近年來，由於烷基硫醇 (alkanethiol) 可於金基材表面形成一緻密且排列有序的單分子層，許多研究即藉由改變硫醇的末端官能基來控制基材的表面性質。然而由於金基材表面極易吸附污染物，因此金基材表面的預處理對於要得到品質較好的單分子層就變的很重要。

本實驗藉由Piranha solution來清洗金基材表面的汙染物，然而由於此方法會於基材上產生氧化金，且氧化金可能會影響到單分子層的排列，因此必須用乙醇將氧化金還原。本實驗發現當使用Piranha solution清洗三十秒後再用絕對乙醇浸泡三小時即可得到氧化金與污染物皆較少的表面。

接著本實驗使用接觸角 (contact angle)、化學分析電子光譜儀 (ESCA)、循環伏安法(cyclic voltammetry)來研究10-硫醇癸烷磺酸 (10-mercaptodecanesulfonic acid，簡稱：10-MDS) 在處理過後的金基材上的成長機制。本實驗發現於不同濃度下，10-硫醇癸烷
磺酸具有不同的成長機制，於0.01 mM下其成長機制與Langmuir-kinetics model相似，可是在2 mM下的成長機制卻與上述模式不合，且發現在2 mM下成長24 hr後，硫醇可能有脫附的現象產生。

Alkanethiols chemisorbed onto gold have been of growing interest in recent years. Many research groups tried to control the interfacial properties of surfaces by varying the terminal group of alkanethiols. However, because gold is easily contaminated by carbonaceous contaminants in the atmosphere, the preconditioning of gold substrate is quite important.

In this study, I use Piranha solution to clean gold substrate. Piranha solution is a strong oxidizing reagent and it may oxidize the gold surface to form gold oxide during preconditioning procedures. Because gold oxide might influence the packing quality of the monolayer, reduction of gold oxide by absolute ethanol is necessary prior monolayer formation. In this work, I found that if we use Piranha solution to clean gold substrate for thirty seconds then immersed in absolute ethanol for three hours, we can get a gold substrate with less gold oxide and contaminants on it.

Then the growth kinetics of 10-Mercaptodecanesulfonic acid (10-MDS) on the pretreated gold substrate was studied by contact angle, ESCA and cyclic voltammetry with different concentration in this work. We found that the growth kinetics was different between 0.01 and 2 mM. In 0.01 mM, it follows the Langmuir kinetics model but it doesn’t follow that model in 2 mM. Moreover, from the ESCA data we found that 10-MDS may desorbed after growing in 2 mM for 24hr and the packing qualities of monolayers are disorganized under this condition.

1. A. Ulman “An Introduction to Ultrathin Organic Films From Langmuir-Blogett to Self-Assembly” by Academic Press, Inc (1991)
2. R. G. Nuzzo, D. L. Allara, “Adsorption of Bifunctional Organic Disulfides on Gold Surfaces”, J. Am. Chem. Soc., 105, 4481-4483 (1983)
3. C. D. Bain, E. B. Troughton, Y. T. Tao, J. Evall, G. M. Whitesides, R. G. Nuzzo, “Formation of Monolayer Films by The Spontaneous Assembly of Organic Thiols from Solution onto Gold”, J. Am. Chem. Soc. , 111, 321-335 (1989)
4. E. B. Troughton, C. D. Bain, G. M. Whitesides, R. G. Nuzzo, “ Monolayer Films Prepared by The Spontaneous Self-assembly of Symmetrical and Unsymmetrical Dialkyl Sulfides from Solution onto Gold Substrates: Structure, Properties, and Reactivity of Constituent Functional Groups”, Langmuir, 4, 365-385 (1988)
5. C. D. Bain, H. A. Biebuyck, G. M. Whitesides, “Comparison of Self-assembled Monolayers on Gold：Coadsorption of Thiols and Disulfides”, Langmuir, 5, 723-727 (1989).
6. P. E. Laibinis, G. M. Whitesides, “ω-terminated Alkanethiolate Monolayers on Surfaces of Copper, Sliver, and Gold Have Similar Wettabilities”, J. Am. Chem. Soc., 114, 1990-1995 (1995)
7. P. E. Laibinis, G. M. Whitesides, D. L. Aiiara, Y. T. Tao, A. N. Parikh, R. G. Nuzzo, “Comparison of The Structures and Wetting Properties of Self-Assembled Monolayers of n-Alkanethiols on The Coinage Metal Surfaces, Cu, Ag, Au”, J. Am. Chem. Soc., 113, 7152-7162 (1991)
8. S. Katsuaki, Y. Ichizo, S. Yukari, K. Uosaki “In Situ and Dynamic Monitoring of The Self-Assembling and Redox Processes of A Ferrocenylundecanethiol Monolayer by Electrochemical Quartz Crystal Microbalance” , Langmuir; 1992; 8(5); 1385-1387.
9. R. F. DeBono, G. D. Loucks, D. Dellamanna, U. J. Krull, “Self-assembly of Short and Long-Chain n-Alkyl Thiols onto Gold Surfaces: A Real-Time Study Using Surface Plasmon Resonance Techniques, Can. J. Chem., 74:677–88 (1996).
10. G. Hähner, C. Woll, M. Buck, M. Grunze, “Investigation of Intermediate Steps in The Self-Assembly of n-Alkanethiols on Gold Surfaces by Soft X-ray Spectroscopy”, Langmuir 9, 1955–58 (1993)
11. S. Pan, A. M. Belu, B. D. Ratner, “Self Assembly of 16-Mercapto-1-hexadecanol on Gold：Surface Characterization and Kinetics” Material Science and Engineering C7, 51-38 (1999)
12. S. Xu, Cruchon-Dupeyrat SJN, J. C. Garno, G. Y. Liu, G. K. Jennings, et al. “In Situ Studies of Thiol Self-Assembly on Gold from Solution Using Atomic Force Microscopy”, J. Chem. Phys., 108, 5002–12 (1998)
13. K. Tamada, M. Hara, H. Sasabe, W. Knoll, “Surface Phase Behavior of n-Alkanethiol Self-Assembled Monolayers Adsorbed on Au(111): An Atomic Force Microscope Study”, Langmuir 13, 1558–66 (1997).
14. D. K. Schwartz, “Mechanism and Kinetics of Self-assembled Monolayer Formation”, Annu. Rev. Phys. Chem., 52, 107–37 (2001)
15. H. Biederman, Y. Osada, “Plasma Ploymerization Process”, Elsevier Science Publishing Co. (1992)
16. J. R. Vig, “UV/ozone Cleaning of Surfaces”, J. Vac. Technol. A 3(3) (1985)
17. H. Ron, S. Matlis, and I. Rubinstein, “Self-Assembled Monolayers on Oxidized Metals. 2. Gold Surface Pretreatment, Monolayer Properties, and Depression Formation”, Langmuir 14, 1116–1121 (1998)
18. T. Ishida, S. Tsuneda, N. Nishida, M. Hara, H. Sasabe, and W. Knoll, ”Surface–Conditioning Effect of Gold Substrate on Octadecanethiol self-assembled Monolayer Growth”, Langmuir, 13, 4638–4643 (1997).

19. J. T. Woodward, M. L. Walker, C. W. Meuse, D. J. Vanderah, G. E. Poirier, A. L. Plant, ”Effect of an Oxidized Gold Substrate on Alkanethiol Self-Assembly”, Langmuir, 16, 5347-5353 (2000)
20. M. Y. Tsai, J. C. Lin, “Preconditioning Gold Substrate Influence Organothiol Self-assembled Monolayer(SAM)Formation”, Journal of Colloid and Interface Science, 238, 259–266 (2001)
21. J. H. Silver, J. W. Marchane and S. L. Cooper, “Effect of Polyol Type on The Physical Properties and Thrombogenicity of Sulfonate Containing Polyurethane”, J. Biomed. Mater. Res., Vol. 27, 1443-1457(1993)
22. J. H. Lee, G. Khang, J. W. Lee, H. B. Lee, “Platelet Adhesion on to Chargeable Functional Group Gradient Surface”, J. Biomed. Mater. Res., Vol. 40,180-186 (1998)
23. C. H. Schramm, H. Lemaire, R. H. Karlson, “The Synthesis of Mercaptoalkanessulfonic acid”, J. Am. Chem. Soc., Vol. 77 6231-6223 (1955)
24. 莊文喜, “各種不同官能基的自我聚集性單分子層之表面分析及血液相容性的探討”, 國立成功大學化工所碩士論文, 民國87年
25. 賴耿陽 編譯， “薄膜製作工藝學”，復漢出版社。(1987)
26. J. D. Andrade, “Surface and Interfacial Aspects of Biomedical Polymers Volume 1 Surface Chemistry and Physics”, Plenum press, New York, 1992
27. J. C. Vickerman, “Surface AnalysisThe Principal Techniques”, Wiley, New York, (1997)
28. T. smith, “The Hydrophilic Nature of A Clean Gold Surface”, J.Coll. Interfac. Sci.,Vol. 75,51-55 (1980)
29. 蔡孟諺, “含亞磷酸酯與亞磷酸官能基的自我聚集性單分子層之合成、表面分
析與血小板吸附之研究”, 國立成功大學化工所碩士論文, 民國88年
30. R. W. Bigelow, “An Xps Study of Air Corona Discharge-induced Corrosion Products at Cu, Ag, and Au Ground Planes”, Appl. Surf. Sci., 32, 122–140 (1988).

31. C. R. Aita., N. C. Tran, “Core Level and Valence Band X-ray Photoelectron Spectroscopy of Gold Oxide”, Vac. Sci. Technol., A9, 1498–1500 (1991).
32. T. Dickinson, A. F. Povey, P. M. A. Sherwood, “X-Ray Photoelectron Spectroscopic Studies of Oxide film on Platinum and Gold electrode”, J. Chem. Soc. Faraday I, 71, 298–311 (1975).
33. D. E. King, “Oxidation of Gold by Ultraviolet Light and Ozone at 25C”, J. Vac. Sci. Technol. A, 13, 1247–1253 (1995).
34. C. Yan, A. Gölzhäuser, M. Grunze, “Formation of Alkanethiolate Self-Assembled monolayers on Oxidized Surfaces”, Langmuir, 15, 2414-2419 (1999)
35. A. Ulman, “Formation and Structure of Self-assembled Monolayers”, Chem. 　Rev., 1533-1554 (1996)
36. T. Matsuua, Y. Shimoyama, “Growth Kinetics of Self –Assembled Monolayers of Thiophene on Au(111)：An Infrared Spectroscopic Study”, Eur. Phys. J. E. 7, 233-240 (2002)
37. I. Turyan, D. Mandler, “Characterization and Electroananlytical Application of -Mercaptoalknesulfonic Acid Monolayers on Gold”, Israel Journal of Chemistry, 225-233 (1997)
38. D.G. Casner, “X-ray Photoelectron Spectroscopy Sulfur 2p Study of Organic Thiol and Disulfide Binding Interactions with Gold Substrates”, Langmuir, 12, 5083-5086 (1996)
39. A. Kakubowica, H. Jia, R. M. Wallace, B. E. Gnade, “Adsorption Kinetics of p-Nitronenzenethiol Self-assembled Monolayers om Gold Surface”, Langmuir, 21, 950-955 (2005)