粒子……………………………………………………………2
1.3 膠體……………………………………………………………………3
1.4 膠體金…………………………………………………………………3
第二章 樣品備製與實驗儀器
2.1.1實驗藥品……………………………………………………………5
2.1.2 基板準備……………………………………………………………7
2.1.3 製作膠體金溶液……………………………………………………9
2.1.4 實驗過程(一)………………………………………………………11
2.1.4 實驗過程(二)………………………………………………………13
2.2.1 動態光散射儀………………………………………………………14
2.2.2 掃描式電子顯微鏡…………………………………………………18
2.2.3 接觸角量測儀………………………………………………………20
第三章 實驗理論
3.1.1 DLVO理論……………………………………………………………23
3.1.2 凡德瓦吸引力………………………………………………………23
3.1.3 靜電排斥力…………………………………………………………24
3.2 德拜長度………………………………………………………………26
3.3 離子濃度………………………………………………………………26
3.4 徑向分佈函數…………………………………………………………27
第四章 實驗結果與分析
4.1 矽基板接觸角量測……………………………………………………29
4.2 膠體金溶液……………………………………………………………31
4.3 不同pH值之覆蓋率比值…………………………………….………34
4.4 奈米金粒子之有效斥力距離估計……………………………………47
4.5.1 最密堆積模型(close packing model)……………………………48
4.5.2 奈米金粒子之排列行為……………………………………………49
4.6.1 Zeta Potential……………………………………………………54
4.6.2 奈米金粒子之間的交互作用能……………………………………55
4.7 浸泡不同碳數硫醇之粒子移動率……………………………………57
第五章 結論………………………………………………………………………60
第六章 參考文獻………………………………………………………………62
附錄一………………………………………………………………………………64

[1] http://www.nanogallery.eu/nanolectures/49-richard-feynman-introduction-
to-nanotechnology.html
[2] http://nobelprize.org/nobel_prizes/physics/laureates/1986/press.html
[3] Giessibl, F.J. Advances in atomic force microscopy. Reviews of Modern Physics 75, 949-983 (2003).
[4] Binnig,G. et al. Atomic force microscope probes start multitasking. Materials Today 11, 47-47 (2008).
[5] Shaw III, C.F. Gold-based therapeutic agents. Chemical reviews 99, 2589–2600 (1999).
[6] Yamamuro, S. et al. Cr cluster deposition by plasma – gas- condensation method. Supramolecular Science 5, 239-245 (1998).
[7] Mafuné, F. et al. Formation of Gold Nanoparticles by Laser Ablation in Aqueous Solution of Surfactant. The Journal of Physical Chemistry B 105, 5114-5120 (2001).
[8] Morales, a M. A Laser Ablation Method for the Synthesis of Crystalline Semiconductor Nanowires. Science 279, 208-211 (1998).
[9] Kimling, J. et al. Turkevich method for gold nanoparticle synthesis revisited. The journal of physical chemistry. B 110, 15700-7 (2006).
[10] Frens, G. Controlled nucleation for the regulation of the particle size in monodisperse gold suspensions, Nature (London), Phys. Sci. 241, 20-22 (1973).
[11] Tsai, C. Shrinking gold nanoparticles: dramatic effect of a cryogenic process on tannic acid/sodium citrate-generated gold nanoparticles. Materials Letters 58, 2023-2026 (2004).
[12] Philip, D. Synthesis and spectroscopic characterization of gold nanoparticles. Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy 71, 80-5 (2008).
[13] Scarpettini, A.F. et al. Coverage and Aggregation of Gold Nanoparticles on Silanized Glasses. Langmuir 26, 15948-15953 (2010).
[14] Khatri, O.P. et al. Structural organization of gold nanoparticles onto the ITO surface and its optical properties as a function of ensemble size. Langmuir 24, 3787-93 (2008).
[15] http://www.bic.com/products/particle_sizing/p_PS_90Plus.html
[16] He, F. et al. High-throughput dynamic light scattering method for measuring viscosity of concentrated protein solutions. Analytical biochemistry 399, 141-3 (2010).
[17] Works, W. et al. Implications of the failure of the Stokes-Einstein equation for measurements with QELSS of polymer adsorption by small particles. Macromolecules 12, 1947-1949 (1983).
[18] Sze, A. et al. Zeta-potential measurement using the Smoluchowski equation and the slope of the current-time relationship in electroosmotic flow. Journal of colloid and interface science 261, 402-10 (2003).
[19] http://www.substech.com/dokuwiki/doku.php?id=stabilization_of_colloids
&DokuWiki=9254b26f6969bc8bf8da63e01bf2b4f7
[20] http://www.nbtc.cornell.edu/facilities/downloads/Zetasizer%20
chapter%2016.pdf
[21] http://www.laborchemie.com/en/brookhaven/introduction/zetapot.html
[22] http://commons.wikimedia.org/wiki/File:Schema_MEB_(it).svg
[23] http://en.wikipedia.org/wiki/File:Contact_angle.svg
[24] http://pubs.rsc.org/en/Content/ArticleLanding/1977/F1/f19777300390
[25] Onda, T. et al. Super-Water-Repellent Fractal Surfaces. Langmuir 12, 2125-2127 (1996).
[26] http://www.firsttenangstroms.com/products/fta100/fta100.html
[27] Levine,S. et al. Interaction between two hydrophobic colloidal particles, using the approximate Debye-Hückel theory. I. General properties. Transactions of the Faraday Society 35,1125-1140 (1939).
[28] Verwey, E. J. W. et al. Theory of the stability of lyophobic colloids (Amsterdam:Elsevier) 1948.
[29] Kim, T. et al. Control of Gold Nanoparticle Aggregates by Manipulation of Interparticle Interaction. Langmuir 21,9524-9528 (2005).
[30] Tadmor, R. et al. Debye Length and Double-Layer Forces in Polyelectrolyte Solutions. Macromolecules 6, 2380-2388 (2002).
[31] Link, S. et al. Spectral properties and relaxation dynamics of surface plasmon electronic oscillations in gold and silver nanodots and nanorods. The Journal of Physical Chemistry B 103, 8410–8426 (1999).
[32] Berryman, J.G. Random close packing of hard spheres and disks. Physical Review A 27, 1053 (1983).